Ambulatory blood-pressure monitoring (ABPM) and arterial stiffness have established their role in the evaluation of hypertension. The application of both parameters among heart failure (HF) patients was less mentioned and investigations were mainly focused on advanced congestive heart failure patients. In addition, the physiological and pathological differences between left and right-sided HF are significant. The information regarding circadian blood pressure variation and arterial stiffness was limited. Our study aimed to investigate the characteristics of hemodynamic alteration between left and right-sided HF with the use of non-invasive hemodynamic measurements.

    Adult patients who presented with heart failure symptoms (NYHA class II or more) were enrolled in this study. Subjects were classified as pulmonary arterial hypertension (PAH) and HF with reduced ejection fraction (HFrEF) to represent right and left-sided HF based on definition, respectively. A detailed chart review was conducted to collect information on demographic characteristics, comorbidities, comedications, and laboratory parameters. The 24-hour ABPM was performed for the measurement of circadian hemodynamic patterns. Pulsatile hemodynamics, including carotid-femoral pulse wave velocity (cf-PWV), carotid augmentation index (cAI), and backward pressure amplitude (Pb) were measured. Echocardiography was performed concordantly as confirmation of HF characteristics. The data were compared using non-parametric methods.

    Among a total of 135 patients who were enrolled in this study (median age 53 years old, 50% male), there were 81 patients were classified as PAH and 54 patients as HFrEF. The PAH group was younger [median age 47 years old vs. 60 years old, p<0.001] and had more female patients (78% vs. 22.6%, p<0.001).    Compared with patients with HFrEF, patients with PAH had lower mean systolic blood pressure (BP) both during daytime {median 104.17 mmHg [interquartile range (IQR) 97.59-114.09 mmHg] vs. 114.11 mmHg (96.43-124.93 mmHg), p=0.062} and night [99.00 mmHg (91.80-109.06 mmHg) vs 111.36 mmHg (96.00-123.83 mmHg), p=0.003]. Lower night mean pulse pressure [36.56 mmHg (32.06-42.25 mmHg) vs. 42.53 (35.85-49.73 mmHg), p=0.008], ambulatory arterial stiffness index [0.50 (0.32-0.63) vs. 0.57 (0.41-0.76), p=0.038] and heart rate were presented in PAH patients.    Regarding circadian blood pressure change, the HFrEF group had more patients presented with loss of normal BP dipping pattern (n=31, 58.4%) than the PAH group (n=35, 45.5%). The median rate of BP dipping (defined as the difference between daytime and night mean SBP) of PAH patients was significantly higher [3.56%, (0.13-8.31%) vs. 0.14% (-3.42-3.35 %), p<0.001) than HFrEF patients. Patients presented with loss of BP dipping had left atrium diameter [38.25 mm (31.0-43.8 mm) vs. 33.65 mm (28.9-38.6), p=0.037].    Regarding arterial stiffness, the HFrEF group had higher arterial stiffness parameters, including cf-PWV [1122.2 cm/s (821.9-1296.3 cm/s) vs. 749.5 cm/s (625.9-952.9 cm/s), p<0.001] and Pb [19.0 kPa (14.5-21.5 kPa) vs. 14.3 kPa (12.1-17.9 kPa)].

    Our study demonstrated the distinctive characteristics between left and right-sided HF from 24-hour ABPM and pulsatile hemodynamics measurements. The loss of normal pressure dipping and increased arterial stiffness were more prominent among left-sided heart failure patients.