Recovery of Left Ventricular Systolic Function and Clinical Outcomes in Young Adults With Myocardial Infarction

BackgroundLeft ventricular ejection fraction (EF) recovery is associated with better long-term outcomes after myocardial infarction (MI). However, the association between long-term outcomes and EF recovery among young MI patients has not been investigated.ObjectivesThis study sought to evaluate the prevalence of left ventricular systolic dysfunction among patients who experience their first MI at a young age and to compare outcomes between those who recovered their EF versus those who did not.MethodsThe YOUNG-MI registry is a retrospective cohort study of patients who experienced an MI at ≤50 years of age. EF at the time of MI and within 180 days post-MI were determined from all available medical records. The primary outcomes were all-cause and cardiovascular mortality.ResultsThere were 1,724 patients with baseline EF data: 503 (29%) had EF <50%, whereas 1,221 (71%) had a normal baseline EF. Patients with lower EF were more likely to have experienced ST-segment elevation MI, have higher troponin values, and have more severe angiographic coronary artery disease. Among patients with abnormal baseline EF, information on follow-up EF was available for 216, of whom 90 (42%) recovered their EF to ≥50%. Patients who experienced EF recovery had less severe angiographic disease, lower alcohol use, and a lower burden of comorbidities. Over a median follow-up of 11.1 years, EF recovery was associated with an ∼8-fold reduction in all-cause mortality (adjusted hazard ratio: 0.12; p = 0.001) and a ∼10-fold reduction in cardiovascular mortality (adjusted hazard ratio: 0.10; p = 0.025).ConclusionsNearly one-third of young patients presented with left ventricular dysfunction post-MI. Among them, EF recovery occurred in more than 40% and was independently associated with a substantial decrease in all-cause and cardiovascular mortality.     

Readmission and Mortality After Hospitalization for Myocardial Infarction and Heart Failure

BackgroundReadmission rates after acute myocardial infarction (AMI) and heart failure (HF) hospitalizations have decreased in the United States since the implementation of the Hospital Readmissions Reduction Program.ObjectivesThis study was designed to examine the temporal trends of readmission and mortality after AMI and HF in Ontario, Canada, where reducing hospital readmissions has not had a policy incentive.MethodsThe cohort was comprised of AMI or HF patients 65 years of age or older who had been hospitalized from 2006 to 2017. Primary outcomes were 30-day readmission and post-discharge mortality. Secondary outcomes included in-hospital mortality, 30-day mortality from admission, and in-hospital mortality or 30-day mortality post-discharge. Adjusted monthly trends for each outcome were examined over the study period.ResultsOur cohorts included 152,808 AMI and 223,283 HF patients. Age- and sex-standardized AMI hospitalization rates in Ontario declined 32% from 2006 to 2017 while HF hospitalization rates declined slightly (9.1%). For AMI, risk-adjusted 30-day readmission rates declined from 17.4% in 2006 to 14.7% in 2017. All AMI risk-adjusted mortality rates also declined from 2006 to 2017 with 30-day post-discharge mortality from 5.1% to 4.4%. For HF, overall risk-adjusted 30-day readmission was largely unchanged from 2006 to 2014 at 21.9%, followed by a decline to 20.8% in 2017. Risk-adjusted 30-day post-discharge mortality declined from 7.1% in 2006 to 6.6% in 2017.ConclusionsThe patterns of outcomes in Ontario are consistent with the United States for AMI, but diverge for HF. For AMI and HF, admissions, readmissions, and mortality rates declined over this period. The reasons for the country-specific patterns for HF need further exploration.     

Attenuated Mitral Leaflet Enlargement Contributes to Functional Mitral Regurgitation After Myocardial Infarction

BackgroundMitral leaflet enlargement has been identified as an adaptive mechanism to prevent mitral regurgitation in dilated left ventricles (LVs) caused by chronic aortic regurgitation (AR). This enlargement is deficient in patients with functional mitral regurgitation, which remains frequent in the population with ischemic cardiomyopathy. Maladaptive fibrotic changes have been identified in post-myocardial infarction (MI) mitral valves. It is unknown if these changes can interfere with valve growth and whether they are present in other valves.ObjectivesThis study sought to test the hypothesis that MI impairs leaflet growth, seen in AR, and induces fibrotic changes in mitral and tricuspid valves.MethodsSheep models of AR, AR + MI, and controls were followed for 90 days. Cardiac magnetic resonance, echocardiography, and computed tomography were performed at baseline and 90 days to assess LV volume, LV function, mitral regurgitation and mitral leaflet size. Histopathology and molecular analyses were performed in excised valves.ResultsBoth experimental groups developed similar LV dilatation and dysfunction. At 90 days, mitral valve leaflet size was smaller in the AR + MI group (12.8 ± 1.3 cm² vs. 15.1 ± 1.6 cm², p = 0.03). Mitral regurgitant fraction was 4% ± 7% in the AR group versus 19% ± 10% in the AR + MI group (p = 0.02). AR + MI leaflets were thicker compared with AR and control valves. Increased expression of extracellular matrix remodeling genes was found in both the mitral and tricuspid leaflets in the AR + MI group.ConclusionsIn these animal models of AR, the presence of MI was associated with impaired adaptive valve growth and more functional mitral regurgitation, despite similar LV size and function. More pronounced extracellular remodeling was observed in mitral and tricuspid leaflets, suggesting systemic valvular remodeling after MI.     

Evolution of Myocardial Tissue Injury: A CMR Study Over a Decade After STEMI

BackgroundIn patients with a first ST-segment elevation myocardial infarction (STEMI), the multi-annual evolution of myocardial tissue injury parameters, as assessed by cardiac magnetic resonance (CMR), has not yet been described.ObjectivesThis study examined myocardial tissue injury dynamics over a decade after STEMI.MethodsSequential CMR examinations (within the first week after STEMI, and at 4, 12, months, and 9 years thereafter) were conducted in 74 patients with STEMI treated with primary percutaneous coronary intervention. Left ventricular function, infarct size (IS), and microvascular obstruction (MVO) were assessed at all time points. T21, T2, and T1 mapping (n = 59) were added at 9-year scan to evaluate the presence of iron and edema within the infarct core, respectively.ResultsIS decreased progressively and significantly between all CMR time points (all P < 0.001), with an average reduction rate of 5.8% per year (IQR: 3.5%-8.8%) and a relative reduction of 49% (IQR: 39%-76%) over a decade. MVO was present in 61% of patients at baseline, but was not present at the follow-up examinations. At 9-year CMR, 17 of 59 (29%) patients showed iron deposition within the infarct core, whereas 82% had persistent edema. Persistent iron and edema were associated with greater IS on any occasion (all P < 0.001), as well as the presence of MVO (P < 0.001). Patients with persistent iron and edema showed a lower relative regression of IS (P = 0.005 and P = 0.032, respectively) and greater end-systolic volumes over a decade (all P < 0.012 and P > 0.023, respectively). A T1 hypointense infarct core without evidence of T21 iron deposition (14 of 59 [24%] patients) was attributed to lipomatous metaplasia of the infarct.ConclusionsThe evolution of IS is a dynamic process that extends well beyond the first few months after STEMI. Persistence of iron and edema within the infarct core occurs up to a decade after STEMI and is associated with initial infarct severity and poor infarct healing.     

Prophylactic Rivaroxaban Therapy for Left Ventricular Thrombus After Anterior ST-Segment Elevation Myocardial Infarction

ObjectivesThe aim of this study was to investigate the effects of rivaroxaban on left ventricle thromboprophylaxis in patients with anterior ST-segment elevation myocardial infarction (STEMI).BackgroundAnterior STEMI is associated with an increased risk of left ventricular thrombus (LVT) formation. The contemporary role of prophylactic rivaroxaban therapy remains unclear.MethodsWe randomly assigned 279 patients with anterior STEMI who had undergone primary percutaneous coronary intervention to receive, in a 1:1 ratio, low-dose rivaroxaban (2.5 mg twice daily for 30 days) and dual antiplatelet therapy (DAPT) or only DAPT. The primary efficacy outcome was the LVT formation within 30 days. Net clinical adverse events were assessed at 30 days and 180 days, including all-cause mortality, LVT, systemic embolism, rehospitalization for cardiovascular events, and bleeding.ResultsThe addition of low-dose rivaroxaban to DAPT reduced LVT formation within 30 days compared with only DAPT (0.7% vs 8.6%; HR: 0.08; 95% CI: 0.01-0.62; P = 0.015; P < 0.001 for superiority). Net clinical adverse events were lower within 30 days in the rivaroxaban group versus those in the only DAPT group and remained relatively low throughout the follow-up period. There were no significant differences in bleeding events between the 2 groups in 30 days and 180 days. However, 1 case of intracranial hemorrhage (major bleeding) occurred in the rivaroxaban group within 30 days.ConclusionsOur results supported that the short-duration addition of low-dose rivaroxaban to DAPT could prevent LVT formation in patients with anterior STEMI following primary percutaneous coronary intervention. A larger multiple-institution study is necessary to determine the generalizability.     

Patient Characteristics and Clinical Outcomes of Type 1 Versus Type 2 Myocardial Infarction

BackgroundType 2 myocardial infarction (MI) patients may have different characteristics and outcomes when compared with type 1 MI.ObjectivesThe purpose of this study was to compare patients with type 1 MI to those with type 2 MI in the United States.MethodsUsing the Nationwide Readmissions Database, MI patients were categorized over the 3 months following the introduction of an International Classification of Diseases-10th Revision code specific for type 2 MI. Baseline characteristics and inpatient and post-discharge outcomes among both cohorts were compared.ResultsThere were 216,657 patients with type 1 MI, 37,765 patients with type 2 MI, and 1,525 patients with both type 1 and 2 MI. Patients with type 2 MI were older (71 years vs. 69 years; p < 0.001), were more likely to be women (47.3% vs. 40%; p < 0.001), and had higher prevalence of heart failure (27.9% vs. 10.9%; p < 0.001), kidney disease (35.7% vs. 25.7%; p < 0.001), and atrial fibrillation (31% vs. 21%; p < 0.001). Rates of coronary angiography (10.9% vs. 57.3%; p < 0.001), percutaneous coronary intervention (1.7% vs. 38.5%; p < 0.001), and coronary artery bypass grafting (0.4% vs. 7.8%; p < 0.001) were lower among type 2 MI patients. Patients with type 2 MI had lower risk of in-hospital mortality (adjusted odds ratio: 0.57 [95% confidence interval: 0.54 to 0.60]) and 30-day MI readmission (adjusted odds ratio: 0.46 [95% confidence interval: 0.35 to 0.59]). There was no difference in risk of 30-day all-cause or heart failure readmission.ConclusionsPatients with type 2 MI have a unique cardiovascular phenotype when compared with type 1 MI, and are managed in a heterogenous manner. Validated management strategies for type 2 MI are needed.     

Sex Differences in Management and Outcomes of Acute Myocardial Infarction Patients Presenting With Cardiogenic Shock

ObjectivesThe aim of this study was to examine the sex differences in the risk profile, management, and outcomes among patients presenting with acute myocardial infarction cardiogenic shock (AMI-CS).BackgroundContemporary clinical data regarding sex differences in the management and outcomes of AMI patients presenting with CS are scarce.MethodsPatients admitted with AMI-CS from the National Cardiovascular Data Registry Chest Pain-MI registry between October 2008 to December 2017 were included. Sex differences in baseline characteristics, in-hospital management, and outcomes were compared. Patients ≥65 years of age with available linkage data to Medicare claims were included in the analysis of 1-year outcomes. Multivariable logistic regression and Cox proportional hazards models adjusting for patient and hospital-related covariates were used to estimate sex-specific differences in in-hospital and 1-year outcomes, respectively.ResultsAmong 17,195 patients presenting with AMI-CS, 37.3% were women. Women were older, had a higher prevalence of comorbidities, and had worse renal function at presentation. Women were less likely to receive guideline-directed medical therapies within 24 hours and at discharge, undergo diagnostic angiography (85.0% vs 91.1%), or receive mechanical circulatory support (25.4% vs 33.8%). Women had higher risks of in-hospital mortality (adjusted OR: 1.10; 95% CI: 1.02-1.19) and major bleeding (adjusted OR: 1.23; 95% CI: 1.12-1.34). For patients ≥65 years of age, women did not have a higher risk of all-cause mortality (adjusted HR: 0.98; 95% CI: 0.88-1.09) and mortality or heart failure hospitalization (adjusted HR: 1.01; 95% CI: 0.91-1.12) at 1 year compared with men.ConclusionsIn this large nationwide analysis of patients with AMI-CS, women were less likely to receive guideline recommended care, including revascularization, and had worse in-hospital outcomes than men. At 1 year, there were no sex differences in the risk of mortality. Efforts are needed to address sex disparities in the initial care of AMI-CS patients.     

Long-Term Outcomes of Biodegradable Versus Second-Generation Durable Polymer Drug-Eluting Stent Implantations for Myocardial Infarction

ObjectivesThis study sought to compare outcomes between biodegradable polymer drug-eluting stent (BP-DES) and second-generation durable polymer drug-eluting stent (DP-DES) implantations for acute myocardial infarction (MI) using a nationwide dataset.BackgroundData regarding outcomes of BP-DES versus second-generation DP-DES are inconclusive.MethodsAmong 13,104 patients with acute MI in a nationwide registry who underwent percutaneous coronary intervention (November 2011 to December 2015), BP-DES and second-generation DP-DES were implanted in 2,261 (21.7%) and 8,182 patients (78.3%), respectively. Major adverse cardiac events (MACE) (all-cause death, recurrent MI, or any revascularization) were compared in multivariable Cox regression, propensity score (PS) matched, and underwent PS-adjusted analyses.ResultsMACE occurred in 1,492 (14.3%) patients during a median 723-day follow-up. MACE were less frequent with BP-DES implantation than with second-generation DP-DES implantation (entire cohort hazard ratio [HR]: 0.845; 95% confidence interval [CI]: 0.740 to 0.965; PS-matched HR: 0.669; 95% CI: 0.550 to 0.814). Risk of all-cause death (entire cohort HR: 0.831; 95% CI: 0.692 to 0.997; PS-matched HR: 0.752; 95% CI: 0.495 to 0.931), cardiac death (entire cohort HR: 0.685; 95% CI: 0.542 to 0.865; PS-matched HR: 0.613; 95% CI: 0.463 to 0.872), recurrent MI (entire cohort HR: 0.662; 95% CI: 0.466 to 0.941; PS-matched HR: 0.611; 95% CI: 0.427 to 0.898), and heart failure readmission (entire cohort HR: 0.625; 95% CI: 0.447 to 0.875; PS-matched HR: 0.584; 95% CI: 0.385 to 0.887) was less with BP-DES implantation. There were no significant group differences in the incidences of any revascularization, stroke, and definite or probable stent thrombosis.ConclusionsIn patients with acute MI who underwent percutaneous coronary intervention, BP-DES implantation is associated with improved outcomes compared with second-generation DP-DES implantation.     

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.     

Long-Term Outcomes of Patients With Late Presentation of ST-Segment Elevation Myocardial Infarction

BackgroundReal-world data on baseline characteristics, clinical practice, and outcomes of late presentation (12 to 48 h of symptom onset) in patients with ST-segment elevation myocardial infarction (STEMI) are limited.ObjectivesThis study aimed to investigate real-world features of STEMI late presenters in the contemporary percutaneous coronary intervention (PCI) era.MethodsOf 13,707 patients from the Korea Acute Myocardial Infarction Registry-National Institutes of Health database, 5,826 consecutive patients diagnosed with STEMI within 48 h of symptom onset during 2011 to 2015 were categorized as late (12 to 48 h; n = 624) or early (<12 h; n = 5,202) presenters. Coprimary outcomes were 180-day and 3-year all-cause mortality.ResultsLate presenters had remarkably worse clinical outcomes than early presenters (180-day mortality: 10.7% vs. 6.8%; 3-year mortality: 16.2% vs. 10.6%; both log-rank p < 0.001), whereas presentation at ≥12 h of symptom onset was not independently associated with increased mortality after STEMI. The use of invasive interventional procedures abruptly decreased from the first (<12 h) to the second (12 to 24 h) 12-h interval of symptom-to-door time (“no primary PCI strategy” increased from 4.9% to 12.4%, and “no PCI” from 2.3% to 6.6%; both p < 0.001). Mortality rates abruptly increased from the first to the second 12-h interval of symptom-to-door time (from 6.8% to 11.2% for 180-day mortality; from 10.6% to 17.3% for 3-year mortality; all p < 0.05).ConclusionsData from a nationwide prospective Korean registry reveal that inverse steep differences in the use of invasive interventional procedures and mortality rates were found between early and late presenters after STEMI. A multidisciplinary approach is required in identifying late presenters of STEMI who can benefit from invasive interventional procedures until further studied.     

1-Year Outcomes of Delayed Versus Immediate Intervention in Patients With Transient ST-Segment Elevation Myocardial Infarction

ObjectivesThe aim of the present study was to determine the effect of a delayed versus an immediate invasive approach on final infarct size and clinical outcome up to 1 year.BackgroundUp to 24% of patients with acute coronary syndromes present with ST-segment elevation myocardial infarction (STEMI) but show complete resolution of ST-segment elevation and symptoms before revascularization. Current guidelines do not clearly state whether these patients with transient STEMI should be treated with a STEMI-like or non–ST-segment elevation acute coronary syndrome–like intervention strategy.MethodsIn this multicenter trial, 142 patients with transient STEMI were randomized 1:1 to either delayed or immediate coronary intervention. Cardiac magnetic resonance imaging was performed at 4 days and at 4-month follow-up to assess infarct size and myocardial function. Clinical follow-up was performed at 4 and 12 months.ResultsIn the delayed (22.7 h) and the immediate (0.4 h) invasive groups, final infarct size as a percentage of the left ventricle was very small (0.4% [interquartile range: 0.0% to 2.5%] vs. 0.4% [interquartile range: 0.0% to 3.5%]; p = 0.79), and left ventricular function was good (mean ejection fraction 59.3 ± 6.5% vs. 59.9 ± 5.4%; p = 0.63). In addition, the overall occurrence of major adverse cardiac events, consisting of death, recurrent infarction, and target lesion revascularization, up to 1 year was low and not different between both groups (5.7% vs. 4.4%, respectively; p = 1.00).ConclusionsAt follow-up, patients with transient STEMI have limited infarction and well-preserved myocardial function in general, and delayed or immediate revascularization has no effect on functional outcome and clinical events up to 1 year.     

Enhanced expression of Galectin-3 in gestational diabetes

Background and aimsGestational diabetes mellitus (GDM), hyperglycemia diagnosed during pregnancy, is one of the most common medical complications of pregnancy, treated primarily by diet and pharmacotherapy, if indicated. It is well-established that GDM increases the risk of adverse pregnancy outcomes and long-term complications in mothers and infants. Galectin-3 (Gal-3) is important in processes of cell growth, differentiation, inflammation, and fibrosis. We evaluated Gal-3 expression in pregnancies complicated by GDM as a parameter that might explain how GDM influences early onset of future complications.Methods and resultsForty-four women with GDM and 40 with normal pregnancy (NP) were recruited during delivery admission. Blood samples were obtained from parturients and umbilical cords blood, as well as placental tissue for analysis. Gal-3 mRNA expression was increased in maternal blood samples and placental tissue of women with GDM compared to NP. In GDM, Gal-3 mRNA was decreased in cord blood compared to maternal blood and placental tissue. Gal-3 GDM placental protein expression was increased compared to NP. Immunostaining revealed that Gal-3 is upregulated in GDM placental extravillous trophoblast. ELISA of Gal-3 maternal serum levels between GDM and NP were similar.ConclusionGal-3 is strongly expressed at molecular levels (mRNA and protein expression) in GDM maternal blood and placental tissue, and decreased in cord blood. These findings highlight the role of the placenta in protecting the fetus from potential Gal-3 damage. Gal-3 expression at mRNA and protein levels might be influenced by diabetes, even if blood glucose is balanced by medication or diet.     

Myocardial Injury and Fibrosis From Acute Carbon Monoxide Poisoning: A Prospective Observational Study

ObjectivesThis study sought to evaluate the prevalence and patterns of late gadolinium enhancement (LGE) after carbon monoxide (CO) poisoning using cardiac magnetic resonance (CMR) imaging (CMRI) and transthoracic echocardiography (TTE).BackgroundIn acute CO poisoning, cardiac injury can predict mortality. However, it remains unclear why increased mortality and cardiovascular events occur despite normalization of CO-induced elevated troponin I (TnI) and cardiac dysfunction.MethodsPatients with acute CO poisoning with elevated TnI were evaluated. CMRI was performed within 7 days of CO exposure and after 4 to 5 months. Patients were divided into LGE (n = 72; 69.2%) and no-LGE (n = 32; 30.8%) groups.ResultsIn the LGE group, 39.4%, 4.8%, and 25.0% of patients exhibited midwall, subendocardial, and right ventricular insertion point injury, respectively. Diffuse injury was observed in 22.1% of patients, and 67.6% of the 37 patients who underwent follow-up CMRI showed no interval change. On TTE, baseline left ventricular ejection fraction and global longitudinal strain were significantly deteriorated in the LGE group; serial TTE within 7 days indicated that only left ventricular global longitudinal strain remained significantly deteriorated. Three cases of mortality occurred in the LGE group during the 1-year follow-up.ConclusionsThe LGE prevalence in patients with acute CO poisoning with elevated TnI levels, with no underlying cardiovascular diseases and eligible for CMRI, was 69.2%; this proportion primarily comprised patients with a midwall injury. Of the 37 patients who underwent follow-up CMRI, most chronic phase images showed no interval change. Myocardial fibrosis detected on CMR images was related to acute myocardial dysfunction and subacute deterioration of myocardial strain on TTE. (Cardiac Magnetic Resonance Image in Acute Carbon Monoxide Poisoning; NCT04419298)     

Changes in Myocardial Native T1 and T2 After Exercise Stress: A Noncontrast CMR Pilot Study

ObjectivesThis study assessed changes in myocardial native T₁ and T₂ values after supine exercise stress in healthy subjects and in patients with suspected ischemia as potential imaging markers of ischemia.BackgroundWith emerging data on the long-term retention of gadolinium in the body and brain, there is a need for an alternative noncontrast cardiovascular magnetic resonance (CMR)−based myocardial ischemia assessment.MethodsTwenty-eight healthy adult subjects and 14 patients with coronary artery disease (CAD) referred for exercise stress and/or rest single-photon emission computed tomography/myocardial perfusion imaging (SPECT/MPI) for evaluation of chest pain were prospectively enrolled. Free-breathing myocardial native T₁ and T₂ mapping were performed before and after supine bicycle exercise stress using a CMR-compatible supine ergometer positioned on the MR table. Differences in T_{1 rest}, T_{2 rest} and T_{1 post-exercise}, T_{2 post-exercise} values were calculated as T₁ and T₂ reactivity, respectively.ResultsThe mean exercise intensity was 104 W, with exercise duration of 6 to 12 min. After exercise, native T₁ was increased in healthy subjects (p < 0.001). T₁ reactivity, but not T₂ reactivity, correlated with the rate−pressure product as the index of myocardial blood flow during exercise (r = 0.62; p < 0.001). In patients with CAD, T₁ reactivity was associated with the severity of myocardial perfusion abnormality on SPECT/MPI (normal: 4.9%; quartiles: 3.7% to 6.3%, mild defect: 1.2%, quartiles: 0.08% to 2.5%; moderate defect: 0.45%, quartiles: −0.35% to 1.4%; severe defect: 0.35%, quartiles: −0.44% to 0.8%) and had similar potential as SPECT/MPI to detect significant CAD (>50% diameter stenosis on coronary angiography). The area under the receiver-operating characteristic curve was 0.80 versus 0.72 (p = 0.40). The optimum cutoff value of T₁ reactivity for predicting flow-limiting stenosis was 2.5%, with a sensitivity of 83% and a specificity of 92%, a negative predictive value of 96%, a positive predictive value of 71%, and an area under the curve of 0.86.ConclusionsFree-breathing stress/rest native T₁ mapping, but not T₂ mapping, can detect physiological changes in the myocardium during exercise. Our feasibility study in patients shows the potential of this technique as a method for detecting myocardial ischemia in patients with CAD without using a pharmacological stress agent.     

Myocardial Infarction Associates With a Distinct Pericoronary Adipose Tissue Radiomic Phenotype: A Prospective Case-Control Study

ObjectivesThis study sought to determine whether coronary computed tomography angiography (CCTA)-based radiomic analysis of pericoronary adipose tissue (PCAT) could distinguish patients with acute myocardial infarction (MI) from patients with stable or no coronary artery disease (CAD).BackgroundImaging of PCAT with CCTA enables detection of coronary inflammation. Radiomics involves extracting quantitative features from medical images to create big data and identify novel imaging biomarkers.MethodsIn a prospective case-control study, 60 patients with acute MI underwent CCTA within 48 h of admission, before invasive angiography. These subjects were matched to patients with stable CAD (n = 60) and controls with no CAD (n = 60) by age, sex, risk factors, medications, and CT tube voltage. PCAT was segmented around the proximal right coronary artery (RCA) in all patients and around culprit and nonculprit lesions in patients with MI. PCAT segmentations were analyzed using Radiomics Image Analysis software.ResultsOf 1,103 calculated radiomic parameters, 20.3% differed significantly between MI patients and controls, and 16.5% differed between patients with MI and stable CAD (critical p < 0.0006); whereas none differed between patients with stable CAD and controls. On cluster analysis, the most significant radiomic parameters were texture or geometry based. At 6 months post-MI, there was no significant change in the PCAT radiomic profile around the proximal RCA or nonculprit lesions. Using machine learning (XGBoost), a model integrating clinical features (risk factors, serum lipids, high-sensitivity C-reactive protein), PCAT attenuation, and radiomic parameters provided superior discrimination of acute MI (area under the receiver operator characteristic curve [AUC]: 0.87) compared with a model with clinical features and PCAT attenuation (AUC: 0.77; p = 0.001) or clinical features alone (AUC: 0.76; p < 0.001).ConclusionsPatients with acute MI have a distinct PCAT radiomic phenotype compared with patients with stable or no CAD. Using machine learning, a radiomics-based model outperforms a PCAT attenuation-based model in accurately identifying patients with MI.     

Clinical Outcomes in Biopsy-Proven Nonalcoholic Fatty Liver Disease Patients: A Multicenter Registry-based Cohort Study

1. Download : Download high-res image (312KB)
2. Download : Download full-size image

     

Cardiac Magnetic Resonance for Evaluating Nonculprit Lesions After Myocardial Infarction: Comparison With Fractional Flow Reserve

ObjectivesThis study sought to determine the agreement between cardiac magnetic resonance (CMR) imaging and invasive measurements of fractional flow reserve (FFR) in the evaluation of nonculprit lesions after ST-segment elevation myocardial infarction (STEMI). In addition, we investigated whether fully quantitative analysis of myocardial perfusion is superior to semiquantitative and visual analysis.BackgroundThe agreement between CMR and FFR in the evaluation of nonculprit lesions in patients with STEMI with multivessel disease is unknown.MethodsSeventy-seven patients with STEMI with at least 1 intermediate (diameter stenosis 50% to 90%) nonculprit lesion underwent CMR and invasive coronary angiography in conjunction with FFR measurements at 1 month after primary intervention. The imaging protocol included stress and rest perfusion, cine imaging, and late gadolinium enhancement. Fully quantitative, semiquantitative, and visual analysis of myocardial perfusion were compared against a reference of FFR. Hemodynamically obstructive was defined as FFR ≤0.80.ResultsHemodynamically obstructive nonculprit lesions were present in 31 (40%) patients. Visual analysis displayed an area under the curve (AUC) of 0.74 (95% confidence interval [CI]: 0.62 to 0.83), with a sensitivity of 73% and a specificity of 70%. For semiquantitative analysis, the relative upslope of the stress signal intensity time curve and the relative upslope derived myocardial flow reserve had respective AUCs of 0.66 (95% CI: 0.54 to 0.77) and 0.71 (95% CI: 0.59 to 0.81). Fully quantitative analysis did not augment diagnostic performance (all p > 0.05). Stress myocardial blood flow displayed an AUC of 0.76 (95% CI: 0.64 to 0.85), with a sensitivity of 69% and a specificity of 77%. Similarly, MFR displayed an AUC of 0.82 (95% CI: 0.71 to 0.90), with a sensitivity of 82% and a specificity of 71%.ConclusionsCMR and FFR have moderate-good agreement in the evaluation of nonculprit lesions in patients with STEMI with multivessel disease. Fully quantitative, semiquantitative, and visual analysis yield similar diagnostic performance.