Risk factors associated with perioperative myocardial damage in patients with severe aortic stenosis.

Aim. Few studies have been performed about the risk factors associated with perioperative myocardial damage in patients undergoing valve surgery for severe aortic stenosis. Methods. To assess the prevalence of perioperative myocardial damage, we studied 103 consecutive patients with aortic stenosis. Perioperative myocardial damage (PMD) was diagnosed by both enzymatic data of peak creatine kinase iso-enzyme (CK-MB) and new appearance of electrocardiographic abnormality. PMD was noticed in 16 patients, and PMD was not noticed in 87 patients. A stepwise multiple logistic regression model was used to investigate predictors of PMD in several categorized parameters such as preoperative data, cardioplegic delivery method, and aortic clamping time. Results. A multivariate analysis identified that cardioplegic delivery method, preoperative left ventricular (LV) wall thickness, and aortic clamping time were independent predictors of PMD. The incidence of PMD in the combined antegrade and continuous retrograde delivery method was significantly lower than that in antegrade delivery method (odds ratio 0.11, CI 0.02-0.61, p=0.011). The peak CK-MB value of the combined antegrade and retrograde method was significantly lower than that of the antegrade method (48 +/- 24 Vs 71 +/- 50 IU/L; 24 Vs 71 +/- 50 IU/L; p=0.009). The peak lactate-dehydrogenase value of the combined method was significantly lower than that of the antegrade method (590 249 vs 1 058 656 IU/L; p < 0.001). The combined method decreased the incidence of PMD in patients with increased total wall thickness. Conclusion. Cardioplegic delivery method, LV total wan thickness, and aortic clamping time were independent predictors for PMD. Combined antegrade and continuous retrograde delivery method may be an important factor to obtain adequate myocardial protection.