21 Mar High risks of mortality following bleeding and ischemic events occurring 1 year after coronary stenting
MedicalResearch.com Interview with:
Dr. Eric Secemsky
Eric A. Secemsky, MD, MSc
Interventional Cardiology Fellow
Massachusetts General Hospital Harvard Medical School
Baim Institute for Clinical Research
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: We know from previous trials that continuing dual antiplatelet therapy longer than 12 months after coronary stenting decreases ischemic events, including spontaneous myocardial infarction and stent thrombosis. However, extending dual antiplatelet therapy is also associated with some increase in bleeding risk. For instance, in the DAPT Study, more than 25,600 patients were enrolled and received both aspirin and a thienopyridine antiplatelet drug (clopidogrel or prasugrel) for one year after stenting. Of these patients, 11,648 participants who had followed the study protocol and had no serious cardiovascular or bleeding events during that first year were then randomized to either continue with dual therapy or to receive aspirin plus a placebo for another 18 months. The overall findings of the DAPT study were that, compared with switching to aspirin only after one year, continuing dual antiplatelet therapy for a total of 30 months led to a 1.6 percent reduction in major adverse cardiovascular and cerebrovascular events – a composite of death, myocardial infarction, stent thrombosis and ischemic stroke – and a 0.9 percent increase in moderate to severe bleeding events.
The prognosis following early ischemic and bleeding events has previously been well described. However, data for events occurring beyond 1 year after PCI are limited. As such, we sought to assess the cumulative incidence of death following ischemic and bleeding events occurring among patients in the DAPT Study beyond 1 year after coronary stenting.
MedicalResearch.com: What are the main findings?
Response: Our findings were as follows. During the 12 to 33 month study period following randomization, 11 percent of the 478 individuals who experienced an ischemic event (myocardial infarction, stent thrombosis or ischemic stroke) died, representing a 0.5 percent incidence of death following such events among all randomized participants. Among the 232 participants who experienced a bleeding event, 18 percent died, although the higher death rate among those with bleeding events was somewhat offset by the smaller incidence of such events. The cumulative incidence of death following a bleeding event was 0.3 percent among all randomized participants Deaths following bleeding events primarily took place within 30 days of the event; and while deaths after ischemic stroke or stent thrombosis usually took place soon after the event, the increased risk of death following a myocardial infarction persisted during the rest of the study period. Overall, having either type of event resulted in a serious mortality risk – an 18-fold increase after any bleeding event and a 13-fold increase after any ischemic event.
MedicalResearch.com: What should readers take away from this report?
Response: Our study demonstrates that both bleeding and ischemic events have important prognostic implications. As such, our efforts need to be focused on individualizing treatment and identifying those who are at the greatest risk of developing recurrent ischemia while also at the lowest risk of developing a bleed. In order to assist in this, our group developed a risk score using data from the DAPT study. This score was based on readily available clinical factors – such as patients’ age, smoking history, presence of diabetes, and details of cardiac disease and treatment – and provides an estimate of expected benefits and risks to help determine whether or not dual antiplatelet therapy should continue past the one-year mark. The risk score tool has recently been included in American College of Cardiology (ACC)/American Heart Association guidelines on the duration of dual antiplatelet therapy, and is available on the ACC website.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Response: Further attention is needed to identify additional methods of secondary prevention of myocardial infarction. Currently, extending dual antiplatelet therapy greater than 12 months after stenting is the primary approach. In addition, further evaluation, validation and implementation of risk tools such as the DAPT Score is needed so that we are treating only those most likely to benefit from extended dual antiplatelet therapy.
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Last Updated on March 22, 2017 by Marie Benz MD FAAD