Percutaneous coronary intervention (PCI) in patients with angina may have limited benefits on symptoms compared to evidence-based medical therapy, according to a meta-analysis.

PCI is widely used in the US for treatment of angina, despite evidence that it is no better than medical therapy for major cardiovascular outcomes according to previous meta-analyses. There has been no systematic appraisal of the evidence for symptomatic relief, however, and the authors of this paper aimed to address that gap. They carried out a comprehensive literature search for randomised trials that compared medical therapy with PCI in patients with stable angina (defined similarly to previous meta-analyses). They used results from the longest available follow-up for each study and a random-effects model; they stratified their analysis on the basis of follow-up duration (<1 year, 1-5 years, >5 years). Other factors used for stratification were inclusion of patients with recent myocardial infarction, coronary stent utilization, recruitment period, and utilization of evidence-based medications.

The initial literature search located 310 potentially relevant papers, of which 22 were reviewed in full and 14 were eligible for analysis (n=7,818). Overall, PCI was associated with an overall benefit on angina relief (odds ratio [OR], 1.69; 95% CI, 1.24 to 2.30), however there was heterogeneity across the studies and the beneficial effect was much greater in early trials compared to later ones. For trials recruiting before 1994, the summary OR was 3.38 (95% CI, 1.89 to 6.04), whereas for those recruiting after 2000, the summary OR was diminished and no longer significant (OR 1.13; 95% CI, 0.76 to 1.68). When the results were analysed according to the extent of evidence-based medication use, there was an inverse relationship between use of evidence-based therapies and incremental benefit from PCI.

The authors conclude that they found a benefit for PCI compared to medical therapies, however this was restricted to older trials. In contemporary trials with high use of evidence-based medications, the incremental benefit of PCI was not statistically significant. They note the potential limitations of their analysis, but suggest that the results support recent US guidelines that emphasise the need to optimise medical therapy before referring patients for coronary intervention.