Early positive exercise test and extensive coronary disease: effect of antianginal therapy

Area of Science:

• Cardiology
• Exercise Physiology

Background:

• Stable angina pectoris management often involves antianginal therapies.
• Exercise testing is a common tool for diagnosing coronary artery disease (CAD).
• The utility of exercise testing may be influenced by therapeutic interventions.

Purpose of the Study:

• To evaluate the impact of antianginal therapy on the diagnostic accuracy of exercise tests.
• To assess how long-acting nitrates or calcium antagonists affect the early positive exercise response in screening for 3-vessel and left main (LM) coronary artery disease (CAD).

Main Methods:

• Fifty-seven men with stable angina underwent bicycle ergometry before and after initiating antianginal therapy (long-acting nitrate or calcium antagonist).
• An early positive exercise response was defined by signs of myocardial ischemia at low workload (<300 kpm/min).
• Coronary angiography was performed on 24 patients to confirm CAD severity.

Main Results:

• The incidence of an early positive exercise response decreased from 68% before therapy to 24% after therapy.
• For predicting 3-vessel/LM CAD, sensitivity dropped from 92% to 42%, and specificity increased from 58% to 75% post-therapy.
• Positive predictive value decreased from 69% to 63%, and negative predictive value decreased from 88% to 63% after therapy.

Conclusions:

• Antianginal therapy, including nitrates and calcium antagonists, diminishes the value of exercise tests as a screening tool for significant coronary artery disease (3-vessel or left main CAD).
• The reduction in early positive exercise responses due to therapy affects the sensitivity and predictive values of the test.