Coronary artery tortuosity is independently associated with stenosis severity, obstructive disease, and hypertension

Background Coronary artery tortuosity alters local hemodynamics and wall shear stress; however, its relationship with stenosis severity, obstructive coronary artery disease (CAD), and the influence of hypertension remains unclear. Purpose We aimed to evaluate vessel-specific associations of tortuosity with stenosis grade and obstructive CAD, and to assess the combined impact of hypertension and obstructive CAD on tortuosity. Methods We analyzed 848 patients from the APOLLO study who underwent coronary CT angiography (CCTA). Tortuosity and stenosis grades were measured for the left anterior descending (LAD), left circumflex (LCX), and right coronary artery (RCA). Automated centerline extraction was performed, and curvature-based tortuosity was quantified over the entire vessel centerline. Local curvature was computed along the three-dimensional centerline trajectory, and the tortuosity index was defined as the mean absolute curvature multiplied by the total vessel length, yielding a dimensionless measure of cumulative vessel bending (Figure 1A). Linear regression assessed associations between tortuosity and stenosis grade, adjusting for age, sex, and hypertension. Logistic regression evaluated obstructive CAD versus non-obstructive CAD, including vessel-specific models and interactions with hypertension. Stratified analyses examined tortuosity across hypertension and obstructive CAD subgroups. Results Mean tortuosity was 14.8±6.1 for LAD, 10.2±4.5 for LCX, and 14.0±8.2 for RCA. Linear regression demonstrated a significant positive association between tortuosity and stenosis severity overall and within each vessel (P<0.0001). Logistic regression confirmed that tortuosity independently predicted obstructive CAD (OR 1.074, 95% CI 1.056-1.092; P<0.0001), with interaction analysis showing amplified effects in hypertensive patients. Stratified analysis revealed progressive increases in mean tortuosity from patients without hypertension or obstructive CAD (12.0±4.9) to those with hypertension only (12.9±5.7), obstructive CAD only (14.2±8.0), and both hypertension and obstructive CAD (16.0±11.3), with significant differences between groups (ANOVA P<0.0001) (Figure 1B). Conclusion Coronary artery tortuosity is independently associated with obstructive CAD in a vessel-specific manner. Hypertension amplifies this relationship, with the highest tortuosity observed in patients with both conditions.