Introduction

In heart failure with preserved ejection fraction (HFpEF) a better characterization of ground lying pathologies might enhance the identification of future targeted therapies. This work sought to assess aortic vessel stiffness in patients with HFpEF.

Methods

Patients with exertional dyspnoea, echocardiographic signs of diastolic dysfunction and a preserved left ventricular ejection fraction ≥ 50 were prospectively recruited. All patients eligible for participation underwent right heart catheterization (RHC) and cardiac magnetic resonance imaging (CMR).

The presence of HFpEF was defined by RHC assessments under rest and exercise.

CMR imaging was performed on a 3T Magnetom Skyra MRI and included a transverse image stack containing the aortic arch, as well as a 2D phase-contrast sequence for blood flow quantification in the ascending and descending aorta. Post-processing analysis was conducted using CVI42.

Vessel stiffness was measured by pulse wave velocity (PWV) and calculated using the formula PWV = Δx / Δt.  The distance along the aortic arch (Dx) was measured by a manually fitted centreline in a sagittal image of the aorta in-between both cross sectional images. The transit time (Dt) of the velocity waveform along the aortic arch was calculated by the Time-To-Foot method using a custom-built tool for Python.

Results

In total, 38 patients were included and classified according to RHC (HFpEF n=21 and non-cardiac dyspnoea n=17).

As presented in figure 1, patients with HFpEF had a higher PWV compared to patients with non-cardiac dyspnoea (7.9m/s vs. 10.6m/s; p < 0.001).

PWV was determined as a predictor for HFpEF in general (OR 1.58 95% CI: 1.15 – 2.58; p = 0.0251) and was shown to have a high diagnostic accuracy for identification of HFpEF (AUC 0.85; 95% CI: 0.73 – 0.98) as shown in figure 1.

Conclusion

Patients with HFpEF have increased aortic vessel stiffness compared to patients with non-cardiac dyspnoea. Aortic stiffness was determined to be an independent predictor for HFpEF. 

Figure 1: Pulse wave velocity and diagnostic accuracy. Left: PWV in patients with non-cardiac dyspnoe and patients with HFpEF. Right: Diagnostic accuracy of PWV for HFpEF. Area under the receiver operating characteristics curve (AUC). + Statistically significant