Roe, Matthew T.

Background: Randomized clinical trials are often criticized for not reflecting real-world practice. To understand the effect of site and patient selection on trial generalizability, we examined US patient and hospital participation within the Dual Antiplatelet Therapy (DAPT) Study, a broadly inclusive trial of PCI patients, using a linked analysis with the CathPCI Registry®. Methods: Within the CathPCI Registry, we identified patients undergoing PCI between September 1, 2009 and July 1, 2011 - the period of DAPT Study enrollment. We compared US patients enrolled in DAPT to CathPCI Registry patients meeting DAPT inclusion criteria. Characteristics of US DAPT sites were also compared to those of hospitals not participating in DAPT. Standardized differences (%) for all variables were estimated, with those greater than 10% considered significant. Results: Among 1,139,932 NCDR patients undergoing PCI, 748374 (65.7%) met the enrollment criteria for DAPT, and 23495 (2.1%) were enrolled. Enrolled patients were younger and had lower rates of prior stroke, CHF and peripheral vascular disease, but were similar with respect to race and gender compared with eligible patients (Table). Of the 1276 hospitals within the NCDR, 309 (24.2%) participated in DAPT. Hospital characteristics differed markedly, with DAPT-participating hospitals being larger (mean beds 468 vs. 311), more often located in urban settings (61.2% vs. 42.6%), more often affiliated with training programs (53.7% vs. 34.1%), and with higher annual PCI volumes (mean annual hospital volume 858 vs. 378 PCIs) compared with non-DAPT hospitals. Conclusions: While liberal inclusion criteria may allow randomized trials to better simulate “real-world” clinical practice, the process of site selection may encourage participation of higher volume, urban hospital settings. These findings are relevant to clinical trial interpretation and implementation of evidence-based practice throughout the healthcare system.

Background: Obstructive hypertrophic cardiomyopathy (oHCM) is characterized by unexplained left ventricular (LV) hypertrophy associated with dynamic LV outflow tract obstruction. Current medical therapies are nonspecific and have limited efficacy in relieving symptoms. Mavacamten is a first-in-class targeted inhibitor of cardiac myosin, which has been shown to reduce LV outflow tract obstruction, improve exercise capacity, and relieve symptoms of oHCM in the PIONEER-HCM phase 2 study. Methods: EXPLORER-HCM is a multicenter, phase 3, randomized, double-blind, placebo-controlled trial to investigate the efficacy and safety of mavacamten in treating symptomatic oHCM. Eligible adults with oHCM and New York Heart Association Functional Class II or III are randomized 1:1 to receive once-daily, oral mavacamten, or matching placebo for 30 weeks. The primary composite functional end point is clinical response at week 30 compared to baseline defined as either (1) an increase in peak oxygen consumption ≥1.5 mL/kg/min and reduction of at least one New York Heart Association class; or (2) an improvement of ≥3.0 mL/kg/min in peak oxygen consumption with no worsening of New York Heart Association class. Secondary end points include change in postexercise LV outflow tract gradient, New York Heart Association class, peak oxygen consumption, and patient-reported outcomes assessed by the Kansas City Cardiomyopathy Questionnaire and a novel HCM-specific instrument. Exploratory end points aim to characterize the effect of mavacamten on multiple aspects of oHCM pathophysiology. Conclusions: EXPLORER-HCM is a phase 3 trial in oHCM testing a first-in-class, targeted strategy of myosin inhibition to improve symptom burden and exercise capacity through reducing LV outflow tract obstruction. Results of this trial will provide evidence to support the first disease-specific treatment for HCM. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03470545.

Background— Current guidelines recommend surgical revascularization (coronary artery bypass graft [CABG]) over percutaneous coronary intervention (PCI) in patients with diabetes mellitus and multivessel coronary artery disease. Few data are available describing revascularization patterns among these patients in the setting of non–ST-segment–elevation myocardial infarction. Methods and Results— Using Acute Coronary Treatment and Intervention Outcomes Network Registry–Get with the Guidelines (ACTION Registry–GWTG), we compared the in-hospital use of different revascularization strategies (PCI versus CABG versus no revascularization) in diabetes mellitus patients with non–ST-segment–elevation myocardial infarction who had angiography, demonstrating multivessel coronary artery disease between July 2008 and December 2014. Factors associated with use of CABG versus PCI were identified using logistic multivariable regression analyses. A total of 29 769 patients from 539 hospitals were included in the study, of which 10 852 (36.4%) were treated with CABG, 13 760 (46.2%) were treated with PCI, and 5157 (17.3%) were treated without revascularization. The overall use of revascularization increased over the study period with an increase in the proportion undergoing PCI (45% to 48.9%; P trend =0.0002) and no change in the proportion undergoing CABG (36.1% to 34.7%; p trend =0.88). There was significant variability between participating hospitals in the use of PCI and CABG (range: 22%–100%; 0%–78%, respectively; P value <0.0001 for both). Patient-level, but not hospital-level, characteristics were statistically associated with the use of PCI versus CABG, including anatomic severity of the disease, early treatment of adenosine diphosphate receptor antagonists at presentation, older age, female sex, and history of heart failure. Conclusions— Among patients with diabetes mellitus and multivessel coronary artery disease presenting with non–ST-segment–elevation myocardial infarction, only one third undergo CABG during the index admission. Furthermore, the use of PCI, but not CABG, increased modestly over the past 6 years.

Background— Temporal trends and contemporary data characterizing the impact of patient age on in-hospital outcomes of percutaneous coronary interventions are lacking. We sought to determine the importance of age by assessing the in-hospital mortality of stratified age groups in the National Cardiovascular Data Registry. Methods and Results— In-hospital mortality after percutaneous coronary intervention on 1 410 069 patients was age stratified into 4 groups—group 1 (age <40, n=25 679), group 2 (40 to 59, n=496 204), group 3 (60 to 79, n=732 574), and group 4 (≥80, n=155 612)—admitted from January 1, 2001, to December 31, 2006. Overall in-hospital mortality was 1.22%; in-hospital mortality was 0.60%, 0.59%, 1.26%, and 3.16% in groups 1 to 4, respectively, P <0.0001. Overall temporal improvement per calendar year in the adjusted in-hospital mortality after percutaneous coronary intervention was noted in most groups; however, this finding was significant only in the 2 older age groups, group 3 (odds ratio, 0.94; 95% CI, 0.92 to 0.96) and group 4 (odds ratio, 0.95; 95% CI, 0.92 to 0.97). The absolute mortality reduction was greatest in the most elderly group, those over the age of 80 years. Conclusions— In-hospital mortality after percutaneous coronary intervention has fallen for all age groups over the past 6 years. However, the largest absolute reduction was seen among patients 80 years of age or older.