Faculty Bibliography

OBJECTIVE:Patients with peripheral artery disease (PAD) undergo lower extremity revascularization (LER) for symptomatic relief or limb salvage. Despite LER, patients remain at increased risk of platelet-mediated complications, such as major adverse cardiac and limb events (MACLEs). Platelet activity is associated with cardiovascular events, yet little is known about the dynamic nature of platelet activity over time. We, therefore, investigated the change in platelet activity over time and its association with long-term cardiovascular risk. METHODS:Patients with PAD undergoing LER were enrolled into the multicenter, prospective Platelet Activity and Cardiovascular Events study. Platelet aggregation was assessed by light transmission aggregometry to submaximal epinephrine (0.4 μmol/L) immediately before LER, and on postoperative day 1 or 2 (POD1 or POD2) and 30 (POD30). A hyperreactive platelet phenotype was defined as >60% aggregation. Patients were followed longitudinally for MACLEs, defined as the composite of death, myocardial infarction, stroke, major lower extremity amputation, or acute limb ischemia leading to reintervention. RESULTS:Among 287 patients undergoing LER, the mean age was 70 ± 11 years, 33% were female, 61% were White, and 89% were on baseline antiplatelet therapy. Platelet aggregation to submaximal epinephrine induced a bimodal response; 15.5%, 16.8%, and 16.4% of patients demonstrated a hyperreactive platelet phenotype at baseline, POD1, and POD30, respectively. Platelet aggregation increased by 18.5% (P = .001) from baseline to POD1, which subsequently returned to baseline at POD30. After a median follow-up of 19 months, MACLEs occurred in 165 patients (57%). After adjustment for demographics, clinical risk factors, procedure type, and antiplatelet therapy, platelet hyperreactivity at POD1 was associated with a significant hazard of long-term MACLE (adjusted hazard ratio, 4.61; 95% confidence interval, 2.08-10.20; P < .001). CONCLUSIONS:Among patients with severe PAD, platelet activity increases after LER. Platelet hyperreactivity to submaximal epinephrine on POD1 is associated with long-term MACLE. Platelet activity after LER may represent a modifiable biomarker associated with excess cardiovascular risk.

BACKGROUND AND AIMS/OBJECTIVE:The aim of this study was to determine the prognostic value of coronary computed tomography angiography (CCTA)-derived atherosclerotic plaque analysis in ISCHEMIA. METHODS:Atherosclerosis imaging quantitative computed tomography (AI-QCT) was performed on all available baseline CCTAs to quantify plaque volume, composition, and distribution. Multivariable Cox regression was used to examine the association between baseline risk factors (age, sex, smoking, diabetes, hypertension, ejection fraction, prior coronary disease, estimated glomerular filtration rate, and statin use), number of diseased vessels, atherosclerotic plaque characteristics determined by AI-QCT, and a composite primary outcome of cardiovascular death or myocardial infarction over a median follow-up of 3.3 (interquartile range 2.2-4.4) years. The predictive value of plaque quantification over risk factors was compared in an area under the curve (AUC) analysis. RESULTS:Analysable CCTA data were available from 3711 participants (mean age 64 years, 21% female, 79% multivessel coronary artery disease). Amongst the AI-QCT variables, total plaque volume was most strongly associated with the primary outcome (adjusted hazard ratio 1.56, 95% confidence interval 1.25-1.97 per interquartile range increase [559 mm3]; P = .001). The addition of AI-QCT plaque quantification and characterization to baseline risk factors improved the model's predictive value for the primary outcome at 6 months (AUC 0.688 vs. 0.637; P = .006), at 2 years (AUC 0.660 vs. 0.617; P = .003), and at 4 years of follow-up (AUC 0.654 vs. 0.608; P = .002). The findings were similar for the other reported outcomes. CONCLUSIONS:In ISCHEMIA, total plaque volume was associated with cardiovascular death or myocardial infarction. In this highly diseased, high-risk population, enhanced assessment of atherosclerotic burden using AI-QCT-derived measures of plaque volume and composition modestly improved event prediction.

IMPORTANCE/UNASSIGNED:In 2013, the Trial to Assess Chelation Therapy (TACT) reported that edetate disodium (EDTA)-based chelation significantly reduced cardiovascular disease (CVD) events by 18% in 1708 patients with a prior myocardial infarction (MI). OBJECTIVE/UNASSIGNED:To replicate the finding of TACT in individuals with diabetes and previous MI. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:A 2 × 2 factorial, double-masked, placebo-controlled, multicenter trial at 88 sites in the US and Canada, involving participants who were 50 years or older, had diabetes, and had experienced an MI at least 6 weeks before recruitment compared the effect of EDTA-based chelation vs placebo infusions on CVD events and compared the effect of high doses of oral multivitamins and minerals with oral placebo. This article reports on the chelation vs placebo infusion comparisons. INTERVENTIONS/UNASSIGNED:Eligible participants were randomly assigned to 40 weekly infusions of an EDTA-based chelation solution or matching placebo and to twice daily oral, high-dose multivitamin and mineral supplements or matching placebo for 60 months. This article addresses the chelation study. MAIN OUTCOMES AND MEASURES/UNASSIGNED:The primary end point was the composite of all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for unstable angina. Median follow-up was 48 months. Primary comparisons were made from patients who received at least 1 assigned infusion. RESULTS/UNASSIGNED:Of the 959 participants (median age, 67 years [IQR, 60-72 years]; 27% females; 78% White, 10% Black, and 20% Hispanic), 483 received at least 1 chelation infusion and 476 at least 1 placebo infusion. A primary end point event occurred in 172 participants (35.6%) in the chelation group and in 170 (35.7%) in the placebo group (adjusted hazard ratio [HR], 0.93; 95% CI, 0.76-1.16; P = .53). The 5-year primary event cumulative incidence rates were 45.8% for the chelation group and 46.5% for the placebo group. CV death, MI, or stroke events occurred in 89 participants (18.4%) in the chelation group and in 94 (19.7%) in the placebo group (adjusted HR, 0.89; 95% CI, 0.66-1.19). Death from any cause occurred in 84 participants (17.4%) in the chelation group and in 84 (17.6%) in the placebo group (adjusted HR, 0.96; 95% CI, 0.71-1.30). Chelation reduced median blood lead levels from 9.03 μg/L at baseline to 3.46 μg/L at infusion 40 (P < .001). Corresponding levels in the placebo group were 9.3 μg/L and 8.7 μg/L, respectively. CONCLUSIONS AND RELEVANCE/UNASSIGNED:Despite effectively reducing blood lead levels, EDTA chelation was not effective in reducing cardiovascular events in stable patients with coronary artery disease who have diabetes and a history of MI. TRIAL REGISTRATION/UNASSIGNED:ClinicalTrials.gov Identifier: NCT02733185.

Platelets are key mediators of atherothrombosis, yet, limited tools exist to identify individuals with a hyperreactive platelet phenotype. In this study, we investigate the association of platelet hyperreactivity and cardiovascular events, and introduce a tool, the Platelet Reactivity ExpreSsion Score (PRESS), which integrates platelet aggregation responses and RNA sequencing. Among patients with peripheral artery disease (PAD), those with a hyperreactive platelet response (>60% aggregation) to 0.4 µM epinephrine had a higher incidence of the 30 day primary cardiovascular endpoint (37.2% vs. 15.3% in those without hyperreactivity, adjusted HR 2.76, 95% CI 1.5-5.1, p = 0.002). PRESS performs well in identifying a hyperreactive phenotype in patients with PAD (AUC [cross-validation] 0.81, 95% CI 0.68 -0.94, n = 84) and in an independent cohort of healthy participants (AUC [validation] 0.77, 95% CI 0.75 -0.79, n = 35). Following multivariable adjustment, PAD individuals with a PRESS score above the median are at higher risk for a future cardiovascular event (adjusted HR 1.90, CI 1.07-3.36; p = 0.027, n = 129, NCT02106429). This study derives and validates the ability of PRESS to discriminate platelet hyperreactivity and identify those at increased cardiovascular risk. Future studies in a larger independent cohort are warranted for further validation. The development of a platelet reactivity expression score opens the possibility for a personalized approach to antithrombotic therapy for cardiovascular risk reduction.

Cardiometabolic comorbidities, diabetes (DM), hypertension (HTN), and obesity, contribute to cardiovascular disease (CVD). Circulating biomarkers facilitate prognostication for patients with CVD. We explored the relationship between cardiometabolic comorbidity burden in patients with chronic coronary disease (CCD) and biomarkers of myocardial stretch, injury, inflammation, and platelet activity. We analyzed participants from the ISCHEMIA Trials biorepository with plasma biomarkers (NT-proBNP, hs-cTnT, hs-CRP, IL-6, sCD40L, and GDF-15) and clinical risk factors [hemoglobin A1c (HbA1c), systolic blood pressure (SBP), and body mass index (BMI)] at baseline. We defined cardiometabolic comorbidities as DM, HTN, and obesity at baseline. Comorbidity burden characterized by number and severity of comorbidities. Controlled comorbidities were defined as HbA1c <7% for those with DM, SBP <130 mmHg for those with HTN and BMI <30 kg/m². Severely uncontrolled was defined as HbA1c ≥8%, SBP ≥160 mmHg, and BMI ≥35 kg/m². We performed linear regression analyses to examine the association between comorbidity burden and log-transformed biomarker levels adjusting for age, sex, eGFR controlled for hemodialysis, and left ventricular ejection fraction. A total of 752 individuals (mean age 66, 19% female, 84% white) were included in this analysis. Self-reported Black race, current smokers, history of MI and HF had greater cardiometabolic comorbidity burden. The presence of ≥ 1 severely uncontrolled comorbidity was associated with significantly higher baseline levels of hs-cTnT, hs-CRP, IL-6, and GDF-15 compared to participants with no comorbidities. In conclusion, increasing cardiometabolic comorbidity burden in patients with CCD is associated with higher levels of circulating biomarkers of myocardial injury and inflammation.

BACKGROUND/UNASSIGNED:ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) did not find an overall reduction in cardiovascular events with an initial invasive versus conservative management strategy in chronic coronary disease; however, there were conservative strategy participants who underwent invasive coronary angiography early postrandomization (within 6 months). Identifying factors associated with angiography in conservative strategy participants will inform clinical decision-making in patients with chronic coronary disease. METHODS/UNASSIGNED:Factors independently associated with angiography performed within 6 months of randomization were identified using Fine and Gray proportional subdistribution hazard models, including demographics, region of randomization, medical history, risk factor control, symptoms, ischemia severity, coronary anatomy based on protocol-mandated coronary computed tomography angiography, and medication use. RESULTS/UNASSIGNED:Among 2591 conservative strategy participants, angiography within 6 months of randomization occurred in 8.7% (4.7% for a suspected primary end point event, 1.6% for persistent symptoms, and 2.6% due to protocol nonadherence) and was associated with the following baseline characteristics: enrollment in Europe versus Asia (hazard ratio [HR], 1.81 [95% CI, 1.14-2.86]), daily and weekly versus no angina (HR, 5.97 [95% CI, 2.78-12.86] and 2.63 [95% CI, 1.51-4.58], respectively), poor to fair versus good to excellent health status (HR, 2.02 [95% CI, 1.23-3.32]) assessed with Seattle Angina Questionnaire, and new/more frequent angina prerandomization (HR, 1.80 [95% CI, 1.34-2.40]). Baseline low-density lipoprotein cholesterol <70 mg/dL was associated with a lower risk of angiography (HR, 0.65 [95% CI, 0.46-0.91) but not baseline ischemia severity nor the presence of multivessel or proximal left anterior descending artery stenosis >70% on coronary computed tomography angiography. CONCLUSIONS/UNASSIGNED:Among ISCHEMIA participants randomized to the conservative strategy, angiography within 6 months of randomization was performed in <10% of patients. It was associated with frequent or increasing baseline angina and poor quality of life but not with objective markers of disease severity. Well-controlled baseline low-density lipoprotein cholesterol was associated with a reduced likelihood of angiography. These findings point to the importance of a comprehensive assessment of symptoms and a review of guideline-directed medical therapy goals when deciding the initial treatment strategy for chronic coronary disease. REGISTRATION/UNASSIGNED:URL: https://www.clinicaltrials.gov; Unique identifier: NCT01471522.

Ubiquitous environmental exposures increase cardiovascular disease risk via diverse mechanisms. This review examines personal strategies to minimize this risk. With regard to fine particulate air pollution exposure, evidence exists to recommend the use of portable air cleaners and avoidance of outdoor activity during periods of poor air quality. Other evidence may support physical activity, dietary modification, omega-3 fatty acid supplementation, and indoor and in-vehicle air conditioning as viable strategies to minimize adverse health effects. There is currently insufficient data to recommend specific personal approaches to reduce the adverse cardiovascular effects of noise pollution. Public health advisories for periods of extreme heat or cold should be observed, with limited evidence supporting a warm ambient home temperature and physical activity as strategies to limit the cardiovascular harms of temperature extremes. Perfluoroalkyl and polyfluoroalkyl substance exposure can be reduced by avoiding contact with perfluoroalkyl and polyfluoroalkyl substance-containing materials; blood or plasma donation and cholestyramine may reduce total body stores of perfluoroalkyl and polyfluoroalkyl substances. However, the cardiovascular impact of these interventions has not been examined. Limited utilization of pesticides and safe handling during use should be encouraged. Finally, vasculotoxic metal exposure can be decreased by using portable air cleaners, home water filtration, and awareness of potential contaminants in ground spices. Chelation therapy reduces physiological stores of vasculotoxic metals and may be effective for the secondary prevention of cardiovascular disease.

BACKGROUND:The ISCHEMIA trial found that patients with chronic coronary disease randomized to invasive strategy had better health status than those randomized to conservative strategy. It is unclear how best to translate these population-level results to individual patients. OBJECTIVES/OBJECTIVE:The authors sought to identify patient characteristics associated with health status from invasive and conservative strategies, and develop a prediction algorithm for shared decision-making. METHODS:One-year disease-specific health status was assessed in ISCHEMIA with the Seattle Angina Questionnaire (SAQ) Summary Score (SAQ SS) and Angina Frequency, Physical Limitations (PL), and Quality of Life (QL) domains (range 0-100, higher = less angina/better health status). RESULTS:Among 4,617 patients from 320 sites in 37 countries, mean SAQ SS was 74.1 ± 18.9 at baseline and 85.7 ± 15.6 at 1 year. Lower baseline SAQ SS and younger age were associated with better 1-year health status with invasive strategy (P interaction = 0.009 and P interaction = 0.004, respectively). For the individual domains, there were significant treatment interactions for baseline SAQ score (Angina Frequency, PL), age (PL, QL), anterior ischemia (PL), and number of baseline antianginal medications (QL), with more benefit of invasive in patients with worse baseline health status, younger age, anterior ischemia, and on more antianginal medications. Parsimonious prediction models were developed for 1-year SAQ domains with invasive or conservative strategies to support shared decision-making. CONCLUSIONS:In the management of chronic coronary disease, individual patient characteristics are associated with 1-year health status, with younger age and poorer angina-related health status showing greater benefit from invasive management. This prediction algorithm can support the translation of the ISCHEMIA trial results to individual patients. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

BACKGROUND:The reduction in cardiovascular disease (CVD) events with edetate disodium (EDTA) in the Trial to Assess Chelation Therapy (TACT) suggested that chelation of toxic metals might provide novel opportunities to reduce CVD in patients with diabetes. Lead and cadmium are vasculotoxic metals chelated by EDTA. We present baseline characteristics for participants in TACT2, a randomized, double-masked, placebo-controlled trial designed as a replication of the TACT trial limited to patients with diabetes. METHODS:TACT2 enrolled 1,000 participants with diabetes and prior myocardial infarction, age 50 years or older between September 2016 and December 2020. Among 959 participants with at least one infusion, 933 had blood and/or urine metals measured at the Centers for Diseases Control and Prevention using the same methodology as in the National Health and Nutrition Examination Survey (NHANES). We compared metal levels in TACT2 to a contemporaneous subset of NHANES participants with CVD, diabetes and other inclusion criteria similar to TACT2's participants. RESULTS:, 4% reported type 1 diabetes, 46.8% were treated with insulin, 22.3% with GLP1-receptor agonists or SGLT-2 inhibitors, 90.2% with aspirin, warfarin or P2Y12 inhibitors, and 86.5% with statins. Blood lead was detectable in all participants; median (IQR) was 9.19 (6.30, 13.9) µg/L. Blood and urine cadmium were detectable in 97% and median (IQR) levels were 0.28 (0.18, 0.43) µg/L and 0.30 (0.18, 0.51) µg/g creatinine, respectively. Metal levels were largely similar to those in the contemporaneous NHANES subset. CONCLUSIONS:TACT2 participants were characterized by high use of medication to treat CVD and diabetes and similar baseline metal levels as in the general US population. TACT2 will determine whether chelation therapy reduces the occurrence of subsequent CVD events in this high-risk population. CLINICAL TRIALS REGISTRATION/BACKGROUND:ClinicalTrials.gov. Identifier: NCT02733185. https://clinicaltrials.gov/study/NCT02733185.