This review concluded that for dialysis patients with end stage renal disease, drug-eluting stents in percutaneous coronary interventions significantly reduced target lesion revascularisation when compared with bare metal stents. Risks of mortality and myocardial infarction were similar. The reliability of the conclusions is unclear given the limited evidence of uncertain quality and the presence of statistical heterogeneity.

To evaluate the safety and effectiveness of percutaneous coronary intervention with drug-eluting stents versus bare metal stents in dialysis patients with end stage renal disease.

PubMed and The Cochrane Library databases and Google Scholar were searched from January 2002 to January 2009 for articles published in English. Search terms were reported. Bibliographies of relevant articles were handsearched.

Comparative studies of percutaneous coronary intervention with drug-eluting stents (DES) versus bare metal stents (BMS) in patients with end stage renal disease on dialysis were eligible for inclusion. Primary outcomes were mortality, myocardial infarction and target lesion revascularisation (TLR). The secondary outcome was late luminal loss. Other eligible outcomes were in-hospital mortality and in-hospital myocardial infarction. Studies were excluded if they were ongoing, unpublished or case reports and if outcomes were not clearly reported or were impossible to extract. Length of follow-up ranged from nine to 12 months. The included studies were performed in USA or Japan.

The authors did not state how many reviewers performed the selection.

No formal validity assessment was performed.

Two reviewers independently extracted data. No disagreement was reported. Continuous variables were extracted as means (with standard deviation) or median (with range) and categorical variables as N (percentage). Data were used to calculate odds ratios (OR) and 95% confidence intervals (CI).

Odds ratios were pooled using a random-effects model since there was significant heterogeneity for most study outcomes. Statistical heterogeneity was determined using the Cochrane Q statistic and I² tests and was considered to be significant if p<0.10 and/or I²≥50%. One study provided data for target vessel revascularisation and not for TLR; this data was used in the meta-analysis of TLR.

Five relevant comparative non-randomised studies were identified (n=641, range 74 to 204).

At follow-up, pooled analyses found: a significantly lower risk of TLR (OR 0.50, 95% CI 0.27 to 0.93, I²=48%; five studies) for drug-eluting stents versus bare metal stents; a non-significant trend for a lower risk of late luminal loss (I²=58%; three studies); and no significant difference in the rates of all-cause mortality or myocardial infarction (five studies with no significant heterogeneity for either analysis).

In-hospital clinical outcomes at 30 days were reported for three studies that gave no significant differences in mortality or myocardial infarction for drug-eluting stents versus bare metal stents. There was significant heterogeneity for the analysis of myocardial infarction, but not for mortality.

In end stage renal disease patients on dialysis, percutaneous coronary intervention with implantation of drug-eluting stents reduced TLR and late luminal loss compared with bare metal stents. There was no increased risk of mortality or myocardial infarction with use of drug-eluting stents.

The review addressed a well-defined question in terms of participants, interventions and relevant outcomes, but relevant information with respect to included study designs was not reported. Relevant databases were searched. Only studies published in English were considered and so some relevant studies may have been missed. Study quality and publication bias were not assessed. There were efforts to reduce errors and bias in data extraction; it was not reported whether this applied to study selection. Few study details were reported, but details of the length of follow-up were given. Statistical heterogeneity was assessed and there was evidence for heterogeneity with some outcomes. The statistical method used for the meta-analysis seemed appropriate. The authors noted that caution was needed when interpreting the results of this review due to the small number of patients and primary study limitations. In view of limitations that arose from the lack of reporting of the review process and study details, uncertainties about the quality of included studies, presence of statistically heterogeneity, the small number of included studies and small samples, the extent to which the authors’ conclusions are reliable is unclear.

The authors did not state any implications for practice.

Research: The authors identified a need for large well-designed randomised controlled trials to determine potential advantages or disadvantages of percutaneous coronary intervention with drug-eluting stents and establish the strategy of management in end stage renal disease patients who underwent percutaneous coronary intervention.

None 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.