Revascularization in Stable Coronary Artery Disease | Journal Scan
What are the comparative effects of coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) on long-term mortality and morbidity by performing a meta-analysis of all randomized clinical trials of the current era that compared the two treatment techniques in patients with multivessel disease?
A systematic literature search was conducted for all randomized clinical trials directly comparing CABG with PCI. To reflect current practice, the investigators included randomized trials with one or more arterial grafts used in at least 90%, and one or more stents used in at least 70% of the cases that reported outcomes in patients with multivessel disease. Numbers of events at the longest possible follow-up and sample sizes were extracted.
A total of six randomized trials enrolling 6,055 patients were included, with a weighted average follow-up of 4.1 years. There was a significant reduction in total mortality with CABG compared with PCI (I2 = 0%; risk ratio [RR], 0.73; 95% confidence interval [CI], 0.62-0.86) (p < 0.001). There were also significant reductions in myocardial infarction (I2 = 8.02%; RR, 0.58; 95% CI, 0.48-0.72) (p < 0.001) and repeat revascularization (I2 = 75.6%; RR, 0.29; 95% CI, 0.21-0.41) (p < 0.001) with CABG. There was a trend toward excess strokes with CABG (I2 = 24.9%; RR, 1.36; 95% CI, 0.99-1.86), but this was not statistically significant (p = 0.06). For reduction in total mortality, there was no heterogeneity between trials that were limited to and not limited to patients with diabetes or whether stents were drug-eluting or not. Owing to lack of individual patient-level data, additional subgroup analyses could not be performed.
The authors concluded that in patients with multivessel coronary disease, compared with PCI, CABG leads to an unequivocal reduction in long-term mortality and myocardial infarctions and to reductions in repeat revascularizations, regardless of whether patients are diabetic.
This meta-analysis suggests that PCI in addition to medical therapy confers little benefit over medical therapy alone for patients with stable coronary artery disease (CAD). Patients with stable angina and multivessel CAD appear to have better outcomes from CABG than PCI. It should be noted that this meta-analysis included only a small number of studies, limiting the power to examine study heterogeneity. Also, patient follow-up duration was variable, creating problems when combining outcomes data, and may have limited generalizability due to changes in revascularization technology and strategies over time. When counseling patients, clinicians must consider limitations in the meta-analyses and the primary trials they summarize because individual patients may not resemble participants included in the studies. In the end, an individualized therapeutic decision made between clinician and patient informed by the best available evidence is indicated. Better evidence provided by pragmatic clinical trials could assist in making more informed decisions in the future.
Keywords: Coronary Artery Bypass, Coronary Artery Disease, Percutaneous Coronary Intervention, Stents, Stroke, Diabetes Mellitus, Myocardial Infarction
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