Effectiveness of Medical and Revascularization Procedures as the Initial Strategy in Stable Coronary Artery Disease: A Cohort Study

Background: Coronary artery bypass grafting surgery (CABG) and percutaneous coronary intervention (PCI) are widely-used strategies in the management of stable coronary artery disease (CAD). Objective: To evaluate the prognosis of patients with stable CAD initially treated by medical therapy (MT), compared to the patients who were submitted to revascularization procedures. Methods: We conducted a prospective cohort study of 560 patients from an outpatient clinic in a tertiary hospital, with a mean follow-up of 5 years. Patients were classified into MT (n = 288), PCI (n = 159) and CABG (n=113) groups according to their initial treatment strategy. Primary endpoints were overall mortality and combined events of death, acute coronary syndrome, and stroke. Results: During follow-up, death rates were 11.1% in MT, 11.9% in PCI and 15.9% in CABG patients, with no statistical difference (hazard ratio [HR] for PCI, 1.05; 95% confidence interval [95%CI], 0.59 to 1.84; and HR for CABG, 1.20; 95% CI: 0.68 to 2.15). Combined outcomes occurred more often among patients initially submitted to PCI compared to MT (HR 1.50, 95% CI 1.05 to 2.14), and did not differ between MT and CABG patients (HR 1.24, 95% CI 0.84 to 1.83). Among patients with diabetes (n=198), PCI was the only therapeutic strategy predictive of combined outcomes (HR 2.14; 95% CI 1.25 to 3.63). Conclusion: In this observational study of stable coronary artery disease, there was no difference in overall mortality between initial medical therapy or revascularization surgery strategies. Patients initially treated with PCI had greater chance to develop combined major cardiovascular events.