Faculty Bibliography

BACKGROUND:Limited contemporary evidence exists on risk prediction by stress imaging and exercise electrocardiography (ECG) among patients with chronic coronary syndromes (CCS). Objectives From the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) study, prognosis was examined by core laboratory-defined stress imaging and exercise ECG findings in CCS patients. METHODS:A total of 5,179 patients (qualifying by stress nuclear imaging [n = 2,567], echocardiography [n = 1,085], cardiac magnetic resonance [CMR] [n = 257], and ECG [n = 1,270]) were randomized. Cox models assessed associations between trial endpoints and the number of scarred and ischemic segments, rest/stress left ventricular ejection fraction (LVEF), and ST-segment depression. HRs and 95% CIs were calculated per millimeter, segment, or 5% of LVEF. We examined prognostic models for the following trial endpoints: 1) the trial's primary endpoint of cardiovascular (CV) death, myocardial infarction (MI), resuscitated cardiac arrest, or hospitalization for unstable angina or heart failure; 2) CV death; 3) spontaneous MI; 4) procedural MI; and 5) type 2 MI. RESULTS:The number of scarred segments (HR: 1.07 [95% CI: 1.02-1.13]; P = 0.0209), rest LVEF (HR: 0.88 [95% CI: 0.83-0.93]; P < 0.001), and stress LVEF (HR: 0.87 [95% CI: 0.83-0.91]; P < 0.001) predicted the trial's primary endpoint of CV death, MI, resuscitated cardiac arrest, or hospitalization for unstable angina or heart failure. The extent of scar and rest/stress LVEF on echocardiography and nuclear imaging predicted several trial endpoints. The number of ischemic segments predicted spontaneous (HR: 1.08 [95% CI: 1.03-1.14]; P = 0.0104) and procedural MI (HR: 1.14 [95% CI: 1.03-1.25]; P = 0.0015) but was of borderline significance for the trial's primary endpoint (P = 0.0746). Ischemia extent by CMR predicted the trial's primary endpoint (P = 0.0068) and spontaneous MI (P = 0.0042). CONCLUSIONS:ISCHEMIA trial findings from 320 worldwide centers revealed that stress imaging and exercise ECG measures exhibited a variable association with key trial endpoints delineating risk patterns for ischemia and infarction. Stress CMR ischemia predicted several trial endpoints, supporting an expanded role in the evaluation of patients with CCS (ISCHEMIA [International Study of Comparative Health Effectiveness With Medical and Invasive Approaches]; NCT01471522).

AIM/OBJECTIVE:To investigate how psychosocial stress contributes to accelerated thrombosis, focusing on platelet activation and hyperreactivity. The specific objective was to identify novel platelet regulators involved in stress-mediated thrombosis, with a particular emphasis on the tetraspanin CD37. METHODS AND RESULTS/RESULTS:To explore how stress contributes to platelet hyperreactivity, platelets were isolated from (1) mice that experienced chronic variable stress and stress-free controls (n=8/group) and (2) human subjects with self-reported high and no stress levels (n=18/group), followed by RNA-sequencing. By comparing mutually expressed transcripts, a subset of genes differentially expressed following psychosocial stress was identified in both human and mouse platelets. In both mice and humans, platelet CD37 positively associates with platelet aggregation responses that underlie thrombosis, with Cd37-/- platelets exhibiting impaired integrin αIIbβ3 signaling, characterized by reduced platelet fibrinogen spreading and decreased agonist-induced αIIbβ3 activation. Consistent with a role for CD37 in regulating platelet activation responses, chimeric mice that received Cd37-/- bone marrow experienced a significantly increased time to vessel occlusion in the carotid artery FeCl3 model compared to mice reconstituted with wild-type bone marrow. CD37 deficiency did not alter hemostasis, as platelet count, coagulation metrics, prothrombin time, and partial thromboplastin time did not differ in Cd37-/- mice relative to wild-type mice. Consistent with this, bleeding time did not differ between wild-type and Cd37-/- mice following tail tip transection. CONCLUSIONS:This study provides new insights into the platelet-associated mechanisms underlying stress-mediated thrombosis. Identifying CD37 as a novel regulator of platelet activation responses offers potential therapeutic targets for reducing the thrombotic risk associated with psychosocial stress. The findings also contribute to understanding how psychosocial stress accelerates thrombotic events and underscore the importance of platelet activation in this process.

BACKGROUND:This study examined stress echocardiography (SE) in relation to coronary artery anatomy, and outcome in subjects randomized in the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) Trial. METHODS:Of 5,179 patients randomized to initial invasive or conservative strategy, SE was performed in 1,079. Coronary computed tomographic angiogram (CCTA) excluded left main disease and quantified coronary lesions. Degree of ischemia was defined by number of segments with stress-induced wall motion abnormalities (WMA) (mild < 3, moderate = 3 and severe > 3). Transient ischemic dilation (TID) was defined as a 10% increase in stress left ventricular (LV) end systolic volume. Primary end point was a composite of cardiovascular death (CVD), nonfatal myocardial infarction (MI), or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. RESULTS:On CCTA, 607/715 (84%) with CCTA evaluable for ≥70% lesion had one such lesion. Features associated with coronary lesions ≥ 70% were number of ischemic/infarcted segments, 3 or more ischemic segments in the anterior territory and inability to augment LV ejection fraction 10 percentage points . TID, present in 28.5%, was significantly associated with severity of ischemia. For every 0.10 increase in peak wall motion score index (WMSI), there was 12% increased risk of CVD or MI (adjusted HR=1.12 (95% CI: 1.04, 1.21), p=0.003. CONCLUSION/CONCLUSIONS:In patients with chronic coronary disease and moderate or severe myocardial ischemia receiving contemporary therapies, stress echocardiography identified subjects with significant CAD and WMSI provided prognostic value.

BACKGROUND:In the ISCHEMIA Trial, 5179 patients with stable coronary disease were randomized to initial invasive or conservative management. METHODS:PCI was recommended with a SYNTAX score 0-22 (low) and CABG with a SYNTAX score ≥33 (high). Either could be recommended for intermediate scores. The composite primary outcome was cardiovascular death, MI, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. There were two cohorts in this analysis. The descriptive cohort included patients who underwent CABG or PCI within 180 days of randomization and had no primary outcome before revascularization. The comparative cohort excluded participants with prior CABG, single vessel disease, SYNTAX score ≥ 45, and without core laboratory assessment. We focused on the intermediate (23-32) SYNTAX comparative group for which either CABG or PCI could be recommended. RESULTS:For 1935 patients in the descriptive cohort (485 CABG, 1450 PCI), the SYNTAX score was 27.3 ± 11.0 in the CABG group and 15.3 ± 8.6 in the PCI group, p<0.0001. Most patients with low SYNTAX scores underwent PCI (87.1%), while most with high SYNTAX scores underwent CABG (72.6%). For the 1203 patients (385 CABG, 818 PCI) in the entire comparative cohort, the adjusted 4-year primary event rate was 14.5% for CABG and 13.2% for PCI (difference 1.3%, 95% CI, -4.9% to 7.7%). For the 346 patients (163 CABG, 183 PCI) in the intermediate SYNTAX group, the adjusted 4-year primary event rate was 10.6% for CABG and 18.3% for PCI (difference -7.6%, 95% CI, -16.1% to 0.9%). CONCLUSIONS:Selection of revascularization method resulted in more PCI in the low SYNTAX group and more CABG in the high SYNTAX group. There was no statistical evidence of a difference between PCI and CABG in the intermediate SYNTAX group but the CIs are broad, reflecting uncertainty. GOV IDENTIFIER/UNASSIGNED:NCT01471522; https://clinicaltrials.gov/ct2/show/NCT01471522.

BACKGROUND/UNASSIGNED:Therapeutic-dose heparin improves outcomes in noncritically ill patients hospitalized for COVID-19. The effect of antiplatelet exposure in addition to therapeutic-dose heparin is unknown. OBJECTIVES/UNASSIGNED:To evaluate the effect of antiplatelet exposure in addition to therapeutic-dose heparin on survival without organ support. METHODS/UNASSIGNED:We conducted an observational secondary analysis of a multiplatform randomized controlled trial, analyzing noncritically ill patients hospitalized for COVID-19 who received an antiplatelet agent (acetylsalicylic acid or P2Y12 inhibitor) and therapeutic-dose heparin (combination) compared with therapeutic-dose heparin alone (control). We used a 3-level ordinal primary outcome: (1) survival without organ support, (2) survival with organ support, and (3) mortality by day 21. Propensity scores were estimated using logistic regression. Balanced analytic groups were established using stabilized inverse probability of treatment weighting. A proportional odds model was used to estimate the effect of antiplatelet exposure. RESULTS/UNASSIGNED:Among 1021 patients, 194 (19.0%) were exposed to an antiplatelet (95.4% acetylsalicylic acid) and therapeutic-dose heparin. All patients were used to calculate the propensity scores and stabilized weights. After applying inverse probability of treatment weighting, the effective sample size was 60 in the combination group and 652 in the control group. Means and prevalences of continuous and dichotomous variables were similar between groups, with no evidence of misclassification. Exposure to an antiplatelet was not associated with improved survival without organ support (76.3% vs 80.5%; odds ratio, 1.07; 95% CI, 0.71-1.64). CONCLUSION/UNASSIGNED:In noncritically ill patients hospitalized for COVID-19 receiving therapeutic-dose heparin, exposure to an antiplatelet agent was not associated with improved survival without organ support.

BACKGROUND:Randomized trials of chronic total occlusion (CTO) revascularization vs medical therapy have yielded inconsistent results. OBJECTIVES/OBJECTIVE:The aim of this study was to evaluate outcomes with an initial invasive strategy (INV) vs an initial conservative strategy (CON) in patients with coronary computed tomographic angiography (CCTA)-determined CTO in the ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) trial. METHODS:Participants in ISCHEMIA who underwent CCTA evaluated for CTO by the core laboratory (3,113 of 5,179 randomized patients [60%]) were categorized into subgroups with (100% stenosis) and without (<100% stenosis) CTO. Primary analysis compared outcomes in those randomized to INV vs CON using an intention-to-treat approach. Secondary analyses compared outcomes using inverse probability weighting to model successful CTO revascularization (REV) in all INV participants vs CON participants. RESULTS:Of the 3,113 CCTA-evaluable participants, 1,470 had at least 1 CTO (752 INV and 718 CON). INV did not reduce cardiovascular (CV) death or myocardial infarction (MI) (5-year difference -3.5%; 95% CI: -7.8% to 0.8%) and resulted in more procedural MIs (2.5%; 95% CI: 1.0%-4.0%) but fewer spontaneous MIs (-6.3%; 95% CI: -9.7% to -3.2%) than CON. CTO REV modeled across INV had a high probability (>90%) of any lower CV death or MI, MI, spontaneous MI, unstable angina, and heart failure counterbalanced by a higher rate of procedural MI. CTO REV significantly improved angina-related quality of life (mean difference 4.6 points), Rose Dyspnea Scale score (rescaled) (mean difference 5.3 points), and EQ-5D visual analog scale score (4.6 points). CONCLUSIONS:In the ISCHEMIA trial, the risks and benefits of INV compared with CON were similar among patients with and without CCTA-determined CTO (more frequent procedural MI, less frequent spontaneous MI, and significantly improved angina and dyspnea-related quality of life). In an observational comparison, successful CTO REV was associated with a high probability of lower CV death or MI (driven by lower MI) compared with CON. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

BACKGROUND:Guideline-directed medical therapy (GDMT) with multiple risk factor goals is recommended for patients with chronic coronary disease (CCD), yet achieving all GDMT goals is uncommon. The relative importance of these goals and timing of their attainment on cardiovascular events is uncertain. OBJECTIVES/OBJECTIVE:This study aims to describe the relationship between achieving specific GDMT goals, when they are achieved, and clinical outcomes. METHODS:This was an observational study of participants with CCD in the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial. The primary outcome was cardiovascular (CV) death or myocardial infarction (MI). GDMT goals were systolic blood pressure (SBP) <130 mm Hg, low-density lipoprotein cholesterol <70 mg/dL, not smoking, and antiplatelet therapy. Frequency of GDMT goals met at baseline and during follow-up is described. Bayesian joint modeling for longitudinal goal status and time-to-event analyses characterized the relative importance of specific GDMT goal attainment and timing with CV death/MI. RESULTS:All 5,179 ISCHEMIA participants were included. Among 4,914 participants with complete data on all 4 GDMT goals at baseline, 386 (9%), 2,073 (42%), 1,843 (38%), and 612 (12%) met 0-1, 2, 3, and 4 GDMT goals, respectively. The 4-year cumulative event rate for CV death/MI was highest for participants who attained no GDMT goals (24.5%; 95% credible interval [CrI]: 13.5%-42.2%) and lowest for those who attained all goals at baseline and remained at goal during follow-up (8.7%; 95% CrI: 6.7%-10.9%). SBP goal attainment was associated with a significant absolute event reduction in CV death/MI (-5.1%; 95% CrI: -11.3% to -1.0%), followed by antiplatelet therapy (-11.2%; 95% CrI: -29.1% to 0.8%), achieving low-density lipoprotein cholesterol <70 mg/dL (-2.0%; 95% CrI: -6.0% to 2.4%), and not smoking (-1.7%; 95% CrI: -9.3% to 4.2%). Ten millimeters of mercury lower SBP during follow-up was associated with 10% relative risk reduction of CV death/MI (RR [relative risk] = 0.90; 95% CrI: 0.82-0.98), after adjusting for other GDMT goals and baseline characteristics. CONCLUSIONS:Among participants with CCD, early attainment and maintenance of GDMT goals, especially SBP, were associated with fewer cardiovascular events. Compared with no GDMT goals at target, having all 4 GDMT goals at target at baseline was associated with an absolute 16% fewer CV deaths and MIs. (ISCHEMIA [International Study of Comparative Health Effectiveness With Medical and Invasive Approaches]; NCT01471522).