Estimated Pulse Wave Velocity-to-Global Longitudinal Strain Ratio: A Tool for Differentiating Heart Failure Subtypes?

Ventricular-arterial coupling (VAC), which refers to harmonious interaction between the ventricles and arteries, is essential for maintenance of optimal cardiovascular function. The ratio of the pulse wave velocity (PWV) to left ventricular global longitudinal strain (GLS) has been established as a reliable noninvasive metric for assessing VAC. This study aimed to assess VAC noninvasively in heart failure (HF) using the estimated pulse wave velocity (ePWV)-to-GLS ratio, defined from speckle tracking imaging.

According to the HF stages by the American Heart Association, 131 subjects were divided into 4 groups: group 1 (n = 36) at risk of developing HF and pre-HF (American College of Cardiology/American Heart Association stages A and B), group 2 (n = 35) having HF with preserved ejection fraction (HFpEF), group 3 (n = 35) having HF with reduced ejection fraction (HFrEF), and group 4 (n = 30) as controls. To determine the ePWV/GLS ratio, the ePWV was calculated based on the previously established formula using age and mean pressure, and the GLS was derived from speckle tracking echocardiography. The study evaluated the VAC in all groups and compared with the established metrics such as arterial elasticity (Ea) and ventricular end-systolic elasticity (Ees) ratios. The correlation between the ePWV/GLS ratio and other parameters obtained by echocardiography was also assessed.

Significant differences in the ePWV/GLS ratio were observed among the groups, and the severity of VAC impairment correlated with the HF stage. The lowest ePWV/GLS ratio was observed in the control and stage A-B group (0.530 ± 0.100 vs. 0.640 ± 0.10), followed by the HFpEF group (0.992 ± 0.215), whereas the HFrEF group had the highest ratio (1.500 ± 0.369). The ePWV/GLS ratio showed a moderate correlation with the Ea/Ees ratio (r = 0.753 95% CI, 0.665-0.821, p < 0.0001), but performed better in distinguishing HF subtypes. A threshold of 0.625 for the ePWV/GLS ratio was established by the ROC curve to detect the impaired VAC, with an AUROC of 0.923 and 95% CI of 0.876-0.969. In addition, the ePWV/GLS ratio was strongly associated with N-terminal pro-B-type natriuretic peptide and moderately correlated with left ventricular mass index, end-diastolic volume, left ventricular ejection fraction, age, and E/e'.

The ePWV/GLS ratio is an easily accessible parameter for evaluating VAC. It is closely related to the HF stage and can effectively differentiate between HF subtypes. Although the ratio was higher in patients with HFpEF than in healthy individuals, it was lower than in patients with HFrEF.