LAS VEGAS—A simple, low-cost approach of four telephone contacts with patients following drug-eluting stent (DES) implantation significantly improves one-year drug adherence of dual antiplatelet therapy (DAPT) to near perfect scores, based on the findings of the single-center, Canadian EASY-IMPACT trial presented May 9 as a scientific poster at the 35th annual meeting of the Society for Cardiovascular Angiography and Interventions (SCAI).
Previous studies have shown that many patients either delay or interrupt DAPT following DES implantation. In fact, one 2007 study by Ho et al found that as many as 20 percent of patients had discontinued clopidogrel therapy within six months of receiving a bare-metal stent or DES (Am Heart J 2007;154: 846-851).
Thus, Stéphane Rinfret, MD, a clinical and interventional cardiology researcher, and his colleagues at the Quebec Heart and Lung Institute in Quebec City, tested the hypothesis that “a simple approach,” consisting of telephone contacts, would improve DAPT adherence. The EASY-IMPACT (Early discharge After transradial Stenting of Coronary ArterY-IMProving Adherence to Clopidogrel Trial) is an open-label, single center, randomized controlled trial that recruited patients immediately after DES implantation who had no contraindication for 12-month DAPT.
“We should make every effort to make sure patients do not interrupt dual antiplatelet therapy once they’ve received a DES,” Rinfret said in a statement. “It’s absolutely crucial. If a patient stops taking clopidogrel or aspirin, it increases the stent thrombosis risk by 100 to 150 times, and that can lead to heart attack, stroke or death.”
The researchers randomized patients to one of two groups: intervention, with telephone follow-up vs. control. In the intervention group, phone calls were made within seven days of implantation, and at one, six and nine months to assess drug adherence, reminding patients of the importance of DAPT. They followed the control patients per usual clinical practice. However, both groups were briefed on the importance of DAPT adherence prior to discharge.
The primary endpoint was the proportion of days covered with aspirin and clopidogrel over the 12-month period following discharge.
The study included a total of 300 randomized patients with a mean age was 63 years, of whom 73 percent were male and 35 percent were diabetics. The participants received a median of two DES. Seventy-three percent of patients underwent DES implant in the context of an acute coronary syndrome. Also, all patients had drug insurance coverage, either from the public plan (59 percent) or through private plans (41 percent). Complete pharmacy follow-up data was available in 98 percent of the participants.
At 12 months, Rinfret et al found that the median adherence to aspirin and clopidogrel were 99.2 percent and 99.2 percent in the intervention group compared with 90.2 percent and 91.5 percent in the control group.
The researchers also calculated medication persistence, which they defined as having less than a 14-day gap between expected and actual prescription refill dates at any point in the study. They found that for aspirin, 91.2 percent of the telephone group and 72.3 percent of the usual care group remained persistent at six months, while 87.8 percent and 39 percent, respectively remained persistent at one-year. For clopidogrel, 90.5 percent of patients in the telephone group and 66.7 percent of patients in the usual care group were still persistent at six months, while 87.2 percent and 43.1 percent, respectively, were still persistent at one year.
“As physicians, we should remember that drugs only work in patients who take them,” Rinfret said. “There are ongoing debates about the best antiplatelet agent based on their biological effects, but new approaches to patient management may have an even stronger effect than new drugs on the prevention of heart attack and other complications following implantation of DES.”
Bristol-Myers Squibb and Sanofi-Aventis provided partial funding for the study.