Chansed Intraoperative Expression Of Ventricular Myosin Light Chain Predicts Heart Failure After Valve Replacement Surgery

BackgroundIt can be dificult to predict which patients will survive and recover cardiac function after valve replacement surgery. We hypothesized that the expression levels of ventricular myosin light chain (MLCv) might relect the severity of disease or the extent of irreversible myocardial damage and might be useful for predicting the postoperative course. Thus, the aim of this study was to explore the relationship between MLCv expression in specimens obtained during valve replacement surgery and the postoperative New York Heart Association (NYHA) class.MethodsThe levels of expression of the regulatory MLCv (MLC-2v) and MLC-lv in papillary muscle specimens from83patients who underwent valve replacement surgery for rheumatic valvular disease were evaluated by Western blot analysis. Cardiac function was assessed before and6months after surgery. ResultsThe preoperative expression of MLC-1v had positive linear correlation with the age, and negative linear correlation with the thickness of Left ventricular literal wall and the duration of disease. The preoperative expression of MLC-2v had positive linear correlation with the preoperative New York Heart Association (NYHA) classification, and negative linear correlation with the left ventricular end-systolic volume. Preoperative expression of MLC-1v and MLC-2v emerged as independent risk factors for NYHA classes III/IV at6mo after surgery. The area under the receiver operating characteristic (ROC) curve was0.91and0.84respectively.ConclusionThe preoperative level of myocardial MLCv expression predictive of patients' cardiac function after valve replacement surgery. This result suggests that future studies evaluating the use of preoperative specimens (such as biopsy or peripheral blood samples) for measurement of MLCv levels could lead to a valuable preoperative tool for the assessment of candidates for valve replacement.