Roela Sadushi-Kolici

Pulmonary Vascular Reactivity and Prognosis in Patients With Chronic Thromboembolic Pulmonary Hypertension A Pilot Study

Background— Surgical pulmonary endarterectomy is the preferred treatment for chronic thromboembolic pulmonary hypertension. Persistent pulmonary hypertension after pulmonary endarterectomy has been recognized as a major determinant of poor outcome. We tested whether acute vasoreactivity identifies chronic thromboembolic pulmonary hypertension patients prone to develop persistent/recurrent pulmonary hypertension after pulmonary endarterectomy and whether the degree of acute vasoreactivity affects survival or freedom from lung transplantation. Methods and Results— Right-sided heart catheterization at baseline and after inhalation of 40 ppm nitric oxide for 20 minutes was performed in 103 patients (56.3±15.3 years old, 53 women). Reductions in mean pulmonary arterial pressure (&Dgr;mPAP; −8.8±12.6%; P<0.0001) and pulmonary vascular resistance (−16.1±18.1%; P<0.0001) and an increase in mixed venous saturation during inhaled nitric oxide (9.1±11.6%; P<0.0001) were observed. Sixty-two patients underwent pulmonary endarterectomy after a median of 49 days (25th and 75th percentiles: 24 and 123 days). Operated patients were followed up for a median of 70.9 months (25th and 75th percentiles: 14 and 97 months). Change in mPAP during inhaled NO was identified as a predictor of persistent/recurrent pulmonary hypertension after pulmonary endarterectomy. Patients experiencing a reduction in mPAP >10.4% with nitric oxide inhalation had a better postoperative outcome. A significant correlation was found between &Dgr;mPAP and immediate postoperative pulmonary vascular resistance (r=0.5, P<0.0001). Conclusions— A total of 80 (77.7%) of 103 patients demonstrated acute pulmonary vascular reactivity of some degree. A decrease in mPAP >10.4% under inhaled nitric oxide is a predictor of long-term survival and freedom from lung transplantation in adult patients with chronic thromboembolic pulmonary hypertension who are undergoing pulmonary endarterectomy.

Imaging in Pulmonary Hypertension

Pulmonary hypertension is defined as an increase in mean pulmonary arterial pressure ≥25 mm Hg at rest and occurs in a majority of patients with heart failure. Diagnostic imaging targets the right ventricle and the pulmonary vasculature. Although echocardiography is cost-effective for screening and follow-up, right heart catheterization is still mandatory to differentiate pre- from post-capillary disease and to directly measure pressure and flow. An important goal is to rule out chronic thromboembolic pulmonary hypertension. This diagnostic step can be achieved by perfusion scintigraphy, whereas computed tomography and cardiac magnetic resonance have become indispensable ancillary methods for the diagnostic allocation to other World Health Organization subtypes of pulmonary hypertension.

Surgical specimens, haemodynamics and long-term outcomes after pulmonary endarterectomy

Background Chronic thromboembolic pulmonary hypertension is surgically curable by pulmonary endarterectomy (PEA). It is unclear whether PEA impacts primarily steady state right ventricular afterload (ie, pulmonary vascular resistance (PVR)) or pulsatile right ventricular afterload (ie, pulmonary arterial compliance (CPA)). Our objectives were to (1) quantify PEA specimens and measure the impact of PEA on PVR and CPA in a structure/function study and (2) analyse the effects of haemodynamic changes on long-term survival/freedom of lung transplantation in an outcome study. Methods Thrombi were laid out, weighed, photographed and measured. PVR, CPA and resistance times compliance (RC-time) were assessed at baseline, within 4 days after PEA (‘immediately postoperative’) and 1 year after PEA, in 110 consecutive patients who were followed for 34.5 (11.9; 78.3) months. Results Lengths and numbers of PEA specimen tails were inversely correlated with immediate postoperative PVR (p<0.0001, r=−0.566; p<0.0001, r=−0.580). PVR and CPA normalised immediately postoperatively while RC-time remained unchanged. Immediate postoperative PVR was the only predictor of long-term survival/freedom of lung transplantation (p<0.0001). Patients with immediate postoperative PVR<590 dynes.s.cm−5 had better long-term outcomes than patients with PVR≥590 dynes.s.cm−5 (p<0.0001, respectively). Conclusions PEA immediately decreased PVR and increased CPA under a constant RC-time. However, immediate postoperative PVR was the only predictor of long-term survival/freedom of lung transplantation. Our study confirms the importance of a complete, bilateral surgical endarterectomy. Low PVR measured immediately postoperative predicts excellent long-term outcome.

Long-term treatment, tolerability, and survival with sub-cutaneous treprostinil for severe pulmonary hypertension

BACKGROUND Randomized controlled trials have resulted in improved outcomes in pulmonary arterial hypertension; however, they are biased by stringent inclusion criteria, pre-specified patient sub-sets, and study durations. In addition, common practice is to start oral therapies ahead of the more potent and titratable prostanoid therapies, despite advanced disease states at diagnosis. The objectives of our prospective registry were to evaluate long-term effects on functional class, 6-minute walking distance, hemodynamics, and survival, and also long-term tolerability of first-line sub-cutaneous treprostinil, a prostacyclin analog, in patients with severe pulmonary hypertension. METHODS Data were collected from patients with functional class III/IV pre-capillary pulmonary hypertension (Dana Point groups 1 and 4; mean right arterial pressure ≥ 10 mmHg, and/or cardiac index ≤ 2.2 liters/min/m(2)). Treprostinil dose adjustments were driven by clinical symptoms and side effects. RESULTS The study included 111 patients (1999 to 2010). Of these, 13 (12%) stopped treatment prematurely because of drug side effects, 11 (9.9%) underwent double lung transplantation, and 49 (44.1%) died of any cause (41 on treatment, 8 after early drug discontinuation). Overall survival rates at 1, 5, and 9 years were 84%, 53%, and 33%. In patients who were able to tolerate treatment > 6 months, survival rates were 57% at 9 years. CONCLUSION First-line treatment of severe pre-capillary pulmonary hypertension with sub-cutaneous treprostinil is safe and efficacious over many years. If up-titration beyond 6 months is tolerated, effective doses are reached and outcomes are good.

Hemodynamic Thresholds for Precapillary Pulmonary Hypertension

BACKGROUND Hemodynamic differentiation between pulmonary arterial hypertension (PAH) and postcapillary pulmonary hypertension (PH) is important because treatment options are strikingly different for the two disease subsets. Whereas patients with PAH can be treated effectively with targeted therapies, their use in postcapillary PH is currently not recommended. Our aim was to establish an algorithm to identify patients who are likely to experience a significant hemodynamic treatment response. METHODS We determined hemodynamic cutoffs to discriminate between idiopathic PAH and postcapillary PH in a large database of 4,363 stable patients undergoing first diagnostic right and left heart catheterizations. In a second step, we performed a patient-level pooled analysis of four randomized, placebo-controlled trials including 541 patients with PAH who received treprostinil or placebo, to validate hemodynamic cutoffs with regard to treatment response. RESULTS Receiver operating characteristic analysis identified mean pulmonary arterial wedge pressure (mPAWP) < 12 mm Hg and diastolic pulmonary vascular pressure gradient (DPG) ≥ 7 mm Hg as the best hemodynamic discriminators between idiopathic PAH and postcapillary PH. In our treatment study, only patients with mPAWP < 12 mm Hg, DPG > 20 mm Hg or a combination of both had a significant placebo-corrected improvement in hemodynamics. CONCLUSIONS mPAWP < 12 mm Hg and DPG > 20 mm Hg identify patients with PAH who are likely to have significant hemodynamic improvement with prostacyclin treatment.

Local and Systemic RAGE Axis Changes in Pulmonary Hypertension: CTEPH and iPAH

Objective The molecular determinants of chronic thromboembolic pulmonary hypertension (CTEPH) and idiopathic pulmonary arterial hypertension (iPAH) remain poorly understood. The receptor for advanced glycation endproducts (RAGE) and its ligands: HMGB1 and S100A9 are involved in inflammatory disorders. We sought to investigate the role of the RAGE axis in patients with CTEPH undergoing pulmonary endarterectomy (PEA), iPAH undergoing lung transplantation (LuTX). The high pulmonary vascular resistance in CTEPH/iPAH results in pressure overload of the right ventricle. We compared sRAGE measurements to that of patients with aortic valve stenosis (AVS) – pressure overload of the left ventricle. Methods We enrolled patients with CTEPH(26), iPAH(15), AVS(15) and volunteers(33). Immunohistochemistry with antibodies to RAGE and HMGB1 was performed on PEA specimens and lung tissues. We employed enzyme-linked immunosorbent assays to determine the concentrations of sRAGE, esRAGE, HMGB1 and S100A9 in serum of volunteers and patients with CTEPH, iPAH, AVS before and after PEA, LuTX and aortic valve replacement (AVR). Results In endarterectomised tissues from patients with CTEPH RAGE and HMGB1 were identified in myofibroblasts (α-SMA+vimentin+CD34−), recanalizing vessel-like structures of distal myofibrotic tissues and endothelium of neointima. RAGE was differentially expressed in prototypical Heath Edwards lesions in iPAH. We found significantly increased serum concentrations of sRAGE, esRAGE and HMGB1 in CTEPH. In iPAH, sRAGE and esRAGE were significantly higher than in controls. Serum concentrations of sRAGE were significantly elevated in iPAH(p<0.001) and CTEPH(p = 0.001) compared to AVS. Serum sRAGE was significantly higher in iPAH compared to CTEPH(p = 0.042) and significantly reduced in AVS compared to controls(p = 0.001). There were no significant differences in sRAGE serum concentrations before and after surgical therapy for CTEPH, iPAH or AVS. Conclusions Our data suggest a role for the RAGE pathway in the pathophysiology of CTEPH and iPAH. PEA improves the local control of disease but may not influence the systemic inflammatory mechanisms in CTEPH patients through the RAGE pathway.

Subcutaneous treprostinil in congenital heart disease-related pulmonary arterial hypertension

Objective To assess the efficacy and safety of subcutaneous treprostinil in adult patients with congenital heart disease (CHD)-associated pulmonary arterial hypertension (PAH) after 12 months of treatment. Methods Consecutive adult patients with CHD–PAH received subcutaneous treprostinil to maximum tolerated doses in an observational study. Results Advanced CHD–PAH patients with WHO class III or IV disease (n=32, age 40±10 years, 20 females) received treprostinil for suboptimal response to bosentan (n=12), WHO functional class IV disease (FC, n=7) or prior to bosentan approval (n=13). In the multivariate mixed model, mean increase in 6 min walk distance (6-MWD) from baseline to 12 months was 114 m (76; 152) (P<0.001). WHO FC improved significantly (P=0.001) and B-type brain natriuretic peptide decreased from 1259 (375; 2368) pg/mL to 380 (144; 1468) pg/mL (P=0.02). In those 14 patients who had haemodynamic data before and after initiation of treprostinil, pulmonary vascular resistance decreased significantly (from 18.4±11.1 to 12.6±7.9 Wood units, P=0.003). The most common adverse events were infusion-site erythema and pain. One patient stopped treatment because of intolerable infusion-site pain after 8 months of treatment. No other major treatment-related complications were observed. Five patients died during early follow-up, having experienced a decrease in their 6-MWD prior. Conclusions Subcutaneous treprostinil therapy is generally safe and effective for at least 12 months and may be used in CHD-related PAH class III and IV.

Usefulness of thrombosis and inflammation biomarkers in chronic thromboembolic pulmonary hypertension—sampling plasma and surgical specimens

BACKGROUND Chronic thromboembolic pulmonary hypertension (CTEPH) results from persistent pulmonary vascular obstructions, presumably due to inflammatory thrombosis. Because estimates of thrombus volume at diagnosis have no predictive value, we investigated the role of the thrombosis marker, D-dimer, and the inflammation marker, C-reactive protein (CRP), for predicting outcomes in CTEPH. METHODS A total 289 consecutive patients with CTEPH were followed for 57 (median 45 to 69) months. One hundred fifty-seven of these patients underwent surgical pulmonary endarterectomy (PEA). D-dimer and CRP were collected at the time of CTEPH diagnosis and their impact on outcome was analyzed using Cox and logistic regression models. Their association with thrombus composition was analyzed utilizing HistoQuest. RESULTS D-dimer and CRP levels were separately and independently predictive of death or need for lung transplantation (p = 0.012 and p = 0.025, respectively). For example, 5-year survival was 90% (confidence limits 84% to 96%) in patients with D-dimer levels <0.5 µg/ml and CRP <1 mg/dl at diagnosis, as compared with 50% (36% to 64%) for patients with D-dimer ≥0.5 µg/ml and CRP ≥1 mg/dl (p < 0.001). D-dimer and CRP both decreased significantly after PEA (p < 0.01). The amount of fresh red thrombus in thrombendarterectomy specimens correlated positively with D-dimer levels at diagnosis (r = 0.37, p = 0.003). CONCLUSIONS D-dimer and CRP at the time of diagnosis are independent and significant predictors of outcome in CTEPH, available at the time of diagnosis. This observation suggests an important role for fibrin turnover and inflammation in the pathogenesis of CTEPH and the associated complications.