Pulmonary arterial capacitance in patients with heart failure and reactive pulmonary hypertension

Abstract

AimsReactive pulmonary hypertension (PH) is a severe form of PH secondary to left-sided heart failure (HF). Given the structural and functional abnormalities in the pulmonary vasculature that occur in reactive PH, we hypothesized that pulmonary artery capacitance (PAC) may be profoundly affected, with implications for clinical outcome. Methods and resultsWe studied 393 HF patients of whom 124 (32%) were classified as having passive PH and 140 (36%) as having reactive PH, and 91 patients with pulmonary arterial hypertension (PAH). Mean PAC was highest in patients without PH (4.5 ± 2.1 mL/mmHg), followed by the passive PH group (2.8 ± 1.4 mL/mmHg) and was lowest in those with reactive PH (1.8 ± 0.7 mL/mmHg) (P = 0.0001). PAC and pulmonary vascular resistance (PVR) fitted well to a hyperbolic inverse relationship (PAC = 0.25/PVR, R 2 = 0.70), with reactive PH patients dispersed almost predominantly on the flat part of the curve where a reduction in PVR is associated with a small improvement in PAC. Elevated PCWP was associated with a significant lowering of PAC for any PVR (P = 0.036). During a median follow-up of 31 months, both reactive PH [hazard ratio (HR) 2.59, 95% confidence interval (CI) 1.14-4.46, P = 0.02] and reduced PAC (HR 0.72 per 1 mL/mmHg increase, 95% CI 0.59-0.88, P = 0.001) were independent predictors of mortality.

Pulmonary vascular resistance and compliance relationship in pulmonary hypertension

“…Recently, TEDFORD et al [22] documented shortened empiric RC-times in post-capillary PH, thus suggesting an increased pulsatile afterload when compared to precapillary PH at a given level of PVR. This has been subsequently confirmed by other authors [23][24][25]. These studies still documented an inverse hyperbolic relationship between PVR and SV/Papp, and supported the concept that the mean PVR×C product was in the 0.25-0.53 s range in post-capillary PH [22][23][24][25].…”

“…A constant RC-time product has important implications for the assessment of RV afterload, namely that PVR and total arterial compliance are redundant measurements and knowledge of one enables the derivation of the other. Exceptions to the constant RC-time product have recently been documented, for example in PH-related to left heart disease [22][23][24][25], prompting a re-evaluation of the concept of RC-time constancy [26][27][28][29].…”

Liver fibrosis score predicts mortality in heart failure patients with preserved ejection fraction

“…All catheterizations were performed in a resting supine position under fluoroscopic guidance. Pulmonary capillary wedge pressure, mean pulmonary artery pressure, mean right atrial pressure, and cardiac output were measured using a 7F Swan‐Ganz catheter (Edwards Lifesciences, Irvine, CA, USA) 25. We used the thermodilution method for the measurement of cardiac output.…”

Clinical Significance of Pulmonary Arterial Capacitance Calculated by Echocardiography in Patients With Advanced Heart Failure

“…This result is consistent to a previous report on PAC obtained by catheterization. 26 Reactive PH is considered to be related to structural abnormality in pulmonary arteries caused by chronic elevation of pulmonary venous pressure, 4 and PVR is a better marker than PAC for distinguishing patients with reactive PH from those with passive PH. On the other hand, PAC, obtained by echocardiography or catheterization, may be a possible early marker of functional changes in the pulmonary vasculature, compared with PVR, in advanced HF patients.…”