Preoperative Estimated Glomerular Filtration Rate is an Independent Predictor of Late Cardiovascular Morbidity after Mitral Valve Surgery

Abstract

Renal dysfunction affects outcomes of cardiac surgery, although its role in mitral valve operation has been limitedly documented. Two hundred and ten patients who underwent mitral valve operation between 2004 and 2011 were divided into 3 groups according to preoperative estimated glomerular filtration ratio (eGFR): group A (eGFR ≥60 ml/min/1.73 m(2), n = 102), group B (eGFR, 59-30 ml/min/1.73 m(2), n = 92) and group C (eGFR <30 ml/min/1.73 m(2), n = 16). Freedom from all-cause and cardiovascular death at 5 years was 77.2% and 93.0%, respectively. No significant differences existed between the 3 groups. In contrast, there was a significant difference in freedom from major adverse cardiovascular events (MACE) between groups (70.4%, 57.1%, and 42.8% in group A, B, and C, respectively; p = 0.008). By univariate and multivariate analysis, eGFR <60 ml/min/1.73 m(2) (HR: 1.92, 95% CI: 1.02-3.68, p = 0.044) and left ventricular ejection fraction <40% (HR: 2.69, 95% CI: 1.17-6.23, p = 0.02) were independent risk factors of MACE, although serum creatinine failed to represent an independent risk factor. Patients who underwent mitral valve surgery had acceptable perioperative and long-term survival, irrespective of preoperative renal function. However, eGFR <60 ml/min/1.73 m(2) was an independent predictor of late MACE.