This article is more than 5 years old. Information may no longer be current.
Shorter DAPT duration after PCI improved outcomes at 1 year
Click Here to Manage Email Alerts
NEW ORLEANS — Patients who took dual antiplatelet therapy after PCI for a shorter amount of time while continuing P2Y12 inhibitor monotherapy did not have an increased risk for MI, death or stroke compared with those who took standard therapy for 1 year, according to data from two studies presented at the American College of Cardiology Scientific Session.
STOPDAPT-2 study
Hirotoshi Watanabe, MD, PhD, interventional cardiologist and assistant professor in the department of cardiovascular medicine at Kyoto University Hospital in Japan, and colleagues analyzed data from 3,009 patients (mean age, 69 years) who underwent PCI with an everolimus-eluting stent (Xience series, Abbott) with no major complications during hospitalization and who were able to take DAPT with P2Y12 inhibitors and aspirin. Data from patients who did not participate in the study (n = 3,287; mean age, 70 years) were also included in the analysis.
Before hospital discharge, patients in the study were assigned 1 month of DAPT (n = 1,500; mean age, 68 years; 79% men) or 12 months of DAPT (n = 1,509; mean age, 69 years; 77% men). In patients assigned 1 month of DAPT, 75 mg clopidogrel once per day was initiated. The 12-month group was treated with aspirin and clopidogrel for up to 12 months, after which patients received aspirin monotherapy for up to 5 years.
A primary noninferiority analysis was performed at 1 year.
The primary endpoint was net adverse CV events, defined as a composite of MI, CV death, stroke, definite stent thrombosis or TIMI minor or major bleeding. Major secondary endpoints were a bleeding endpoint — TIMI minor or major bleeding — and an ischemic composite endpoint, defined as MI, CV death, stroke or definite stent thrombosis.
In the 1-month and 12-month groups, there were similar rates of stable CAD (62% vs. 61%, respectively) and diabetes (39% vs. 38%, respectively). Most patients assigned 1 month or 12 months of DAPT were at low (71% vs. 68% respectively) or intermediate (21% vs. 24%; respectively) thrombotic risk, in addition to low (66% for both) or intermediate (27%) bleeding risk defined as CREDO-Kyoto risk scores.
At 1 year, the primary endpoint occurred in 3.7% of patients assigned 12 months of DAPT vs. 2.4% of those assigned 1 month of DAPT (HR = 0.64; 95% CI, 0.42-0.98; P for noninferiority < .001; P for superiority = .04).
One-month DAPT was also noninferior to 12-month DAPT for the major secondary ischemic endpoint at 1 year, although the difference between both groups was not significant (2% vs. 2.5%, respectively; HR = 0.79; 95% CI, 0.49-1.29; P for noninferiority = .005; P for superiority = .34).
Superiority was seen in patients assigned 1-month DAPT vs. those assigned 12-month DAPT for the major secondary bleeding endpoint (0.4% vs. 1.5%, respectively; HR = 0.26; 95% CI, 0.11-0.64; P for superiority = .004).
Regarding clinical outcomes at 1 year, the rate of BARC type 3 or 5 bleeding was lower in the 1-month DAPT group vs. the 12-month DAPT group (0.5% vs. 1.8%; P = .003). There were no significant differences in the incidence of MI, stent thrombosis, all-cause death and stroke between both groups.
A low risk for the primary endpoint in patients assigned 1 month of DAPT was seen in all subgroups except in a small group of those with severe chronic kidney disease defined as estimated glomerular filtration rate less than 30 ml/min/1.73m2. Patients who had intermediate or high thrombotic risk scores were more likely to experience the primary endpoint compared with those with low thrombotic risk scores. There was no interaction between the subgroup of thrombotic risk scores and the effects of 1 month of DAPT, according to the presentation.
“One-month DAPT followed by clopidogrel monotherapy provided a net clinical benefit for ischemic and bleeding events over 12-month DAPT with aspirin and clopidogrel after cobalt-chromium EES implantation,” Watanabe said during the presentation. “The benefit was driven by significant reduction in bleeding events without increase in ischemic events.”
SMART-CHOICE study
In another study presented at ACC, Joo-Yong Hahn, MD, PhD, professor in the department of internal medicine at Samsung Medical Center in Seoul, South Korea, and colleagues analyzed data from 2,993 patients who underwent PCI with a cobalt-chromium EES (Xience series, Abbott), platinum-chromium EES (Promus series, Boston Scientific; Synergy, Boston Scientific) or a bioresorbable polymer sirolimus-eluting stent (Orsiro, Biotronik). Patients were assigned 12 months of DAPT (n = 1,498; mean age, 64 years; 74% men) or P2Y12 inhibitor monotherapy after 3 months of DAPT (n = 1,495; mean age, 65 years; 73% men).
The primary endpoint was MACCE, which was defined as a composite of MI, all-cause death or stroke at 12 months after the index procedure. Secondary endpoints were cardiac death, individual components of the primary endpoint, BARC type 2 to 5 bleeding, definite or probably stent thrombosis and net adverse clinical and cerebral events.
In the 3-month and 12-month DAPT groups, there were similar rates of ACS (58.2% vs. 58.3%, respectively). In addition, clopidogrel was the most commonly used P2Y12 inhibitor (76.9% vs. 77.6%, respectively).
At 12 months, MACCE occurred in 2.9% of patients assigned P2Y12 inhibitor monotherapy vs. 2.5% of those assigned DAPT for 12 months (difference = 0.4 percentage points; HR = 1.19; 95% CI, 0.76-1.85; upper limit of 1-sided 95% CI, 1.3%; P for noninferiority = .007). No significant differences were seen in both groups in a landmark analysis of MACCE during 90 days of DAPT (HR = 1.31; 95% CI, 0.57-2.98) and from 90 days to 1 year (HR = 1.14; 95% CI, 0.67-1.93).
At 12 months, there were no significant differences between the P2Y12 inhibitor monotherapy and DAPT groups for secondary endpoints such as death (1.4% vs. 1.2%; respectively), MI (0.8% vs. 1.2%, respectively), stroke (0.8% vs. 0.3%, respectively) and stent thrombosis (0.2% vs. 0.1%, respectively).
Patients assigned P2Y12 inhibitor monotherapy had a lower rate of BARC type 2 to 5 bleeding compared with those assigned DAPT (2% vs. 3.4%), although there were no significant differences in major bleeding (0.8% vs. 1%, respectively) and net adverse clinical and cerebral events (4.5% vs. 5.6%, respectively).
Researchers also performed per protocol analyses, which found that MACCE occurred in 3.1% of patients assigned P2Y12 inhibitor monotherapy and 2.5% of those assigned DAPT, although the difference was not statistically significant (HR = 1.25; 95% CI, 0.79-1.99). No statistical differences were seen in secondary endpoints, although the risk for BARC type 2 to 5 bleeding was significantly lower in the P2Y12 inhibitor monotherapy group vs. the DAPT group (1.8% vs. 3.1%; HR = 0.58; 95% CI, 0.34-0.97).
“Our trial suggests that P2Y12 inhibitor monotherapy after short duration of DAPT is a novel antiplatelet strategy balancing ischemic and bleeding sick in patients undergoing PCI,” Hahn said during the presentation. – by Darlene Dobkowski
References:
Hahn J-Y, et al.
Watanabe H, et al. Late-Breaking Clinical Trials IV: Interventional. Both presented at: American College of Cardiology Scientific Session; March 16-18, 2019; New Orleans.
Disclosures: The STOPDAPT-2 study was funded by Abbott Vascular Japan. The SMART-CHOICE study was sponsored by Abbott Vascular, Biotronik, Boston Scientific and the Korean Society of Interventional Cardiology. Watanabe report no relevant financial disclosures. Hahn reports he received consulting fees/honoraria from AstraZeneca, Daiichi Sankyo and Sanofi Aventis and research support from Abbott Korea, Biotronik, Boston Scientific Korea and Medtronic Korea.