Abstract 14976: Influence of Myocardial Viability on the Outcome of Patients with Coronary Artery Disease and Left Ventricular Dysfunction Undergoing Coronary Bypass Surgery With and Without Surgical Ventricular Reconstruction: Results of the Surgical Treatment for Ischemic Heart Failure (STICH) Trial
Background: In the STICH study, adding surgical ventricular reconstruction (SVR) to coronary bypass surgery (CABG) was not associated with a reduction in the rate of death or hospitalization for cardiac causes compared to results of CABG alone. We tested the hypothesis that the absence of viable myocardium identifies patients with coronary artery disease (CAD) and left ventricular (LV) dysfunction who have the greatest benefit with CABG + SVR compared to CABG alone.
Methods: Myocardial viability was assessed by single photon computed tomography (SPECT) in 267 of the 1,000 patients randomized to CABG or CABG + SVR in STICH. All had severe regional LV dysfunction involving the anteroapical wall. A 17-segment LV model was used and segments were determined to be viable based on pre-specified criteria. A patient was deemed as having viable myocardium if 11 or more LV segments were viable.
Results: Among the 267 patients, 226 (85%) were men, mean age 61±9 years. Mean LV ejection fraction was 27±5%, and 89% of patients had a previous myocardial infarction. Myocardial viability was identified in 191 (72%) of the study patients; the remaining 76 were classified as nonviable. Patients with and without viability were similar in age (61±10 vs. 62±9) and ejection fraction (27±6 vs. 28±5%). Patients without viability had larger LV end-diastolic and systolic volume indices than those with viability (143±53 vs. 115±41 and 112±48 vs. 85±38 ml/m2, respectively; p<0.0001 for both). However, at 3 years, there was no difference in mortality (19 vs. 22%, p=0.84) or the combined outcome of death or cardiac hospitalization (48 vs. 62%, p=0.17) between those with and those without viability. Of the 191 patients with viability, 99 (52%) underwent CABG + SVR and 92 (48%) underwent CABG alone. Of the patients without viability, 42 (55%) underwent CABG+ SVR and 34 (45%) underwent CABG alone. There was no significant interaction between outcome (death or death plus cardiac hospitalization), type of surgery, and survival.
Conclusion: In patients with CAD and severe regional LV dysfunction, assessment of myocardial viability does not identify patients who will benefit in terms of survival or cardiac hospitalization from adding SVR to CABG.
- © 2012 by American Heart Association, Inc.