In certain patients, clopidogrel monotherapy better than aspirin after PCI: HOST-EXAM
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In patients who underwent PCI with a drug-eluting stent and took dual antiplatelet therapy for 6 to 18 months, subsequent clopidogrel monotherapy was superior to aspirin monotherapy, according to data from the HOST-EXAM trial.
The researchers randomly assigned 5,438 patients (mean age, 63 years; 75% men) who had no ischemic or major bleeding complications with DAPT for 6 to 18 months after PCI with a DES to receive clopidogrel 75 mg daily monotherapy or aspirin 100 mg daily monotherapy for 24 months. The results were presented at the American College of Cardiology Scientific Session and simultaneously published in The Lancet.
“Previous trials have shown that clopidogrel may have benefits in patients with atherosclerotic vascular disease. However, no trial has addressed which antiplatelet agent may be the optimal choice during the chronic maintenance period after PCI with DES,” Hyo-Soo Kim, MD, PhD, interventional cardiologist at the Cardiovascular Center at Seoul National University Hospital in South Korea, said during a press conference.
The primary endpoint of all-cause death, nonfatal MI, ischemic stroke, readmission for ACS or Bleeding Academic Research Consortium (BARC) bleeding type 3 or greater at 24 months occurred in 5.7% of the clopidogrel group and 7.7% of the aspirin group (HR = 0.73; 95% CI, 0.59-0.9; P = .0035; log-rank P = .005; risk difference, –2 percentage points; 95% CI, –3.3 to –0.6; number needed to treat to prevent one event = 50.6) in the intention-to-treat analysis, Kim said during the press conference.
A per-protocol analysis of the primary endpoint also favored clopidogrel (5.6% vs. 7.8%; HR = 0.72; 95% CI, 0.58-0.89; P = .002; log-rank P = .002), he said.
He said the thrombotic composite outcome of cardiac death, nonfatal MI, stroke, readmission for ACS or definite or probable stent thrombosis favored the clopidogrel group (3.7% vs. 5.5%; HR = 0.68; 95% CI, 0.52-0.87; P = .003; log-rank P = .002; risk difference, –1.7 percentage points; 95% CI, –2.8 to –0.6; number needed to treat = 59), as did BARC bleeding type 2 or greater (2.3% vs. 3.3%; HR = 0.7; 95% CI 0.51-0.98; P = .036; risk difference, –0.9 percentage points; 95% CI, –1.8 to –0; number needed to treat = 111).
According to the researchers, the components of the primary endpoint that favored the clopidogrel group at 24 months were stroke (HR = 0.42; 95% CI, 0.24-0.73; P = .002), readmission due to ACS (HR = 0.61; 95% CI, 0.45-0.82; P = .001) and BARC 3 or greater bleeding (HR = 0.63; 95% CI, 0.41-0.97; P = .035).
In addition, minor gastrointestinal complaints were lower in the clopidogrel group (HR = 0.85; 95% CI, 0.72-1; P = .048).
The treatment effect did not vary according to any prespecified subgroups, according to the researchers.
“In patients who were event-free under DAPT for 6 to 18 months after PCI with DES, clopidogrel was better than aspirin monotherapy in reducing the risk of the composite [primary outcome],” Kim said during the press conference. “Long-term follow-up of this cohort will give us the concrete conclusion on the optimal single agent during the chronic maintenance period after PCI with DES.”
In a discussion at the press conference, Claire Duvernoy, MD, FACC, professor of medicine at the University of Michigan Health System, said, “For a long time, we have been looking for alternatives” because of the bleeding risk posed by aspirin.
“In this U.S., most of us use aspirin as long-term monotherapy after stent placement, so I think [clopidogrel monotherapy] is going to be a fascinating alternative,” she said. “We are going to have to see how widely applied these results are.”