Does 3-Vessel Atherosclerosis Affect Ejection Fraction?
Yes, 3-vessel coronary atherosclerosis can significantly affect ejection fraction, particularly during stress conditions, and is associated with worse outcomes when baseline ejection fraction is already reduced.
Impact on Ejection Fraction During Stress
The most compelling evidence shows that 3-vessel disease causes a paradoxical decrease in ejection fraction during stress testing, unlike less severe disease. During dipyridamole stress echocardiography, patients with 3-vessel or left main coronary artery disease demonstrate a mean change in ejection fraction of -2.8 ± 5.1%, compared to increases of 10.2 ± 5.1% in single-vessel disease and 6.2 ± 4.1% in two-vessel disease 1. This negative change occurs primarily due to increased end-systolic volume at peak stress, reflecting the inability of the severely ischemic myocardium to contract effectively under increased demand 1.
Resting Ejection Fraction and Clinical Significance
At rest, 3-vessel disease may or may not reduce ejection fraction depending on:
- Extent of prior myocardial infarction or chronic ischemia - Extensive myocardial necrosis or chronic stunning can reduce resting ejection fraction 2
- Presence of viable but hibernating myocardium - Chronically ischemic but viable tissue may maintain some function at rest 3
- Compensatory mechanisms - The left ventricle may maintain normal resting function through hypertrophy and remodeling initially 4
Prognostic Implications
The combination of 3-vessel disease and reduced ejection fraction carries particularly grave prognostic significance:
- Survival benefit from coronary artery bypass surgery is greatest in patients with 3-vessel disease when ejection fraction is less than 0.50 3
- Low ejection fraction combined with coronary atherosclerosis progression is a strong independent predictor of cardiac death (p = 0.001) 5
- Patients with reduced LVEF (≤35%) after acute myocardial infarction have a 2.6% incidence of sudden cardiac death at 1 year, with 67% occurring within 4 months of discharge 6
Clinical Decision-Making Algorithm
When evaluating a patient with suspected or known 3-vessel disease:
Assess resting ejection fraction - If EF <50%, this represents Class I indication for coronary artery bypass surgery in the presence of 3-vessel disease 3
Consider stress testing with ejection fraction measurement - A decrease in ejection fraction during stress (negative ΔLVEF) has excellent accuracy (area under curve 0.96) for identifying severe multivessel disease 1
Evaluate for ischemia burden - Extensive ischemia on noninvasive testing upgrades treatment recommendations even with preserved ejection fraction 3
Monitor for progression - Even with initially preserved ejection fraction, coronary atherosclerosis progression increases risk of future cardiac events and death 5
Important Caveats
The relationship between 3-vessel disease and ejection fraction is dynamic, not static. Patients may have:
- Normal resting ejection fraction but demonstrate ischemia-induced dysfunction during stress 1
- Preserved ejection fraction at rest but develop heart failure with preserved ejection fraction (HFpEF) over time, as coronary artery disease is a significant risk factor for HFpEF through effects on diastolic function 4
- Low-normal ejection fraction (50-55%) which carries 3.64-fold increased risk of incident heart failure compared to normal EF (≥55%) 7
Avoid the pitfall of assuming normal resting ejection fraction excludes significant functional impairment in 3-vessel disease - stress testing reveals the true functional limitation 1.