Effectiveness of medical and revascularization procedures as the initial strategy in stable coronary artery disease : a cohort study

Abstract

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.

Fundamento: A cirurgia de revascularização miocárdica (CRM) e a intervenção coronária percutânea (ICP) são estratégias amplamente utilizadas no manejo da doença arterial coronariana (DAC) estável. Objetivo: Avaliar o prognóstico de pacientes com DAC estável inicialmente tratada com terapia médica (TM), em comparação com os pacientes submetidos a procedimentos de revascularização. Métodos: Estudo prospectivo de coorte com 560 pacientes ambulatoriais de um hospital terciário com seguimento médio de 5 anos. Os pacientes foram classificados nos grupos TM (n = 288), ICP (n = 159) e CRM (n = 113) de acordo com sua estratégia inicial de tratamento. Os desfechos primários foram mortalidade global e eventos combinados de morte, síndrome coronária aguda e AVC. Resultados: Durante o seguimento, as taxas de mortalidade foram de 11,1% em TM, 11,9% em ICP e 15,9% em pacientes submetidos à CRM, sem diferença estatística (Hazard Ratio [HR] para ICP, 1,05; Intervalo de Confiança de 95% [IC95%], 0,59 a 1,84; e HR para CRM, 1,20; IC95%, 0,68 a 2,15). Os desfechos combinados ocorreram com maior frequência entre os pacientes inicialmente submetidos à ICP em relação à TM (HR 1,50, IC 95% 1,05 a 2,14) e não diferiram entre TM e CRM (HR 1,24, IC95% 0,84 a 1,83). Entre os pacientes com diabetes (n = 198), a ICP foi a única estratégia terapêutica preditiva de desfechos combinados (HR 2,14; IC 95%: 1,25 a 3,63). Conclusão: Neste estudo observacional de doença arterial coronariana estável, não houve diferença na mortalidade global entre as estratégias iniciais de terapia médico ou de cirurgia de revascularização. Os pacientes inicialmente tratados com ICP tiveram maior chance de desenvolver eventos cardiovasculares maiores combinados.