On-pump versus off-pump coronary artery bypass surgery in patients older than 60 years: five-year follow-up of MASS III trial

BACKGROUND: We aim to evaluate in-hospital events and long-term clinical outcomes in patients over 60 years of age with stable coronary artery disease and preserved left ventricular ejection fraction undergoing off-pump or on-pump coronary artery bypass grafting. METHODS: The MASS III was a single-center randomized trial that evaluate 308 patients with stable coronary artery disease and preserved ventricular function assigned for: 155 to off-pump and 153 to on-pump CABG. Of this, 176 (58.3%) patients were 60 years or older at the time of randomization (90 of-pump and 86 on-pump). The primary short-term end point was a composite of myocardial infarction, stroke, and overall mortality occurring within 30 days after surgery or before discharge, whichever was later. The primary long-term end point was death from any cause within 5 years, non-fatal myocardial infarction between 30 days and 5 years, or additional revascularization between 30 days and 5 years. RESULTS: On-pump CABG had a higher incidence of 30-day composite outcome than off-pump CABG (15,1% and 5.6%, respectively; P = 0.036). However, after the multivariate analysis, this association lost statistical significance, P = 0.05. After 5-year follow-up, there were no significant differences between both strategies of CABG in the composite end points 16.7% and 15.1%; Hazard Ratio 1.07; CI 0.41 – 1.82; P = 0.71, for off-pump and on-pump CABG respectively. CONCLUSIONS: On-pump and off-pump CABG achieved similar results of combined events at short-term and 5-year follow-up. TRIAL REGISTRATION: Clinical Trial Registration Information—URL: http://www.controlled-trials.com. Registration number: ISRCTN59539154.