Abstract 10852: Lower Global Strain Predicts Left Main and Multi-Vessel Coronary Artery Disease in Asymptomatic Diabetic Patients. Factor 64 Study

Abstract

Background: Detection of left main and multi-vessel CAD has important prognostic and therapeutic implications. Identifying early to intermediate left main (LMD) and multi-vessel (MVD) disease may facilitate early and aggressive treatment, especially in diabetic patients. Several novel markers of regional LV function were proposed, but their ability in predicting significant CAD has not been validated in asymptomatic diabetic patients.

Methods: FACTOR-64 study is designed to evaluate the effect of screening for CAD in asymptomatic diabetic patients on future cardiovascular events. Participants were randomized to screening coronary CT angiography (64 MDCT, Toshiba) or control. Eighty two consecutive patients randomized to screening also underwent 2-D echo with speckle tracking. Using offline software, regional systolic circumferential strain (Ecc) and early diastolic strain (E') were determined from short axis images. Relationship between regional systolic and diastolic function and presence of LMD (any obstructive disease) or MVD (≥50% stenosis of LAD, LCX or RCA) was determined using Mann-Whitney, Fisher exact test or logistic regression.

Results: For the entire group (mean age = 60 yrs, 55% females, 57% with history of hypertension), median calcium score was 31 Agatston Units. Mean global Ecc was -11.4% and E' was 0.85 sec^-1. There were 12 patients with LMD, and 19 with LM or MVD (2/ 3 vessel disease). Absolute Ecc value in patients with LMD was significantly lower than in patients without LMD (-8.5 vs -11.9%, p=0.007), and in those with LMD or MVD compared with those without significant CAD (-9.2 vs -12.0%, p=0.0084). When Ecc >-10% was used to define abnormal strain, 11.6% of the participants with nonsignificant or one vessel CAD had abnormal strain, whereas 35.9% of those with LM or MVD had abnormal strain (p=0.017). After adjusting for age, gender, history of HTN and DM type, decreased Ecc predicted LM (odds ratio [OR]=8.6, p=0.017), and LM or MVD disease (OR=2.4, p=0.011).

Conclusion: Among asymptomatic diabetic patients, decreased global circumferential strain predicts the presence of early and intermediate left main and multi-vessel CAD disease. Strain analysis may be a useful non-invasive tool for detecting important CAD in diabetic patients.