Impact of Lateral Wall Myocardial Infarction on Outcomes After Surgical Ventricular Restoration

Background: Surgical ventricular restoration (SVR) attempts to reverse negative ventricular remodeling after anterior myocardial infarction (MI). However, the impact of lateral wall MI (LMI) on SVR outcomes is unknown. Methods: We retrospectively reviewed SVR patients between January 2002 and December 2005. Patients were grouped into those with and without LMI. Lateral wall myocardial infarction patients were further subdivided into those with anterior-lateral and anterior-inferior-lateral MI. Extent of LMI was assessed intraoperatively as less than 25%, 25% to 49%, 50% to 75%, and more than 75% of the lateral wall. Follow-up was 100%. Results: Seventy-eight patients underwent SVR; all had anterior MI. Forty-one percent (32 of 78) had LMI; 19% (6 of 32) had anterior-lateral MI; and 81% (26 of 32) had anterior-inferior-lateral MI. The remaining 59% (46 of 78) comprised the no-LMI group. Among LMI patients, 6% (2 of 32) had more than 75% involvement of the lateral wall. Lateral wall myocardial infarction patients were more likely to be New York Heart Association (NYHA) class IV preoperatively. There were 2 operative deaths in the LMI group. Surgical ventricular restoration significantly improved ejection fraction and end-systolic volume index for patients with and without LMI. Sixty-three percent of patients (20 of 32) with LMI and 83% of patients (38 of 46) without LMI improved to NYHA class I/II at follow-up. Three-year Kaplan-Meier survival for LMI patients was 67%, which trended toward a decreased survival versus patients without LMI (85%; p = 0.18). Three-year Kaplan-Meier survival for anterior-lateral MI patients was 100%, and for anterior-inferior-lateral MI patients, it was 60%. Lateral wall myocardial infarction involving >50% of the lateral wall was a significant predictor of mortality (odds ratio = 8.3, 95% confidence interval: 1.3 to 54.1, p = 0.03). Conclusions: Cardiac function is improved after SVR for patients with and without LMI. However, anterior-inferior-lateral MI and LMI involving 50% or more of the lateral wall may predict mortality. Our results should prompt further investigation to determine the role of SVR for patients with LMI.