Related Experiment Videos
Relation between exertional ischemia and prognosis in mildly symptomatic patients with single or double vessel
G Mazzotta1, R O Bonow, L Pace
1Cardiology Branch, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892.
Insights
For patients with one or two vessel coronary artery disease and impaired left ventricular function, exercise ejection fraction predicts survival. An ejection fraction above 30% indicates a significantly better long-term survival rate on medical therapy.
Area of Science:
- Cardiology
- Cardiovascular Surgery
Background:
- Randomized trials show surgical therapy improves survival in coronary artery disease (CAD) with left ventricular dysfunction, particularly for three-vessel or left main disease.
- The benefit of surgery in one or two-vessel CAD with left ventricular dysfunction remains less clear, especially in mildly symptomatic patients.
Purpose of the Study:
- To assess the risk of death or cardiac events in mildly symptomatic patients with one or two-vessel CAD and left ventricular dysfunction undergoing medical therapy.
- To identify predictors of mortality in this specific patient subgroup.
Main Methods:
- Prospective study of 53 consecutive patients with one or two-vessel CAD and impaired left ventricular function (ejection fraction 20%-40%).
- Utilized exercise electrocardiography (ECG) and rest/exercise radionuclide angiography.
- Analyzed mortality using univariate life table analysis.
Main Results:
- Mortality was significantly associated with ST segment response during exercise, exercise ejection fraction, and the change in ejection fraction with exercise.
- Patients with an exercise ejection fraction >30% had a 6-year survival of 97%, compared to 62% for others (p<0.005).
- Survival was 100% at 6 years if ejection fraction increased with exercise, versus 74% for those without an increase (p<0.005).
Conclusions:
- Exercise ejection fraction is a significant predictor of long-term survival in patients with one or two-vessel CAD and left ventricular dysfunction on medical therapy.
- Mildly symptomatic patients with impaired left ventricular function and specific exercise-induced changes in ejection fraction may have a better prognosis.
Abstract:
The randomized multicenter trials indicate that survival in patients with coronary artery disease and left ventricular dysfunction is enhanced by surgical therapy compared with medical therapy. This beneficial effect of coronary bypass surgery was demonstrated in patients with either three vessel or left main coronary artery disease, but not in those with one or two vessel disease. To determine whether subgroups of mildly symptomatic patients with one or two vessel coronary artery disease and left ventricular dysfunction have an increased risk of death or cardiac events during medical therapy, 53 consecutive patients with angiographically defined one or two vessel disease and impaired left ventricular function (ejection fraction 20% to 40%) were studied by exercise electrocardiography (ECG) and rest and exercise radionuclide angiography. All but two patients had previous myocardial infarction, and all were asymptomatic or only mildly symptomatic during medical therapy. By univariate life table analysis, mortality during medical therapy was associated significantly with the ST segment response to exercise (p less than 0.05) and with both the exercise ejection fraction (p less than 0.05) and the magnitude of change in ejection fraction with exercise (p less than 0.005). In patients with an exercise ejection fraction greater than 30%, the probability of survival at 6 years was 97 +/- 3% (+/- SE) compared with a survival rate of 62 +/- 14% in the remaining subjects (p less than 0.005). Similarly, 6 year survival was 100% in patients whose ejection fraction increased from the value at rest but was only 74 +/- 10% in the remaining patients (p less than 0.005). Exercise capacity was not associated with survival.(ABSTRACT TRUNCATED AT 250 WORDS)