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Failure to improve left ventricular function after coronary revascularization for ischemic cardiomyopathy is not
H Samady1, J A Elefteriades, B G Abbott
1Department of Internal Medicine, Section of Cardiovascular Medicine , Yale University School of Medicine, New Haven, CT 06520-8042, USA.
Insights
Coronary artery bypass grafting (CABG) outcomes in patients with ischemic cardiomyopathy are similar whether or not left ventricular (LV) function improves post-surgery. Effective revascularization protects cardiac patients, regardless of LV ejection fraction (LVEF) changes.
Area of Science:
- Cardiology
- Cardiac Surgery
- Myocardial Viability
Background:
- Preoperative assessment of viable myocardium is crucial for patients with ischemic cardiomyopathy undergoing coronary artery bypass grafting (CABG).
- Improved left ventricular (LV) function post-CABG can enhance patient outcomes, but the impact of unchanged LV function is less understood.
Purpose of the Study:
- To investigate the association between the improvement of left ventricular ejection fraction (LVEF) after CABG and patient outcomes.
- To determine if a lack of LVEF improvement post-CABG correlates with poorer long-term prognosis.
Main Methods:
- Compared outcomes in patients with ischemic LV dysfunction (LVEF ≤ 0.30) who did and did not show significant LVEF improvement after CABG.
- Assessed pre- and post-CABG LVEF in 104 patients, categorizing them into groups with LVEF improvement (Group A) and no significant change (Group B).
- Monitored survival free of cardiac death and symptom scores at a mean follow-up of 32 months.
Main Results:
- No significant differences in baseline characteristics or intraoperative variables were observed between groups.
- Group A showed a significant LVEF increase (0.24 to 0.39), while Group B had no significant change (0.24 to 0.23).
- Postoperative symptom improvement was similar in both groups, and survival free of cardiac death was comparable (93% in Group A vs. 94% in Group B).
Conclusions:
- Lack of global LVEF improvement after CABG is not associated with poorer outcomes compared to patients with improved LVEF.
- Effective myocardial revascularization, even without immediate functional improvement, appears to protect against future cardiac events.
- The study suggests that successful revascularization is a key determinant of long-term survival in ischemic cardiomyopathy patients post-CABG.
Abstract:
Background-Preoperative identification of viable myocardium in patients with ischemic cardiomyopathy is considered important because CABG can result in recovery of left ventricular (LV) function. However, the hypothesis that lack of improvement of LV function after CABG is associated with poorer patient outcome is untested. Methods and Results-Outcome was compared in patients with ischemic LV dysfunction (LVEF =0.30) with and without improvement in LVEF after CABG. Of 135 consecutive patients, 128 (95%) survived CABG and 104 (77%) had pre- and post-CABG LVEF assessment. Of these 104 patients, 68 (65%) had >0.05 increase in LVEF (group A) and 36 (35%) had no significant change, or =0.05 decrease in LVEF (group B) compared with pre-CABG LVEF. No significant differences existed in age, gender, comorbidities, baseline symptoms, baseline LVEF, or intraoperative variables between groups A and B. Group A increased LVEF from 0.24+/-0.05 to 0.39+/-0.1 (P<0.005). In Group B, LVEF did not change significantly postoperatively, 0.24+/-0.05 to 0.23+/-0.06 (P=NS). Postoperative improvement in angina and heart failure scores were similar between the 2 groups. Survival free of cardiac death was similar for both groups (93% in group A and 94% in group B, P=NS) at a mean follow-up of 32+/-23 months. Conclusions-Lack of improvement of global LVEF after CABG is not associated with poorer outcome compared with that of patients with improved LVEF, presumably because effective revascularization of ischemic myocardium, even without improvement in ventricular function, protects against future infarction and death.