Introduction: Although coronary tortuosity is relatively common in coronary angiograms, there is much debate over the significance of this anatomical variation. So in this study the relation between significant coronary tortuosity (SCT) and coronary artery disease (CAD) was examined. Methods: The cross-sectional study included 737 patients (57% male) who were admitted to the hospital for a coronary angiography, based on their symptoms or non-invasive imaging. Coronary arteries defined as SCT are in the presence of either ≥3 consecutive curvatures of 90◦ to 180◦ or ≥2 consecutive curvatures of ≥180◦ measured at the end-diastole, in a major epicardial coronary artery ≥2 mm in diameter. Results: 29.17% of the patients had SCT of which females (64.7% vs. 34.1%, P < 0.001) and higher aged persons (62.9±8.4 vs. 57.8±10.7 years ± SD; P < 0.001) were significantly associated with SCT compared to non-SCT. Left anterior descending artery (LAD), left circumflex artery (LCX) and right coronary artery (RCA) with SCT in comparison to non-SCT, had lesser probability of CAD with stenosis severity of ≥50% (34.5% vs. 46.1%; P = 0.019 and 17.7% vs. 31.1%; P = 0.001 and 27.9% vs. 43.5%; P = 0.013 respectively) and also had significant lower Gensini scores (4.1±5.3 vs. 8.4±11.9; P = 0.011; 2.1±3.4 vs. 5.2±9.5; P = 0.01 and 1.2±1.9 vs. 5.03±8.9; P < 0.001 respectively) but higher TIMI frame count (15.7±5.3 vs. 11.9±4.6; P < 0.001 and 17.1±4.4 vs. 12.7±4.4; P < 0.001 and 15.2±3.9 vs. 11.6±4.8; P < 0.001 respectively). Conclusion: SCT is negatively correlated with CAD and there is a significant association between SCT and reduced coronary flow rate.

The 2D speckle-tracking echocardiography-derived indices of longitudinal deformation of the left ventricular myocardium were not significantly different between the patients with severe CAT and controls.