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Anatomic and prognostic implications of an early positive treadmill exercise test
Insights
An early positive treadmill exercise test may indicate left main coronary artery stenosis, even in minimally symptomatic patients. Coronary angiography may be warranted for early positive treadmill tests to identify significant coronary artery disease.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Preventive Medicine
Background:
- Clinical coronary artery disease diagnosis often relies on symptoms and prior treatments.
- Treadmill exercise testing is a common tool for assessing cardiac function.
- Left main coronary artery stenosis is a critical condition requiring timely diagnosis.
Purpose of the Study:
- To investigate the correlation between early positive treadmill exercise tests and the prevalence of left main coronary artery stenosis.
- To evaluate the diagnostic utility of treadmill testing in identifying significant coronary artery disease, including left main stenosis.
- To determine the appropriate role of coronary angiography in patients with positive treadmill tests.
Main Methods:
- Coronary angiography was performed on two groups of men with clinical coronary artery disease and positive treadmill tests (Groups A and B).
- A control group of catheterized patients with non-early positive treadmill tests was also analyzed.
- Prevalence of left main coronary artery stenosis (≥50% diameter) and multi-vessel coronary artery disease (≥75% stenosis) was compared.
Main Results:
- Left main coronary artery stenosis was found in 28% of Group A and 35% of Group B, significantly higher than the 10% in patients with non-early positive tests (p<0.001).
- In patients without significant left main stenosis, 85% had multi-vessel disease (≥75% stenosis).
- Medical management in this subgroup yielded a 36-month survival rate of 89.2%.
Conclusions:
- An early positive treadmill test is a strong indicator of potential left main coronary artery stenosis, irrespective of symptom severity.
- Coronary angiography is justified in patients with early positive treadmill responses, even with mild or undertreated angina.
- Excluding left main stenosis allows for effective medical management with favorable long-term survival.
Abstract:
Eighty men (group A) with clinical coronary artery disease underwent coronary angiography regardless of symptoms and previous therapy because they had a positive treadmill exercise test in stage I or II of the Bruce protocol. Thirty-four other men (group B) who also had an early positive treadmill test underwent coronary angiography because they had disabling angina pectoris despite medical therapy. We found left main coronary artery stenosis of 50% or greater of the vessel diameter in 28% of group A and 35% of group B (p greater than 0.3). In contrast, only 10% of 93 other catheterized patients who had treadmill tests that were not early positive had left main coronary disease (p less than 0.001). Fifty-four patients from group A who did not have left main stenosis of 50% or greater were treated medically. In this subgroup, 85% had 2 or 3 major coronary vessels with 75% or greater stenosis. These patients had a 36 month survival rate of 89.2%. We conclude that an early positive treadmill test identifies patients who have an increased likelihood of having left main coronary stenosis, even if they are minimally symptomatic. To identify left main coronary stenosis, catheterization may be justified in patients whose angina pectoris has been mild or not intensively treated when they have an early positive treadmill response. After left main coronary stenosis has been excluded, these patients may be treated medically with a low mortality.