[Aortic valve replacement in patients over 70 years old: determinants of early death]

There is controversy regarding the risk factors associated with early death in geriatric patients undergoing aortic valve replacement. We analyzed the risks in these patients and established an accurate model for predicting in-hospital mortality.

Univariate and multivariate analyses were made of the risk factors associated with early death in a group of 129 patients older than 70 years who underwent aortic valve replacement (May 1994-June 2001). The variables obtained by multivariate logistic regression were combined to produce an equation for the prediction of early death. The equation was tested using a receiver operating characteristic curve.

Univariate analysis identified four factors related to early death: NYHA III-IV (p < 0.0001), ejection fraction < 40% (p < 0.05), aortic regurgitation (p < 0.05) and high left ventricular mass index (p < 0.05). Multivariate analysis revealed three independent risk factors: NYHA III-IV (p < 0.01), aortic regurgitation (p < 0.05), and small body surface area (p < 0.05). A lower mortality was observed in patients with a larger body surface area (0% for > 1.90 m2, 20% for < 1.40 m2). The estimated mortality with the predictive model was 7.06%, which was similar to the observed mortality of 7.80% (area under the ROC curve 0.87) and better than estimates obtained with the EuroSCORE (6.5%; area under the ROC curve 0.56).

Risk factors associated with early death after aortic valve replacement in geriatric patients include functional status, aortic regurgitation, and small body surface area. Our model based on these factors accurately predicted operative mortality in our patients. Gender, prosthesis size, and pump time were not identified as risk factors.