Prophylactic aortic valve replacement in older patients for mild aortic stenosis during coronary bypass surgery

Coronary bypass surgery (CBS) is performed in many older patients who frequently also have mild calcific aortic stenosis. It is important that a correct assessment of the severity of aortic stenosis is done by calculating the aortic valve area. Mild aortic stenosis is aortic valve area >1.5 cm(2), >0.9 cm(2)/m(2); severe aortic stenosis is aortic valve area < or =1.0 cm(2), < or =0.6 cm(2)/m(2). Patients who have severe aortic stenosis should have aortic valve replacement (AVR) at the time of CBS. Patients with mild aortic stenosis should not have AVR simultaneously with CBS because: 1) patients having AVR+CBS have a higher operative and 10-year mortality; 2) prosthetic heart valves are associated with a complication rate of 2%-6% per year; and 3) only about 12% of patients with mild aortic stenosis will have developed severe aortic stenosis in 10 years. Performing AVR for mild aortic stenosis at the time of CBS will probably result in 91 unnecessary AVRs and 29 excess deaths in 10 years.