Impedance Cardiography Is a Potent Non-Invasive Method in Cardiac Output Measurement and Pulmonary Arterial Hypertension Risk Assessment.

BACKGROUND

Impedance cardiography (ICG) offers a potential alternative for hemodynamic assessment in pulmonary arterial hypertension (PAH) as a non-invasive technique.

METHODS

A total of 132 patients who underwent right heart catheterization (RHC) were included. Cardiac output (CO) and stroke volume (SV) measured by thermodilution during RHC (COTD) and ICG (COICG) were compared. The capacity of ICG in PAH risk stratification and clinical deterioration prediction was also analyzed.

RESULTS

Ninety-three pre-capillary pulmonary hypertension patients were enrolled, 54 (58.06%) patients belong to Group 1 PAH, and 39 (41.94%) patients were diagnosed with chronic thromboembolic pulmonary hypertension. The mean COTD was 4.93 ± 1.06 L/min, while the COICG was 4.41 ± 1.23 L/min, showing a moderate correlation (r = 0.49, P < .001). In Group 1 PAH patients, the COTD was 5.13 ± 1.10 L/min, and COICG was 4.57 ± 1.22 L/min (r = 0.52, P < .001). Bland-Altman analysis indicated a mean difference of 0.52 L/min and limits of agreement from -1.76 to 2.80 L/min. The mean SVTD was 64.63 ± 17.10 mL, and the SVICG was 60.94 ± 18.03 mL (r = 0.53, P < .001) with a mean difference of 3.69 mL. After a 1-year follow-up, the CIICG and SVIICG showed potential power in predicting clinical deterioration in PAH patients, with area under the curves of 0.76 and 0.81, respectively.

CONCLUSION

Impedance cardiography measured CO and SV presented an acceptable correlation with RHC in PAH patients. Stroke volume index and cardiac index measured by ICG is potent to identify the low-risk status and predict clinical deterioration in PAH patients.