Left ventricular circumferential strain and coronary microvascular dysfunction: A report from the Women's Ischemia Syndrome Evaluation Coronary Vascular Dysfunction (WISE-CVD) Project

Abstract

Aims: Women with ischemia but no obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD). Left ventricular (LV) circumferential strain (CS) is often lower in INOCA compared to healthy controls; however, it remains unclear whether CS differs between INOCA women with and without CMD. We hypothesized that CS would be lower in women with CMD, consistent with CMD-induced LV mechanical dysfunction.

Methods and results: Cardiac magnetic resonance (cMR) images were examined from women enrolled in the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction Project. CS by feature tracking in INOCA women with CMD, defined as myocardial perfusion reserve index (MPRI) <1.84 during adenosine-stress perfusion cMR, was compared with CS in women without CMD. In a subset who had invasive coronary function testing (CFT), the relationship between CS and CFT metrics, LV ejection fraction (LVEF) and cardiovascular risk factors was investigated. Among 317 women with INOCA, 174 (55%) had CMD measured by MPRI. CS was greater in women with CMD compared to those without CMD (23.2 ± 2.5% vs. 22.1 ± 3.0%, respectively, P = 0.001). In the subset with CFT (n = 153), greater CS was associated with increased likelihood of reduced vasodilator capacity (OR = 1.33, 95%CI = 1.02-1.72, p = 0.03) and discriminated abnormal vs. normal coronary vascular function compared to CAD risk factors, LVEF and LV concentricity (AUC: 0.82 [0.73-0.96 95%CI] vs. 0.65 [0.60-0.71 95%CI], respectively, P = 0.007).

Conclusion: The data indicate that LV circumferential strain is related to and predicts CMD, although in a direction contrary with our hypothesis, which may represent an early sign of LV mechanical dysfunction in CMD.

Keywords: Circumferential strain; Coronary microvascular disease; Coronary microvascular dysfunction; Mechanical dysfunction; Subclinical dysfunction.

Fig. 1.

Receiver-operating characteristic curves show an improved ability to predict coronary microvascular dysfunction as defined by ≥1 abnormal pathway on CFT using a model that included LVEF LV concentricity, MPRI, circumferential strain, longitudinal strain, circumferential strain rates, longitudinal strain rates and presence of >1 CAD risk factor (red line) compared to a model that only included LVEF, LV concentricity and > 1 CAD risk factor alone (black line; 0.82 vs. 0.65, P = 0.007). CFT - coronary reactivity testing; CAD - coronary artery disease; LVEF – left ventricular ejection fraction; MPRI - myocardial perfusion reserve index.