Impairment of pulmonary vascular reserve and right ventricular systolic reserve in pulmonary arterial hypertension

Abstract

BackgroundExercise capacity is impaired in pulmonary arterial hypertension (PAH). We hypothesized that cardiovascular reserve abnormalities would be associated with impaired hemodynamic response to pharmacological stress and worse outcome in PAH.MethodsEighteen PAH patients (p) group 1 NYHA class II/III and ten controls underwent simultaneous right cardiac catheterization and intravascular ultrasound at rest and during low dose-dobutamine (10 mcg/kg/min) with trendelenburg (DST). We estimated cardiac output (CO), pulmonary vascular resistance (PVR) and capacitance (PC), and PA elastic modulus (EM). We concomitantly measured tricuspid annular plane systolic excursion (TAPSE), RV myocardial peak systolic velocity (Sm) and isovolumic myocardial acceleration (IVA) in PAH patients. Based on the rounded mean + 2 SD of the increase in mPAP in our healthy control group during DST (2.8 + 1.8 mm Hg), PAH p were divided into two groups according to mean PA pressure (mPAP) response during DST, 1: ΔmPAP > 5 mm Hg and 2: ΔmPAP ≤ 5 mm Hg. Cardiovascular reserve was estimated as the change (delta, Δ) during DST compared with rest, including ΔmPAP with respect to ΔCO (ΔmPAP/ΔCO). All patients were prospectively followed up for 2 years.ResultsPAH p showed significant lower heart rate and CO increase than controls during DST, with a significant mPAP and pulse PAP increase and higher ΔmPAP/ΔCO (p < 0.05). Neither hemodynamic, IVUS and echocardiographic data were different between both PAH groups at rest. In group 1, DST caused a higher ΔEM, ΔmPAP/ΔCO, ΔPVR, and ΔTAPSE than group 2, with a lower IVA increase and a negative ΔSV (p < 0.05). TAPSE correlated with mPAP and RVP (p < 0.05) and, IVA and Sm correlated with CO (p < 0.05). ΔEM correlated with ΔmPAP and ΔIVA with ΔCO (p < 0.05). There were two deaths/pulmonary transplantations in group 1 and one death in group 2 during the follow-up (p > 0.05).ConclusionsPulmonary vascular reserve and RV systolic reserve are significantly impaired in patients with PAH. The lower recruitable cardiovascular reserve is significantly related to a worse hemodynamic response to DST and it could be associated with a poor clinical outcome.

Pulmonary arterial wall thickness in Eisenmenger Syndrome: Prospective, cross-sectional, controlled clinical trial

“…RVWT is <5 mm in adults . Human and animal studies have shown that RVWT is a dynamic and varying parameter and is correlated with pulmonary arterial peak pressure, TAPSE, and some other echocardiographic parameters . The results of this study yielded a strong positive correlation between PAWT and RVWT (r = 0.893, P < 0.001).…”

High levels of serum lactate dehydrogenase correlate with the severity and mortality of idiopathic pulmonary arterial hypertension

“…Right ventricular failure can lead to liver function abnormalities, which increase the level of certain liver enzymes, such as transaminase and LDH, in the serum. Liver function is associated with the prognosis of patients with heart failure (10)(11)(12)(13). The aim of the present study was to determine whether S-LDH is a prognostic marker in patients with IPAH.…”

The emerging role of the contractile and vascular reserves in pulmonary arterial hypertension

“…We recently reported that only IVA and ΔIVA are significantly correlated to cardiac output (CO) and ΔCO. In contrast, S′ showed a moderate correlation and TAPSE did not correlate with CO [8]. Besides this, the lower values of TAPSE and S′ at rest in the PAH group compared with controls, as reported by SHARMA et al [1], illustrate the significant afterload dependence of TAPSE and S′, and hence, the inaccurate assessment of the contractile reserve.…”

“…LAU et al [10] showed that patients with PAH had an average dobutamine-induced mPAP-CO slope that was significantly higher than in healthy controls, with a markedly reduced distensibility coefficient α. Accordingly, we reported a significant increase of the elastic modulus (EM) of the pulmonary artery (PA) in PAH patients during pharmacological stress, with a negative change of EM in controls [8]. The positive correlation between ΔEM and ΔmPAP suggests that PA remodelling and buffering function impairment could be associated with the lower vascular reserve of PAH patients.…”

“…The positive correlation between ΔEM and ΔmPAP suggests that PA remodelling and buffering function impairment could be associated with the lower vascular reserve of PAH patients. The patients with high vascular reserve (EM and mPAP-CO) and contractile reserve (IVA) had a more preserved haemodynamic response (ΔmPAP <5 mmHg) during dobutamine stress testing, and could have a better clinical outcome [8]. However, not every patient with high vascular reserve had a preserved contractile reserve ( fig.…”