[Pre and perioperative factors determining early in-hospital mortality in patients over 75 years of age undergoing cardiac surgery]. / Factores pre y perioperatorios determinantes de la mortalidad precoz en pacientes mayores de 75 años sometidos a circulación extracorpórea.

INTRODUCTION AND OBJECTIVES: To know the in-hospital morbidity and mortality and the related factors in patients over 75 years old undergoing cardiac surgery. PATIENTS AND METHODS: A retrospective analysis was carried out in 252 out of 2043 consecutive patients (129 female, 123 male) over 75 years of age (mean age 77.8 years; range 75 to 89 years) undergoing open heart surgery from january 1, 1994 to november 30, 1997. Isolated aortic valve replacement was performed in 128 patients, 78 underwent isolated coronary artery bypass grafting and 46 combined surgery. Preoperative determinants of morbidity and mortality were analyzed. RESULTS: The overall hospital mortality was 15.1%, 13.2% in the aortic group, 12.8% in the coronary group and 23.9% in the combined surgery group. The overall morbidity rate was 38.6% and 25.8%, 34.2% in the aortic and coronary groups, respectively. Preoperative risk factors were prior surgery (p < 0.0004) and emergency operation (p < 0.04). In aortic valve replacement, NYHA class IV (p < 0.05), prior operation (p < 0. 01) and emergency surgery (p < 0.01) were determinant. Perioperative factors of early mortality were: prolonged cross-clamping > 60 min (p < 0.02), cardiopulmonary bypass time > 90 min (p < 0.002), need for inotropic drugs (p < 0.005) and postoperative complications (p < 0.00001). Mean postoperative length of hospital stay was 12.8 +/- 8. 5 days. CONCLUSIONS: Despite the greater rate of early morbimortality in patients over 75 years of age, cardiac surgery may be performed avoiding emergency surgery, functional grade IV and prolonged length of surgery.