Men with non-obstructive coronary disease have higher risk of exercise-induced myocardial ischemia detected by cardiopulmonary exercise test

Abstract

Abstract Background Non-obstructive coronary artery disease (NOCAD) had similar morbidity and mortality as patients with obstructive coronary artery disease but less understood. Limited studies analyzed the gender differences in inducible myocardial ischemia assessed by cardiopulmonary exercise test (CPET) in NOCAD. Methods A total of 289 NOCAD patients (mean age 60, 56% women) who had ischemic symptoms and ⫹ 50% coronaries stenoses confirmed by coronary angiography performed the symptom-limited CPET. We used the predicted % peak VO2, O2 pulse trajectory, and exercise ECG test to assess inducible myocardial ischemia. Results Compared with women, men with NOCAD had significantly lower predicted % peak VO2 (62% vs. 73%), higher proportions of flattening pattern (16% vs. 2%) and downward pattern of O2 pulse trajectory (2% vs. 0%) (P < 0.0001). Instead, women with NOCAD had higher prevalence of shallow pattern of O2 pulse trajectory (21% vs. 6%, P < 0.0001). Men with NOCAD had higher proportions of increased risk of exercise-induced myocardial ischemia (medium risk: 63% vs. 54%, high risk: 18% vs. 4%, P < 0.0001). After adjustment, men with NOCAD demonstrated significantly lower predicted % peak VO2 (β -27.4, 95% CI -30.74 – -24.07), higher risk for abnormal O2 pulse trajectories (OR 4.21, 95% CI 1.93 – 9.19) and myocardial ischemia risk detected by CPET (OR 3.14, 95% CI 1.78 – 5.54) (P < 0.0001). Conclusion Men with NOCAD had higher risk of exercise-induced myocardial ischemia detected by CPET that should be given rigorous management and follow-up to prevent cardiovascular events.