Obesity and the risk of late mortality after aortic valve replacement with small prosthesis

BACKGROUND: Whether obesity is related to late mortality with implantation of small aortic prosthesis remains to be clarified. This study was aimed to evaluate the effect of obesity on late survival of patients after aortic valve replacement (AVR) with implantation of small aortic prosthesis (size ≤ 21 mm). METHODS: From January 1998 to December 2008, 307 patients in our institution who underwent primary AVR with smaller prostheses survived the 30 days after surgery. Patients were defined as normal if body mass index (BMI) was < 24 kg/m(2), as overweight if BMI 24–27.9 kg/m(2), and as obese if BMI ≥ 28 kg/m(2). Data of New York Heart Association (NYHA) functional classification, left ventricular ejection fraction (LVEF), effective orifice area index (EOAI), and left ventricular mass index (LVMI) of the patients collected at the 3rd month (M), 6th M, 1st year (Y), 3rd Y, 5th Y, 8th Y after operation respectively. RESULTS: By multivariable analysis, obesity was an independent factor of late mortality (hazard ratio [HR]: 1.62; P = 0.01). The obesity and overweight group had more poor survival (p < 0.001) and higher proportion of NYHA class III/IV (p < 0.01) compared with the normal group. Lower EOAI and higher LVMI were found in obesity and overweight group, but we saw no significant difference about LVEF among the three groups. CONCLUSIONS: Obesity was associated with increased late mortality of patients after AVR with implantation of small aortic prosthesis. Being obese or and overweight may also affect the NYHA classification, even in the longer term. EOAI should be improved where possible, as it may reduce late mortality and improve quality of life in obese or overweight patients.