Related Experiment Videos
Five-year effect of medical and surgical therapy on resting left ventricular function in stable angina: Veterans
Insights
Coronary artery bypass grafting (CABG) and medical therapy showed no significant difference in 5-year left ventricular (LV) function for stable angina patients. Both groups maintained similar ejection fractions over time.
Area of Science:
- Cardiology
- Cardiac Surgery
- Clinical Trials
Background:
- Stable angina patients often undergo medical therapy or coronary artery bypass grafting (CABG).
- Long-term effects of CABG versus medical therapy on left ventricular (LV) function require further investigation.
- Previous studies indicated similar short-term LV function outcomes between CABG and medical therapy.
Purpose of the Study:
- To compare the 5-year resting left ventricular (LV) function in patients with stable angina treated with CABG versus medical therapy.
- To assess the impact of intervening myocardial infarction (MI) on LV function in both treatment groups.
- To extend previous short-term findings on LV function to a 5-year follow-up period.
Main Methods:
- A randomized trial involving 194 patients with stable angina.
- Patients were assigned to either medical therapy (92 patients) or CABG (102 patients).
- Left ventricular ejection fraction (EF) was measured at baseline and 5-year follow-up.
Main Results:
- No significant change in mean LV ejection fraction (EF) was observed between baseline and 5 years in either the medical or surgical group (56% to 58%).
- Intervening myocardial infarction (MI) significantly reduced EF in medically treated patients (59% to 46%, p<0.01).
- Late MI in surgically treated patients showed a non-significant decrease in EF (58% to 47%), and perioperative MI did not impact EF (56% to 58%).
Conclusions:
- CABG and medical therapy yield comparable resting LV function at 5 years in stable angina patients.
- Medical therapy alone may be insufficient to prevent LV dysfunction following MI.
- Surgical intervention does not appear to negatively impact long-term LV function, even after late MI.
Abstract:
The effect of coronary artery bypass grafting (CABG) and medical therapy on 5-year resting left ventricular (LV) function was studied in 194 randomized patients with stable angina in the Veterans Administration Study of Coronary Artery Bypass Surgery. LV ejection fraction (EF) was determined in a central laboratory. The 92 medical and 102 surgical patients were comparable at entry with respect to historic, angiographic and electrocardiographic prognostic indicators. Twenty-eight percent of the medical and 30% of the surgical patients had a baseline EF of less than 50%. There was no significant change in mean EF between baseline and 5-year values in either treatment group. The baseline and 5-year values were 56 and 58% in each treatment group. Intervening myocardial infarction (MI) had an adverse effect in medically treated patients (59 to 46%, p less than 0.01) and in surgically treated patients with late MI (58 to 47%, difference not significant). Perioperative MI was not associated with a decrease in EF (56 to 58%, difference not significant). These findings extend the similar results of previous short-term studies of the effect of coronary bypass surgery on resting LV function to 5 years, and provide data in a comparable medical control group.