This article is more than 5 years old. Information may no longer be current.
Prolonged post-PCI DAPT may reduce late mortality in some patients with diabetes
Prolonged dual antiplatelet therapy improved late mortality outcomes in certain patients with diabetes who were treated with drug-eluting stents, according to recent findings.
The researchers used Veterans Affairs data for 28,849 patients undergoing PCI between 2002 and 2006 to compare the effect of prolonging clopidogrel therapy for more than 12 months after PCI with that of 12 months or less of clopidogrel in patients with diabetes.
The analysis included 16,332 patients without diabetes, 9,905 patients with diabetes treated with oral medications or dietary interventions, and 2,612 patients with diabetes treated with insulin. Patients were stratified by stent type and assessed for clinical outcomes up to 4 years after PCI.
All-cause mortality or MI served as the primary endpoints.
Prolonged clopidogrel therapy reduced mortality risk in patients with diabetes who were treated with insulin and DES (HR = 0.59; 95% CI, 0.42-0.82). The risk for a composite of death or MI also was reduced by extended clopidogrel in this patient population (HR = 0.67; 95% CI, 0.49-0.92).
Among patients with diabetes who were treated with DES and without insulin, prolonged clopidogrel also reduced mortality risk (HR = 0.61; 95% CI, 0.48-0.77) and the risk for death or MI (HR = 0.61; 95% CI, 0.5-0.75).
Patients without diabetes and those treated with bare-metal stents did not benefit from longer clopidogrel therapy, the researchers wrote.
Mortality was lower with DES compared with BMS among patients not requiring insulin who were treated with prolonged clopidogrel (P for interaction = .03). Similarly, risk for death or MI was lower with DES vs. BMS in this population (P for interaction = .005). In the insulin treatment group, researchers observed trends toward reduced mortality (P for interaction = .055) and death or MI (P for interaction = .19) among patients receiving prolonged clopidogrel and DES vs. BMS.
In an editorial comment, John A. Bittl, MD, of the interventional cardiology section of Munroe Regional Medical Center in Ocala, Florida, described the trial as a “fine observational study,” but noted that observational studies lack the power of randomization.
“In an observational analysis, something other than chance leads to early DAPT discontinuation and potentially puts a subject in double jeopardy from stopping therapy early and having an underlying condition such as major surgery or bleeding, leading to platelet activation and hyperfibrinogenemia,” he wrote.
Bittl suggested that the failure to demonstrate a benefit in the BMS arm reduces support for extended DAPT among patients with diabetes in current practice. “Before prolonged DAPT can be routinely recommended for diabetic patients undergoing stent implantation, additional investigation is needed to define the pathogenetic links between the metabolic changes and clinical manifestations of diabetes mellitus, and dedicated clinical trials are needed to identify best practices,” he wrote. – by Rob Volansky
Disclosure: One researcher reports receiving research grants from Medtronic and The Medicines Company. Bittl reports no relevant financial disclosures.