How long to keep on dual clot prevention after a heart stent? New studies open to interpretation

Related articles

PCI and stentA study evaluating outcomes among almost 10,000 patients post-cardiac stent insertion to determine optimal duration of anti-platelet therapy provided fans of both maintaining the current 12-month schedule, and proponents of longer duration, reassurance.

How could that be? First the data: a multi-center group led by Dr. Laura Mauri of Brigham-Women s Hospital/Harvard Medical School followed a group of 9,961 patients for up to 30 months after placement of a drug-eluting coronary artery stent. The subjects were randomly divided into a 12-month group, who received aspirin and an anti-platelet agent (APA, either Plavix or Effient) for the standard 12-months after stenting; this control group was then compared to a group who received dual APA plus aspirin for 30 months post-stenting.

The results in terms of cardiovascular outcomes: stent thrombosis (clotting), heart attack or stroke, were quite clear: significant benefits for the longer-term dual therapy. However, there was (predictably) an increased risk of bleeding among the 30-month group. Surprisingly, there was an increase in all-cause mortality (death) among the longer-term APA group, despite the vascular benefits. It was found on re-analysis that the increased mortality derived almost solely from an increase in cancer death rate among the longer-term APA group a red herring, as one commentator put it.

The official advisory of the FDA, at whose behest this study was done as part of their mandated post-marketing evaluation of the specific stent made by Taxus/Boston Scientific, was that [h]ealth care professionals should not change the way they prescribe these drugs at this time.

Various opinions were voiced by attendees at the AHA meeting at which these results were announced, simultaneously with their publication in the New England Journal of Medicine. These findings run counter to the trend toward shorter and shorter dual antiplatelet therapy duration within interventional cardiology, Antonio Colombo, MD, and Alaide Chieffo, MD, both of the San Raffaele Scientific Institute in Milan, noted in an editorial accompanying the study paper. The apparent contradiction between findings that 3 to 6 months appears safe, at least in selected patients, and the study s findings of benefit from prolonged treatment can be explained as the shorter period of being "mandatory" and the longer period being "possibly beneficial," they said.

There's no single answer to the best duration of dual antiplatelet therapy, they told MedPage Today. The decision should be individualized.

ACSH s Dr. Gil Ross had this comment: First of all, let me make it clear that there is no debate about the requirement that all patients who have a cardiac stent inserted must be on DAPT for at least 12 months, absent serious bleeding. The picture as far as longer-term DAPT remains a decision made by the doctor in concert with the patient, whose individual concerns should take precedence in most cases. I imagine that those taking care of Justice Ruth Bader Ginsburg, who only last week had such a stent inserted, had a long discussion with her as to the planned duration of her therapy based upon this exact study.