New analyses from the Boston Scientific Corporation sponsored PLATINUM Diversity study underscore the need for greater understanding of the clinical and nonclinical barriers that can adversely affect stent-related outcomes. Aligned with the Boston Scientific “Close the Gap” health equity initiative, PLATINUM Diversity is a first-of-its-kind study focusing exclusively on women and minorities with coronary artery disease that is designed to shed light into the clinical, social, behavioral and economic determinants of health treatment outcome disparities in these groups. The findings of these new analyses were presented today during the Late-Breaking Clinical Trial Session at the 40th Annual Society for Cardiac Angiography and Interventions (SCAI) Scientific Sessions in New Orleans.
“Clinicians need data that explore both the clinical and social determinants of health that influence outcomes in cardiovascular disease in order to provide all patients with the best possible care,” said Wayne Batchelor, M.D., co-principal investigator and chair of the Interventional Cardiology Council at Tallahassee Memorial Hospital, Tallahassee, Florida. “These data from PLATINUM Diversity provide important insights for the cardiology community to consider in addressing inequities in cardiovascular care.”
Historically, large-scale clinical trials in cardiology have had a disproportionately low inclusion rate of women and non-white patients, and disparities in clinical trial enrollment are a reflection of differences in treatment rates seen in clinical practice.1 New analyses of PLATINUM Diversity data show the impact of demographic and economic factors on outcomes one year after stent implantation:
Several clinical and angiographic risk factors, including diabetes, renal disease, hypertension and coronary calcification were more prevalent in non-whites and women compared to white men, whereas white men more likely presented with visible thrombus;
Unadjusted rates of combined death, myocardial infarction (MI) and target vessel revascularization (TVR) were higher in minority women than white men;
Unadjusted rates of death were higher in white women and minority men than white men;
Unadjusted rates of combined death and MI were higher in minority men and women than white men;
After accounting for the differences in baseline clinical and angiographic risk factors, minority women still showed a higher rate of combined death, MI and TVR, combined death and MI and MI alone than white men, a result driven by a nearly four-fold increased risk of MI;
After accounting for the differences in baseline clinical and angiographic risk factors, rates of repeat hospitalization for TVR and stent thrombosis (ST) were similar across all four groups included in the analysis (white men, white women, non-white men and non-white women).
“The most vulnerable populations who are at the greatest risk of heart disease are the ones who are being studied in clinical trials the least,” said Paul Underwood, M.D., medical director of clinical interventional cardiology at Boston Scientific. “It’s of critical importance to us to have real-world clinical evidence of how our products work in all populations, including those most susceptible to coronary artery disease. We hope that the insights yielded from PLATINUM Diversity are a catalyst for industry-wide change, beginning in clinical trial recruitment.”
The analyses of PLATINUM Diversity also revealed socioeconomic disparities. Among patients who disclosed annual household income, the study indicated significant differences in the primary clinical endpoint of the composite of death, MI and TVR at 12 months.
Annual household income
Composite rate of death, MI and TVR at 12 months
After adjustment for all other clinical and angiographic variables, annual income remained an independent predictor of death and combined death and MI.
“These are daunting results for our patients with low socio-economic status, and a call to action to pay close attention to their post hospital care and follow up,” said Roxana Mehran, M.D., FACC, co-principal investigator, professor of medicine (cardiology) and population health science and policy director of interventional cardiovascular research and clinical trials at the Icahn School of Medicine at Mount Sinai.
The PLATINUM Diversity study is an observational, prospective, multicenter, open-label, single-arm, post-approval study that enrolled 1,501 patients at 52 sites in the U.S. from understudied populations, specifically women, African Americans, Latinos/Hispanics, American Indians or Alaska Natives. All patients in this single arm study received at least one Promus PREMIER™ Everolimus-Eluting Platinum Chromium Coronary Stent System. Patient data from the PROMUS Element™ Plus post-approval study were included in the full analysis to allow for comparisons to white men, increasing the total number of patients to 4,188.* The study’s primary endpoints were presented at the 28th Transcatheter Cardiovascular Therapeutics (TCT), the annual scientific symposium of the Cardiovascular Research Foundation, on November 1, 2016.
The Promus PREMIER Stent System received CE Mark approval in February 2013 and has been available in the U.S. since November 2013. The PROMUS Element Plus stent system received CE Mark approval in 2009 and FDA approval in 2011.