Impact of varying degrees of renal dysfunction on transcatheter and surgical aortic valve replacement

BackgroundRenal impairment portends adverse outcomes in patients undergoing valvular heart surgery. The relationship between renal dysfunction in patients undergoing transcatheter aortic valve replacement (TAVR) is incompletely understood.MethodsA retrospective review of 1336 patients undergoing surgical aortic valve replacement (SAVR; 2002-2012) and 321 patients undergoing TAVR (2007-2012) was performed. Patients were divided into 3 glomerular filtration rate (GFR) groups: GFR greater than 60 mL/min, GFR 31 to 60 mL/min, and GFR 30 mL/min or less. Logistic and linear regression analysis was performed to estimate the TAVR effect on outcomes. Risk adjustments were made using the Society for Thoracic Surgeons (STS) predicted risk of mortality (PROM).ResultsTAVR patients were older (82 vs 65 years; P < .001), had a poorer ejection fraction (48% vs 53%; P < .001), were more likely female (45% vs 41%; P = .23), and had a higher STS PROM (11.9% vs 4.6%; P < .001). In-hospital mortality rates for TAVR and SAVR were 3.5% and 4.1%, respectively (P = .60), a result that marginally favors TAVR after risk adjustment (adjusted odds ratio = .52, P = .06). In SAVR patients, worsening preoperative renal failure was associated with increased in-hospital mortality (P = .004) and hospital (P < .001) and intensive care unit (ICU) (P < .001) lengths of stay. In contrast, worsening renal function did not influence in-hospital mortality (P = .78) and hospital (P < .23) and ICU (P = .88) lengths of stay in TAVR patients.ConclusionsWorsening renal function was associated with increased in-hospital mortality, hospital length of stay, and ICU length of stay in SAVR patients, but not in TAVR patients. This unexpected finding may have important clinical implications in patients with aortic stenosis and preoperative renal dysfunction.