LEFT ATRIAL STRAIN INDEX IN PATIENTS WITH HEART FAILURE WITH PRESERVED EJECTION FRACTION

Background. In patients with heart failure with preserved ejection fraction(HFpEF), assessment of left ventricular end-diastolic pressure (LVEDP) is crucial but challenging. Left atrial(LA) reservoir strain was found to improve the diagnostic accuracy of conventional echocardiography parameters, but with limited utility in patients with normal LV function. Left atrial strain index(LASi) is a machine learning-derived measure that integrates the entire LA strain curve, and has been validated against invasive measure to indicate normal or elevated LVEDP. However, its clinical value in patients with HFpEF has not been explored. We therefore measured LASi in a well characterized HFpEF cohort and evaluated its association with outcomes.
Methods. 211 HFpEF patients from a dedicated outpatient program were included. Study outcome was a composite of heart failure hospitalization and all-cause mortality.
Results. A total of 117(55%) patients presented with elevated LVEDP based on LASi measure. These patients were older, more often had atrial fibrillation, higher HFA-PEFF score, NT-proBNP, and more impaired diastolic parameters compared to patients with normal LVEDP. During a follow-up of 61 months, 95 events occurred. Patients with elevated LVEDP showed worse outcome (p<0.001), irrespective of HFA-PEFF score. Multivariable analysis demonstrated that LASi was independently associated with the composite endpoint, after correcting for age, sex, NYHA class, comorbidities, and HFA-PEFF score≥5 (HR2.72 [1.61-4.58],p<0.001). Likelihood analysis showed an incremental predictive value of LASi on top of clinical and standard echocardiographic variables.
Conclusion. LASi, as a new index of elevated LVEDP, is associated with outcome in patients with HFpEF, and may be an adjunct to current diastolic dysfunction assessment to improve risk stratification.