Coronary Artery Target Selection and Survival After Bilateral Internal Thoracic Artery Grafting

BackgroundThe importance of a coronary artery, based on the myocardial mass it perfuses, is well documented, but little is known about the importance of a vessel that has been bypassed and its effect on survival in the context of bilateral internal thoracic artery (BITA) grafting.ObjectivesThis study determined the effect of a dominant left anterior descending (LAD) artery and important non-LAD targets on outcomes after BITA grafting.MethodsFrom January 1972 to January 2011, of 6,127 patients who underwent BITA grafting, 2,551 received 1 ITA grafted to the LAD and had an evaluable coronary angiogram. A dominant LAD was defined as one that was wrapped around the left ventricular apex. Non-LAD targets were graded based on their terminal reach toward the apex: important: >75% (n = 1,698); and less important: ≤75% (n = 853). Mean follow-up was 14 ± 8.7 years. Multivariable analysis was performed to identify risk factors for time-related mortality.ResultsA dominant LAD was present more frequently in patients with less important additional targets (51% vs. 35%; p < 0.0001). A total of 179 patients (7.0%) received a second ITA to multiple targets, 77 (43%) of which were to multiple important target vessels. Unadjusted late survival was similar regardless of degree of importance of the second ITA target—77% at 15 years (p = 0.70) for the important and less important targets, respectively. In the multivariable model, grafting the second ITA to multiple important targets was associated with better long-term survival (p = 0.005). In patients with a nondominant LAD, a second ITA grafted to a less important artery was associated with higher risk of operative mortality (2.4% vs. 0.51%; p = 0.007). A saphenous vein graft to an important or less important target did not influence long-term survival.ConclusionsIn BITA grafting, bypassing multiple important targets to maximize myocardium supplied by ITAs improved long-term survival. In patients with a nondominant LAD, selecting an important target for the second ITA lowered operative mortality.     

Vein Graft Use and Long-Term Survival Following Coronary Bypass Grafting

BackgroundAlthough placement of at least 1 arterial graft during coronary artery bypass grafting (CABG) has a proven survival benefit, it is unknown what degree of revascularization with saphenous vein grafting (SVG) is associated with improved survival.ObjectivesThe authors sought to determine whether undergoing surgery performed by a surgeon who is liberal with vein graft utilization is associated with improved survival in patients undergoing single arterial graft CABG (SAG-CABG).MethodsThis was a retrospective, observational study of SAG-CABG performed in Medicare beneficiaries from 2001 to 2015. Surgeons were stratified by number of SVG utilized per SAG-CABG into conservative (≥1 SD below mean), average (within 1 SD of mean), and liberal (≥1 SD above mean). Long-term survival was estimated using Kaplan-Meier analysis and compared among surgeon groups before and after augmented inverse-probability weighting.ResultsThere were 1,028,264 Medicare beneficiaries undergoing SAG-CABG from 2001 to 2015 (mean age 72.0 ± 7.9 years, 68.3% male). Over time, 1-vein and 2-vein SAG-CABG utilization increased, whereas 3-vein and ≥4-vein SAG-CABG utilization decreased (P < 0.001). Surgeons who were conservative vein graft users performed a mean 1.7 ± 0.2 vein grafts per SAG-CABG, whereas those who were liberal vein graft users performed a mean 2.9 ± 0.2 vein grafts per SAG-CABG. Weighted analysis demonstrated no difference in median survival among patients undergoing SAG-CABG by liberal vs conservative vein graft users (adjusted median survival difference 27 days).ConclusionsAmong Medicare beneficiaries undergoing SAG-CABG, there is no association between surgeon proclivity for vein graft utilization and long-term survival, suggesting that a conservative approach to vein graft utilization is reasonable.     

Coronary 18F-Sodium Fluoride Uptake Predicts Outcomes in Patients With Coronary Artery Disease

BackgroundReliable methods for predicting myocardial infarction in patients with established coronary artery disease are lacking. Coronary ¹⁸F-sodium fluoride (¹⁸F-NaF) positron emission tomography (PET) provides an assessment of atherosclerosis activity.ObjectivesThis study assessed whether ¹⁸F-NaF PET predicts myocardial infarction and provides additional prognostic information to current methods of risk stratification.MethodsPatients with known coronary artery disease underwent ¹⁸F-NaF PET computed tomography and were followed up for fatal or nonfatal myocardial infarction over 42 months (interquartile range: 31 to 49 months). Total coronary ¹⁸F-NaF uptake was determined by the coronary microcalcification activity (CMA).ResultsIn a post hoc analysis of data collected for prospective observational studies, the authors studied 293 study participants (age: 65 ± 9 years; 84% men), of whom 203 (69%) showed increased coronary ¹⁸F-NaF activity (CMA >0). Fatal or nonfatal myocardial infarction occurred only in patients with increased coronary ¹⁸F-NaF activity (20 of 203 with a CMA >0 vs. 0 of 90 with a CMA of 0; p < 0.001). On receiver operator curve analysis, fatal or nonfatal myocardial infarction prediction was highest for ¹⁸F-NaF CMA, outperforming coronary calcium scoring, modified Duke coronary artery disease index and Reduction of Atherothrombosis for Continued Health (REACH) and Secondary Manifestations of Arterial Disease (SMART) risk scores (area under the curve: 0.76 vs. 0.54, 0.62, 0.52, and 0.54, respectively; p < 0.001 for all). Patients with CMA >1.56 had a >7-fold increase in fatal or nonfatal myocardial infarction (hazard ratio: 7.1; 95% confidence interval: 2.2 to 25.1; p = 0.003) independent of age, sex, risk factors, segment involvement and coronary calcium scores, presence of coronary stents, coronary stenosis, REACH and SMART scores, the Duke coronary artery disease index, and recent myocardial infarction.ConclusionsIn patients with established coronary artery disease, ¹⁸F-NaF PET provides powerful independent prediction of fatal or nonfatal myocardial infarction.     

Relationship Between Coronary Artery Calcium and Atherosclerosis Progression Among Patients With Suspected Coronary Artery Disease

BackgroundAmong symptomatic patients, it remains unclear whether a coronary artery calcium (CAC) score alone is sufficient or misses a sizeable burden and progressive risk associated with obstructive and nonobstructive atherosclerotic plaque.ObjectivesAmong patients with low to high CAC scores, our aims were to quantify co-occurring obstructive and nonobstructive noncalcified plaque and serial progression of atherosclerotic plaque volume.MethodsA total of 698 symptomatic patients with suspected coronary artery disease (CAD) underwent serial coronary computed tomographic angiography (CTA) performed 3.5 to 4.0 years apart. Atherosclerotic plaque was quantified, including by compositional subgroups. Obstructive CAD was defined as ≥50% stenosis. Multivariate linear regression models were used to measure atherosclerotic plaque progression by CAC scores. Cox proportional hazard models estimated CAD event risk (median of 10.7 years of follow-up).ResultsAcross baseline CAC scores from 0 to ≥400, total plaque volume ranged from 30.4 to 522.4 mm³ (P < 0.001) and the prevalence of obstructive CAD increased from 1.4% to 49.1% (P < 0.001). Of those with a 0 CAC score, 97.9% of total plaque was noncalcified. Among patients with baseline CAC <100, nonobstructive CAD was prevalent (40% and 89% in CAC scores of 0 and 1-99), with plaque largely being noncalcified. On the follow-up coronary CTA, volumetric plaque growth (P < 0.001) and the development of new or worsening stenosis (P < 0.001) occurred more among patients with baseline CAC ≥100. Progression varied compositionally by baseline CAC scores. Patients with no CAC had disproportionate growth in noncalcified plaque, and for every 1 mm³ increase in calcified plaque, there was a 5.5 mm³ increase in noncalcified plaque volume. By comparison, patients with CAC scores of ≥400 exhibited disproportionate growth in calcified plaque with a volumetric increase 15.7-fold that of noncalcified plaque. There was a graded increase in CAD event risk by the CAC with rates from 3.3% for no CAC to 21.9% for CAC ≥400 (P < 0.001).ConclusionsCAC imperfectly characterizes atherosclerotic disease burden, but its subgroups exhibit pathogenic patterns of early to advanced disease progression and stratify long-term prognostic risk.     

Intravascular Polarimetry in Patients With Coronary Artery Disease

ObjectivesThe aims of this first-in-human pilot study of intravascular polarimetry were to investigate polarization properties of coronary plaques in patients and to examine the relationship of these features with established structural characteristics available to conventional optical frequency domain imaging (OFDI) and with clinical presentation.BackgroundPolarization-sensitive OFDI measures birefringence and depolarization of tissue together with conventional cross-sectional optical frequency domain images of subsurface microstructure.MethodsThirty patients undergoing polarization-sensitive OFDI (acute coronary syndrome, n = 12; stable angina pectoris, n = 18) participated in this study. Three hundred forty-two cross-sectional images evenly distributed along all imaged coronary arteries were classified into 1 of 7 plaque categories according to conventional OFDI. Polarization features averaged over the entire intimal area of each cross section were compared among plaque types and with structural parameters. Furthermore, the polarization properties in cross sections (n = 244) of the fibrous caps of acute coronary syndrome and stable angina pectoris culprit lesions were assessed and compared with structural features using a generalized linear model.ResultsThe median birefringence and depolarization showed statistically significant differences among plaque types (p < 0.001 for both, one-way analysis of variance). Depolarization differed significantly among individual plaque types (p < 0.05), except between normal arteries and fibrous plaques and between fibrofatty and fibrocalcified plaques. Caps of acute coronary syndrome lesions and ruptured caps exhibited lower birefringence than caps of stable angina pectoris lesions (p < 0.01). In addition to clinical presentation, cap birefringence was also associated with macrophage accumulation as assessed using normalized SD.ConclusionsIntravascular polarimetry provides quantitative metrics that help characterize coronary arterial tissues and may offer refined insight into coronary arterial atherosclerotic lesions in patients.     

The Relationship Between Coronary Calcification and the Natural History of Coronary Artery Disease

ObjectivesThe aim of the current study was to explore the impact of plaque calcification in terms of absolute calcified plaque volume (CPV) and in the context of its percentage of the total plaque volume at a lesion and patient level on the progression of coronary artery disease.BackgroundCoronary artery calcification is an established marker of risk of future cardiovascular events. Despite this, plaque calcification is also considered a marker of plaque stability, and it increases in response to medical therapy.MethodsThis analysis included 925 patients with 2,568 lesions from the PARADIGM (Progression of Atherosclerotic Plaque Determined by Computed Tomographic Angiography Imaging) registry, in which patients underwent clinically indicated serial coronary computed tomography angiography. Plaque calcification was examined by using CPV and percent CPV (PCPV), calculated as (CPV/plaque volume) × 100 at a per-plaque and per-patient level (summation of all individual plaques).ResultsCPV was strongly correlated with plaque volume (r = 0.780; p < 0.001) at baseline and with plaque progression (r = 0.297; p < 0.001); however, this association was reversed after accounting for plaque volume at baseline (r = –0.146; p < 0.001). In contrast, PCPV was an independent predictor of a reduction in plaque volume (r = –0.11; p < 0.001) in univariable and multivariable linear regression analyses. Patient-level analysis showed that high CPV was associated with incident major adverse cardiac events (hazard ratio: 3.01: 95% confidence interval: 1.58 to 5.72), whereas high PCPV was inversely associated with major adverse cardiac events (hazard ratio: 0.529; 95% confidence interval: 0.229 to 0.968) in multivariable analysis.ConclusionsCalcified plaque is a marker for risk of adverse events and disease progression due to its strong association with the total plaque burden. When considered as a percentage of the total plaque volume, increasing PCPV is a marker of plaque stability and reduced risk at both a lesion and patient level. (Progression of Atherosclerotic Plaque Determined by Computed Tomographic Angiography Imaging [PARADIGM]; NCT02803411)     

Simultaneous Hybrid Coronary Revascularization vs Conventional Strategies for Multivessel Coronary Artery Disease: A 10-Year Follow-Up

BackgroundAlthough evidence is sufficient to confirm that hybrid coronary revascularization (HCR) is safe and effective in the short term, its value in the long run is debatable.ObjectivesThis study sought to compare the long-term outcomes of HCR with coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) for multivessel disease.MethodsThree groups of patients, 540 each, receiving HCR, CABG, or PCI between June 2007 to September 2018, were matched using propensity score matching. Patients were stratified by EuroSCORE (European System for Cardiac Operative Risk Evaluation) II (low ≤0.9; 0.9 < medium <1.5; high ≥1.5) and SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score (low ≤22; 22 < medium <33; high ≥33). Major adverse cardiac and cerebrovascular events (MACCE) and Seattle Angina Questionnaire (SAQ) scores were compared among the 3 groups.ResultsIn terms of MACCE and SAQ, HCR performed similarly to off-pump CABG but significantly outperformed PCI (P < 0.001). In the low-to-medium EuroSCORE II and medium-to-high SYNTAX score tertiles, MACCE rates in the HCR group were significantly lower than those in the PCI (EuroSCORE II: low, 30.7% vs 41.2%; P = 0.006; medium, 31.3% vs 41.7%; P = 0.013; SYNTAX score: medium, 27.6% vs 41.2%; P = 0.018; high, 32.4% vs 52.7%; P = 0.011) but were similar to those in the CABG group. In the high EuroSCORE II stratum, HCR had a lower MACCE rate than CABG (31.9% vs 47.0%; P = 0.041) and PCI (31.9% vs 53.7%; P = 0.015).ConclusionsCompared with conventional strategies, HCR provided satisfactory long-term outcomes in MACCE and functional status for multivessel disease.     

Automated Echocardiographic Detection of Severe Coronary Artery Disease Using Artificial Intelligence

ObjectivesThe purpose of this study was to establish whether an artificially intelligent (AI) system can be developed to automate stress echocardiography analysis and support clinician interpretation.BackgroundCoronary artery disease is the leading global cause of mortality and morbidity and stress echocardiography remains one of the most commonly used diagnostic imaging tests.MethodsAn automated image processing pipeline was developed to extract novel geometric and kinematic features from stress echocardiograms collected as part of a large, United Kingdom-based prospective, multicenter, multivendor study. An ensemble machine learning classifier was trained, using the extracted features, to identify patients with severe coronary artery disease on invasive coronary angiography. The model was tested in an independent U.S. study. How availability of an AI classification might impact clinical interpretation of stress echocardiograms was evaluated in a randomized crossover reader study.ResultsAcceptable classification accuracy for identification of patients with severe coronary artery disease in the training data set was achieved on cross-fold validation based on 31 unique geometric and kinematic features, with a specificity of 92.7% and a sensitivity of 84.4%. This accuracy was maintained in the independent validation data set. The use of the AI classification tool by clinicians increased inter-reader agreement and confidence as well as sensitivity for detection of disease by 10% to achieve an area under the receiver-operating characteristic curve of 0.93.ConclusionsAutomated analysis of stress echocardiograms is possible using AI and provision of automated classifications to clinicians when reading stress echocardiograms could improve accuracy, inter-reader agreement, and reader confidence.     

Myocardial Flow Reserve and Coronary Calcification in Prognosis of Patients With Suspected Coronary Artery Disease

ObjectivesThe aim of this analysis is to examine the incremental prognostic value of coronary artery calcium (CAC) score and myocardial flow reserve (MFR) in patients with suspected coronary artery disease (CAD) undergoing positron emission tomography (PET) myocardial perfusion imaging (MPI).BackgroundAdvances in cardiac PET and computed tomography imaging enabled the simultaneous acquisition of anatomic and physiological data for patients suspected of CAD.MethodsConsecutive patients who underwent PET MPI and CAC score calculation at King Abdulaziz Cardiac Center, Riyadh, Saudi Arabia, between May 2011 and May 2018 were included in the study. MPI and CAC images were obtained in the same setting. The primary endpoint of the study was a composite of cardiac death and nonfatal myocardial infarction. Cox proportional hazard regression was used to assess the incremental prognostic value of CAC and MFR by sequentially adding the variables to a model that included clinical and PET variables.ResultsA total of 4,008 patients (mean age 59.7 ± 11.6 years, 55% women) were included in the analysis. Risk factors were prevalent (77.6% hypertension, 58.1% diabetes). In total, 35.9% of the cohort had CAC of 0, 16.5% had CAC ≥400, and 43.9% had MFR <2. Over a median follow up of 1.9 years, 130 (3.2%) patients had cardiac death/nonfatal myocardial infarction. CAC and MFR score added incremental prognostic value over clinical and perfusion variables (base model: c-index 0.8137; Akaike information criterion [AIC]: 1,865.877; p = 0.0011; CAC model: c-index = 0.8330; AIC: 1,850.810; p = 0.045 vs. base model; MFR model: c-index = 0.8279; AIC: 1,859.235; p = 0.024). Combining CAC and MFR did not enhance risk prediction (c-index = 0.8435; AIC: 1,846.334; p = 0.074 vs. MFR model; p = 0.21 vs. CAC model.)ConclusionsIn this large cohort of patients referred for PET MPI, both CAC and MFR independently added incremental prognostic value over clinical and MPI variables. Although combining both may have synergetic prognostic effect, this relation was not shown in multivariable model of this analysis.     

Impact of SYNTAX Score on 10-Year Outcomes After Revascularization for Left Main Coronary Artery Disease

ObjectivesThe aim of this study was to investigate the long-term impact of SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score (SS) on differential outcomes after percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for left main coronary artery (LMCA) disease.BackgroundThe very long term prognostic effect of SS on mortality and major cardiovascular events after LMCA revascularization is still undetermined.MethodsIn the MAIN-COMPARE (Ten-Year Outcomes of Stents Versus Coronary-Artery Bypass Grafting for Left Main Coronary Artery Disease) registry, patients with baseline SS measurements were analyzed. The 10-year rates of all-cause mortality, the composite of death, Q-wave myocardial infarction, or stroke, and target vessel revascularization after PCI or CABG were compared according to baseline SS.ResultsAmong 1,580 patients with baseline SS, 547 patients (34.6%) had low SS (≤22), 350 (22.2%) had intermediate SS (23 to 32), and 683 (43.2%) had high SS (≥33). In patients with low to intermediate SS, the adjusted 10-year risks for death and serious composite outcome were similar between the PCI group and the CABG group. However, in patients with high SS, PCI with stenting, compared with CABG, was associated with a higher risk for death (hazard ratio: 1.39; 95% confidence interval: 1.00 to 1.92; p = 0.048) and serious composite outcome (hazard ratio: 1.27; 95% confidence interval: 0.94 to 1.74; p = 0.123). In each revascularization group, conventional tertiles of SS had a differential prognostic impact on 10-year clinical outcomes in the PCI arm but not in the CABG arm.ConclusionsIn this 10-year extended follow-up of patients undergoing LMCA revascularization, CABG showed a clear prognostic benefit over PCI in patients with high anatomic complexity measured by SS at baseline. The discriminative capacity of SS on long-term outcomes was relevant in the PCI group but not in the CABG group. (Ten-Year Outcomes of Stents Versus Coronary-Artery Bypass Grafting for Left Main Coronary Artery Disease [MAIN-COMPARE]; NCT02791412)     

Coronary Calcium to Rule Out Obstructive Coronary Artery Disease in Patients With Acute Chest Pain

ObjectivesThis study aimed to evaluate the ability of coronary artery calcium (CAC) as an initial diagnostic tool to rule out obstructive coronary artery disease (CAD) in a very large registry of patients presenting to the emergency department (ED) with acute chest pain (CP) who were at low to intermediate risk for acute coronary syndrome (ACS).BackgroundIt is not yet well established whether CAC can be used to rule out obstructive CAD in the ED setting.MethodsWe included patients from the Baptist Health South Florida Chest Pain Registry presenting to the ED with CP at low to intermediate risk for ACS (Thrombolysis In Myocardial Infarction risk score ≤2, normal/nondiagnostic electrocardiography, and troponin levels) who underwent CAC and coronary computed tomography angiography (CCTA) procedures for evaluation of ACS. To assess the diagnostic accuracy of CAC testing to diagnose obstructive CAD and identify the need for coronary revascularization during hospitalization, we estimated sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV).ResultsOur study included 5,192 patients (mean age: 53.5 ± 10.8 years; 46% male; 62% Hispanic). Overall, 2,902 patients (56%) had CAC = 0, of which 135 (4.6%) had CAD (114 [3.9%] nonobstructive and 21 [0.7%] obstructive). Among those with CAC >0, 23% had obstructive CAD. Sensitivity, specificity, PPV, and NPV of CAC testing to diagnose obstructive CAD were 96.2%, 62.4%, 22.4%, and 99.3%, respectively. The NPV for identifying those who needed revascularization was 99.6%. Among patients with CAC = 0, 11 patients (0.4%) underwent revascularization, and the number needed to test with CCTA to detect 1 patient who required revascularization was 264.ConclusionsIn a large population presenting to ED with CP at low to intermediate risk, CAC = 0 was common. CAC = 0 ruled out obstructive CAD and revascularization in more than 99% of the patients, and <5% with CAC = 0 had any CAD. Integrating CAC testing very early in CP evaluation may be effective in appropriate triage of patients by identifying individuals who can safely defer additional testing and more invasive procedures.     

Impact of Coronary Artery Disease on Outcomes in Patients Undergoing Percutaneous Edge-to-Edge Repair

ObjectivesThe aim of this observational study was to evaluate the impact of concomitant coronary artery disease (CAD) on outcomes in patients undergoing percutaneous valve repair with the MitraClip system.BackgroundMitral valve regurgitation and CAD are often coexistent in elderly patients undergoing percutaneous mitral valve repair. The impact of CAD and revascularization on outcomes in this patient cohort, however, remains uncertain.MethodsIn 444 MitraClip patients, CAD severity was assessed, represented by the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score (SS), as well as the residual SS (rSS) and SYNTAX score II (SS-II). Patients were stratified according to CAD severity and SS-II values (SS ≤3 vs. SS >3 and SS-II ≤45 vs. SS-II >45) and according to remaining CAD burden into 2 groups (rSS = 0 vs. rSS >0) to compare 1-year all-cause mortality.ResultsHigher SS, rSS, and SS-II were associated with mortality (22% for SS >3 vs. 9.6% for SS ≤3 [p < 0.001], 31.4% for rSS >0 vs. 9.6% for rSS = 0 [p < 0.001], and 17.1% for SS-II > 45 vs. 11.2% for SS-II ≤45 [p = 0.044]). The rSS was an independent predictor of 1-year all-cause mortality (p = 0.001) in multivariate analysis.ConclusionsThe complexity of CAD, as assessed using the SS, is associated with outcomes in patients undergoing MitraClip procedures. The burden of residual CAD after percutaneous coronary intervention is an independent predictor of 1-year all-cause mortality. Patients undergoing complete revascularization had the most favorable outcomes independent of mitral regurgitation etiology.     

Discordance Between Coronary Artery Calcium Area and Density Predicts Long-Term Atherosclerotic Cardiovascular Disease Risk

BackgroundCoronary artery calcium (CAC) is commonly quantified as the product of 2 generally correlated measures: plaque area and calcium density.ObjectivesThe authors sought to determine whether discordance between calcium area and density has long-term prognostic importance in atherosclerotic cardiovascular disease (ASCVD) risk.MethodsThe authors studied 10,373 primary prevention participants from the CAC Consortium with CAC >0. Based on their median values, calcium area and mean calcium density were divided into 4 mutually exclusive concordant/discordant groups. Cox proportional hazards regression assessed the association of calcium area/density groups with ASCVD mortality over a median of 11.7 years, adjusting for traditional risk factors and the Agatston CAC score.ResultsThe mean age was 56.7 years, and 24% were female. The prevalence of plaque discordance was 19% (9% low calcium area/high calcium density, 10% high calcium area/low calcium density). Female sex (odds ratio [OR]: 1.48 [95% CI: 1.27-1.74]) and body mass index (OR: 0.81 [95% CI: 0.76-0.87], per 5 kg/m² higher) were significantly associated with high calcium density discordance, whereas diabetes (OR: 2.23 [95% CI: 1.85-3.19]) was most strongly associated with discordantly low calcium density. Compared to those with low calcium area/low calcium density, individuals with low calcium area/high calcium density had a 71% lower risk of ASCVD death (HR: 0.29 [95% CI: 0.09-0.95]).ConclusionsFor a given CAC score, high calcium density relative to plaque area confers lower long-term ASCVD risk, likely serving as an imaging marker of biological resilience for lesion vulnerability. Additional research is needed to define a robust definition of calcium area/density discordance for routine clinical risk prediction.     

Prognostic Implications of Plaque Characteristics and Stenosis Severity in Patients With Coronary Artery Disease

BackgroundAlthough the presence of ischemia is a key prognostic factor in patients with coronary artery disease, the presence of high-risk plaque characteristics (HRPC) is also associated with increased risk of cardiovascular events. Limited data exist regarding the prognostic implications of combined information on physiological stenosis severity assessed by fractional flow reserve (FFR) and plaque vulnerability by coronary computed tomography angiography (CTA)–defined HRPC.ObjectivesThe current study aimed to evaluate the: 1) association between physiological stenosis severity and coronary CTA-defined HRPC; and 2) prognostic implications of coronary CTA-defined HRPC according to physiological stenosis severity in patients with coronary artery disease.MethodsA total of 772 vessels (299 patients) evaluated by both coronary CTA and FFR were analyzed. The presence and number of HRPC (minimum lumen area <4 mm², plaque burden ≥70%, low attenuating plaque, positive remodeling, napkin-ring sign, or spotty calcification) were assessed using coronary CTA images. The risk of vessel-oriented composite outcome (VOCO) (a composite of vessel-related ischemia-driven revascularization, vessel-related myocardial infarction, or cardiac death) at 5 years was compared according to the number of HRPC and FFR categories.ResultsThe proportion of lesions with ≥3 HRPC was significantly decreased according to the increase in FFR values (58.6%, 46.5%, 36.8%, 15.7%, and 3.5% for FFR ≤0.60, 0.61 to ≤0.70, 0.71 to ≤0.80, 0.81 to ≤0.90, and >0.90, respectively; overall p value <0.001). Both FFR and number of HRPC showed significant association with the estimated risk of VOCO (p = 0.008 and p = 0.023, respectively). In the FFR >0.80 group, lesions with ≥3 HRPC showed significantly higher risk of VOCO than those with <3 HRPC (15.0% vs. 4.3%; hazard ratio: 3.964; 95% confidence interval: 1.451 to 10.828; p = 0.007). However, there was no significant difference in the risk of VOCO according to HRPC in the FFR ≤0.80 group. By multivariable analysis, the presence of ≥3 HRPC was independently associated with the risk of VOCO in the FFR >0.80 group.ConclusionsPhysiological stenosis severity and the number of HRPC were closely related, and both components had significant association with the risk of clinical events. However, the prognostic implication of HRPC was different according to FFR. Integration of both physiological stenosis severity and plaque vulnerability would provide better prognostic stratification of patients than either individual component alone, especially in patients with FFR >0.80. (Clinical Implication of 3-vessel Fractional Flow Reserve [3V FFR-FRIENDS study]; NCT01621438)     

Assessment of Multivessel Coronary Artery Disease Using Cardiovascular Magnetic Resonance Pixelwise Quantitative Perfusion Mapping

ObjectivesThe authors sought to compare the diagnostic accuracy of quantitative perfusion maps to visual assessment (VA) of first-pass perfusion images for the detection of multivessel coronary artery disease (MVCAD).BackgroundVA of first-pass stress perfusion cardiac magnetic resonance (CMR) may underestimate ischemia in MVCAD. Pixelwise perfusion mapping allows quantitative measurement of regional myocardial blood flow, which may improve ischemia detection in MVCAD.MethodsOne hundred fifty-one subjects recruited at 2 centers underwent stress perfusion CMR with myocardial perfusion mapping, and invasive coronary angiography with coronary physiology assessment. Ischemic burden was assessed by VA of first-pass images and by quantitative measurement of stress myocardial blood flow using perfusion maps.ResultsIn patients with MVCAD (2-vessel [2VD] or 3-vessel disease [3VD]; n = 95), perfusion mapping identified significantly more segments with perfusion defects (median segments per patient 12 [interquartile range (IQR): 9 to 16] by mapping vs. 8 [IQR: 5 to 9.5] by VA; p < 0.001). Ischemic burden (IB) measured using mapping was higher in MVCAD compared with IB measured using VA (3VD mapping 100 % (75% to 100%) vs. first-pass 56% (38% to 81%) ; 2VD mapping 63% (50% to 75%) vs. first-pass 41% (31% to 50%); both p < 0.001), but there was no difference in single-vessel disease (mapping 25% (13% to 44%) vs. 25% (13% to 31%). Perfusion mapping was superior to VA for the correct identification of extent of coronary disease (78% vs. 58%; p < 0.001) due to better identification of 3VD (87% vs. 40%) and 2VD (71% vs. 48%).ConclusionsVA of first-pass stress perfusion underestimates ischemic burden in MVCAD. Pixelwise quantitative perfusion mapping increases the accuracy of CMR in correctly identifying extent of coronary disease. This has important implications for assessment of ischemia and therapeutic decision-making.     

10-Year Follow-Up After Revascularization in Elderly Patients With Complex Coronary Artery Disease

BackgroundThe optimal revascularization strategy for the elderly with complex coronary artery disease remains unclear.ObjectivesThe goal of this study was to investigate 10-year all-cause mortality, life expectancy, 5-year major adverse cardiac or cerebrovascular events (MACCE), and 5-year quality of life (QOL) after percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) in elderly individuals (>70 years old) with 3-vessel disease (3VD) and/or left main disease (LMD).MethodsIn the present pre-specified analysis on age of the SYNTAX Extended Survival study, 10-year all-cause death and 5-year MACCE were compared with Kaplan-Meier estimates and Cox proportional hazards models among elderly or nonelderly patients. Life expectancy was estimated by restricted mean survival time within 10 years, and QOL status according to the Seattle Angina Questionnaire up to 5 years was assessed by linear mixed-effects models.ResultsAmong 1,800 randomized patients, 575 patients (31.9%) were elderly. Ten-year mortality did not differ significantly between PCI and CABG in elderly (44.1% vs. 41.1%; hazard ratio [HR]: 1.08; 95% confidence interval [CI]: 0.84 to 1.40) and nonelderly patients (21.1% vs. 16.6%; HR: 1.30; 95% CI: 1.00 to 1.69; p_interaction = 0.332). Among elderly patients, 5-year MACCE was comparable between PCI and CABG (39.4% vs. 35.1%; HR: 1.18; 95% CI: 0.90 to 1.56), whereas it was significantly higher in PCI over CABG among nonelderly patients (36.3% vs. 23.0%; HR: 1.69; 95% CI: 1.36 to 2.10; p_interaction = 0.043). There were no significant difference in life expectancy (mean difference: 0.2 years in favor of CABG; 95% CI: ?0.4 to 0.7) and 5-year QOL status between PCI and CABG among elderly patients.ConclusionsElderly patients with 3VD and/or LMD had comparable 10-year all-cause death, life expectancy, 5-year MACCE, and 5-year QOL status irrespective of revascularization mode. (Synergy Between PCI With TAXUS and Cardiac Surgery: SYNTAX Extended Survival [SYNTAXES]; NCT03417050) (SYNTAX Study: TAXUS Drug-Eluting Stent Versus Coronary Artery Bypass Surgery for the Treatment of Narrowed Arteries [SYNTAX]; NCT00114972)     

Sex Differences in Compositional Plaque Volume Progression in Patients With Coronary Artery Disease

ObjectivesThis study sought to explore sex-based differences in total and compositional plaque volume (PV) progression.BackgroundIt is unclear whether sex has an impact on PV progression in patients with coronary artery disease (CAD).MethodsThe study analyzed a prospective multinational registry of consecutive patients with suspected CAD who underwent 2 or more clinically indicated coronary computed tomography angiography (CTA) at ≥2-year intervals. Total and compositional PV at baseline and follow-up were quantitatively analyzed and normalized using the analyzed total vessel length. Multivariate linear regression models were constructed.ResultsOf the 1,255 patients included (median coronary CTA interval 3.8 years), 543 were women and 712 were men. Women were older (62 ± 9 years of age vs. 59 ± 9 years of age; p < 0.001) and had higher total cholesterol levels (195 ± 41 mg/dl vs. 187 ± 39 mg/dl; p = 0.002). Prevalence of hypertension, diabetes, and family history of CAD were not different (all p > 0.05). At baseline, men possessed greater total PV (31.3 mm³ [interquartile range (IQR): 0 to 121.8 mm³] vs. 56.7 mm³ [IQR: 6.8 to 152.1 mm³] p = 0.005), and there was an approximately 9-year delay in women in developing total PV than in men. The prevalence of high-risk plaques was greater in men than women (31% vs. 20%; p < 0.001). In multivariate analysis, after adjusting for age, clinical risk factors, medication use, and total PV at baseline, despite similar total PV progression rates, female sex was associated with greater calcified PV progression (β = 2.83; p = 0.004) but slower noncalcified PV progression (β = –3.39; p = 0.008) and less development of high-risk plaques (β = –0.18; p = 0.049) than in men.ConclusionsThe compositional PV progression differed according to sex, suggesting that comprehensive plaque evaluation may contribute to further refining of risk stratification according to sex. (NCT02803411).     

Physiological Distribution and Local Severity of Coronary Artery Disease and Outcomes After Percutaneous Coronary Intervention

ObjectivesThe aim of this study was to evaluate prognostic implications of physiological 2-dimensional disease patterns on the basis of distribution and local severity of coronary atherosclerosis determined by quantitative flow ratio (QFR) virtual pull back.BackgroundThe beneficial effect of percutaneous coronary intervention (PCI) is determined by physiological distribution and local severity of coronary atherosclerosis.MethodsThe study population included 341 patients who underwent angiographically successful PCI and post-PCI fractional flow reserve (FFR) measurement. Using pre-PCI virtual pull backs of QFR, physiological distribution was determined by pull back pressure gradient index, with a cutoff value of 0.78 to define predominant focal versus diffuse disease. Physiological local severity was assessed by instantaneous QFR gradient per unit length, with a cutoff value of ≥0.025/mm to define a major gradient. Suboptimal post-PCI physiological results were defined as both post-PCI FFR ≤0.85 and percentage FFR increase ≤15%. Clinical outcome was assessed by target vessel failure (TVF) at 2 years.ResultsQFR pull back pressure gradient index was correlated with post-PCI FFR (R = 0.423; P < 0.001), and instantaneous QFR gradient per unit length was correlated with percentage FFR increase (R = 0.370; P < 0.001). Using the 2 QFR-derived indexes, disease patterns were classified into 4 categories: predominant focal disease with and without major gradient (group 1 [n = 150] and group 2 [n = 21], respectively) and predominant diffuse disease with and without major gradient (group 3 [n = 115] and group 4 [n = 55], respectively). Proportions of suboptimal post-PCI physiological results were significantly different according to the 4 disease patterns (18.7%, 23.8%, 22.6%, and 56.4% from group 1 to group 4, respectively; P < 0.001). Cumulative incidence of TVF after PCI was significantly higher in patients with predominant diffuse disease (8.1% in group 3 and 9.9% in group 4 vs 1.4% in group 1 and 0.0% in group 2; overall P = 0.024).ConclusionsBoth physiological distribution and local severity of coronary atherosclerosis could be characterized without pressure-wire pull backs, which determined post-PCI physiological results. After successful PCI, TVF risk was determined mainly by the physiological distribution of coronary atherosclerosis. (Automated Algorithm Detecting Physiologic Major Stenosis and Its Relationship With Post-PCI Clinical Outcomes [Algorithm-PCI], NCT04304677; Influence of FFR on the Clinical Outcome After Percutaneous Coronary Intervention [PERSPECTIVE], NCT01873560)     

Biolimus-Coated Balloon in Small-Vessel Coronary Artery Disease: The BIO-RISE CHINA Study

BackgroundDrug-coated balloons are a safe and effective option for patients undergoing percutaneous coronary intervention, but prior randomized studies have exclusively used paclitaxel-coated devices.ObjectivesThe aim of this study was to assess for the first time the safety and efficacy of a novel biolimus-coated balloon (BCB) in patients with small-vessel coronary disease.MethodsIn a prospective trial conducted at 10 centers in China, 212 patients with small-vessel native coronary disease (reference vessel diameter 2.0-2.75 mm, lesion length ≤25 mm) were randomized to receive a BCB or an uncoated balloon. The primary endpoint was in-segment late lumen loss at 9 months.ResultsIn the per-protocol population, angiographic late lumen loss at 9 months was 0.16 ± 0.29 mm in the BCB group vs 0.30 ± 0.35 mm with the plain balloon (P = 0.001). Late luminal enlargement (positive remodeling) occurred in 29.7% of patients in the BCB group vs 9.8% of patients with plain balloons (P = 0.007). In the full analysis set population, after 12 months, target lesion failure rates were 6.7% in the BCB group vs 13.9% with the plain balloon (HR: 0.47; 95% CI: 0.19-1.16), and rates of the patient-oriented clinical outcome were 14.3% with the BCB vs 21.8% with the plain balloon (HR: 0.64; 95% CI: 0.33-1.24).ConclusionsIn this first-in-human study, a novel BCB showed superior efficacy to plain balloon angioplasty in patients with small-vessel coronary disease undergoing percutaneous coronary intervention. Positive vascular remodeling was more frequent, and there was a trend toward improved clinical outcomes. (A Randomized Trial of a Biolimus-Coated Balloon Versus POBA in Small Vessel Coronary Artery Disease [Brave]; NCT03769623)     

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.