Glycoprotein IIb/IIIa inhibitors with or without thienopyridine pretreatment improve outcomes after primary percutaneous coronary intervention in high-risk patients with ST elevation myocardial infarction--a meta-regression of randomized controlled trials

Abstract

Background: Recent studies have casted a doubt on usefulness of routine glycoprotein IIb/IIIA inhibitors (GPI) in patients, pretreated with aspirin and clopidogrel, undergoing primary percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI).

Objective: We aimed to investigate the effect of relevant factors, particularly thienopyridine pretreatment, on clinical benefit from GPI in randomized controlled trials (RCT).

Methods: We searched electronic databases for RCT comparing GPI to control in patients with STEMI undergoing primary PCI. Relevant study covariates and clinical outcomes were extracted. A random effect cumulative and subgroup analyses (thienopyridine non-pretreated studies vs. pretreated studies) were performed. A weighted random effect meta-regression to determine the effect of thienopyridine pretreatment, enrollment year, control group mortality, and ischemic time on mortality benefit from GPI use was conducted.

Results: Twenty studies (9 non-pretreated, 11 pretreated) with a total of 7,414 patients (3,811 GPI, 3,603 control) were included. GPI use reduces mortality (risk ratio, RR = 0.75 95% confidence interval (CI) 0.57-0.97, P = 0.03), target vessel revascularization (TVR) (RR = 0.63, 95% CI 0.50-0.80, P = 0.0002), but not reinfarction (RR = 0.66, 95% CI 0.44-1.0, P = 0.05) at 30 days. There was no effect of thienopyridine pretreatment on reduction in mortality (P = 0.39), reinfarction (P = 0.46), or TVR (P = 0.95) in subgroup analysis. Meta-regression analyses showed significant effect of control group mortality risk (B = -12.15, P = 0.034) but not of thienopyridine pretreatment, enrollment year or control group ischemic time on mortality reduction from GPI use.

Conclusion: The benefit from GPI use in primary PCI for STEMI appears to depend on mortality risk, and not on thienopyridine pretreatment.