Left Atrial Strain Echocardiography May Be Correlated with Coronary Microvascular Dysfunction

Abstract

BACKGROUND: Coronary microvascular dysfunction (CMD) and left atrial (LA) strain abnormality are more common in patients with Heart Failure with Preserved Ejection Fraction (HFpEF), but the relationship between CMD and LA strain is not well characterized. HFpEF is a major health burden in the United States, representing the number one cause of hospitalization for Americans over 65 years old. (1) Understanding how coronary microvascular dysfunction impacts HFpEF is important because CMD may be an important prognostic sign of deteriorating heart function, particularly in the HFpEF subset of heart failure. Despite CMD’s prognostic potential, it is currently difficult to measure; only invasive techniques can measure CMD. OBJECTIVE: We undertook a study to see if non-invasive measurements of LA strain could be correlated with invasive measurements of CMD. We additionally looked at differences between HFpEF and control patients to see if LASr and CMD correlations were generalizable across disease states. METHODS: We performed a retrospective, observational study of 90 patients at the University of Chicago Medical Center who had an indication for coronary angiography with coronary physiology testing from 2010-2021. CMD was defined as having an invasively-determined coronary flow reserve (CFR) ≤ 2.0. Non-invasive echocardiographic auto-strain analysis was used to obtain LA reservoir strain (LASr), LA conduit strain, and LA contractile strain. Univariable and multivariable logistic regression was performed for HFpEF patients with various degrees of CMD. RESULTS: For both HFpEF and control patients, lower LASr was more commonly found in patients with abnormal CFR (HFpEF: 22.5% ± 12.1 vs. 30.7% ± 10.7, P = 0.018; control: 26.0% ± 16.4 vs. 31.0% ± 9.8 , P = 0.185). Both a univariable and multivariable logistic regression of HFpEF patients found LASr to be a significant predictor of abnormal CFR (OR: 0.94, P =0.041). CONCLUSIONS: There were substantially more patients with CFR ≤ 2.0 in the HFpEF group (50%) compared to control (28%). In HFpEF patients, non-invasively measured LASr showed significant correlation with invasively measured CFR, thus emerging as a potential predictive variable for CFR ≤ 2.0 in patients with this form of heart failure.