Risk model of aortic valve replacement after cardiovascular surgery based on a National Japanese Database

OBJECTIVES: The aims of this study were to investigate early results of aortic valve replacement (AVR) after cardiovascular surgery and create a risk model using a national database in Japan. METHODS: We used the Japan Adult Cardiovascular Surgery Database. Between 2008 and 2013, 2157 patients who underwent AVR for aortic stenosis after cardiovascular surgery or redo AVR were retrospectively analysed. RESULTS: The background of prior surgery (including overlapping cases) was as follows: coronary artery bypass grafting (CABG), 31.9%; valve, 67.5% and thoracic aorta, 9.0%. The mean age was 70.4. Concomitant procedures were as follows: CABG, 14.5%; mitral valve surgery, 29.9% and aortic surgery, 5.9%. The 30-day and operative mortality rates were 5.5 and 8.5%, respectively. Major morbidity occurred in 25.7%. The incidence rate of stroke was 3.8%, and that of pacemaker implantation was 3.7%. There were seven risk factors for both the operative mortality and composite outcome: age, active endocarditis, ejection fraction < 30%, New York Heart Association classification IV, mitral regurgitation ≥2, renal failure and other concomitant cardiac procedure. The C-indexes of operative mortality and the composite outcome were 0.761 and 0.709, respectively. CONCLUSIONS: We could identify risk factors predicting the operative mortality and composite outcome associated with AVR after prior cardiovascular surgery based on a national Japanese database. Early outcomes were acceptable despite these operations being associated with a higher risk than primary AVR. Our results may be informative when treating such high-risk patients.