Having diabetes was associated with higher risk of a major cardiovascular event (MACE) after implementation of a drug-eluting stent (DES), according to a systematic review of randomized controlled trials (RCTs), which also compared long-term (≥12 months) with short-term (three to six months) DAPT after percutaneous coronary intervention (PCI). Overall, the review found no significant differences between long-term and short-term therapy on the outcomes of MACE, all-cause mortality, cardiac mortality, or myocardial infarction (MI) in patients with or without diabetes.
The study was published by The BMJ on Nov. 3, 2016. The following commentary by Richard G. Bach, MD, ACP Member, was published in the ACP Journal Club section of the Feb. 21 Annals of Internal Medicine.
Recent RCTs have found that long-term DAPT after implantation of newer-generation DESs reduces adverse ischemic events in higher-risk, but not lower-risk, patients and increases risk for bleeding in all patients. The presence of diabetes increases risk for ischemic events after PCI, and in some trials long-term DAPT has been found to reduce death and MI and target vessel failure in patients with diabetes.
Gargiulo and colleagues' review of 6 RCTs confirmed that diabetes was associated with a greater risk for MACE but found that long-term DAPT did not reduce MACE at 1 year, even in patients with diabetes. In those patients, long-term DAPT reduced the risk for definite/probable stent thrombosis compared with short-term DAPT (HR 0.26, 95% CI 0.09 to 0.80), but the number of events was small (7 vs 16), substantial heterogeneity existed among the trials, and no resultant change occurred in the rate of death or MI. The analyses also confirmed that long-term DAPT increased the risk for bleeding in patients with diabetes.
A recent meta-regression analysis suggested that bleeding may have a greater effect on mortality than does stent thrombosis, and Gargiulo and colleagues have provided evidence that, in patients with diabetes, long-term DAPT increases bleeding but does not protect against ischemic events. In the absence of other high-risk characteristics, patients with diabetes can be treated with short-term DAPT, supporting the guideline recommendation that decisions about DAPT duration should be based on careful analysis of individual ischemic and bleeding risks.