Multimodality imaging for evaluation of chest pain using strain analysis at rest and peak exercise.

BACKGROUND: Exercise stress echocardiography (SE) is commonly used for diagnosing coronary artery disease (CAD). The use of quantitative echocardiographic measures such as strain imaging is expected to improve the sensitivity of conventional SE which relies on the visual diagnosis of wall-motion abnormalities (WMAs). This study is set to demonstrate the added value of resting and exercise strain analysis to detect underlying microangiopathy and inducible myocardial ischemia during a resting and SE in comparison with the results of coronary computed tomographic angiogram (CCTA).

METHODS: A total of 103 consecutive outpatients from the executive screening program were identified and underwent resting and SE. Global longitudinal strain (GLS) and wall-motion changes at rest and peak exercise were analyzed and compared. Baseline demographics, heart rate, and blood pressure measurements were retrospectively extracted for analysis. CCTA was chosen as an alternative test to match with wall motion and strain imaging.

RESULTS: Patients who had abnormal CCTA had lower resting GLS (14.85% ± 3.05 vs 17.99% ± 2.88, P-value = .001) when compared to patients with normal CCTA. All patients who had abnormal CCTA had higher wall-motion score index (1.35 ± 0.2 vs 1.00, P-value < .0001) and lower and abnormal peak stress GLS (pGLS) as compared to patients with normal CCTA (14.89% ± 3.35 vs 18.44% ± 4.27, P-value = .007). However, all patients with pGLS ≥ 20% had normal/nonobstructive CCTA. Patients with multiple comorbidities showed reduced and lower values of resting and pGLS (P-value < .0001), suggesting associated subclinical left ventricular dysfunction.

CONCLUSIONS: Global longitudinal strain offers quantitative interpretation of the resting and SE study, detects underlying subclinical left ventricular dysfunction and a peak stress value more than 20% excludes obstructive CAD on CCTA.