The authors concluded that no difference could be identified between abciximab and small-molecule glycoprotein IIb/IIIa inhibitors in patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction. The authors’ conclusions reflected the evidence presented, but incomplete reporting of review methods and lack of reporting of trial validity make it difficult to assess their reliability.

To compare abciximab with small-molecule glycoprotein IIb/IIIa inhibitors for patients with ST-segment elevation myocardial infarction who are undergoing primary percutaneous coronary intervention.

MEDLINE, EMBASE, Web of Knowledge, Current Contents, International Pharmaceutical Abstracts and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from 2000 to October 2008. Search terms were reported. In addition, searches were conducted in abstract lists from 2008 scientific meetings of three specified societies, published reviews, editorials and internet-based information sources.

Randomised controlled trials (RCTs) of patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction were eligible for inclusion if they compared abciximab with small-molecule glycoprotein IIb/IIIa inhibitors. Eligible trials had to assess all-cause mortality, reinfarction and bleeding at 30 days. The review also assessed medium-term mortality and reinfarction and angiographic outcomes (thrombolysis in myocardial infarction-3 flow and ST resolution).

All but one of the included trials compared abciximab with tirofiban; one trial used eptifibatide. In all of the trials, the majority of patients were male (range 69 to 84%). The mean/median age of included patients ranged from 59 to 65 years, and between 12 and 19% had diabetes. The mean/median symptom to balloon time ranged from 96 to 263 minutes. The included trials used slightly different definitions of reinfarction and bleeding (details were reported).

The authors did not state how papers were selected for the review.

Validity was assessed by considering concealment of allocation during randomisation, intention-to-treat analysis and blinded assessment of outcomes.

It was not clear whether methods used for data extraction also applied to the validity assessment.

Outcome data were extracted to complete 2x2 tables and used to calculate odds ratios (OR) on an intention-to-treat basis.

Two reviewers independently extracted data and resolved disagreements by consensus.

Pooled odds ratios and 95% confidence intervals (CI) were calculated using fixed-effect and random-effects models; since results were similar, results from fixed-effect models were preferentially reported. Heterogeneity was assessed using the Cochran Q test. Influence analysis was used to examine the effect of each trial in turn.

The possibility of publication bias was explored using funnel plots and the fail-safe N statistic.

Five RCTs were included (n=2,138 patients). The duration of follow-up ranged from 30 to 240 days.

There was no statistically significant difference between abciximab and small-molecule glycoprotein IIb/IIIa inhibitors for all-cause mortality, reinfarction or major or minor bleeding at 30 days. No significant heterogeneity was found for any of these analyses. Results were similar after omitting each trial in turn.

There was also no statistically significant difference between abciximab and small-molecule glycoprotein IIb/IIIa inhibitors for mortality or reinfarction at eight months (both analyses based on 919 patients).

There was no evidence of publication bias.

No difference could be identified between abciximab and small-molecule glycoprotein IIb/IIIa inhibitors in patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction.

The review question was clearly stated and inclusion criteria were appropriately defined. Several relevant sources were searched. Attempts were made to minimise publication bias, but it was not clear if attempts were made to minimise language bias. The potential for publication bias was assessed, but the small number of trials limited the usefulness of the funnel plot. Methods were used to minimise reviewer errors and bias in the extraction of data, but it was not clear whether similar steps were taken in study selection and validity assessment.

Although study validity was assessed, results of the assessment were not reported, which made it difficult to judge the likely reliability of the results. Appropriate methods were used for the meta-analyses; heterogeneity was assessed. Some limitations of the review were discussed including low event rates and the absence of long-term data.

The authors’ conclusions reflected the evidence presented, but incomplete reporting of review methods and lack of reporting of trial validity make it difficult to assess their reliability.

Practice: The authors stated that the review findings provide support for the current use of small-molecule glycoprotein IIb/IIIa inhibitors in patients undergoing primary percutaneous coronary intervention.

Research: The authors did not state any implications for research.

Not stated.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.