Resultados del reemplazo valvular aórtico con prótesis mecánica en el Instituto Nacional del Tórax / Early and long term results of mechanical aortic valve replacement at the Instituto Nacional del Torax in Chile

RESUMO

Background: Mechanical aortic valve replacement (AVR) results have been published extensively in industrialized countries. Aim: To assess our immediate and late results in patients subjected to AVR. Patients and Methods: We retrospectively studied 194 patients subjected to isolated AVR between 1995 and 2003. Mean age was 57 ± 13 years and 119 (61%) were male. One hundred thirty nine (73%) were in functional class III-IV, 20 (10%) had a previous cardiac operation and 25 (13%) were operated as an emergency. Surgical indication was stenosis in 110 (58%), regurgitation in 49 (26%) and stenosis/regurgitation in 31 (16%). Etiology was bicuspid valve 56 (29%), degenerative lesions 55 (28%), rheumatic valve disease 38 (20%) and endocarditis 27 (14%). Medtronic Hall was the most common prosthesis used in 157 patients (81%). Mean cardiopulmonary bypass time 97 ± 29 min and mean cross clamp time was 69 ± 21 min. Results: Operative mortality was 4.6% (3% in elective surgery, 16% in emergency surgery and 0% in reoperations). Follow-up was complete in 100% of cases, totalizing 636 patients-year. Survival was 91 ± 2%, 80 ± 4% and 73 ± 6%, at 1, 5 and 7 years, respectively. Multivariate risk analysis identified renal failure and endocarditis as predictors of early and late mortality. During follow up, the linear incidence rate for hemorrhage was 3.29% /patients-year, thromboembolism 2.04% patients-year and endocarditis 1.1% patients-year. Conclusions: AVR has low overall and elective mortality. Midterm survival is good but linear event rates related to anticoagulant treatment are higher than those previously published in industrialized countries. Renal failure and endocarditis were risk factors for early and late death.