Abstract 2935: Persistence of Severe Cardiac Dyssynchrony is Associated with Significant Morbidity and Mortality after CABG: a Study of 183 Patients with Ischemic Cardiomyopathy Undergoing CABG
Background. Presence of cardiac dyssynchrony (DYS) is associated with poor prognosis in patients with ischemic left ventricular (LV) dysfunction. Therefore, the objective of the present study was to assess the relationship between presence of DYS and clinical outcome in patients with ischemic cardiomyopathy undergoing surgical myocardial revascularization (CABG).
Methods: The study consisted of 184 consecutive patients with ischemic cardiomyopathy and dyspnea (age 66 ± 8y; 84% males, NYHA 2.5 ± 1, LV ejection fraction 30 ± 6%) undergoing CABG. DYS was calculated by tissue-Doppler imaging from measurements of regional electromechanical coupling times in basal segments of the left ventricle before and within 7 days after CABG. According to composite clinical endpoint (death from any cause, hospitalization for heart failure, NYHA class and global assessment) patients were classified as responders (improved in composite endpoint) or nonresponders (worse or unchanged).
Results. At the end of follow-up (427 ± 259 days), 101 patients were classified as responders and 83 as nonresponders (19 deaths, 34 hospitalizations, 30 clinically unimproved). Nonresponders showed higher follow-up DYS than responders (95 ± 69 ms vs. 36 ± 27 ms, p < 0.0001). Persistence of severe DYS (72 ms and more) after CABG was associated with 78% occurence of composite endpoinds. In contrast, only 21% of patients without post-CABG DYS (< 72 ms) were classified as nonresponders. Furthermore, patients with persistent DYS had significantly shorter event-free and cummulative survival and less “happy” days out of the hospital than patients without DYS (all p < 0.0001). Finaly, responders showed significant reverse LV remodeling as compared to nonresponders (LV end-systolic volume change baseline vs. 1-year follow-up −25 ± 35ml vs. 4 ± 36 ml, p < 0.0001; LV ejection fraction change 14 ± 9% vs. 3 ± 7%, p < 0.0001).
Conclusions. Persistence of severe dyssynchrony after CABG is associated with unfavorable clinical and functional outcomes despite revascularization. These results call for the prospective study testing use of cardiac resynchronization therapy in patients with severe ischemic dysfunction and persistent cardiac dyssynchrony after CABG.