Shorter DAPT with DES trumps BMS for patients over 75 in SENIOR
Using bioabsorbable polymer drug-eluting stents (DES) with a shorter duration of double antiplatelet therapy (DAPT) in elderly patients undergoing percutaneous coronary intervention (PCI) leads to fewer adverse events than bare-metal stents (BMS) without increasing bleeding risk, according to the SENIOR* trial presented at TCT 2017 Congress.
“[B]ecause of their increased risk of coronary artery disease [CAD] … the elderly represent a fast-growing segment of the population undergoing PCI. They have been poorly represented in prior studies on DES and DAPT duration, so there is no clear recommended PCI strategy for this group,” said lead author Dr Olivier Varenne from Cochin Hospital in Paris, France.
Contemporary DES reduce the risk of repeat revascularizations in elderly patients and are safer in terms of stent thrombosis compared with BMS. [J Am Coll Cardiol 2014;63:1371-1375; N Engl J Med 2015;373:2038-2047; J Am Coll Cardiol 2015;65:2496-2507] “However, elderly patients regularly receive BMS during PCI since BMS require a shorter DAPT course than do DES to minimize the risk of bleeding complications associated with long antiplatelet therapy,” according to Varenne and co-authors.
“A strategy of combination of a DES to reduce the risk of subsequent repeat revascularizations with a short … DAPT regimen [traditionally reserved for BMS] to reduce the risk of bleeding event is an attractive option for elderly patients who have PCI,” they added.
DES superior to BMS
At 1 year, the primary composite outcome of major adverse cardiac and cerebrovascular events (MACCE), including all-cause mortality, stroke, myocardial infarction (MI), or ischaemia-driven target lesion revascularization, occurred in fewer patients in the DES than the BMS groups (12 percent vs 16 percent, relative risk [RR], 0.71; p=0.02). [Lancet 2017;doi:10.1016/S0140-6736(17)32713-7]
The difference was driven mainly by the lower rate of ischaemia-driven target lesion revascularization in the DES vs the BMS groups (1.7 percent vs 5.9 percent, RR, 0.29; p=0.0002), while the other components of MACCE such as all-cause mortality, stroke, and MI were not significantly different between the two groups.
“Please note that the two curves [of the rates of primary endpoint] are still diverging at 1 year. I am looking forward to the predefined analysis of primary endpoint at 2 years,” said Varenne.
Also, the rates of bleeding complications based on BARC** 2–5 (4.5 percent vs 5.0 percent, RR, 0.90; p=0.68) and stent thrombosis (0.5 percent vs 1.4 percent, RR, 0.38; p=0.13) were similarly low in both groups.
“SENIOR demonstrates that PCI with a contemporary bioabsorbable polymer DES is more effective, and as safe as BMS in elderly patients with CAD, on a short DAPT tailored to their clinical presentation,” concluded Varenne. “BMS should no longer be used as a strategy to reduce DAPT duration in these patients.”
The single-blind, multinational, all-comer trial randomized 1,200 patients aged ≥75 years (mean age 81.4 years) with silent ischaemia, stable angina, or acute coronary syndrome (ACS), who were undergoing PCI to receive either a DES or BMS. Before randomization, the patients were subjected to a 1-month DAPT course for stable patients or a 6-month course for unstable patients (with ACS).
“The picture is not completely rosy as event rates in SENIOR were very low [166 (14 percent) of 1200],” wrote Drs Robert Gerber and Anthony Gershlick of Conquest Hospital in East Sussex, UK, in a commentary, reflecting the challenge of recruiting elderly high-risk patients into randomized trials. [Lancet 2017;doi:10.1016/S0140-6736(17)32803-9]
On whether the data were sufficient to change practice guidelines, Gerber and Gershlick said, “We feel it is not, as it is a single trial with only two variables and a small number of patients with a median age of 81 years,” noting that 37 percent of the patients were aged 75–79 years.
“However, what it might do is suggest that if an elderly patient at high bleeding risk is having PCI, then a DES might now be considered with the knowledge that a shorter duration of DAPT may not lead to more ischaemic events and will probably reduce the risk of bleeding,” they advised.
Varenne and co-authors cautioned that the safety of short DAPT course following DES implantation should be interpreted cautiously as “the study was not designed to evaluate the optimal duration of DAPT.” Also, the findings only apply to a specific DES platform in the study.
“However, if a stable patient receiving a DES has a bleed at 6 weeks or a patient with ACS receiving a DES has a bleed at 7 months, the interventionist could be reassured they could stop the DAPT,” suggested Gerber and Gershlick.