Coronary artery disease is associated with impaired atrial function regardless of left ventricular filling pressure

Abstract

Background

Left atrial (LA) strain is impaired in left ventricular (LV) diastolic dysfunction, associated with increased LV end diastolic pressure (LVEDP). In patients with preserved LV ejection fraction (LVEF), coronary artery disease (CAD) is known to impair LV diastolic function. The relationship of LVEDP with CAD and impact on LA strain is not well studied.

Methods and results

Patients with LVEF >50% (n = 37, age 61 ± 7 years) underwent coronary angiography, high-fidelity LV pressure measurements and cardiac magnetic resonance imaging. LA volumes, LA emptying fraction (LAEF), LA reservoir strain (LARS) and LA long-axis shortening (LALAS) were measured. By coronary angiography, patients were assigned into 3 groups: severe-CAD (n = 19, with obstruction of major coronary arteries >70% and/or history of coronary revascularization), mild-to-moderate-CAD (n = 10, obstruction of major coronary arteries 30–60%), and no-CAD (n = 8, obstruction of major coronary arteries and branches <30%). Overall, LVEF was 65 ± 8% and LVEDP was 14.4 ± 5.6 mmHg. Clinical characteristics, LVEDP and LV function measurements were similar in 3 groups. Severe-CAD group had lower LAEF, LALAS and LARS than those in no-CAD group (P < 0.05 all). In regression analysis, LARS and LALAS were associated with CAD severity and treatment with Nitrates, whereas LAEF and LAEF_active were associated with CAD severity, treatment with Nitrates and LA minimum volume (P < 0.05 all). LAEF_passive was associated with LVED volume (P < 0.05).

Conclusions

LA functional impairment may be affected by coexistent CAD severity, medications, in particular, Nitrates, and loading conditions, which should be considered when assessing LA function and LA-LV interaction. Our findings inspire exploration in a larger cohort.