Ischemic heart disease and early diagnosis. Study on the predictive value of 2D strain.

Introduction: Two-dimensional strain echocardiography (2D-SE) quantifies left ventricular global longitudinal strain (GLS) and global circumferential strain (GCS). Our aim was to test 2D-SE during dipyridamole stress echocardiography (Dipy-Stress) in patients with non-diagnostic result, checking by way of coronary CT angiography (CCTA) the possible presence of coronary artery disease (CAD).

Methods: Over twenty-four months 65 consecutive patients with non-diagnostic Dipy-Stress were studied by 2D-SE and by CCTA. GCS and GLS at rest and after stress were compared according to data derived from CCTA. CAD was graded as significant (stenosis ≥50%), mild (stenosis between 15 and 50%) or absent (stenosis <15%). CCTA was defined as "positive" in presence of mild CAD and "negative" in absence of stenoses. Furthermore, Δ strain was defined as follows: [(stressS-restS)/restS]×100.

Results: GCS at rest and after stress was similar in CCTA-positive (26±5% and 27±5% respectively) and CCTA-negative groups (27±3% and 28±3% respectively). GLS at rest was significantly reduced (P<0.0001) in CCTA-positive (23±3%) compared to CCTA-negative group (25±2%). GLS after stress was lower (P<0.0001) in CCTA-positive group (20±3%) than CCTA-negative one (26±2%). A significant reduction (P<0.0001) of GLS at rest versus after stress was found in positive-CCTA group. ΔGLS showed a significant decrease (P<0.0001) in CCTA-positive (-10±8%) compared to CCTA-negative (4.4±5.8%) group. ROC analysis of ΔGLS showed high accuracy (area under the ROC curve 0.916, 95% CI: 0.820-0.970) in distinguishing positive and negative CCTA groups.

Conclusions: 2D-SE during Dipy-Stress allows, in case of non-diagnostic test, identification of mild-CAD with high sensitivity and specificity.