A dual antiplatelet therapy regimen of up to 24 months was associated with a significantly lower risk of death, MI or cerebrovascular accidents in patients with peripheral artery disease (PAD) who underwent PCI.
The subgroup analysis of a randomized trial also found that prolonged dual antiplatelet therapy did not increase the risk of bleeding compared with a shorter period of treatment.
Still, patients undergoing PCI who had concomitant PAD had a two-fold increased risk of ischemic events compared with those who did not have PAD.
Lead researcher Anna Franzone, MD, of Bern University Hospital in Switzerland, and colleagues published their results online in JAMA Cardiology on Aug. 30.
The findings were also presented at the European Society of Cardiology Congress in Rome, Italy.
The researchers evaluated 1,970 patients who enrolled in the PRODIGY (Prolonging Dual Antiplatelet Treatment After Grading Stent-Induced Intimal Hyperplasia Study) trial from December 2006 to December 2008. The analysis included 246 patients with PAD and 1,724 patients without PAD. They all came from tertiary care hospitals, had stable coronary artery disease or acute coronary syndromes and underwent PCI.
In the PAD group, 118 patients were randomized to receive prolonged dual antiplatelet therapy and 128 patients were randomized to receive shorter treatment. Of the non-PAD patients, 869 and 855 were assigned to the respective treatment groups.
The prolonged group received dual antiplatelet therapy for 24 months following PCI, while the shorter treatment group received therapy for 6 months or less.
At baseline, patients with PAD were older and more often had hypertension, type 1 or type 2 diabetes, previous MI and previous CABG and were more likely to present with non–ST-segment elevation MI, have more complex coronary artery disease and have had undergone a multivessel intervention.
After two years of follow-up, the composite of death, MI or cerebrovascular accidents was 21.9 percent in patients with PAD and 8.4 percent in patients without PAD. The mortality rates were 15.8 percent and 5.3 percent, respectively, while cardiac death was reported in 10.0 percent and 2.9 percent of patients, respectively.
In addition, the rates of Bleeding Academic Research Consortium type 2, 3 or 5 bleeding were 6.0 percent in patients with PAD and 5.5 percent in patients without PAD.
Among the patients with PAD, 16.1 percent who received the prolonged dual antiplatelet therapy regimen and 27.3 percent who received the shorter therapy had the composite of death, MI or cerebrovascular accidents. Meanwhile, among patients without PAD, the rates were 9.3 percent and 7.4 percent, respectively, which was not a statistically significant difference.
In the PAD group, the risk of definite or probable stent thrombosis was significantly lower among patients who received prolonged dual antiplatelet therapy.
The researchers mentioned a few limitations of the study, including that this was not a prespecified analysis and had a limited number of patients and events. They also said they only determined PAD status based on clinical history, so they may have underreported the number of patients with PAD. In addition, dual antiplatelet therapy only consisted of aspirin and clopidogrel and did not include newly FDA-approved P2Y12 receptor inhibitors.
“Peripheral artery disease confers a poor prognosis in patients undergoing PCI in the setting of stable coronary artery disease or acute coronary syndromes,” the researchers wrote. “Prolonged [dual antiplatelet therapy] lowers the risk of ischemic events with no apparent bleeding liability in this high-risk group.”