Cardiac Surgery for Octogenarians - a Suitable Procedure? Twelve-Year Operative and Post-Hospital Mortality in 641 Patients over 80 Years of Age - Schmidtler, F W; Tischler, I; Lieber, M; Weingartner, J; Angelis, I; Wenke, K; Kemkes, B M; Gansera, B (The Thoracic and Cardiovascular Surgeon, 2008)