Prolonged DAPT after stenting yields similar ischemic, bleeding risks in women, men
In a secondary analysis of the DAPT study, late risk for ischemic and bleeding events was similar in women and men who received prolonged dual antiplatelet therapy beyond 1 year after coronary stenting.
Natalia C. Berry, MD, interventional cardiology specialist at Brigham and Women’s Hospital and instructor in medicine at Harvard Medical School, and fellow researchers for the DAPT study performed the secondary analysis to determine whether risks and benefits of prolonged dual antiplatelet therapy (DAPT) are different among women and men. DAPT is a randomized, double-blind, placebo-controlled trial to compare continued thienopyridine therapy vs. placebo in patients treated with aspirin after receiving a drug-eluting or bare-metal stent.
Among 11,648 patients randomized to thienopyridine or placebo beyond 12 months of the index procedure, 2,925 were women. The mean age was 63.3 years among women and 60.7 years among men. Specific treatment use varied by sex, with clopidogrel used in more women (71.2% vs. 67.6%) and prasugrel used in more men (32.4% vs. 28.8%).
At 12 to 30 months following the index PCI procedure, women and men had similar risk for stent thrombosis (0.71% vs. 0.91%; P = .23; adjusted P = .87), MI (3.2% vs. 3%; P = .47; adjusted P = .17), and major adverse CV and cerebrovascular events (4.9% vs. 5.1%; P = .93; adjusted P = .12). Women had lower rates of death (1.1% vs. 1.9%; P = .01; adjusted P = .06) and cardiac death (0.5% vs. 1%; P = .004; adjusted P = .13) compared with men. The researchers observed similar rates of non-CV death, vascular death and GUSTO moderate/severe bleeding. The rate of thienopyridine interruption was higher among women than men (24.2% vs. 19%; P < .001).
According to the findings, the effects of continued thienopyridine therapy did not differ among women and men for stent thrombosis (women: HR = 0.54; men: HR = 0.26), MI (women: HR = 0.75; men: HR = 0.46), MACCE (women: HR = 0.87; men: HR = 0.7) and bleeding (women: HR = 1.45; men: HR = 1.78).
The researchers also analyzed the impact of DAPT score stratification. As previously reported by Cardiology Today’s Intervention, a DAPT score was created to aid physicians in determining which patients should and should not receive DAPT for more than 1 year after stenting. A score of less than 2 indicates that bleeding risk may outweigh ischemic benefit of long-term DAPT, while a score of 2 or more indicates that ischemic benefit may outweigh bleeding risk. In the current analysis, women had a higher proportion of DAPT scores of less than 2 (51% vs. 48.6%) compared with men. The researchers noted that DAPT score predicted ischemic benefit vs. bleeding risk in both women and men.
“These data are consistent with other recent observations that both women and men, when similarly diagnosed with an acute coronary event or when undergoing percutaneous coronary intervention, benefit from potent antiplatelet therapy. However, the clinical implications of this study are important,” Fatima Rodriguez, MD, MPH, assistant professor of medicine (cardiovascular medicine), and Robert A. Harrington, MD, interventional cardiologist, Arthur L. Bloomfield Professor of Medicine and chairman of the department of medicine, both at Stanford University, wrote in an accompanying editorial. “The findings counter the common misperception that women may have less to gain from prolonged DAPT after coronary stenting and once again demonstrate the critical importance of clinical trials enrolling participants that mirror those that we see in clinical practice. It seems clear that patients with high DAPT scores ≥ 2, irrespective of their sex, will benefit from DAPT beyond a year after coronary artery stenting.
“As with all antithrombotic management decisions, providers must weigh the ischemic benefit vs. bleeding risks. This secondary analysis of the DAPT study suggests that patient sex should not be a primary factor in that consideration. The plea to the cardiovascular community is to design and carry out trials that allow these statements to be made based on high-quality evidence,” Rodriguez and Harrington wrote.
Disclosures: Berry reports no relevant financial disclosures. Please see the full study for the other authors’ relevant financial disclosures. Harrington reports he receives research grants to Stanford in his name from Apple, AstraZeneca, Bristol-Myers Squibb, Commonwealth Serum Laboratories, Janssen, Novartis, Portola, Sanofi and The Medicines Company; consults or serves on advisory boards for Amgen, Bayer, Element Science, Gilead, MyoKardia and WebMD; and is on the board of directors for the American Heart Association, Scanadu, Signal Path and Stanford HealthCare. Rodriguez reports no relevant financial disclosures.