SENIOR, DAPT-STEMI and REDUCE: TCT 2017 Late Breaking Trial Results
Reported from the TCT 2017 Scientific Sessions in Denver, United States
Three trials focused on important discussion points for daily practice on the third day of TCT 2017, with two clinical questions in the spotlight: 1) is there still a niche for bare metal stents (BMS) in elderly patients? 2) Is a 12-month duration of DAPT a must-have for all acute coronary syndrome (ACS) patients in the current era?
SENIOR: Final call or final nail in the coffin for Bare Metal Stents?
Bare metal stents have been already proven to be inferior to modern drug-eluting stents in many clinical settings including areas where you would expect a residual net clinical benefit, such as STEMI (i.e., EXAMINATION trial) and high bleeding risk (i.e., LEADERS-FREE trial). Now the question is whether BMS are still applicable to elderly patients undergoing PCI, and the answer seems to be no.
In the SENIOR trial, presented at TCT and simultaneously published in The Lancet, a biodegradable-polymer DES reduced MACE compared with its BMS counterpart, with most of the benefit attributable to less target lesion revascularization. Interestingly, there was a significant interaction between the treatment effect and the presence of atrial fibrillation (with patients presumably on oral anticoagulant therapy), which calls for further subanalyses.
DAPT-STEMI and REDUCE: is less more (more or less) for DAPT in Acute Coronary Syndromes?
In DAPT STEMI the investigators randomized about 1,100 STEMI patients with no ischemic events during the first 6 months after primary PCI to additional 6 months of DAPT or P2Y12 inhibitor discontinuation. It turned out that the primary endpoint, a composite of ischemic and bleeding outcomes, met the primary hypothesis of shorter DAPT being noninferior to longer DAPT.
Yet, the observed rate of events was lower than anticipated, which may have some impact of the power of the study. This potential caveat was even more pronounced in the subsequently presented REDUCE trial, where the investigators compared 3-month DAPT versus 12-month DAPT in patients with acute coronary syndromes who received the so-called “dual-therapy” stent.
Again, the noninferiority hypothesis was met, but the margin of noninferiority was quite generous, and the direction of the estimates for some important component ischemic endpoints disfavored the 3-month DAPT group (lacking anyway formal statistical significance), which warrants some cautious interpretation. That being said, these are investigator-initiated trials with courageous hypotheses, opening the door to new research studies of “less-is-more” approaches for DAPT in selected patients with ACS. How these results should be interpreted in view of trials that actually suggest a benefit in prolonging DAPT in patients with prior myocardial infarction (i.e., PEGASUS) is a matter of debate.