Abstract
BACKGROUND: Comparison of thermodilution (TD) and indirect Fick (iFick) methods of cardiac output (CO) measurement has not been well described in patients with World Health Organization (WHO) group 3 pulmonary hypertension (PH). METHODS: We conducted a single-center retrospective chart review of 96 patients with WHO group 3 PH who underwent lung transplantation. For comparison, 32 WHO group 1 pulmonary arterial hypertension patients who were followed in our PH clinic during the same period were also included in the study. RESULTS: TThere was a significant difference between iFick CO and TD CO (5.93+/ -1.5 versus 5.46+/ -1.8 liter/minute, p=0.0061) in WHO group 3 PH. Pulmonary vascular resistance (PVR) calculated using iFick and TD-CO values also differed significantly. TD-PVR was more strongly associated with measures of poor outcomes after lung transplant. CONCLUSIONS: iFick-CO and TD-CO can be significantly different in WHO group 3 PH. In cases of discrepancy between iFick and TD-COs, TD-CO correlates better with clinical outcomes after lung transplantation.