Faculty Bibliography

BACKGROUND:Coronary microvascular dysfunction (CMD) is a mechanism of ischemia with nonobstructive coronary arteries (INOCA) diagnosed by invasive coronary function testing (CFT). It is unknown whether CMD reflects a systemic microcirculatory disorder. Sidestream darkfield (SDF) microscopy permits noninvasive imaging of red blood cells (RBCs) in the sublingual microcirculation. OBJECTIVES/OBJECTIVE:We sought to evaluate whether SDF microscopy identifies sublingual microvascular abnormalities in patients with INOCA due to CMD. METHODS:Adults with INOCA underwent CFT for CMD, defined by abnormal coronary flow reserve <2.5 or index of microcirculatory resistance ≥25. Sublingual SDF microscopy was performed to determine the endothelial glycocalyx perfused boundary region (PBR), RBC filling percentage (%RBC), and perfused microvascular density (PMVD). RESULTS:A total of 135 participants with INOCA (mean age 59.3 ± 12.1 years, 80% female) underwent CFT and sublingual SDF microscopy. CMD was present in 63 participants (46.7%). The median PBR was 1.96 (IQR: 0.4), median %RBC was 72.6 (IQR: 8.0), and median PMVD was 406 (IQR: 141). No differences in sublingual PBR, %RBC, and PMVD were observed by CMD status. No correlations between sublingual parameters and continuous measures of coronary flow reserve or index of microcirculatory resistance were observed. CONCLUSIONS:Noninvasive SDF microscopy did not identify sublingual microvascular abnormalities in INOCA patients with CMD.

BACKGROUND:Myocardial Infarction with No Obstructive Coronary Arteries (MINOCA) or Nonischemic Myocardial Injury affects approximately 1 in 9 patients presenting with acute coronary syndrome, yet evidence-based therapies are lacking. Coronary microvascular dysfunction is implicated in the pathogenesis of suspected MINOCA, but its prevalence, prognostic implications and treatment are uncertain. The objectives are, first, to assess the prevalence of coronary microvascular dysfunction in patients with suspected MINOCA and, second, to implement endotype-informed stratified medicine involving patients with coronary microvascular dysfunction to treatment with eplerenone, a cardio- and vasculo-protective mineralocorticoid receptor antagonist. METHODS:This is a prospective, registry-based, multicenter, diagnostic study and nested, randomized, controlled, open-label, blinded-endpoint (PROBE) basket trial. Up to 400 patients with clinically suspected MINOCA and one or more cardiovascular risk factors will be enrolled into a registry-based diagnostic study. Coronary microvascular function will be assessed during invasive angiography using thermodilution. Patients with an index of coronary microvascular resistance (IMR) ≥25 will be randomized 1:1 to eplerenone (25-50 mg daily for 6 months) or standard care without eplerenone (control group) (n=150 randomized). Final endotypes will be centrally adjudicated by a panel of blinded cardiologists. The primary outcome of the diagnostic study is the proportion of patients with IMR ≥25 during index coronary angiography. Secondary outcomes include coronary flow reserve, cardiovascular MRI parameters, patient-reported outcome measures, biomarkers of myocardial fibrosis and vascular inflammation, health outcomes and health economic assessments. The primary outcome of the randomized trial is the within-individual change in NT-proBNP at baseline, 1 month, and 6 months, based on intention-to-treat. Secondary outcomes include mechanistic blood biomarkers and patient-reported outcome measures. VALUE/METHODS:This registry-based randomized trial will provide novel evidence on endotype-informed secondary prevention therapy with eplerenone for suspected MINOCA.

BACKGROUND/UNASSIGNED:Cardiac stress testing is a cornerstone of risk stratification and management in patients with chronic coronary disease, yet the consistency and accuracy of its interpretation remain poorly defined. This analysis evaluated variation in the interpretation of myocardial ischemia between enrollment sites and core laboratories in the ISCHEMIA trial (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches). METHODS/UNASSIGNED:ISCHEMIA was a global (37 countries, 2012-2018) randomized trial of an initial invasive versus conservative strategy in patients with chronic coronary disease and moderate or severe ischemia. This analysis included participants with site-interpreted qualifying stress tests-nuclear, echocardiography (echo), cardiac magnetic resonance, or exercise tolerance test-and independent core laboratory adjudication. Core laboratories, serving as the reference standard, reinterpreted tests blinded to site results. A trinary outcome variable (site underestimation, concordance, or overestimation) was defined by comparing site-determined ischemia levels to standardized core lab assessments. Adjusted mixed-effects logistic regression models with random site intercepts assessed variability. RESULTS/UNASSIGNED:Among 6971 participants (mean age, 62.8 years; 73% men), site interpretations showed 0% no/mild (by design), 43% moderate, and 57% severe ischemia. Core labs reclassified these as 8% none, 11% mild, 30% moderate, and 51% severe ischemia. For the imaging modalities, median site-core lab agreement rates were ≈55%; nearly 25% of site-classified moderate/severe cases were downgraded to no or mild ischemia by core labs. Adjusted median odds ratios for site overestimation were 2.36 (95% CI, 2.02-2.82; nuclear), 1.98 (95% CI, 1.62-2.60; echo), 1.89 (95% CI, 1.0-5.41; cardiac magnetic resonance), and 2.15 (95% CI, 1.76-2.79; exercise tolerance test). Adjusted median odds ratios for underestimation ranged from 1.25 to 1.77. CONCLUSIONS/UNASSIGNED:In ISCHEMIA, enrollment sites frequently overestimated or underestimated the severity of myocardial ischemia compared with core laboratory assessments, highlighting the need for strategies to improve the consistency and accuracy of stress testing interpretation in patients with chronic coronary disease. REGISTRATION/UNASSIGNED:URL: https://www.clinicaltrials.gov; Unique identifier: NCT01471522.

BACKGROUND:Persons with HIV have an increased risk of cardiovascular and metabolic diseases compared to HIV serostatus-negative individuals. OBJECTIVE:We conducted a pilot wait-list control randomized trial to assess the feasibility and acceptability of a virtual environment for CVD and metabolic disease prevention education in men living with HIV. METHODS:In phase one, we conducted interviews and virtual environment beta testing with (n=25) individuals. In phase two, reported here, we conducted a wait-list control trial with permuted block randomization. Participants were allocated to the virtual environment intervention (n = 40) or a wait-list control arm (n = 38). The primary outcomes were feasibility (defined by recruitment and retention metrics) and acceptability (defined by levels of engagement) with virtual environment. We also examined preliminary effect sizes across several cardiovascular health-related indicators. RESULTS:Participants had a mean age of 41.8 years (SD=10.4) and had been living with HIV for an average of 15.9 years (SD=9.7). Participants were 62.5% Black and 26.7% Hispanic. A total of 45.0% of the intervention arm engaged with the virtual environment, with an average session duration of 110 minutes. The most engaged content modules were nutrition (146 engagements), oral health (138 engagements), fitness tips and videos (82 engagements), and relaxation techniques (75 engagements). Retention was 61.5% at final assessment, which to our knowledge, is notably higher than the typical retention rates seen in remote digital health research and all behavioral intervention research. Preliminary efficacy analyses across 3- and 6-month changes revealed medium effect sizes favoring the intervention for key nutritional outcomes (vegetable consumption: d=0.59-0.66; whole grain intake: d=0.41-0.46); and vigorous physical activity (d=0.38-0.57). Small-to-medium effect sizes were observed for fast food reduction (d=0.37 at 6-months), total physical activity (d=0.37 at 6-months), and depressive symptoms (d=0.22 at 3-months), as well as HIV illness perceptions, including timeline acute/chronic (d=0.44 at 3-months), illness coherence (d=0.33 at 3-months), and emotional representations (d=0.23-0.33). CONCLUSIONS:The LEARN Study demonstrated the feasibility and acceptability of a virtual environment designed for cardiovascular and metabolic disease prevention education in persons with HIV. The high engagement rates with specific educational content and strong retention highlight the promise of this innovative approach. Preliminary effect sizes suggested positive trends in cardiovascular health indicators and mental well-being, indicating further potential benefits of the intervention. These findings support progression to a fully powered randomized controlled trial. Subsequent funding has been awarded, based on this work, to expand the research in LEARN2. We will integrate lessons learned and focus on HIV- related conditions with shared risk factors to enhance the study's impact. By addressing HIV conditions with interrelated risk factors, we aim to provide a more comprehensive intervention to improve the overall health and well-being of individuals living with HIV. CLINICALTRIAL/BACKGROUND:ClinicalTrials.gov NCT05242952. INTERNATIONAL REGISTERED REPORT/UNASSIGNED:RR2-10.2196/38348.

BACKGROUND:Myocardial infarction with non-obstructive coronary arteries (MINOCA) has several underlying causes, including mimicking conditions in some cases. Imaging is recommended to identify MINOCA etiologies, but it remains unclear which patients are most likely to have abnormal findings. We characterized MINOCA mechanisms, analyzed predictors of imaging abnormalities and explored sex differences. METHODS:We enrolled patients with clinical diagnosis of MI in an international, prospective, diagnostic study at 28 sites in US, Canada and UK. After a women-only phase, we included both sexes. Individuals with ≥50% diameter stenosis or coronary dissection on angiography, or alternate causes for the clinical presentation, were excluded. Participants had multi-vessel coronary optical coherence tomography (OCT) during index coronary angiography and cardiac magnetic resonance imaging (CMR) within one week. Independent core laboratories interpreted imaging, blinded to other results. RESULTS:Among 754 patients enrolled, 389 had MINOCA and 336 with MINOCA underwent OCT (270 women and 66 men); CMR was completed in 284 (85%). An OCT-defined culprit lesion was identified in 45% (116/270 women [43% ] and 35/66 men [53%], p=0.18). CMR demonstrated an ischemic pattern in 114/284 (40%), similar by sex (96/225 women [43%] vs. 18/59 men [31%], p=0.12). A non-ischemic pattern was observed in 23% (23% of women, 25% of men, p=0.78). We identified a cause of the clinical presentation in 79% of patients with both tests completed: 59% had an ischemic cause of MINOCA and 20% had a non-ischemic mimicking condition. OCT alone found a MINOCA etiology in 151/336 (45%) and CMR alone in 180/284 (63%). Predictors of an OCT culprit lesion included age, abnormal angiogram, and number of vessels imaged, but 27% of normal angiograms harbored a culprit lesion. Predictors of abnormal CMR were peak troponin, shorter time to CMR, and non-Asian race, but CMR was abnormal in 40% when troponin was <4-fold above the upper reference limit. CONCLUSIONS:The combination of multi-vessel coronary OCT and CMR in patients with a clinical diagnosis of MINOCA confirmed MI in 59% and identified an alternate cause (MINOCA mimic) in 20%. Clinical factors had limited utility to predict imaging abnormalities. No sex differences in imaging results were detected.

BACKGROUND:The frequency of residual angina and its impact on health status and death following anatomic complete revascularization in symptomatic patients with chronic coronary disease are unknown. METHODS:Data were analyzed from ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) trial participants randomized to invasive management with baseline angina (Seattle Angina Questionnaire Angina Frequency score <100), no prior coronary artery bypass graft surgery, and anatomic complete revascularization within 90 days of randomization. The primary outcome was frequency of residual angina after revascularization, defined as a Seattle Angina Questionnaire Angina Frequency score <100 within 6 months of randomization. Secondary outcomes included 6-month health status and medication use and 5-year all-cause and cardiovascular death. RESULTS:=0.006). Five-year all-cause and cardiovascular death did not differ significantly between groups. CONCLUSIONS:Residual angina is common (>40%) following anatomic complete revascularization for chronic coronary disease and is associated with reduced quality of life and greater antianginal medication use but no increase in death. REGISTRATION/BACKGROUND:Unique Identifier: NCT01471522.

BACKGROUND:Coronary microvascular dysfunction (CMD) is present in approximately 40% of patients with ischemia with no obstructive coronary arteries (INOCA) and has been associated with inflammation. We investigated associations between measures of inflammation of the coronary perivascular adipose tissue assessed by coronary computed tomography angiography (CCTA) and results of invasive coronary function testing (CFT) to diagnose CMD. METHODS:Adults referred for clinically indicated invasive coronary angiography who had less than 50% stenosis in all epicardial arteries were prospectively enrolled. CMD was defined as a coronary flow reserve (CFR) less than 2.5 or index of microvascular resistance (IMR) greater than or equal to 25 using bolus thermodilution in the left anterior descending (LAD) coronary artery. Coronary perivascular fat attenuation index was assessed by CCTA in the right coronary artery (RCA) and LAD. T tests were used to evaluate differences in perivascular FAI by CMD status. RESULTS:A total of 31 participants underwent CFT and CCTA. The mean age was 58 ± 11.7 years, 77% were female, and 61% were white. CMD was present in 15 participants (48%). No differences in perivascular FAI were observed in patients with and without CMD, either in the RCA [-74.2 ± 9.8 vs. -69.9 ± 10.3 Hounsfield units (HU), P = 0.24] or LAD (-76.4 ± 10.2 vs. -74.8 ± 12.7 HU, P = 0.69). Perivascular FAI was not correlated with CFR or IMR measurements in the RCA or LAD. CONCLUSION/CONCLUSIONS:There were no associations between CMD diagnosed by invasive CFT and perivascular FAI by CCTA in patients with INOCA. Further research is needed to understand the relationship between vascular inflammation and CMD in INOCA.

AIMS/OBJECTIVE:To assess whether baseline functional performance assessed by exercise treadmill stress testing (EST) has additive value to coronary computed tomography angiography (CCTA) for risk stratification among patients with chronic coronary disease (CCD) and moderate or severe ischemia. METHODS AND RESULTS/RESULTS:We performed a subgroup analysis of the ISCHEMIA trial including participants who underwent EST and CCTA. EST data and severity of coronary artery disease (CAD) on CCTA were evaluated by core laboratories, blinded to clinical data and results of the other test. The primary outcome for this analysis was all-cause death. Secondary outcomes were cardiovascular death, cardiovascular death or myocardial infarction (MI), MI and a composite of cardiovascular death, MI, or hospitalization for heart failure, unstable angina, or resuscitated cardiac arrest. EST and number of vessels diseased on CCTA were both interpretable in 1864 patients (median age 62 years, IQR 55-68, 83% males). During a median follow-up of 3.1 years, 69 patients died. Higher peak metabolic equivalents (METs) achieved on the qualifying stress test was associated with lower all-cause death (HR 0.86, CI 0.76-0.98; p=0.025). The addition of peak METs to CAD severity improved the predictive ability of the all-cause death and CV death models by 10-20% and 8-13% respectively, depending on the metrics used for CCTA. Adding peak METs to CCTA anatomical models resulted in better prediction of MI by 11-17%, cardiovascular death or MI by 10-14%, and 5-component composite outcome by 12-16%. CONCLUSION/CONCLUSIONS:Peak METs on EST, a marker of functional performance, added prognostic value to models including CCTA anatomical findings in patients with CCD and moderate or severe ischemia.

BACKGROUND:Guidelines on primary prevention of atherosclerotic cardiovascular disease (ASCVD) recommend considering risk enhancing factors (REFs) to inform decisions on use of lipid-lowering therapies for the 44 million Americans with borderline or intermediate estimated ASCVD risk. OBJECTIVE:To quantify REF burden and estimate whether REFs are associated with higher likelihood of statin use. DESIGN/METHODS:Cross-sectional using National Health and Nutrition Examination Survey pooled 2015 to March 2020. PARTICIPANTS/METHODS:Adults aged 40-75 without known ASCVD. MAIN MEASURES/METHODS:Nine REFs were measurable in NHANES including family history of premature ASCVD, rheumatoid arthritis, metabolic syndrome, premature menopause, chronic kidney disease and biomarkers of hypercholesteremia, hypertriglyceridemia, elevated low-density lipoprotein cholesterol and elevated C-reactive protein. Prevalence of REFs and association with statin use were calculated overall and across ASCVD treatment categories based on diabetes and 10-year ASCVD risk.  KEY RESULTS: In the sample of 3,111 participants (mean age 56 years; 52.6% female) weighted to represent 115.7 million US adults, 77% had at least one REF and 28% had at least three. The most common REFs were elevated high sensitivity C-reactive protein (49.6%) metabolic syndrome (48.3%), and hypertriglyceridemia (18.9%). The presence of any REF was associated with a 2.17 (95% CI, 1.42-3.33) greater odds of statin use. Metabolic syndrome, family history of premature ASCVD, hypertriglyceridemia and hypercholesteremia were associated with greater odds of statin use (aORs ranging from 1.5 to 2.3). The presence of any REF was associated with higher likelihood of statin use in participants with low (< 5%), intermediate (7.5-19%), and high ASCVD risk (≥ 20%), but not borderline ASCVD risk (5-7.4%) or diabetes categories. CONCLUSIONS:REFs are highly prevalent and inconsistently associated with statin use. Achieving the potential benefit of individualizing ASCVD risk estimates will require clearer guidance on when and how to incorporate REFs into primary prevention prescribing decisions.

BACKGROUND:Research comparing the prognostic value of stress cardiac magnetic resonance (CMR) to other stress modalities in patients with coronary disease is limited. OBJECTIVES/OBJECTIVE:The authors compared the prognostic value of stress CMR vs alternative testing by either single-photon emission computed tomography or stress echocardiography (SPECT/echo) in the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial. METHODS:CMR vs SPECT/echo was compared in 3,909 patients randomized in ISCHEMIA after sites' interpretation of moderate to severe ischemia. Ischemia and infarct extent, measured by either CMR or SPECT/echo, were each associated with the trial's primary outcome of cardiovascular death, nonfatal myocardial infarction (MI), or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest, at a median follow-up of 3.37 years (Q1-Q3: 2.20-4.56 years). RESULTS:Compared with SPECT/echo (n = 5,627), CMR participants (n = 313) were not different in key demographic factors but were more likely to have severe ischemia (57% vs 38%; P < 0.001) and to be randomized (n = 257, 82%, vs n = 3,652, 65%; P < 0.001). Ischemia severity (no/mild, moderate, severe) by CMR core laboratory was associated with cumulative 4-year event rates of all trial-specific endpoints, including the primary outcome (P = 0.042), cardiovascular death/MI (P = 0.041), and nonfatal MI (P = 0.03), but SPECT/echo ischemia severity was not. No/mild, moderate, and severe ischemia by CMR were associated with 0%, 14%, and 23% 4-year primary outcome rates, respectively, compared with 18%, 15%, and 16%, by SPECT/echo. After adjustment for age, estimated glomerular filtration rate, and diabetes, the association between ischemia extent and the primary endpoint differed by imaging modality, with each additional ischemic segment on CMR associated with a 13% increase in hazard (interaction P = 0.02). In participants assigned to initial conservative management who had no/mild ischemia on imaging, 4-year rates of invasive referral and coronary revascularization were lower in the CMR than SPECT/echo group (16.7% and 0%, respectively, for CMR; and 31% and 13.3%, respectively, for SPECT/echo). CONCLUSIONS:Ischemia severity by CMR had a stronger association with all ISCHEMIA trial endpoints compared with SPECT/echo.