REGIONAL MULTI-LAYER STRAIN MEASUREMENTS USING TRANSTHORACIC ECHOCARDIOGRAM WITH EXERCISE STRESS CAN DETECT CLINICALLY STABLE MYOCARDIAL ISCHEMIC SEGMENTS
We investigated whether multi-layer regional longitudinal strain (LS) measurement on transthoracic echocardiogram (TTE) with exercise stress can detect functional myocardial ischemic segments, as confirmed by fractional flow reserve (FFR), in patients with coronary artery disease.
This is a prospective-analysis of 46 coronary arteries in 16 stable patients (14 males, 68±11 yrs) undergoing invasive FFR measurement and ergometer exercise stress TTE (Vivid E9). On TTE, regional LS in whole, endocardial, and epicardial layers were calculated at baseline (at rest) and at 1 minute and 8 minutes after the exercise test.
FFR was <0.75 and ≥0.75 in 16 and 30 vessels, respectively. The absolute value of regional endocardial LS at 1 minute after the exercise in myocardial territories supplied by the coronary vessels with FFR <0.75 was smaller than those supplied by vessels with FFR ≥0.75 (12.9±5.0 vs 15.7±3.7% P=0.036). No significant differences were observed at baseline and at 8 minutes after the exercise between vessels with FFR <0.75 and ≥0.75. Receiver operating characteristic curves showed the best cutoff values of the whole, endocardial, and epicardial layer LS at 1 minute after exercise in detecting myocardial territories with FFR <0.75 as 11.0, 11.0 and 14.0%, respectively.
Regional multi-layer (particularly, the endocardial layer) LS on exercise stress TTE is useful in detecting functional myocardial ischemic segments confirmed by FFR in stable patients.
Autor / Fonte:Takeshi Nishi; Nobusada Funabashi; Koya Ozawa; et al. J Am Coll Cardiol. 2016;67(13_S):1630-1630. doi:10.1016/S0735-1097(16)31631-X.