Long-term Survival in Elderly Patients after Coronary Artery Bypass Grafting Compared to the Age-matched General Population: A Meta-analysis of Reconstructed Time-to-Event Data.

Background:  Coronary artery disease (CAD) limits life expectancy compared to the general population. Myocardial infarctions (MIs) are the primary cause of death. The incidence of MI increases progressively with age and most MI deaths occur in the population older than 70 years. Coronary artery bypass grafting (CABG) may prevent the occurrence of new MIs by bypassing most CAD lesions, providing downstream "collateralization" to the diseased vessel, and consequently prolonging survival. We systematically assessed the survival-improving potential of CABG by comparing elderly CABG patients to the age-matched general population.

Methods:  Three databases were assessed. The primary and single outcome was long-term all-cause mortality. Time-to-event data of the individual studies were extracted and reconstructed in an overall survival curve. As a sensitivity analysis, summary hazard ratios (HRs) and 95% confidence intervals (CIs) for all individual studies were pooled and meta-analytically addressed. The control group was based on the age-matched general population of each individual study.

Results:  From 1,352 records, 4 studies (4,045 patients) were included in the analysis. Elderly patients (>70 years) who underwent CABG had a significantly lower risk of death in the follow-up compared to the general age-matched population in the overall survival analysis (HR: 0.88; 95% CI: 0.83, 0.94; p < 0.001: mean follow-up was 7 years).

Conclusion:  Elderly patients who undergo CABG appear to have significantly better long-term survival compared to the age-matched general population. This advantage becomes visible after the first year and underscores the life-prolonging effect of bypass surgery, which may eliminate the expected reduction in life expectancy through CAD.