Background: Previous studies showed 75% mortality before hospital discharge in patients with a ventricular assist device (VAD) placed for post-cardiac surgery shock. We examined a large national clinical database to assess trends in the incidence of post-cardiac surgery shock requiring VAD implantation, survival rates, and risk factors for mortality.
Methods and results: We identified patients undergoing a VAD procedure after cardiac surgery at US hospitals participating in the Society of Thoracic Surgeons' National Cardiac Database during the years 1995 to 2004. Baseline characteristics and operative outcomes were analyzed in 2.5-year increments. Logistic regression modeling was performed to provide risk-adjusted operative mortality and morbidity odds ratios. A total of 5735 patients had a VAD placed during the 10-year period (0.3% cardiac surgeries). Overall survival rate to discharge after VAD placement was 54.1%. With the earliest period (January 1995 through June 1997) used as reference, the mortality odds ratio declined to 0.72 (July 1997 through December 1999) and eventually to 0.41 (July 2002 through December 2004; P<0.0001). The combined mortality/morbidity odds ratio also declined, to 0.84 and 0.48 over identical periods (P<0.0001). Preoperative characteristics associated with increased mortality were urgency of procedure, reoperation, renal failure, myocardial infarction, aortic stenosis, female sex, race, peripheral vascular disease, New York Heart Association class IV, cardiogenic shock, left main coronary stenosis, and valve procedure (c index=0.755).
Conclusions: After adjustment for clinical characteristics of patients requiring mechanical circulatory support, rates of survival to hospital discharge have improved dramatically. Insertion of a VAD for post-cardiac surgery shock is an important therapeutic intervention that can salvage most of these patients.