SECURITY: Six-Month DAPT Noninferior to 12 Months with Second-Generation DES

Patients undergoing PCI with a second-generation drug-eluting stent (DES) have similar outcomes no matter whether they receive 6 or 12 months of dual antiplatelet therapy (DAPT), leading the SECURITY trial investigators to report at TCT 2014 that the shorter regimen appears noninferior to the longer. Results were published simultaneously in the Journal of the American College of Cardiology.

The SECURITY trial addressed the need for prolonged DAPT use after implantation of a variety of second-generation DES, including Biomatrix (Biosensors Europe), Endeavor Resolute (Medtronic), Nobori (Terumo Medical), Promus (Boston Scientific) and Xience (Abbott Vascular). Patients without high-risk ACS were randomly assigned to DAPT for 6 months (n=682) or 12 months (n=717). At 12 months of follow-up, DAPT use was 33.8% in the 6-month group and 96.1% in the 12-month group; at 24 months, 96.5% of the 6-month group and 97.9% of the 12-month group were on aspirin monotherapy.

Antonio Colombo, MD, from Columbus Hospital/San Raffaele Hospital, Milan, Italy, presented data suggesting that 6-month DAPT is noninferior to 12-month DAPT for the primary composite at 12 months (P<.05 for noninferiority). The two regimens also were equivalent for the secondary composite endpoint both at 12 months and from 12 to 24 months (see Table).

Also at 24 months, both the 6- and 12-month DAPT regimens showed similar rates of individual endpoints including cardiac death (0.9% vs. 0.8%; P=.925), MI (3.1% vs. 2.6%; P=.636), stroke (0.9% vs. 0.4%; P=.636), definite/probable stent thrombosis (0.4% vs. 0.4%; P=.951) and BARC type 3 or 5 bleeding (0.7% vs. 1.1%; P=.496).

In other results, rates of urgent target vessel revascularization and all bleeding were low with both DAPT regimens at all time points studied, Colombo said. When the researchers used landmark analysis to examine events that occurred in patients after 6 months, they found no difference between the two DAPT groups.

Age older than 75 years, stent type, number of stents implanted, stent length and stent size were identified as independent predictors of the primary endpoint on multivariable analysis. “Age was the strongest predictor,” Colombo said.

SECURITY was a 1:1 randomized, prospective, investigator-driven, noninferiority study conducted at 38 centers in Italy, Spain and the Netherlands from July 2009 to June 2014. Patients were eligible for inclusion if they had a diagnosis of stable or unstable angina or documented silent ischemia undergoing revascularization with at least one second-generation DES. At baseline, about 31% of patients had diabetes. Almost half of patients had one-vessel disease. Radial artery access was used in more than two-thirds of patients.

Disclosures:

• Colombo reports being a minor shareholder of Direct Flow.