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

Purpose: Renal dysfunction affects outcomes of cardiac surgery, although its role in mitral valve operation has been limitedly documented. Methods: 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). Results: 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. Conclusion: 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.