Heart rate variability in patients with pulmonary hypertension as assessed with long-term continuous cardiac monitoring correlates with other established risk assessment parameters

Abstract

Abstract Background A few short-term monitoring studies (10 minutes–24 hours) have revealed lower heart rate variability (HRV) in patients with pulmonary hypertension (PH). This is the first study to apply continuous heart rate variability monitoring in pulmonary hypertension. Purpose Assessment of HRV as a non-invasive risk marker in pulmonary hypertension (PH) using long-term continuous monitoring. Methods Patients diagnosed with PH according to international guidelines were included in this prospective single-centre study. Patients were implanted with a Reveal LINQ (Medtronic) insertable cardiac monitor to record HRV. HRV was expressed as the mean of HRV in sinus rhythm during the full day for all days per patient (SDANN method). Pearson and Spearman correlations between HRV and established risk determinants were estimated. Results Thirty-two patients with PH were included. Twenty-two patients had pulmonary arterial hypertension (PAH) and 10 had chronic thromboembolic PH. During 50 patient-years of continuous monitoring (median: 654 (range: 394–714) days per patient), HRV was significantly correlated to the following risk determinants in PH (variable 1–3) in addition to other variables (variable 4–8): (1) WHO functional class (FC) (r=−0.55, p = <0.001) (Figure 1), (2) NT-proBNP (r=−0.5, p=0.003), (3) cardiac index (r=−0.45, p=0.03), (4) heart rate at night time (0 am–4 am) (r=−0.68, p=<0.001) (Figure 1), (5) TAPSE (r=0.41, p=0.025), (6) right ventricle ejection fraction (r=−0.37, p=0.014), (7) tricuspid regurgitation gradient (r=−0.38, p=0.045) and (8) right ventricle end diastolic volume (ml) (r=−0.37, p=0.035). Conclusions This is the first study to apply continuous monitoring of HRV in patients with PH. HRV was significantly correlated with several variables already being used in risk stratification. HRV may be an additional non-invasive variable in risk assessment in PH aiding in optimization of treatment. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Janssen