Prolonged dual antiplatelet therapy (DAPT) actually conferred a survival advantage for prior MI patients, found an updated meta-analysis done as one argument in a set of viewpoints dueling over the 2016 guidelines.
Patients with stable MI on extended DAPT showed a reduction in cardiovascular mortality (HR 0.835, 95% CI 0.720-0.969), although not in other causes of mortality (HR 0.965, 95% CI 0.80-1.164), that lowered their overall all-cause mortality risk (HR 0.89, 95% CI 0.79-0.99), reported Marc P. Bonaca, MD, MPH, and Marc S. Sabatine, MD, MPH, of Brigham and Women’s Hospital in Boston, in JAMA Cardiology.
“Long-term intensive antiplatelet therapy in addition to low-dose aspirin reduces MACE, cardiovascular mortality, and all-cause mortality in patients with a history of MI who are not at high bleeding risk, with a benefit-risk profile that is comparable with the evidence base for long-term aspirin itself,” they argued.
Their post-hoc sub group analysis with data from the PEGASUS-TIMI 54 trial and others previously failed to show any mortality effect of DAPT using P2Y12 inhibitors in post-MI patients, as had a meta-analysis overall in acute coronary syndrome patients.
The reanalysis added subgroup data from the TRA 2°P-TIMI 50 trial of vorapaxar (Zontivity).
However, the opposing viewpoint by John A. Bittl, MD, of Munroe Regional Medical Center in Ocala, Fla., and colleagues questioned the methodology.
“The successive mixing of different trials with different antiplatelet agents and different durations of follow-up not only adds clinical heterogeneity to the analysis but also unfortunately produces a perception that repetitive statistical analyses were performed to obtain a certain desired result,” they wrote.
“Investigators and practitioners cannot be criticized for trying to identify treatments that reduce cardiovascular complications in patients with prior MI, but an estimate of mortality risk derived from pooling subgroups with negative or inconclusive results from a series of inadequately powered studies carries a heightened risk of producing a false-positive conclusion.”
“Current evidence does not support a clear-cut survival advantage of extending DAPT beyond 1 year in patients with prior MI. Rather, a survival advantage is more likely to result from established guideline-directed therapies, including smoking cessation and the use of regular exercise, aspirin, statins, angiotensin-converting enzyme inhibitors, and β-blockers,” Bittl’s group concluded.
Bonaca declared consulting for AstraZeneca, Merck, and Bayer.
Sabatine disclosed institutional grants from Abbott Laboratories, Amgen, AstraZeneca, Critical Diagnostics, Daiichi-Sankyo, Eisai, Gilead, GlaxoSmithKline, Intarcia, Janssen Research Development, MedImmune, Merck, Novartis, Poxel, Roche Diagnostics, Sanofi-aventis, and Takeda; as well as consulting for Alnylam, AstraZeneca, CVS Caremark, Ionis, and Merck.
Bittl reported no relevant conflicts of interest.
Mauri L, et al “Focused update on duration of dual antiplatelet therapy for patients with coronary artery disease” JAMA Cardiol 2016; DOI: 10.1001/jamacardio.2016.2171.
Bittl JA, et al “Extended dual antiplatelet therapy in patients with prior myocardial infarction” JAMA Cardiol 2016; DOI: 10.1001/jamacardio.2016.252.
Bonaca MP, et al “Antiplatelet therapy for long-term secondary prevention after myocardial infarction” JAMA Cardiol 2016; DOI: 10.1001/jamacardio.2016.2110.