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.

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.