Exercise Provocation Test in Patients with Vasospastic Angina: Graded vs. Non-Graded Exercise Test

Kim, Young Kwon; Shin, Hyun Deok; Rhee, Moo Yong; Lee, Myoung Yong; Choi, You Sik; Kim, Byoung Ha

Abstract

BACKGROUND AND OBJECTIVES
We investigated in patients with coronary vasospastic angina whether the exercise ECG test results are influenced by the different modes of exercise load and compared the clinical characteristics including coronary risk factors between patients with positive and negative exercise tests.
MATERIALS AND METHODS
This study comprised 34 patients with documented coronary artery spasm without significant stenosis (coronary artery luminal diameter narrowing <70%) and treadmill exercise test. Treadmill exercise ECG test was performed based on Bruce's protocol (graded exercise test, GET) and sudden rapid exercise protocol (non-graded exercise test, NGET) in the morning of the same day.
RESULTS
1) Of 29 patients who underwent both GET and NGET, 19 patients manifested positive result by NGET, whereas only 11 patients did by GET (66 vs. 38%, P=0.04). All patients with positive GET had positive NGET and 8 of 18 patients with negative GET had positive NGET. 2) Of 34 patients who underwent GET, there was no significant difference in frequency of hypertension, diabetes, current smoking, presence of effort chest pain by history, mixed disease (fixed stenosis >50%, <70% of luminal diameter) or total cholesterol level between patients with positive and negative results. In 18 typical variant angina patients by clinical history, 8 of 10 patients with high disease activity (5 times or more attack per week) manifested positive result by GET or NGET, whereas 4 of 8 patients with low disease activity (80 vs. 50%, P=NS).
CONCLUSION
In patients with coronary vasospastic angina, sudden rapid exercise could induce more frequently coronary artery spasm than multistage exercise. The result of an exercise test may not be correlated with coronary risk factors, coronary anatomy, effort chest pain, and the disease activity.