Synergism between infarct-borne left ventricular dysfunction and cardiomegaly in increasing the risk of coronary...

Area of Science:

• Cardiology
• Cardiac Surgery
• Cardiovascular Imaging

Background:

• Left ventricular dysfunction is a significant risk factor for adverse outcomes after coronary artery bypass grafting (CABG).
• Cardiomegaly, an enlarged heart, may further compromise outcomes in these vulnerable patients.

Purpose of the Study:

• To investigate the impact of cardiomegaly on operative and late mortality in patients with left ventricular dysfunction undergoing CABG.
• To identify risk factors associated with mortality in this patient cohort.

Main Methods:

• Retrospective analysis of 178 patients with left ventricular ejection fraction < 45% who underwent CABG between 1978 and 1985.
• Patients were stratified based on left ventricular dysfunction severity (severe: EF < 30%; moderate: 30% < EF < 45%) and presence of cardiomegaly (cardiothoracic ratio > 0.5).
• Operative and long-term survival rates were compared between groups with and without cardiomegaly.

Main Results:

• Overall hospital mortality was 6%, with all deaths occurring in patients with cardiomegaly.
• Patients with cardiomegaly had significantly higher operative mortality (9% vs. 4.5%) and reduced 5-year survival (67% vs. 91%) compared to those with normal heart size.
• Age > 65, prolonged bypass time (> 2 hours), and incomplete revascularization were identified as independent risk factors for mortality.

Conclusions:

• Cardiomegaly is a critical independent predictor of both operative and late mortality in patients with left ventricular dysfunction undergoing CABG.
• Maintaining a normal heart size, alongside addressing other risk factors, is crucial for improving survival after CABG in patients with compromised left ventricular function.