Long-term absolute and relative survival after aortic valve replacement: a prospective cohort study

Abstract

Background: Aortic valve replacement is one of the most common cardiac surgical procedures, especially in elderly patients. Whether or not there is a net life gain over a long period of time is a matter for debate.

Objective: To compare survival of patients with that of the age, sex, and follow-up year-matched normal population (relative survival).

Design: Single-centre, prospectively collected data.

Setting: Tertiary care centre, Vienna, Austria.

Patients: We enrolled 1848 patients undergoing elective aortic valve replacement between 1997 and the end of 2008.

Interventions: None.

Main outcome measurement: Relative survival at the end of 2011 as determined by relative Cox regression analysis.

Results: Sixty-nine patients (3.7%) died within the first 30 days. Another 70 patients (3.8%) died within the first year and 429 (23.2%) died during the remaining follow-up period. The longest follow-up period was 14 years (median, 5.8; interquartile range, 3.2 to 8.9). Medical risk indicators for relative survival were diabetes mellitus [hazard ratio 1.69, 95% confidence interval, CI 1.37 to 2.07, P<0.001], pulmonary disease (hazard ratio 1.45, 95% CI 1.16 to 1.81, P=0.001), history of atrial fibrillation (hazard ratio 1.35, 95% CI 1.10 to 1.66, P=.005) and angiotensin-converting enzyme inhibitor medication (hazard ratio 1.21, 95% CI 1.02 to 1.44, P=0.031). Perioperative risk indicators were urgent surgery (hazard ratio 1.40, 95% CI 1.00 to 1.94, P=0.047), resternotomy at 48 h or less (hazard ratio 1.87, 95% CI 1.29 to 2.70, P=0.001), resternotomy at more than 48 h (hazard ratio 1.80, 95% CI 1.32 to 2.45, P<0.001), blood transfusion (hazard ratio 1.06, 95% CI 1.01 to 1.12, P=0.018) and renal replacement therapy (hazard ratio 2.02, 95% CI 1.41 to 2.90, P<0.001). Relative survival was highest in the oldest age quartile (76 to 94 years) and lowest in the youngest (19 to 58 years) (hazard ratio 0.27, 95% CI 0.21 to 0.36; P<0.001).

Conclusion: Patients who survived the first year after aortic valve replacement had a similar chance of survival as the matched normal population. Relative survival benefit was higher in the oldest age quartile.