Analyses of PLATINUM Diversity Trial Evaluates PCI Outcomes for Underrepresented Populations
May 12, 2017—Boston Scientific Corporation announced that new analyses from the company-sponsored PLATINUM Diversity study underscore the need for greater understanding of the clinical and nonclinical barriers that can adversely affect stent-related outcomes. The findings were presented during the late-breaking clinical trial session at SCAI 2017, the 40th annual Society for Cardiac Angiography and Interventions scientific sessions in New Orleans, Louisiana.
According to the company, PLATINUM Diversity is designed to shed light into the clinical, social, behavioral, and economic determinants of health treatment outcome disparities in women and minorities with coronary artery disease. The study aligns with Boston Scientific's "Close the Gap" initiative, which aims to promote health equity by reducing barriers to care by educating patients and advocating for adherence to clinical guidelines. Historically, large-scale clinical trials in cardiology have had a disproportionately low inclusion rate of women and nonwhite patients. These disparities in clinical trial enrollment are a reflection of differences in treatment rates seen in clinical practice, noted Boston Scientific.
The PLATINUM Diversity study is an observational, prospective, multicenter, open-label, single-arm, postapproval study that enrolled 1,501 patients at 52 sites in the United States from understudied populations (ie, women, African Americans, Latinos/Hispanics, American Indians, or Alaska Natives). All patients received at least one Promus Premier everolimus-eluting platinum chromium coronary stent system. Patient data from the Promus Element Plus postapproval study were included in the full analysis to allow for comparisons to white men, increasing the total number of patients to 4,188.
The PLATINUM Diversity trial's primary endpoints were presented as a First Report Investigation at TCT 2016, the 28th annual Transcatheter Cardiovascular Therapeutics scientific symposium in Washington, DC.
At SCAI 2017, the new analyses of PLATINUM Diversity data showed the impact of demographic and economic factors on outcomes at 1 year after stent implantation. The study found that:
- Several clinical and angiographic risk factors, including diabetes, renal disease, hypertension, and coronary calcification were more prevalent in nonwhites and women compared with white men, whereas white men were more likely to present 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 compared with white men, a result driven by a nearly fourfold increased risk of MI.
- Rates of repeat hospitalization for TVR and stent thrombosis were similar across all four groups included in the analysis (white men, white women, nonwhite men, and nonwhite women).
The analyses of PLATINUM Diversity also revealed socioeconomic disparities. Among patients who disclosed annual household income, there were significant differences in the primary clinical endpoint of the composite of death, MI, and TVR at 12 months. The composite rates in patients with annual household incomes of < $25,000, $25,000 to $49,000, and > $50,000 were 9.8%, 8.1%, and 4.1%, respectively. After adjusting for all other clinical and angiographic variables, annual income remained an independent predictor of death and combined death and MI.
In Boston Scientific's announcement, the study's Coprincipal Investigator Wayne Batchelor, MD, commented, "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. These data from PLATINUM Diversity provide important insights for the cardiology community to consider in addressing inequities in cardiovascular care." Dr. Batchelor is Chair of the Interventional Cardiology Council at Tallahassee Memorial Hospital in Tallahassee, Florida.
Coprincipal Investigator Roxana Mehran, MD, added, "These are daunting results for our patients with low socioeconomic status, and a call to action to pay close attention to their post-hospital care and follow up." Dr. Mehran is Professor of Cardiology and Population Health Science and Policy Director of interventional cardiovascular research and clinical trials at the Icahn School of Medicine at Mount Sinai in New York, New York.
The Promus Premier stent system received European CE Mark approval in February 2013 and has been available in the United States since November 2013. The Promus Element Plus stent system received CE Mark approval in 2009 and US Food and Drug Administration approval in 2011, advised Boston Scientific.