Incident Clinical and Mortality Associations of Myocardial Native T1 in the UK Biobank

BackgroundCardiac magnetic resonance native T1-mapping provides noninvasive, quantitative, and contrast-free myocardial characterization. However, its predictive value in population cohorts has not been studied.ObjectivesThe associations of native T1 with incident events were evaluated in 42,308 UK Biobank participants over 3.17 ± 1.53 years of prospective follow-up.MethodsNative T1-mapping was performed in 1 midventricular short-axis slice using the Shortened Modified Look-Locker Inversion recovery technique (WIP780B) in 1.5-T scanners (Siemens Healthcare). Global myocardial T1 was calculated using an automated tool. Associations of T1 with: 1) prevalent risk factors (eg, diabetes, hypertension, and high cholesterol); 2) prevalent and incident diseases (eg, any cardiovascular disease [CVD], any brain disease, valvular heart disease, heart failure, nonischemic cardiomyopathies, cardiac arrhythmias, atrial fibrillation [AF], myocardial infarction, ischemic heart disease [IHD], and stroke); and 3) mortality (eg, all-cause, CVD, and IHD) were examined. Results are reported as odds ratios (ORs) or HRs per SD increment of T1 value with 95% CIs and corrected P values, from logistic and Cox proportional hazards regression models.ResultsHigher myocardial T1 was associated with greater odds of a range of prevalent conditions (eg, any CVD, brain disease, heart failure, nonischemic cardiomyopathies, AF, stroke, and diabetes). The strongest relationships were with heart failure (OR: 1.41 [95% CI: 1.26-1.57]; P = 1.60 × 10^-9) and nonischemic cardiomyopathies (OR: 1.40 [95% CI: 1.16-1.66]; P = 2.42 × 10^-4). Native T1 was positively associated with incident AF (HR: 1.25 [95% CI: 1.10-1.43]; P = 9.19 × 10^-4), incident heart failure (HR: 1.47 [95% CI: 1.31-1.65]; P = 4.79 × 10^-11), all-cause mortality (HR: 1.24 [95% CI: 1.12-1.36]; P = 1.51 × 10^-5), CVD mortality (HR: 1.40 [95% CI: 1.14-1.73]; P = 0.0014), and IHD mortality (HR: 1.36 [95% CI: 1.03-1.80]; P = 0.0310).ConclusionsThis large population study demonstrates the utility of myocardial native T1-mapping for disease discrimination and outcome prediction.     

Derivation,Validation, and Prognostic Utility of a Prediction Rule for Nonresponse to Clopidogrel: The ABCD-GENE Score

ObjectivesThe aim of this study was to develop a risk score integrating cytochrome P450 2C19 loss-of-function genotypes with clinical risk factors influencing clopidogrel response that would allow the identification with more precision of subjects at risk for high platelet reactivity (HPR) and adverse clinical outcomes.BackgroundClopidogrel is the most broadly used platelet P2Y₁₂ inhibitor. However, a considerable number of patients achieve inadequate platelet inhibition, with persistent HPR, an established marker of increased thrombotic risk, underscoring the need for tools to help identify these subjects. Although carriers of loss-of-function alleles of the cytochrome P450 2C19 enzyme have reduced clopidogrel metabolism leading to increased rates of HPR and thrombotic complications, this explains only a fraction of the pharmacodynamic response to clopidogrel, and a number of clinical factors have also been shown to have contributing roles.MethodsThree prospective and independent studies were used to: 1) develop a risk score integrating genetic and clinical factors to identify patients with HPR while on clopidogrel; 2) investigate the external validity of the risk score; and 3) define clinical outcomes associated with the risk score in a cohort of patients with myocardial infarction treated with clopidogrel.ResultsA risk score ABCD-GENE (Age, Body Mass Index, Chronic Kidney Disease, Diabetes Mellitus, and Genotyping) was developed incorporating 5 independent predictors of HPR: 4 clinical (age >75 years, body mass index >30 kg/m², chronic kidney disease [glomerular filtration rate <60 ml/min], and diabetes mellitus) and 1 genetic (cytochrome P450 2C19 loss-of-function alleles). The C-statistics for the score as an integer variable were 0.71 (95% confidence interval [CI]: 0.68 to 0.75) and 0.64 (95% CI: 0.60 to 0.67) in the pharmacodynamic derivation and validation cohorts, respectively. A cutoff score ≥10 was associated with the best sensitivity and specificity to identify HPR status. The C-statistics for the score were 0.67 (95% CI: 0.64 to 0.71) for all-cause death and 0.66 (95% CI: 0.63 to 0.69) for the composite of all-cause death, stroke, or myocardial infarction at 1 year. Using multiple models for adjustment, the ABCD-GENE score consistently and independently correlated with all-cause death, as well as with the composite of all-cause death, stroke, or myocardial infarction, both as a continuous variable and by using the cutoff of ≥10. The score did not predict bleeding.ConclusionsThe ABCD-GENE score is a simple tool to identify patients with HPR on clopidogrel and who are at increased risk for adverse ischemic events, including mortality, following an acute myocardial infarction. In patients with a high ABCD-GENE score, long-term oral P2Y₁₂ inhibitors other than clopidogrel should be considered.     

A Noncontrast CMR Risk Score for Long-Term Risk Stratification in Reperfused ST-Segment Elevation Myocardial Infarction

ObjectivesThis study compared the prognostic value of a noncontrast CMR risk score for the composite of all-cause death, nonfatal myocardial infarction, and new congestive heart failure.BackgroundA cardiovascular magnetic resonance (CMR) risk score including left ventricular ejection fraction (LVEF), myocardial infarct (MI) size, and microvascular obstruction (MVO) was recently proposed to risk-stratify patients with ST-segment elevation myocardial infarction (STEMI).MethodsThe Eitel CMR risk score and GRACE (Global Registry of Acute Coronary Events) score were used as a reference (Score 1: acute MI size ≥19% LV, LVEF ≤47%, MVO >1.4% LV and GRACE score). MVO was replaced by intramyocardial hemorrhage (IMH) in Score 2 (acute MI size ≥19% LV, LVEF ≤47%, IMH, and GRACE score). Score 3 included only LVEF ≤45%, IMH, and GRACE score.ResultsThere were 370 patients in the derivation cohort and 234 patients in the validation cohort. In the derivation cohort, the 3 scores performed similarly and better than GRACE score to predict the 1-year composite endpoint with C-statistics of 0.83, 0.83, 0.82, and 0.74, respectively. In the validation cohort, there was good discrimination and calibration of score 3, with a C-statistic of 0.87 and P = 0.71 in a Hosmer-Lemeshow test for goodness of fit, on the 1-year composite outcome. Kaplan-Meier curves for 5-year composite outcome showed that those with LVEF ≤45% (high-risk) and LVEF >45% and IMH (intermediate-risk) had significantly higher cumulative events than those with LVEF >45% and no IMH (low-risk), log-rank tests: P = 0.02 and P = 0.03, respectively. The HR for the high-risk group was 2.3 (95% CI: 1.1-4.7) and for the intermediate-risk group was 2.0 (95% CI: 1.0-3.8), and these remained significant after adjusting for the GRACE score.ConclusionsThis noncontrast CMR risk score has performance comparable to an established risk score, and patients with STEMI could be stratified into low risk (LVEF >45% and no IMH), intermediate risk (LVEF >45% and IMH), and high risk (LVEF ≤45%). (A Trial of Low-dose Adjunctive alTeplase During prIMary PCI [T-TIME]; NCT02257294) (Detection and Significance of Heart Injury in ST Elevation Myocardial Infarction [BHF MR-MI]; NCT02072850)     

MIRACLE2 Score and SCAI Grade to Identify Patients With Out-of-Hospital Cardiac Arrest for Immediate Coronary Angiography

ObjectivesThe purpose of this study was to evaluate the impact of performing immediate coronary angiography (CAG) after out-of-hospital cardiac arrest (OHCA) with stratification of predicted neurologic injury and cardiogenic shock on arrival to a center.BackgroundThe role of immediate CAG for patients with OHCA is unclear, which may in part be explained by the majority of patients dying of hypoxic brain injury.MethodsBetween May 2012 and July 2020, patients from 5 European centers were included in the EUCAR (European Cardiac Arrest Registry). Patients were retrospectively classified into low vs high neurologic risk (MIRACLE₂ score 0-3 vs ≥4) and degree of cardiogenic shock on arrival (Society for Cardiovascular Angiography and Interventions [SCAI] grade A vs B-E). A multivariable logistic regression analysis including immediate CAG was performed for the primary outcome of survival with good neurologic outcome (Cerebral Performance Category 1 or 2) at hospital discharge.ResultsNine hundred twenty-six patients were included in the registry, with 405 (43.7%) in the low-risk group and 521 (56.3%) in the high-risk group. Immediate CAG was independently associated with improved survival with good neurologic outcome in the low MIRACLE₂ risk group with ST-segment elevation myocardial infarction (OR: 11.80; 95% CI: 2.24-76.74; P = 0.048) and with SCAI grade B to E shock (OR: 3.23; 95% CI: 1.10-9.50; P = 0.031). No subgroups, including those with ST-segment elevation myocardial infarction and with SCAI grade B to E shock, achieved any benefit from early CAG in the high MIRACLE₂ group.ConclusionsCombined classification of patients with OHCA with 12-lead electrocardiography, MIRACLE₂ score 0 to 3, and SCAI grade B to E identifies a potential cohort of patients at low risk for neurologic injury who benefit most from immediate CAG.     

A Clinical Tool to Identify Candidates for Stress-First Myocardial Perfusion Imaging

ObjectivesThis study sought to develop a clinical model that identifies a lower-risk population for coronary artery disease that could benefit from stress-first myocardial perfusion imaging (MPI) protocols and that can be used at point of care to risk stratify patients.BackgroundThere is an increasing interest in stress-first and stress-only imaging to reduce patient radiation exposure and improve patient workflow and experience.MethodsA secondary analysis was conducted on a single-center cohort of patients undergoing single-photon emission computed tomography (SPECT) and positron emission tomography (PET) studies. Normal MPI was defined by the absence of perfusion abnormalities and other ischemic markers and the presence of normal left ventricular wall motion and left ventricular ejection fraction. A model was derived using a cohort of 18,389 consecutive patients who underwent SPECT and was validated in a separate cohort of patients who underwent SPECT (n = 5,819), 1 internal cohort of patients who underwent PET (n=4,631), and 1 external PET cohort (n = 7,028).ResultsFinal models were made for men and women and consisted of 9 variables including age, smoking, hypertension, diabetes, dyslipidemia, typical angina, prior percutaneous coronary intervention, prior coronary artery bypass graft, and prior myocardial infarction. Patients with a score ≤1 were stratified as low risk. The model was robust with areas under the curve of 0.684 (95% confidence interval [CI]: 0.674 to 0.694) and 0.681 (95% CI: 0.666 to 0.696) in the derivation cohort, 0.745 (95% CI: 0.728 to 0.762) and 0.701 (95% CI: 0.673 to 0.728) in the SPECT validation cohort, 0.672 (95% CI: 0.649 to 0.696) and 0.686 (95% CI: 0.663 to 0.710) in the internal PET validation cohort, and 0.756 (95% CI: 0.740 to 0.772) and 0.737 (95% CI: 0.716 to 0.757) in the external PET validation cohort in men and women, respectively. Men and women who scored ≤1 had negative likelihood ratios of 0.48 and 0.52, respectively.ConclusionsA novel model, based on easily obtained clinical variables, is proposed to identify patients with low probability of having abnormal MPI results. This point-of-care tool may be used to identify a population that might qualify for stress-first MPI protocols.     

Development and Validation of a Practical Model to Identify Patients at Risk of Bleeding After TAVR

ObjectivesNo standardized algorithm exists to identify patients at risk of bleeding after transcatheter aortic valve replacement (TAVR). The aim of this study was to generate and validate a useful predictive model.BackgroundBleeding events after TAVR influence prognosis and quality of life and may be preventable.MethodsUsing machine learning and multivariate regression, more than 100 clinical variables from 5,185 consecutive patients undergoing TAVR in the prospective multicenter RISPEVA (Registro Italiano GISE sull’Impianto di Valvola Aortica Percutanea; NCT02713932) registry were analyzed in relation to Valve Academic Research Consortium-2 bleeding episodes at 1 month. The model’s performance was externally validated in 5,043 TAVR patients from the prospective multicenter POL-TAVI (Polish Registry of Transcatheter Aortic Valve Implantation) database.ResultsDerivation analyses generated a 6-item score (PREDICT-TAVR) comprising blood hemoglobin and serum iron concentrations, oral anticoagulation and dual antiplatelet therapy, common femoral artery diameter, and creatinine clearance. The 30-day area under the receiver-operating characteristic curve (AUC) was 0.80 (95% confidence interval [CI]: 0.75–0.83). Internal validation by optimism bootstrap-corrected AUC was 0.79 (95% CI: 0.75–0.83). Score quartiles were in graded relation to 30-day events (0.8%, 1.1%, 2.5%, and 8.5%; overall p <0.001). External validation produced a 30-day AUC of 0.78 (95% CI: 0.72–0.82). A simple nomogram and a web-based calculator were developed to predict individual patient probabilities. Landmark cumulative event analysis showed greatest bleeding risk differences for top versus lower score quartiles in the first 30 days, when most events occurred. Predictivity was maintained when omitting serum iron values.ConclusionsPREDICT-TAVR is a practical, validated, 6-item tool to identify patients at risk of bleeding post-TAVR that can assist in decision making and event prevention.     

Impact of Intravascular Ultrasound on Long-Term Clinical Outcomes in Patients With Acute Myocardial Infarction

ObjectivesThe aim of this study was to examine the impact of intravascular ultrasound (IVUS)–guided percutaneous coronary intervention (PCI) on long-term clinical outcomes in patients with acute myocardial infarction (AMI).BackgroundIVUS-guided PCI has been associated with improved cardiovascular outcomes. However, the beneficial effect of IVUS-guided PCI in patients with AMI in the drug-eluting stent era remains unclear.MethodsPatients who underwent PCI with drug-eluting stents were selected from 10,719 patients enrolled in a multicenter AMI registry. The included patients were classified into 2 groups according to the use or nonuse of IVUS. The primary outcome was a composite of major adverse cardiovascular events (MACE), including cardiovascular death, myocardial infarction, and target lesion revascularization, during long-term follow-up.ResultsA total of 9,846 patients were treated with IVUS-guided PCI (n = 2,032) or angiography-guided PCI (n = 7,814). IVUS-guided PCI was associated with reduced MACE (HR: 0.779; 95% CI: 0.689-0.880; P < 0.001). The results were consistent after multivariable regression and propensity score matching. One-year landmark analysis showed a lower risk for MACE within 1 year (HR: 0.766; 95% CI: 0650-0.903; P = 0.002) and beyond 1 year (HR: 0.796; 95% CI: 0663-0.956; P = 0.014) after index PCI.ConclusionsThe use of IVUS was associated with better long-term cardiovascular outcomes. The clinical benefit of IVUS was maintained both within and beyond 1 year after index PCI. The use of IVUS in PCI should be considered for patients with AMI.     

Pericoronary Adipose Tissue Attenuation,Low-Attenuation Plaque Burden,and 5-Year Risk of Myocardial Infarction

BackgroundPericoronary adipose tissue (PCAT) attenuation and low-attenuation noncalcified plaque (LAP) burden can both predict outcomes.ObjectivesThis study sought to assess the relative and additive values of PCAT attenuation and LAP to predict future risk of myocardial infarction.MethodsIn a post hoc analysis of the multicenter SCOT-HEART (Scottish Computed Tomography of the Heart) trial, the authors investigated the relationships between the future risk of fatal or nonfatal myocardial infarction and PCAT attenuation measured from coronary computed tomography angiography (CTA) using multivariable Cox regression models including plaque burden, obstructive coronary disease, and cardiac risk score (incorporating age, sex, diabetes, smoking, hypertension, hyperlipidemia, and family history).ResultsIn 1,697 evaluable participants (age: 58 ± 10 years), there were 37 myocardial infarctions after a median follow-up of 4.7 years. Mean PCAT was ?76 ± 8 HU and median LAP burden was 4.20% (IQR: 0%-6.86%). PCAT attenuation of the right coronary artery (RCA) was predictive of myocardial infarction (HR: 1.55; P = 0.017, per 1 SD increment) with an optimum threshold of ?70.5 HU (HR: 2.45; P = 0.01). In multivariable analysis, adding PCAT-RCA of ≥?70.5 HU to an LAP burden of >4% (the optimum threshold for future myocardial infarction; HR: 4.87; P < 0.0001) led to improved prediction of future myocardial infarction (HR: 11.7; P < 0.0001). LAP burden showed higher area under the curve compared to PCAT attenuation for the prediction of myocardial infarction (AUC = 0.71 [95% CI: 0.62-0.80] vs AUC = 0.64 [95% CI: 0.54-0.74]; P < 0.001), with increased area under the curve when the 2 metrics are combined (AUC = 0.75 [95% CI: 0.65-0.85]; P = 0.037).ConclusionCoronary CTA–defined LAP burden and PCAT attenuation have marked and complementary predictive value for the risk of fatal or nonfatal myocardial infarction.     

Impact of Early Revascularization on Major Adverse Cardiovascular Events in Relation to Automatically Quantified Ischemia

ObjectivesUsing a contemporary, multicenter international single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) registry, this study characterized the potential major adverse cardiovascular event(s) (MACE) benefit of early revascularization based on automatic quantification of ischemia.BackgroundPrior single-center data reported an association between moderate to severe ischemia SPECT-MPI and reduced cardiac death with early revascularization.MethodsConsecutive patients from a multicenter, international registry who underwent ^99mTc SPECT-MPI between 2009 and 2014 with solid-state scanners were included. Ischemia was quantified automatically as ischemic total perfusion deficit (TPD). Early revascularization was defined as within 90 days. The primary outcome was MACE (death, myocardial infarction, and unstable angina). A propensity score was developed to adjust for nonrandomization of revascularization; then, multivariable Cox modeling adjusted for propensity score and demographics was used to predict MACE.ResultsIn total, 19,088 patients were included, with a mean follow-up of 4.7 ± 1.6 years, during which MACE occurred in 1,836 (9.6%) patients. There was a significant interaction between ischemic TPD modeled as a continuous variable and early revascularization (interaction p value: 0.012). In this model, there was a trend toward reduced MACE in patients with >5.4% ischemic TPD and a significant association with reduced MACE in patients with >10.2% ischemic TPD.ConclusionsIn this large, international, multicenter study reflecting contemporary cardiology practice, early revascularization of patients with >10.2% ischemia on SPECT-MPI, quantified automatically, was associated with reduced MACE.     

Randomized Trial of Targeted Transendocardial Mesenchymal Precursor Cell Therapy in Patients With Heart Failure

BackgroundMesenchymal precursor cells (MPCs) are allogeneic, immunoselected cells with anti-inflammatory properties that could improve outcomes in heart failure with reduced ejection fraction (HFrEF).ObjectivesThis study assessed the efficacy and safety of MPCs in patients with high-risk HFrEF.MethodsThis randomized, double-blind, multicenter study evaluated a single transendocardial administration procedure of MPCs or sham-control in 565 intention-to-treat patients with HFrEF on guideline-directed therapies. The primary endpoint was time-to-recurrent events caused by decompensated HFrEF or successfully resuscitated symptomatic ventricular arrhythmias. Hierarchical secondary endpoints included components of the primary endpoint, time-to-first terminal cardiac events, and all-cause death. Separate and composite major adverse cardiovascular events analyses were performed for myocardial infarction or stroke or cardiovascular death. Baseline and 12-month echocardiography was performed. Baseline plasma high-sensitivity C-reactive protein levels were evaluated for disease severity.ResultsThe primary endpoint was similar between treatment groups (HR: 1.17; 95% CI: 0.81-1.69; P = 0.41) as were terminal cardiac events and secondary endpoints. Compared with control subjects, MPCs increased left ventricular ejection fraction from baseline to 12 months, especially in patients with inflammation. MPCs decreased the risk of myocardial infarction or stroke by 58% (HR: 0.42; 95% CI: 0.23-0.76) and the risk of 3-point major adverse cardiovascular events by 28% (HR: 0.72; 95% CI: 0.51-1.03) in the analysis population (n = 537), and by 75% (HR: 0.25; 95% CI: 0.09-0.66) and 38% (HR: 0.62; 95% CI: 0.39-1.00), respectively, in patients with inflammation (baseline high-sensitivity C-reactive protein ≥2 mg/L).ConclusionsThe primary and secondary endpoints of the trial were negative. Positive signals in prespecified, and post hoc exploratory analyses suggest MPCs may improve outcomes, especially in patients with inflammation.     

Prognostic Value of Stress Cardiac Magnetic Resonance in Patients With Known Coronary Artery Disease

ObjectivesThis study sought to determine whether stress cardiac magnetic resonance (CMR) provides clinically relevant risk reclassification in patients with known coronary artery disease (CAD) in a multicenter setting in the United States.BackgroundDespite improvements in medical therapy and coronary revascularization, patients with previous CAD account for a disproportionately large portion of CV events and pose a challenge for noninvasive stress testing.MethodsFrom the Stress Perfusion Imaging in the United States (SPINS) registry, we identified consecutive patients with documented CAD who were referred to stress CMR for evaluation of myocardial ischemia. The primary outcome was nonfatal myocardial infarction (MI) or cardiovascular (CV) death. Major adverse CV events (MACE) included MI/CV death, hospitalization for heart failure or unstable angina, and late unplanned coronary artery bypass graft. The prognostic association and net reclassification improvement by ischemia for MI/CV death were determined.ResultsOut of 755 patients (age 64 ± 11 years, 64% male), we observed 97 MI/CV deaths and 210 MACE over a median follow-up of 5.3 years. Presence of ischemia demonstrated a significant association with MI/CV death (HR: 2.30; 95% CI: 1.54-3.44; P < 0.001) and MACE (HR: 2.24 ([95% CI: 1.69-2.95; P < 0.001). In a multivariate model adjusted for CV risk factors, ischemia maintained strong association with MI/CV death (HR: 1.84; 95% CI: 1.17-2.88; P = 0.008) and MACE (HR: 1.77; 95% CI: 1.31-2.40; P < 0.001) and reclassified 95% of patients at intermediate pretest risk (62% to low risk, 33% to high risk) with corresponding changes in the observed event rates of 1.4% and 5.3% per year for low and high post-test risk, respectively.ConclusionsIn a multicenter cohort of patients with known CAD, CMR-assessed ischemia was strongly associated with MI/CV death and reclassified patient risk beyond CV risk factors, especially in those considered to be at intermediate risk. Absence of ischemia was associated with a <2% annual rate of MI/CV death. (Stress CMR Perfusion Imaging in the United States [SPINS] Study; NCT03192891)     

Clinical Deployment of Explainable Artificial Intelligence of SPECT for Diagnosis of Coronary Artery Disease

BackgroundExplainable artificial intelligence (AI) can be integrated within standard clinical software to facilitate the acceptance of the diagnostic findings during clinical interpretation.ObjectivesThis study sought to develop and evaluate a novel, general purpose, explainable deep learning model (coronary artery disease–deep learning [CAD-DL]) for the detection of obstructive CAD following single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI).MethodsA total of 3,578 patients with suspected CAD undergoing SPECT MPI and invasive coronary angiography within a 6-month interval from 9 centers were studied. CAD-DL computes the probability of obstructive CAD from stress myocardial perfusion, wall motion, and wall thickening maps, as well as left ventricular volumes, age, and sex. Myocardial regions contributing to the CAD-DL prediction are highlighted to explain the findings to the physician. A clinical prototype was integrated using a standard clinical workstation. Diagnostic performance by CAD-DL was compared to automated quantitative total perfusion deficit (TPD) and reader diagnosis.ResultsIn total, 2,247 patients (63%) had obstructive CAD. In 10-fold repeated testing, the area under the receiver-operating characteristic curve (AUC) (95% CI) was higher according to CAD-DL (AUC: 0.83 [95% CI: 0.82-0.85]) than stress TPD (AUC: 0.78 [95% CI: 0.77-0.80]) or reader diagnosis (AUC: 0.71 [95% CI: 0.69-0.72]; P < 0.0001 for both). In external testing, the AUC in 555 patients was higher according to CAD-DL (AUC: 0.80 [95% CI: 0.76-0.84]) than stress TPD (AUC: 0.73 [95% CI: 0.69-0.77]) or reader diagnosis (AUC: 0.65 [95% CI: 0.61-0.69]; P < 0.001 for all). The present model can be integrated within standard clinical software and generates results rapidly (<12 seconds on a standard clinical workstation) and therefore could readily be incorporated into a typical clinical workflow.ConclusionsThe deep-learning model significantly surpasses the diagnostic accuracy of standard quantitative analysis and clinical visual reading for MPI. Explainable artificial intelligence can be integrated within standard clinical software to facilitate acceptance of artificial intelligence diagnosis of CAD following MPI.     

Transcatheter Versus Surgical Aortic Valve Replacement in Patients With Complex Coronary Artery Disease

ObjectivesThe aim of this study was to compare, in a cohort of patients with complex coronary artery disease (CAD) and severe aortic stenosis (AS), the clinical outcomes associated with transfemoral transcatheter aortic valve replacement (TAVR) (plus percutaneous coronary intervention [PCI]) versus surgical aortic valve replacement (SAVR) (plus coronary artery bypass grafting [CABG]).BackgroundPatients with complex CAD were excluded from the main randomized trials comparing TAVR with SAVR, and no data exist comparing TAVR + PCI vs SAVR + CABG in such patients.MethodsA multicenter study was conducted including consecutive patients with severe AS and complex CAD (SYNTAX [Synergy Between PCI with Taxus and Cardiac Surgery] score >22 or unprotected left main disease). A 1:1 propensity-matched analysis was performed to account for unbalanced covariates. The rates of major adverse cardiac and cerebrovascular events (MACCE), including all-cause mortality, nonprocedural myocardial infarction, need for new coronary revascularization, and stroke, were evaluated.ResultsA total of 800 patients (598 undergoing SAVR + CABG and 202 undergoing transfemoral TAVR + PCI) were included, and after propensity matching, a total of 156 pairs of patients were generated. After a median follow-up period of 3 years (interquartile range: 1-6 years), there were no significant differences between groups for MACCE (HR for transfemoral TAVR vs SAVR: 1.33; 95% CI: 0.89-1.98), all-cause mortality (HR: 1.25; 95% CI: 0.81-1.94), myocardial infarction (HR: 1.16; 95% CI: 0.41-3.27), and stroke (HR: 0.42; 95% CI: 0.13-1.32), but there was a higher rate of new coronary revascularization in the TAVR + PCI group (HR: 5.38; 95% CI: 1.73-16.7).ConclusionsIn patients with severe AS and complex CAD, TAVR + PCI and SAVR + CABG were associated with similar rates of MACCE after a median follow-up period of 3 years, but TAVR + PCI recipients exhibited a higher risk for repeat coronary revascularization. Future trials are warranted.     

Coronary Atherosclerosis,Cardiac Troponin,and Interleukin-6 in Patients With Chest Pain: The PROMISE Trial Results

BackgroundIncreased inflammation and myocardial injury can be observed in the absence of myocardial infarction or obstructive coronary artery disease (CAD).ObjectivesThe authors determined whether biomarkers of inflammation and myocardial injury—interleukin (IL)-6 and high-sensitivity cardiac troponin (hs-cTn)—were associated with the presence and extent of CAD and were independent predictors of major adverse cardiovascular events (MACEs) in stable chest pain.MethodsUsing participants from the PROMISE trial, the authors measured hs-cTn I and IL-6 concentrations and analyzed computed tomography angiography (CTA) images in the core laboratory for CAD characteristics: significant stenosis (≥70%), high-risk plaque (HRP), Coronary Artery Disease Reporting and Data System (CAD-RADS) categories, segment involvement score (SIS), and coronary artery calcium (CAC) score. The primary endpoint was a composite MACE (death, myocardial infarction, or unstable angina).ResultsThe authors included 1,796 participants (age 60.2 ± 8.0 years; 47.5% men, median follow-up 25 months). In multivariable linear regression adjusted for atherosclerotic cardiovascular disease (ASCVD) risk, hs-cTn was associated with HRP, stenosis, CAD-RADS, and SIS. IL-6 was only associated with stenosis and CAD-RADS. hs-cTn above median (1.5 ng/L) was associated with MACEs in univariable analysis (HR: 2.1 [95% CI: 1.3-3.6]; P = 0.006), but not in multivariable analysis adjusted for ASCVD and CAD. IL-6 above median (1.8 ng/L) was associated with MACEs in multivariable analysis adjusted for ASCVD and HRP (HR: 1.9 [95% CI: 1.1-3.3]; P = 0.03), CAC (HR: 1.9 [95% CI: 1.0-3.4]; P = 0.04), and SIS (HR: 1.8 [95% CI: 1.0-3.2]; P = 0.04), but not for stenosis or CAD-RADS. In participants with nonobstructive CAD (stenosis 1%-69%), the presence of both hs-cTn and IL-6 above median was strongly associated with MACEs (HR: 2.5-2.7 after adjustment for CAD characteristics).ConclusionsConcentrations of hs-cTn and IL-6 were associated with CAD characteristics and MACEs, indicating that myocardial injury and inflammation may each contribute to pathways in CAD pathophysiology. This association was most pronounced among participants with nonobstructive CAD representing an opportunity to tailor treatment in this at-risk group. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550)     

Early Diagnosis of Myocardial Infarction With Point-of-Care High-Sensitivity Cardiac Troponin I

BackgroundUntil now, high-sensitivity cardiac troponin (hs-cTn) assays were mainly developed for large central laboratory platforms.ObjectivesThis study aimed to assess the clinical performance of a point-of-care (POC)-hs-cTnI assay in patients with suspected myocardial infarction (MI).MethodsThis study enrolled patients presenting to the emergency department with symptoms suggestive of MI. Two cardiologists centrally adjudicated the final diagnosis using all clinical data including cardiac imaging. The primary objective was to directly compare diagnostic accuracy of POC-hs-cTnI-TriageTrue versus best-validated central laboratory assays. Secondary objectives included the derivation and validation of a POC-hs-cTnI-TriageTrue–specific 0/1-h algorithm.ResultsMI was the adjudicated final diagnosis in 178 of 1,261 patients (14%). The area under the curve (AUC) for POC-hs-cTnI-TriageTrue at presentation was 0.95 (95% confidence interval [CI]: 0.93 to 0.96) and was at least comparable to hs-cTnT-Elecsys (AUC: 0.94; 95% CI: 0.93 to 0.96; p = 0.213) and hs-cTnI-Architect (AUC: 0.92; 95% CI: 0.90 to 0.93; p < 0.001). A single cutoff concentration <3 ng/l at presentation identified 45% of patients at low risk with a negative predictive value (NPV) of 100% (95% CI: 99.4% to 100%). A single cutoff concentration >60 ng/l identified patients at high risk with a positive predictive value (PPV) of 76.8% (95% CI: 68.9% to 83.6%). The 0/1-h algorithm ruled out 55% of patients (NPV: 100%; 95% CI: 98.8% to 100%), and ruled in 18% of patients (PPV: 76.8%; 95% CI: 67.2% to 84.7%). Ruled-out patients had cumulative event rates of 0% at 30 days and 1.6% at 2 years. This study confirmed these findings in a secondary analysis including hs-cTnI-Architect for central adjudication.ConclusionsThe POC-hs-cTnI-TriageTrue assay provides high diagnostic accuracy in patients with suspected MI with a clinical performance that is at least comparable to that of best-validated central laboratory assays. (Advantageous Predictors of Acute Coronary Syndromes Evaluation Study [APACE]; NCT00470587)     

Implications of Periprocedural Myocardial Biomarker Elevations and Commonly Used MI Definitions After Left Main PCI

ObjectivesThe aim of this study was to: 1) assess the relationship of different thresholds of creatine kinase–myocardial band (CK-MB) and cardiac troponin with subsequent mortality; and 2) evaluate the prognostic significance of periprocedural myocardial infarction (PMI) according to various definitions of myocardial infarction in patients with left main (LM) coronary artery disease.BackgroundThe magnitude of postprocedural biomarker elevation representing a clinically meaningful PMI after percutaneous coronary intervention (PCI) is controversial.MethodsA total of 4,013 consecutive patients undergoing LM PCI at a single center from January 2004 to December 2016 were enrolled. CK-MB and cardiac troponin I (cTnI) were routinely collected at baseline and at frequent intervals between 8 and 48 hours after PCI. The primary and secondary outcomes were the covariate-adjusted 3-year rates of cardiovascular (CV) and all-cause mortality, respectively.ResultsThe 3-year rate of CV mortality progressively increased with higher peak CK-MB values. CV mortality was first independently predicted by postprocedural CK-MB 3 to 5 times the upper reference limit (URL) (adjusted hazard ratio [aHR]: 2.93; 95% confidence interval [CI]: 1.02-8.40), whereas all-cause death was independently predicted only by CK-MB ≥ 10 × URL (aHR: 3.25; 95% CI: 1.37-7.70). In contrast, no level of peak postprocedural cTnI was associated with CV or all-cause death. PMI by the Society for Cardiovascular Angiography and Interventions (SCAI), Academic Research Consortium-2 (ARC-2), and fourth universal definition of myocardial infarction (UDMI) occurred in 1.3%, 3.1%, and 5.1% of patients, respectively. The SCAI definition was significantly associated with 3-year CV mortality (aHR: 4.93; 95% CI: 1.92-12.69) and all-cause mortality (aHR: 3.11; 95% CI: 1.33-7.27), whereas the ARC-2 and fourth UDMI definitions were not.ConclusionsIn a large cohort of consecutive patients undergoing LM PCI, intermediate (≥3 × URL) and high (≥10 × URL) levels of peak postprocedural CK-MB independently predicted 3-year CV and all-cause mortality, respectively, whereas even large elevations of post-PCI cTnI did not. The SCAI definition (but not the ARC-2 or fourth UDMI) of PMI was independently associated with mortality after LM PCI.     

Global Circumferential and Radial Strain Among Patients With Immune Checkpoint Inhibitor Myocarditis

BackgroundGlobal circumferential strain (GCS) and global radial strain (GRS) are reduced with cytotoxic chemotherapy. There are limited data on the effect of immune checkpoint inhibitor (ICI) myocarditis on GCS and GRS.ObjectivesThis study aimed to detail the role of GCS and GRS in ICI myocarditis.MethodsIn this retrospective study, GCS and GRS from 75 cases of patients with ICI myocarditis and 50 ICI-treated patients without myocarditis (controls) were compared. Pre-ICI GCS and GRS were available for 12 cases and 50 controls. Measurements were performed in a core laboratory blinded to group and time. Major adverse cardiovascular events (MACEs) were defined as a composite of cardiogenic shock, cardiac arrest, complete heart block, and cardiac death.ResultsCases and controls were similar in age (66 ± 15 years vs 63 ± 12 years; P = 0.20), sex (male: 73% vs 61%; P = 0.20) and cancer type (P = 0.08). Pre-ICI GCS and GRS were also similar (GCS: 22.6% ± 3.4% vs 23.5% ± 3.8%; P = 0.14; GRS: 45.5% ± 6.2% vs 43.6% ± 8.8%; P = 0.24). Overall, 56% (n = 42) of patients with myocarditis presented with preserved left ventricular ejection fraction (LVEF). GCS and GRS were lower in myocarditis compared with on-ICI controls (GCS: 17.5% ± 4.2% vs 23.6% ± 3.0%; P < 0.001; GRS: 28.6% ± 6.7% vs 47.0% ± 7.4%; P < 0.001). Over a median follow-up of 30 days, 28 cardiovascular events occurred. A GCS (HR: 4.9 [95% CI: 1.6-15.0]; P = 0.005) and GRS (HR: 3.9 [95% CI: 1.4-10.8]; P = 0.008) below the median was associated with an increased event rate. In receiver-operating characteristic (ROC) curves, GCS (AUC: 0.80 [95% CI: 0.70-0.91]) and GRS (AUC: 0.76 [95% CI: 0.64-0.88]) showed better performance than cardiac troponin T (cTnT) (AUC: 0.70 [95% CI: 0.58-0.82]), LVEF (AUC: 0.69 [95% CI: 0.56-0.81]), and age (AUC: 0.54 [95% CI: 0.40-0.68]). Net reclassification index and integrated discrimination improvement demonstrated incremental prognostic utility of GRS over LVEF (P = 0.04) and GCS over cTnT (P = 0.002).ConclusionsGCS and GRS are lower in ICI myocarditis, and the magnitude of reduction has prognostic significance.     

Comparative Safety of Transcatheter LAAO With the First-Generation Watchman and Next-Generation Watchman FLX Devices

BackgroundProcedural complications limit the clinical benefit of transcatheter left atrial appendage occlusion (LAAO). Next-generation devices incorporate design modifications intended to improve procedural safety, but their clinical impact has not been described.ObjectivesThe aim of this study was to compare in-hospital outcomes for the Watchman FLX with the predicate Watchman 2.5 device.MethodsThe National Cardiovascular Data Registry LAAO Registry was used to identify patients who received the Watchman FLX and an identical number of patients receiving the Watchman 2.5 at the same sites directly preceding the first Watchman FLX case at each site. The primary endpoint was in-hospital major adverse events (MAE), defined as a composite of death, cardiac arrest, stroke, transient ischemic attack, intracranial hemorrhage, systemic arterial embolism, major bleeding, major vascular complication, myocardial infarction, pericardial effusion requiring intervention (percutaneous or surgical), and device embolization. A secondary analysis was performed using 2:1 propensity score matching of patients receiving the Watchman 2.5 or Watchman FLX.ResultsThe study cohort consisted of 27,013 patients receiving each device. The rate of in-hospital MAE was significantly lower for the Watchman FLX compared with the Watchman 2.5 (1.35% vs 2.40%; adjusted OR: 0.57; 95% CI: 0.50-0.65; P < 0.0001), driven largely by fewer pericardial effusions requiring intervention (0.42% vs 1.23%; adjusted OR: 0.34; 95% CI: 0.28-0.42; P < 0.0001). The Watchman FLX was also associated with significant lower rates of the individual endpoints of in-hospital mortality (0.12% vs 0.24%; P < 0.0001), major bleeding (1.08% vs 2.05%; P < 0.0001), cardiac arrest (0.13% vs 0.24%; P = 0.006), and device embolization (0.02% vs 0.06%; P = 0.028), while myocardial infarction, stroke, and major vascular complications did not differ between groups. Propensity score matching analysis demonstrated similar results, with lower rates of MAE with the Watchman FLX (1.34% vs 2.58%; OR: 0.51; 95% CI: 0.46-0.58; P < 0.0001).ConclusionsTranscatheter LAAO with the Watchman FLX was associated with lower rates of in-hospital MAE compared with the predicate Watchman device, including mortality, pericardial effusion, major bleeding, cardiac arrest, and device embolization. This may favorably influence the balance of risks and benefits of transcatheter LAAO for stroke prevention in patients with atrial fibrillation.     

Direct Risk Assessment From Myocardial Perfusion Imaging Using Explainable Deep Learning

BackgroundMyocardial perfusion imaging (MPI) is frequently used to provide risk stratification, but methods to improve the accuracy of these predictions are needed.ObjectivesThe authors developed an explainable deep learning (DL) model (HARD MACE [major adverse cardiac events]-DL) for the prediction of death or nonfatal myocardial infarction (MI) and validated its performance in large internal and external testing groups.MethodsPatients undergoing single-photon emission computed tomography MPI were included, with 20,401 patients in the training and internal testing group (5 sites) and 9,019 in the external testing group (2 different sites). HARD MACE-DL uses myocardial perfusion, motion, thickening, and phase polar maps combined with age, sex, and cardiac volumes. The primary outcome was all-cause mortality or nonfatal MI. Prognostic accuracy was evaluated using area under the receiver-operating characteristic curve (AUC).ResultsDuring internal testing, patients with normal perfusion and elevated HARD MACE-DL risk were at higher risk than patients with abnormal perfusion and low HARD MACE-DL risk (annualized event rate, 2.9% vs 1.2%; P < 0.001). Patients in the highest quartile of HARD MACE-DL score had an annual rate of death or MI (4.8%) 10-fold higher than patients in the lowest quartile (0.48% per year). In external testing, the AUC for HARD MACE-DL (0.73; 95% CI: 0.71-0.75) was higher than a logistic regression model (AUC: 0.70), stress total perfusion deficit (TPD) (AUC: 0.65), and ischemic TPD (AUC: 0.63; all P < 0.01). Calibration, a measure of how well predicted risk matches actual risk, was excellent in both groups (Brier score, 0.079 for internal and 0.070 for external).ConclusionsThe DL model predicts death or MI directly from MPI, by estimating patient-level risk with good calibration and improved accuracy compared with traditional quantitative approaches. The model incorporates mechanisms to explain to the physician which image regions contribute to the adverse event prediction.     

Plaque Burden and 1-Year Outcomes in Acute Chest Pain: Results From the Multicenter RAPID-CTCA Trial

BackgroundIn patients with stable chest pain, computed tomography (CT) plaque burden is an independent predictor of future coronary events.ObjectivesThe purpose of this study was to determine whether plaque burden and characteristics can predict subsequent death or myocardial infarction in patients with acute chest pain.MethodsIn a post hoc analysis of a multicenter trial of early coronary CT angiography, the authors performed quantitative plaque analysis to assess the association between primary endpoint of 1-year all-cause death or nonfatal myocardial infarction and the GRACE (Global Registry of Acute Coronary Events) score, presence of obstructive coronary artery disease, and plaque burden in 404 patients with suspected acute coronary syndrome.ResultsFollowing the index event, 25 patients had a primary event that was associated with a higher GRACE score (134 ± 44 vs 113 ± 35; P = 0.012), larger burdens of total (46% [IQR: 43%-50%] vs 36% [IQR: 21%-46%]; P < 0.001), noncalcified (41% [IQR: 37%-%47] vs 33% [IQR: 20%-41%]; P < 0.001), and low-attenuation plaque (4.22% [IQR: 3.3%-5.68%] vs 2.14% [IQR: 0.5%-4.88%]; P < 0.001), but not obstructive coronary artery disease (P = 0.065). Total, noncalcified, and low-attenuation plaque burden were the strongest predictors of future events independent of GRACE score and obstructive coronary artery disease (P ≤ 0.002 for all). Patients with a low-attenuation burden above the median had nearly an 8-fold increased risk of the primary endpoint (HR: 7.80 [95% CI: 2.33-26.0]; P < 0.001), outperforming either a GRACE score of >140 (HR: 3.80 [95% CI :1.45-6.98]; P = 0.004) or obstructive coronary artery disease (HR: 2.07 [95% CI: 0.94-4.53]; P = 0.07).ConclusionsIn patients with suspected acute coronary syndrome, low-attenuation plaque burden is a major predictor of 1-year death or recurrent myocardial infarction. (Rapid Assessment of Potential Ischaemic Heart Disease With CTCA [RAPID-CTCA]; NCT02284191)