Left Atrial Strain in Evaluation of Heart Failure with Preserved Ejection Fraction

Patients with heart failure with preserved ejection fraction (HFpEF) may have elevated left ventricular filling pressure with exercise (LVFP-ex), despite normal LVFP at rest. The aim of this study was to assess the diagnostic value of resting left atrial strain (LAS) in detecting elevated LVFP-ex in patients with dyspnea evaluated on exercise stress echocardiography.

Two-dimensional speckle-tracking analysis for LAS was performed in 669 consecutive patients (mean age, 64 ± 14 years; 53% men) who underwent treadmill echocardiographic evaluation and had left ventricular ejection fractions ≥ 50%. Assessment of LVFP at rest LVFP-ex was based on the 2016 American Society of Echocardiography guidelines for diastolic function assessment. An E/e' ratio ≥ 15 after exercise is considered to indicate elevated LVFP-ex. A continuous diagnostic score of HFpEF was calculated on the basis of the European Society of Cardiology HFA-PEFF diagnostic algorithm.

LAS_reservoir was lowest in patients with elevated LVFP at rest (n = 81) and lower in those with normal resting filling pressure who developed elevated LVFP-ex (n = 108) compared with those who maintained normal LVFP-ex (29.0 ± 5.2% vs 33.1 ± 5.0% vs 39.3 ± 4.8%, P < .001). Lower LAS_reservoir was associated with worse exercise capacity as assessed by metabolic equivalents, exercise time, and functional aerobic capacity (multivariate-adjusted P values all < .05). In patients with normal or indeterminate LVFP at rest (n = 587), LAS_reservoir and preexercise HFA-PEFF score demonstrated areas under the curve of 0.82 and 0.7, respectively, for elevated LVFP-ex. There were 28% higher odds of developing elevated LVFP-ex per 1% decrease in LAS_reservoir (odds ratio, 0.78; 95% CI, 0.74-0.82). Among patients with intermediate scores (n = 461), 123 developed elevations in LVFP-ex and were classified as having HFpEF per the diagnostic algorithm. The addition of LAS_reservoir improved the diagnostic value of HFA-PEFF score for HFpEF (area under the curve increased from 0.71 to 0.80, P = .01).

LAS_reservoir has potential to identify patients with intermediate scores for HFpEF who may develop elevated LVFP-ex only and is therefore a promising alternative to aid in diagnosis when exercise testing is not feasible.