Effect of Pulmonary Artery Catheter Balloon Inflation on Pulmonary Hemodynamics

Background: Right heart catheterization (RHC), including a pulmonary artery wedge pressure (PAWP) determination, is necessary to categorize the hemodynamic type of pulmonary hypertension (PH). The potential hemodynamic implications of a pulmonary artery catheter (PAC) balloon inflation in PH have not been formally tested. Methods: We assessed the hemodynamic impact of the PAC balloon inflation during RHC by measuring systolic, diastolic, and mean pulmonary artery pressure (mPAP) in all patients, and cardiac output (CO) by thermodilution in a subgroup of patients. Hemodynamic measurements were obtained both with PAC balloon deflated and fully inflated (1.5 mL of air), while the PAC was free floating in the pulmonary artery before wedging. We calculated total pulmonary resistance (TPR). Results: We included 210 patients, age 58 +/- 14 years, 134 (64%) women. Patients had no PH (n: 12, 6%), PH group 1 (n: 68, 33%), 2 (n: 86, 41%), 3 (n: 11, 5%), 4 (n: 29, 14%), and 5 (n: 3, 1%). The mean +/- standard deviation (SD) at end-expiration mPAP (balloon-up minus down) (n: 209) was -0.02 +/- 1.59 mmHg (range, -5.0 to 4.0 mmHg; P=0.84), while the TPR (n: 62) was -0.27 +/- 1.2 Wood units (WU) (range, -4.8 to 2.2 WU; P=0.08); without significant variation based on the type of PH group or degree of pulmonary vascular resistance (PVR). Interestingly, the change in mPAP at end-expiration with PAC balloon inflation was higher in women (mean +/- SD: 0.31 +/- 1.43 mmHg) than men (mean +/- SD: -0.61 +/- 1.70 mmHg) (P<0.001). Conclusions: Balloon inflation of the PAC in the main pulmonary artery had no significant impact on the mPAP or TPR, even when only including patients with group 1 PH or selecting a subgroup with a higher PVR.