Peak atrial longitudinal strain predicts exercise tolerance in heart failure with preserved ejection fraction

Abstract

Purpose The present study i) determined left atrial (LA) and left ventricular (LV) strains at rest and in response to exercise in patients with heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF), and ii) assessed the relationship between LA and LV strains and exercise tolerance. Methods Forty HFpEF patients (age 59±7 yrs; 25 females), 40 stable HFrEF patients (age 57+6 yrs, 15 females) and 20 controls (age 56+6 yrs, 13 females) underwent baseline clinical and biochemical assessment, resting and exercise stress transthoracic echocardiography using modified Bruce protocol. Speckle-tracking echocardiography was performed to define peak atrial longitudinal strain (PALS) and left ventricular global longitudinal strain (LVGLS). LA stiffness index and LV stiffness index were also derived. Results Compared to healthy controls, HFpEF and HFrEF showed significantly lower PALS at rest (34.03±1.85 vs. 23.06±4.69 vs. 11.51±1.44%, p<0.01) and after exercise (34.41±1.24 vs. 18.48±3.51 vs 10.47±1.49, p<0.01 for both). In response to exercise, the PALS significantly reduced in HFpEF by 26%, but only 8% in HFrEF and remained unchanged in controls. LA stiffness index was higher in HFpEF and HFrEF compared to healthy controls at rest (0.57±0.22 vs. 1.19±0.63 vs. 0.27±0.06, p<0.01) and in response to exercise (0.83±0.46 vs. 1.37±0.63 vs. 0.33±0.04, p<0.01). Compared to healthy controls, HFpEF and HFrEF demonstrated significantly lower LVGLS at rest (−20.27±0.98 vs. −15.89±2.72 vs.-11.14±3.40%, p<0.01) and after exercise (−19.9±0.8 vs.-15.5±3.18 vs.-11.01±2.6%, p<0.01). LV stiffness index was significantly higher in HFpEF and HFrEF compared to healthy controls at rest (0.16±0.05 vs. 0.14±0.07 vs. 0.11±0.02, p<0.01) and in response to exercise (0.18±0.07 vs. 0.15±0.06 vs. 0.13±0.02, p<0.01). Exercise tolerance i.e. exercise duration was significantly lower by 28% and 30% in HFpEF and HFrEF compared with controls (363±152 vs. 352±91 vs. 505±42, p<0.01). There was a significant relationship between peak atrial longitudinal strain and exercise tolerance in HFpEF (r=0.32, p=0.04).There was no significant relationship between exercise tolerance and LVGLS (r=0.058, p=0.72), LA stiffness (r=−0.17, p=0.3), LV stiffness (r=0.88, p=.59). There was no significant relationship between exercise tolerance and PALS (r=0.021, p=0.89) or LVGLS (r=0.12, p=0.48) in HFrEF. Conclusion HFpEF and HFrEF are associated with reduced left atrial and left ventricular strains and increased arial and ventricular stiffness.Peak atrial longitudinal strain is a significant determinant of exercise tolerance in HFpEF but not in HFrEF. Funding Acknowledgement Type of funding sources: None.