Venous endotelin-1 (ET-1) and brain natriuretic peptide (BNP) plasma levels during 6-month bosentan treatment for pulmonary arterial hypertension

Objective: Bosentan, an endothelin (ET) ETA-ETB receptors antagonist, is an effective therapy for idiopathic pulmonary arterial hypertension (PAH) and for PAH related to connective tissue disease (CTD). The aim of this study was to evaluate the behaviour of ET-1 and brain natriuretic peptide (BNP) venous plasma levels during a 6-month dual ET-1 receptor blockade and the potential influence of baseline ET-1 venous plasma levels on the clinical efficacy of bosentan. Setting and patients: Twenty-five patients with PAH (idiopathic n = 16, CTD n = 9) in WHO functional class II-III were included in this study. After initial evaluation, patients' WHO class, 6-minute walking-test (6MWT), ET-1 and BNP venous plasma levels were assessed at baseline and after 6-month bosentan therapy. To evaluate whether the ET-1 levels could influence the clinical response to bosentan, data were analyzed for the whole population which was stratified according to high and low ET-1 plasma levels (on the basis of the baseline median value of ET-1 plasma: Gr.1 18.7 pg/ml). Results: Study population included patients with moderate-severe PAH. After 6-month of treatment we observed a significant increase in 6MWT distance (from 435 ± 85) m to 467 ± 77 m, p > 0.001) and an improvement in WHO class (from 2.4 ± 0.5 to 2 ± 0.6 p > 0.01), with a significant decrease in BNP (from 87 ± 33 pg/ml to 67 ± 41 pg/ml, p = 0.006) and a trend towards lower ET-1 plasma levels (from 17.7 ± 5 pg/ml to 16 ± 6 pg/ml, p = ns). Improvement in effort tolerance (Δ distance) was not correlated to modification in ET-1 (ΔET-1) and BNP (ΔBNP) plasma levels, while we found a significant correlation between ΔET-1 and ΔBNP (r = 0.63, p = 0.0006). Analyzing the subpopulation, Gr.2 patients were older (Gr.1: 41 ± 10 years vs Gr.2: 50 ± 9 years, p = 0.04), had less effort capacity (6MWT distance, Gr.1: 469 ± 76 m, vs Gr.2: 398 ± 82 m, p = 0.03), and showed a trend towards higher BNP values (Gr.1: 82 ± 41 pg/ml vs Gr.2: 92 ± 23 pg/ml, p = 0.051), but no significant differences in pulmonary hemodynamics. After the 6-month treatment both groups showed a significant improvement in 6MWT (Gr.1: + 32 ± 24 m, Gr.2: + 32 ± 21 m p = 0.05) without differences between groups. WHO class had a trend towards lower class (Gr.1: - 0.5 ± 0.5, Gr.2: - 0.3 ± 0.4 p = 0.15) in both groups. BNP plasma levels showed a significant decrease only in Gr.2 (Gr.1: - 6 ± 41 pg/ml, Gr.2: - 34 ± 19 pg/ml p = 0.02); similarly ET-1 plasma levels showed a trend towards a decrease only in Gr.2 (Gr.1: 0.2 ± 4.6 pg/ml, Gr.2: - 3.8 ± 6.6 pg/ml p = 0.09). Conclusions: Our data confirm that bosentan is an effective therapy for patients with PAH. Its clinical efficacy (effort tolerance and NYHA) seems to be independent from baseline venous ET1 plasma levels. Bosentan therapy seems to elicit different patterns in ET-1 and BNP plasma levels, with decrease of the peptides only in patients with higher activation of the systemic endothelin system. Further studies are warranted to explore the potential impact of baseline ET-1 levels on the long-term effects (clinical worsening) of bosentan therapy. © 2008 Elsevier B.V. All rights reserved

Right ventricular dyssynchrony in idiopathic pulmonary arterial hypertension: determinants and impact on pump function

Background: Right ventricular (RV) dyssynchrony has been described in pulmonary arterial hypertension (PAH), but no evidence is available on its morphologic determinants and its effect on systolic function. The aim of this study was to evaluate the morphologic determinants of RV dyssynchrony by echocardiographic and cardiac magnetic resonance imaging and its effect on systolic function. Methods: In 60 consecutive idiopathic PAH (IPAH) patients with narrow QRS, RV dyssynchrony was evaluated by 2D speckle-tracking echocardiography, calculating the standard deviation of the times to peak systolic strain for the four mid-basal RV segments (RV-SD4). Patients were grouped by the median value of RV-SD4 (19 milliseconds) and compared for RV remodeling and systolic function parameters, WHO class, pulmonary hemodynamics and 6-minute walk test (6MWT). Results: Despite similar pulmonary vascular resistance and mean pulmonary arterial pressure, patients with RV-SD4 at >19 milliseconds had advanced WHO class and worse 6MWT, RV hemodynamics, RV remodeling and systolic function parameters compared with patients at ≤19 milliseconds. The morphologic determinants of RV dyssynchrony resulted RV end-diastolic area, LV diastolic eccentricity index and RV mass volume ratio (r = 0.69, r(2) = 0.47, p < 0.0001). Finally, we found a significant inverse correlation between RV mid-basal segments post-systolic shortening time and cardiac index (r = -0.64, r(2) = 0.41, p = 0.001), accounting for the significant correlation between RV-SD4 and cardiac index (r = 0.57, r(2) = 0.32, p = 0.003). Conclusions: In IPAH with narrow QRS, RV dyssynchrony is associated with RV dilation and eccentric hypertrophy pattern, suggesting a role of segmental wall stress heterogeneity as the major determinant of mechanical delay. Post-systolic shortening, as inefficient contraction, contributes to pump dysfunction

Pulmonary Arterial Dilatation in Pulmonary Hypertension: Prevalence and Prognostic Relevance

Objectives: Pulmonary arterial dilatation is considered a consequence of chronic pulmonary hypertension (PH), but despite its relatively common detection, its prevalence and prognostic impact have not yet been systematically investigated. The aim of the study was to investigate these factors in a relatively large cohort of severe PH patients. Methods: One hundred and forty-one consecutive patients diagnosed with PH were monitored for a mean of 957 days. Data including functional class, exercise capacity, invasive hemodynamics and pulmonary artery (PA) echo/CT scan measurement were performed and outcomes prospectively collected. Results: PA dilatation is a common feature, present in the 76.6% of cases in this cohort of severe PH patients. Survival at 1, 2 and 3 years was 83, 71 and 58%, respectively. On univariate analysis, the baseline variables associated with a poor outcome were related to pulmonary arterial hypertension associated with connective tissue disease (CDT-PAH), New York Heart Association (NYHA) functional class, 6-min walk and right atrial pressure. On multivariate analysis only CDTPAH and NYHA functional class remained independently associated with poor survival. Conclusions: PA dilatation is commonly detected in severe PH patients and is not associated with an increased risk of death. Copyright (C) 2012 S. Karger AG, Base

Relationship between baseline ET-1 plasma levels and outcome in patients with idiopathic pulmonary hypertension treated with bosentan

Objectives: To address if baseline endothelin-1 (ET-1) plasma levels might predict clinical worsening (CW) in patients with idiopathic pulmonary hypertension (IPAH) treated with bosentan. Methods: Forty-four consecutive patients with IPAH (WHO classes II–III) were included in this study. After an initial assessment (clinical status, pulmonary hemodynamics, samples for adrenomedullin (ADM), ET-1 and brain natriuretic peptide (BNP) plasma levels), patients were treated with bosentan and followed-up for CW. Results: WeobservedCWin 24 patients. Actuarial rates of freedom fromCWwere 74% at 1 year, 56% at 2 years, and 43% at 3 years. Patients with CW had a worseWHO functional class (II/III; no-CW 14/6 vs CW5/19, p=0.002), sixminute walk-test distance (no-CW 439+94 mvsCW385+82 m, p=0.04), mean pulmonary artery pressure (no- CW47.4+10.6 mmHg vs CW56+12.6 mmHg, p=0.02) and pulmonary vascular resistance (PVR no-CW12.5+ 4.8 WU vs CW 16.4+6.3 WU, p=0.03) than the no-CW group. Moreover ET-1 (no-CW 14.1+4.2 pg/ml vs CW 21.3+6.3 pg/ml, p=0.0001), ADM (no-CW 14.9+7 pg/ml vs CW 21.5+10.4 pg/ml p=0.002) and BNP (no- CW 82.8+35.3 pg/ml vs CW 115.4+39.6 pg/ml, p=0.007) plasma levels were significantly higher in the CW group than in the no-CW group. The multivariate Cox proportional hazards model identified WHO class III (RR 4.6, 95%CI 14.6–1.45), ET-1 plasma levels (RR 1.1, 95%CI 2.05–1.01) and PVR (RR 1.2, 95%CI 1.3–1.03) as independent risk factors for CW. Conclusions: These data confirm the high rate of CW in patients with IPAH treated with bosentan and document the impact of the endothelin system on CW of these patients

Associations of autozygosity with a broad range of human phenotypes

Abstract: In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (FROH) for >1.4 million individuals, we show that FROH is significantly associated (p < 0.0005) with apparently deleterious changes in 32 out of 100 traits analysed. These changes are associated with runs of homozygosity (ROH), but not with common variant homozygosity, suggesting that genetic variants associated with inbreeding depression are predominantly rare. The effect on fertility is striking: FROH equivalent to the offspring of first cousins is associated with a 55% decrease [95% CI 44–66%] in the odds of having children. Finally, the effects of FROH are confirmed within full-sibling pairs, where the variation in FROH is independent of all environmental confounding