Impact of Sub-Clinical Systolic Dysfunction on Exercise Haemodynamics in HFpEF

Abstract

Aims: Subclinical systolic impairment may be a contributor to the pathophysiology and outcomes of heart failure with preserved ejection fraction (HFpEF). In this study, we characterised the relationship between left ventricular mechanical function assessed by strain imaging with the key haemodynamic features of HFpEF at rest and during exercise. Methods: Simultaneous echocardiography and exercise right heart catheterisation was performed in 90 subjects (68 HFpEF, 22 control) referred for assessment of dyspnea. HFpEF was defined as left ventricular ejection fraction (LVEF) ≥50% with a pulmonary capillary wedge pressure (PCWP) ≥15 mmHg at rest and/or ≥25 mmHg at maximal exertion. Measures of LV strain were taken using speckle tracking and analysed together with natriuretic peptides and rest and exercise haemodynamics. Results: At rest, HFpEF patients had impaired GLS compared to control subjects (−18.4 ± 2.5 vs −21.2 ± 3.5%, p = ≤ 0.001. Ejection fraction was similar (62 ± 6 vs 61 ± 6%, p = 0.81). With worsening global longitudinal strain, patients with HFpEF displayed a worse cardiac index at both rest and exercise (p < 0.001 for both), but similar filling pressure (p = 0.85). The tertile with the worst strain had the highest level of natriuretic peptide. The association of strain with peak cardiac index was independent of LVEF, BNP, age, LAVI, LVMI, and systolic blood pressure. Conclusions: Despite a preserved ejection fraction, a proportion of patients with HFpEF display impaired GLS, which correlates with a worse cardiac output. Impaired GLS was not associated with higher filling pressures at rest or exercise.