Related Experiment Videos
Severe myocardial dysfunction and coronary revascularization
1Department of Cardiology and Cardiac Surgery, University Medical School, Federico II, Naples, Italy.
Insights
Coronary artery bypass grafting (CABG) can benefit patients with severe myocardial dysfunction and low ejection fraction (EF). Viable myocardium identified through imaging suggests CABG can improve heart function and offer an alternative to heart transplantation.
Area of Science:
- Cardiology
- Cardiac Surgery
- Medical Imaging
Background:
- Severe myocardial dysfunction with low ejection fraction (EF) was traditionally a contraindication for coronary artery bypass grafting (CABG).
- Emerging evidence from myocardial scintigraphy and echo-stress tests indicated potential for recovery of contractile function in dysfunctional areas.
Purpose of the Study:
- To evaluate the safety and efficacy of expanding CABG indications to patients with severely depressed left ventricular function.
- To assess the functional recovery of viable myocardium in patients undergoing CABG despite low EF.
Main Methods:
- Retrospective analysis of 352 CABG patients between January 1993 and June 1995.
- Inclusion of 85 patients with resting EF < 0.35 (27 with EF < 0.25) who underwent CABG.
- Assessment of myocardial viability using scintigraphy and dobutamine-echocardiography.
Main Results:
- All patients demonstrated viable myocardium dependent on significant coronary lesions.
- Mean ejection fraction improved significantly at 6-month follow-up in most patients.
- Scintigraphy and echocardiography confirmed improved function in previously akinetic/hypokinetic areas.
Conclusions:
- Expanded indications for CABG are feasible in selected patients with severe myocardial dysfunction and low EF.
- CABG offers a viable therapeutic option, improving cardiac function and potentially avoiding the need for heart transplantation.
- Myocardial viability assessment is crucial for identifying suitable candidates for revascularization.
Abstract:
Severe myocardial dysfunction, characterized by global hypokinesis, or akinetic areas with hypokinesis of the remaining wall, and a very low ejection fraction (EF), has been considered to be a contraindication for coronary revascularization (CABG). However, myocardial scintigraphy and echo-stress data have shown that hypo- or akinetic areas can regain their contractility. Therefore, we expanded the indications for CABG, and performed operations even upon patients who were waiting for a heart transplant. Between January 1993 and June 1995, among 352 patients who underwent CABG, 85 had highly depressed left ventricular function. Their resting EF was lower than 0.35, and in 27 it was lower than 0.25. Viable areas of myocardium were found in all of the patients through the combination of scintigraphy and dobutamine-echocardiography: these areas depended on significant coronary lesions. The mean age of the patients was 48.2 years (range 33-62 years); angina was present in 62 patients. A mean of 3.1 grafts/patient were implanted; enoximone was used in all but 5 patients upon weaning from cardiopulmonary bypass; intra-aortic balloon pump was used in 9 cases. Operative mortality was 10.6% (9 patients), due to low-output syndrome in 5, acute myocardial infarction in 2, cerebral damage in 1, and respiratory failure in 1. At the 6-month follow-up, EF was improved in all but 7 patients, in whom it remained unchanged. Scintigraphic and echocardiographic tests revealed good function in most of the areas that had been previously recognized as hypo- or akinetic. These results suggest that the indications for standard myocardial revascularization can be expanded, and a promising option can be offered to patients who may otherwise be destined to wait for an uncertain transplantation.