Validity of tortuosity severity index in chest pain patients with abnormal exercise test and normal coronary angiography

Abstract

Background: Coronary tortuosity (CT) had different definitions and scores in literature with unclear pathophysiological impact.

Objectives: To study degree of CT and it's relation to ischemic changes in patients with angina but normal coronary angiography (CA).

Methods: We conducted a prospective study at University hospitals between May 2016 and January 2017. We included 200 consecutive patients who underwent CA due to chest pain assumed to be of cardiac origin, and their CA was normal (no diameter stenosis >30%, nor myocardial bridging). Patients were prospectively divided into 2 groups based on the presence (n = 113) or absence (n = 87) of ischemic changes during stress study and compared for clinical, echocardiographic and CA characteristics. A newly proposed Tortuosity Severity Index (TSI) was developed into significant (mild/moderate CT with more than 4 curvatures in total, or severe/extreme CT with any number of curvatures) or not significant TSI (mild CT with curvatures less than or equal to 4 curvatures in total).

Results: Patients with ischemic changes had the highest rate of CT (76.5 vs 18%, p = 0.004) compared to those without. CT mostly affects the left anterior descending (LAD) coronary artery in mid and distal segments. Females, elderly, and hypertensives with left ventricular hypertrophy were strongly related to CT. Multivariate logistic regression analysis identified CT with significant TSI as the only predictor of ischemic changes in these patients (OR = 6.2, CI = 2.5-15.3, P = <0.001).

Conclusions: Coronary tortuosity is a strong predictor of anginal pain among patients with normal CA, despite positive stress study. This finding is more pronounced among elderly, hypertensive female patients.

Keywords: Chest pain; Coronary tortuosity; Normal coronary angiography.

Fig. 1

Flow chart of the study. ^*Ischemic changes = dynamic ECG changes in ST/T waves related to chest pain on stress ECG or reversible wall motion abnormalities on stress ECHO; ^**exclusion criteria for this part of our study and will be discussed in details in another report; # excluded patients was based on the exclusion criteria presented previously. CA = coronary angiography; CAD = coronary artery disease; CT = coronary tortuosity; TSI = tortuosity severity index; pts = patients.

Fig. 2

Consist of 4 parts describing the degree of angulation of coronary tortuosity (CT). A = Mild CT in Ramus intermedius, B = Moderate CT in LAD, C = Extreme CT with loop in RCA, D = Sever CT in LAD. LAD; left anterior descending artery, LCX; left circumflex artery, RCA; right coronary artery.

Fig. 3

Consist of 4 parts analyzing the anatomical variation of coronary tortuosity (CT). A. shows that the percentage of patients with CT more common in LAD than LCX or RCA. B. shows that the percentage of single vessel with CT is more common than multi-vessel CT. C panel represent the grading of tortuosity severity index (TSI) either significant or not in each category of CT based on degree of the angle of deviation either mild, moderate, severe or extreme tortuosity. D panel present which segment of the coronary artery, according to SYNTAX score segmentation, is more affected by CT. segments 7 and 8 in LAD are more affected than other segments then segments 13 and 14 in LCX. LAD; left anterior descending artery, LCX; left circumflex artery, RCA; right coronary artery.