Prognostic impact of left ventricular global longitudinal strain in atrial mitral regurgitation

Left atrial (LA) and left ventricular (LV) mechanics are impaired in patients with atrial functional mitral regurgitation (AFMR), but their prognostic value in this subset of patients remains unknown. The present study aimed to evaluate the association between LA and LV longitudinal strain and clinical outcomes in patients with AFMR.

A total of 197 patients (mean age 73±10 years, 44% men) with at least moderate AFMR were retrospectively identified. LV global longitudinal strain (GLS) and left atrial reservoir strain (LAS) were calculated by two-dimensional speckle tracking echocardiography. All-cause mortality was the primary endpoint of the study. The threshold value of LV GLS (≤16.3%) to identify impaired LV mechanics was defined based on the risk excess of the primary endpoint described with a spline curve analysis.

Impaired LV GLS (≤16.3%) was found in 89 (45%) patients. During a median follow-up of 69 months, 45 (23%) subjects experienced the primary endpoint. Patients with impaired LV GLS (≤16.3%) had a significantly lower cumulative survival rate at 5 years, as compared with patients with LV GLS (>16.3%) (74% vs 93%, p<0.001). On multivariable Cox regression analysis, LV GLS expressed as continuous variable was independently associated with the occurrence of all-cause mortality (HR 0.856, 95% CI 0.763 to 0.960; p=0.008) after adjustment for age, LAS, pulmonary artery systolic pressure and severe tricuspid regurgitation. Conversely, LAS was not significantly associated with patients' outcome.

In patients with significant AFMR, the impairment of LV GLS was independently associated with worse outcomes.