Relationship between Coronary Artery Tortuosity and Cardiorespiratory Fitness in Patients without Obstructed Coronaries

Objective: This study aimed to analyze the relationship between cardiorespiratory fitness (CRF) and the increasing severity of coronary artery tortuosity (CAT) in patients with non-stenosed coronaries.

Methods: A total of 396 patients who underwent coronary angiography and cardiopulmonary exercise testing (CPET) between August 2020 and July 2021 were included in this single-center retrospective study after excluding patients with significant coronary artery disease (≥50% stenosis). Patients were divided into two groups: no or mild coronary artery tortuosity (N/M-CAT) and moderate to severe coronary artery tortuosity (M/S-CAT) and laboratory electrocardiographic, echocardiographic, and CPET parameters were compared between two groups.

Results: M/S-CAT was found in 46.9% of the study participants, with 66.7% being women. M/S-CAT was significantly associated with advanced age (P=0.014) and females (P=0.001). Diastolic dysfunction parameters, E velocity (P=0.011), and E/A ratio (P=0.004) also revealed significant differences between the M/S-CAT group and N/M-CAT group. VO₂@peak (1.22±0.39 vs. 1.07±0.39, P<0.01) and VO₂@AT (0.77±0.22 vs. 0.71±0.21, P=0.017) were significantly lower in the M/S-CAT group than in the N/M-CAT group. Multivariate logistic regression analysis identified females (OR=0.448; 95% CI, 0.296-0.676; P=0.000) and E/A ratio (OR=0.307; 95% CI, 0.139-0.680; P=0.004) to be independent risk factors of M/S-CAT and showed no association of CPET parameters to M/S-CAT.

Conclusion: The results indicate that increasing severity of CAT is strongly associated with female gender and E/A ratio and is not directly correlated with decreasing CRF. Further research with a larger patient population and a longer follow-up time is required to fully comprehend the impact of CAT on CRF.