Andrea Maria D'Armini

Bosentan for Treatment of Inoperable Chronic Thromboembolic Pulmonary Hypertension: BENEFiT (Bosentan Effects in iNopErable Forms of chronIc Thromboembolic pulmonary hypertension), a Randomized, Placebo-Controlled Trial

OBJECTIVES Our goal was to investigate the effect of treatment with the oral dual endothelin receptor antagonist bosentan on the hemodynamics and exercise capacity of patients with chronic thromboembolic pulmonary hypertension (CTEPH). BACKGROUND CTEPH is characterized by vascular obstruction and remodeling, leading to increased pulmonary vascular resistance (PVR). Although pulmonary endarterectomy (PEA) is potentially curative, medical therapy is needed in patients with inoperable disease or persistent/recurrent pulmonary hypertension after PEA. METHODS The BENEFiT (Bosentan Effects in iNopErable Forms of chronIc Thromboembolic pulmonary hypertension) study was a double-blind, randomized, placebo-controlled study in CTEPH including patients with either inoperable CTEPH or persistent/recurrent pulmonary hypertension after PEA (>6 months after PEA). Independent coprimary end points were change in PVR as a percentage of baseline and change from baseline in 6-min walk distance after 16 weeks of treatment with bosentan or placebo. Secondary end points included change from baseline in World Health Organization functional class and other hemodynamic parameters. RESULTS One hundred fifty-seven patients were enrolled and randomized: 80 to placebo, 77 to bosentan. A statistically significant treatment effect (TE) of bosentan over placebo on PVR was demonstrated: -24.1% of baseline (95% confidence interval [CI]: -31.5% to -16.0%; p < 0.0001). Total pulmonary resistance (TE: -193 dynxsxcm(-5); 95% CI: -283 to -104 dyn.s.cm(-5); p < 0.0001) and cardiac index (TE: 0.3 lxmin(-1)xm(-2); 95% CI: 0.14 to 0.46 lxmin(-1)xm(-2); p = 0.0007) improved. Mean TE on 6-min walk distance was +2.2 m (95% CI: -22.5 to 26.8 m; p = 0.5449). Bosentan treatment was well tolerated. CONCLUSIONS This study demonstrated a positive TE of bosentan on hemodynamics in this patient population. No improvement was observed in exercise capacity. Further trials are needed to define the role of medical therapy in patients with CTEPH (Bosentan Effects in Inoperable Forms of Chronic Thromboembolic Pulmonary Hypertension; NCT00313222).

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) Results From an International Prospective Registry

Background— Chronic thromboembolic pulmonary hypertension (CTEPH) is often a sequel of venous thromboembolism with fatal natural history; however, many cases can be cured by pulmonary endarterectomy. The clinical characteristics and current management of patients enrolled in an international CTEPH registry was investigated. Methods and Results— The international registry included 679 newly diagnosed (≤6 months) consecutive patients with CTEPH, from February 2007 until January 2009. Diagnosis was confirmed by right heart catheterization, ventilation-perfusion lung scintigraphy, computerized tomography, and/or pulmonary angiography. At diagnosis, a median of 14.1 months had passed since first symptoms; 427 patients (62.9%) were considered operable, 247 (36.4%) nonoperable, and 5 (0.7%) had no operability data; 386 patients (56.8%, ranging from 12.0%– 60.9% across countries) underwent surgery. Operable patients did not differ from nonoperable patients relative to symptoms, New York Heart Association class, and hemodynamics. A history of acute pulmonary embolism was reported for 74.8% of patients (77.5% operable, 70.0% nonoperable). Associated conditions included thrombophilic disorder in 31.9% (37.1% operable, 23.5% nonoperable) and splenectomy in 3.4% of patients (1.9% operable, 5.7% nonoperable). At the time of CTEPH diagnosis, 37.7% of patients initiated at least 1 pulmonary arterial hypertension–targeted therapy (28.3% operable, 53.8% nonoperable). Pulmonary endarterectomy was performed with a 4.7% documented mortality rate. Conclusions— Despite similarities in clinical presentation, operable and nonoperable CTEPH patients may have distinct associated medical conditions. Operability rates vary considerably across countries, and a substantial number of patients (operable and nonoperable) receive off-label pulmonary arterial hypertension–targeted treatments. # Clinical Perspective {#article-title-40}Background— Chronic thromboembolic pulmonary hypertension (CTEPH) is often a sequel of venous thromboembolism with fatal natural history; however, many cases can be cured by pulmonary endarterectomy. The clinical characteristics and current management of patients enrolled in an international CTEPH registry was investigated. Methods and Results— The international registry included 679 newly diagnosed (⩽6 months) consecutive patients with CTEPH, from February 2007 until January 2009. Diagnosis was confirmed by right heart catheterization, ventilation-perfusion lung scintigraphy, computerized tomography, and/or pulmonary angiography. At diagnosis, a median of 14.1 months had passed since first symptoms; 427 patients (62.9%) were considered operable, 247 (36.4%) nonoperable, and 5 (0.7%) had no operability data; 386 patients (56.8%, ranging from 12.0%– 60.9% across countries) underwent surgery. Operable patients did not differ from nonoperable patients relative to symptoms, New York Heart Association class, and hemodynamics. A history of acute pulmonary embolism was reported for 74.8% of patients (77.5% operable, 70.0% nonoperable). Associated conditions included thrombophilic disorder in 31.9% (37.1% operable, 23.5% nonoperable) and splenectomy in 3.4% of patients (1.9% operable, 5.7% nonoperable). At the time of CTEPH diagnosis, 37.7% of patients initiated at least 1 pulmonary arterial hypertension–targeted therapy (28.3% operable, 53.8% nonoperable). Pulmonary endarterectomy was performed with a 4.7% documented mortality rate. Conclusions— Despite similarities in clinical presentation, operable and nonoperable CTEPH patients may have distinct associated medical conditions. Operability rates vary considerably across countries, and a substantial number of patients (operable and nonoperable) receive off-label pulmonary arterial hypertension–targeted treatments.

Surgical management and outcome of patients with chronic thromboembolic pulmonary hypertension: Results from an international prospective registry

OBJECTIVE Pulmonary endarterectomy is a curative surgical treatment option for the majority of patients with chronic thromboembolic pulmonary hypertension. The current surgical management and postoperative outcome of patients enrolled in an international registry on chronic thromboembolic pulmonary hypertension were investigated. METHODS The registry included newly diagnosed (≤6 months) consecutive patients with chronic thromboembolic pulmonary hypertension from February 2007 to January 2009. RESULTS A total of 679 patients were registered from 1 Canadian and 26 European centers, of whom 386 (56.8%) underwent surgery. The median age of patients undergoing surgery was 60 years, and 54.1% were male. Previous pulmonary embolism was confirmed for 79.8% of patients. Perioperative complications occurred in 189 patients (49.2%): infection (18.8%), persistent pulmonary hypertension (16.7%), neurologic (11.2%) or bleeding (10.2%) complications, pulmonary reperfusion edema (9.6%), pericardial effusion (8.3%), need for extracorporeal membrane oxygenation (3.1%), and in-hospital mortality due to perioperative complications (4.7%). Documented 1-year mortality was 7%. Preoperative exercise capacity was predictive of 1-year mortality. Postoperative pulmonary vascular resistance predicted in-hospital and 1-year mortality. In patients evaluated within 1 year after surgery, the median pulmonary vascular resistance had decreased from 698 to 235 dyn x s x cm(-5) (95% confidence limit, 640-874 and 211-255, respectively, n = 70) and the median 6-minute walk distance had increased from 362 to 459 m (95% confidence limit, 340-399 and 440-473, respectively, n = 168). New York Heart Association functional class improved with most patients progressing from class III/IV to class I/II. CONCLUSIONS Pulmonary endarterectomy is associated with a low in-hospital mortality rate and improvements in hemodynamics and exercise capacity.

Prognostic relevance of the echocardiographic assessment of right ventricular function in patients with idiopathic pulmonary arterial hypertension

BACKGROUND In patients with idiopathic pulmonary hypertension (IPAH) progression of the disease and survival are related to the capability of the right ventricle to adapt to the chronically elevated pulmonary artery pressure. Although several echocardiographic variables have been associated with outcome in previous studies, a comparative evaluation of all right ventricular (RV) function indices obtainable at echocardiography has never been performed. METHODS 59 patients consecutively admitted in a tertiary referral centre because of IPAH (22 males, mean age 46.3+/-16.1 years, 68% in WHO class III/IV at referral) underwent right heart catheterization and echocardiography. During a median follow-up period of 52 months, 21 patients died and 2 underwent lung transplantation in emergency conditions. RESULTS The following parameters were associated with survival: tricuspid annular plane systolic excursion (TAPSE), RV fractional area change, degree of tricuspid regurgitation, inferior vena cava collapsibility, superior vena cava flow velocity pattern, left ventricular diastolic eccentricity index. Patients with TAPSE<or=15 mm and left ventricular eccentricity index >or=1.7 had the highest event rate (51.7 per 100 person year); patients with TAPSE>15 mm and mild or no tricuspid regurgitation had the lowest event rate (2.6 per 100 person year). CONCLUSIONS A comprehensive echocardiographic assessment of RV systolic and diastolic function based on TAPSE, left ventricular diastolic eccentricity index and degree of tricuspid regurgitation allows an accurate prognostic stratification of patients with IPAH.

Long-term Outcome after Pulmonary Endarterectomy

RATIONALE There are few follow-up studies on long-term cardiopulmonary function after pulmonary endarterectomy (PEA), the operation of choice for chronic thromboembolic pulmonary hypertension (CTEPH). OBJECTIVES To prospectively evaluate long-term outcome of patients with CTEPH treated with PEA. METHODS Between 1994 and 2006, 157 patients (mean age 55 yr) were treated with PEA at Pavia University Hospital. The patients were evaluated before PEA and at 3 months (n = 132), 1 year (n = 110), 2 years (n = 86), 3 years (n = 69), and 4 years (n = 49) afterward by NYHA class, right heart hemodynamic, spirometry, carbon monoxide transfer factor (Tl(CO)), arterial blood gas, and treadmill incremental exercise test. MEASUREMENTS AND MAIN RESULTS Cumulative survival was 84%. Within 3 months, 18 patients died in-hospital and 2 had lung transplantation; during long-term follow-up, 6 died, 1 had lung transplantation, and 3 had a second PEA (2.5 events per 100 person-years). NYHA class III-IV was the most important predictor of late death, lung transplant, or PEA redo (hazard ratio, 3.94). Extraordinary improvement in NYHA class, hemodynamic, and Pa(O(2)) were achieved in the first 3 months (P < 0.001) and persisted during follow-up; exercise tolerance progressively increased over time (P < 0.001). At 4 years, although 74% of the patients were in NYHA class I and none was in class IV, 24% had pulmonary vascular resistance greater than 500 dyne.s/cm(5) or Pa(O(2)) less than 60 mm Hg; they were significantly older and were more frequently in NYHA class III-IV 3 months after surgery than the others. CONCLUSIONS After PEA, long-term survival and cardiopulmonary function recovery is excellent in most patients.

Plaque composition in plexogenic and thromboembolic pulmonary hypertension: the critical role of thrombotic material in pultaceous core formation.

Background: Patients with pulmonary hypertension develop intimal plaques in large pulmonary arteries. Objective: To test the hypothesis that the composition of such plaques differs depending on whether the aetiology of the disease is thromboembolic or hypertensive. Design: Chronic thromboembolic and plexogenic pulmonary hypertension (primary and secondary (Eisenmenger syndrome)) were investigated. These are spontaneous human models and were used to examine the independent role of thrombus and hypertension in plaque composition. Setting: A national tertiary referral centre for lung transplantation and pulmonary thromboendoarterectomy. Patients: Thirty nine patients with chronic thromboembolic pulmonary hypertension who had undergone thromboendoarterectomy (n = 32) or lung transplantation (n = 7), 28 with plexogenic diseases (nine primary and 19 Eisenmenger), and three with Eisenmenger syndrome complicated by thromboembolic events. Interventions: The lung and thromboendoarterectomy samples were sectioned, stained with Movat pentachrome, and immunostained with antibodies for fibrin, platelets, inflammatory cells, smooth muscle cells, and erythrocyte membrane glycophorin A. Main outcome measure: Composition of the plaques affecting large pulmonary arteries. Results: Two types of intimal lesion were distinguished in chronic thromboembolic pulmonary hypertension: fibrous plaques with angioneogenesis; and core-rich atherosclerotic plaques with pultaceous cores largely consisting of glycophorin immunoreactive material, with cholesterol clefts (61.5%), CD68 positive macrophages (84.6%), T lymphocytes (87%), and calcification (46.1%). The samples from the patients with Eisenmenger syndrome and thromboembolic complications had similar characteristics, whereas those from patients with uncomplicated primary pulmonary hypertension had core-free fibrous plaques, spotted with macrophages and T lymphocytes. Conclusions: Chronic thromboembolic pulmonary hypertension is associated with atherosclerotic plaques with glycophorin-rich pultaceous cores, and plexogenic pulmonary hypertension with fibrous plaques. Thromboembolic material thus plays a critical role in the formation of pultaceous cores, of which erythrocyte membrane derived glycophorin is a major component.

Pulmonary thromboendarterectomy in patients with chronic thromboembolic pulmonary hypertension: hemodynamic characteristics and changes.

OBJECTIVE To see whether degree of pulmonary hypertension or severity of cardiac failure affect the success of pulmonary thromboendarterectomy (PTE) in chronic thromboembolic pulmonary hypertension. METHODS From May 1996 to June 1999, 33 patients, all in New York Heart Association (NYHA) class 3 or 4 were treated with PTE. Preoperative hemodynamic values were: central venous pressure (CVP) 8+/-6 (1-23), mean pulmonary artery pressure (mPAP) 50+/-10 (30-69), cardiac output (CO) 3.3+/-0.9 (1.8-5.2), pulmonary vascular resistance (PVR) 1056+/-344 (523-1659), and right ventricle ejection fraction (RVEF) 12+/-5 (5-21). To establish whether some hemodynamic or cardiac variables correlate with surgical failure (early death or functional non-success), these patients were divided into a low risk or a high risk group for each variable: CVP (<9 or > or =9), mPAP (<50 or > or =50), CO (> or =3.5 or <3.5), PVR (> or =1100 or <1100), and RVEF (> or = 10 or <10). The duration of 3-4 NYHA class period (<24 or > or = 24 months) was also included in the study. RESULTS Three patients (9. 1%) died in hospital, one (3.0%) underwent lung transplant shortly after PTE, and in five cases (15.2%) mPAP and PVR at the 3-month follow-up examination corresponded with our definition of functional nonsuccess (mPAP and PVR decreased by less than 40% of preoperative values). One of the five functional nonsuccess patients underwent lung transplant 3 months after the operation and another died 17 months after the operation from a non-related cause. Thus PTE was successful in 24 patients and unsuccessful in nine. None of the hemodynamic variables considered was found to be associated with the disparate outcomes. At the 3-month examination, all surviving patients were in NYHA class 1 or 2 except for three in NYHA class 3. At 2 years, hemodynamic values were: CVP 2+/-2 (0-4), mPAP 16+/-3 (12-21), CO 5.0+/-1.0 (3.4-6.5), PVR 182+/-51 (112-282), and RVEF 35+/-5 (26-40). All differences were significant with respect to baseline values (P<0.001). Preoperative mPAP and RVEF values had a strict linear correlation (R=0.45; P=0.014). CONCLUSIONS None of the variables considered was correlated with early death or functional nonsuccess. Neither preoperative severity of pulmonary hypertension nor degree of cardiac failure influenced the outcome of the operation. PTE leads to hemodynamic recovery even in very compromised patients.

Long-Term Outcome of Patients With Chronic Thromboembolic Pulmonary Hypertension (CTEPH): Results From an International Prospective Registry

Background— Chronic thromboembolic pulmonary hypertension, a rare complication of acute pulmonary embolism, is characterized by fibrothrombotic obstructions of large pulmonary arteries combined with small-vessel arteriopathy. It can be cured by pulmonary endarterectomy, and can be clinically improved by medical therapy in inoperable patients. A European registry was set up in 27 centers to evaluate long-term outcome and outcome correlates in 2 distinct populations of operated and not-operated patients who have chronic thromboembolic pulmonary hypertension. Methods and Results— A total of 679 patients newly diagnosed with chronic thromboembolic pulmonary hypertension were prospectively included over a 24-month period. Estimated survival at 1, 2, and 3 years was 93% (95% confidence interval [CI], 90–95), 91% (95% CI, 87–93), and 89% (95% CI, 86–92) in operated patients (n=404), and only 88% (95% CI, 83–91), 79% (95% CI, 74–83), and 70% (95% CI, 64–76) in not-operated patients (n=275). In both operated and not-operated patients, pulmonary arterial hypertension–targeted therapy did not affect survival estimates significantly. Mortality was associated with New York Heart Association functional class IV (hazard ratio [HR], 4.16; 95% CI, 1.49–11.62; P=0.0065 and HR, 4.76; 95% CI, 1.76–12.88; P=0.0021), increased right atrial pressure (HR, 1.34; 95% CI, 0.95–1.90; P=0.0992 and HR, 1.50; 95% CI, 1.20–1.88; P=0.0004), and a history of cancer (HR, 3.02; 95% CI, 1.36–6.69; P=0.0065 and HR, 2.15; 95% CI, 1.18–3.94; P=0.0129) in operated and not-operated patients, respectively. Additional correlates of mortality were bridging therapy with pulmonary arterial hypertension–targeted drugs, postoperative pulmonary hypertension, surgical complications, and additional cardiac procedures in operated patients, and comorbidities such as coronary disease, left heart failure, and chronic obstructive pulmonary disease in not-operated patients. Conclusions— The long-term prognosis of operated patients currently is excellent and better than the outcome of not-operated patients.

Clinical and prognostic relevance of echocardiographic evaluation of right ventricular geometry in patients with idiopathic pulmonary arterial hypertension.

The aim of the present study was to assess the clinical and prognostic significance of right ventricular (RV) dilation and RV hypertrophy at echocardiography in patients with idiopathic pulmonary arterial hypertension. Echocardiography and right heart catheterization were performed in 72 consecutive patients with idiopathic pulmonary arterial hypertension admitted to our institution. The median follow-up period was 38 months. The patients were grouped according to the median value of RV wall thickness (6.6 mm) and the median value of the RV diameter (36.5 mm). On multivariate analysis, the mean pulmonary artery pressure (p = 0.018) was the only independent predictor of RV wall thickness, and age (p = 0.011) and moderate to severe tricuspid regurgitation (p = 0.027) were the independent predictors of RV diameter. During follow-up, 22 patients died. The death rate was greater in the patients with a RV diameter >36.5 mm than in patients with a RV diameter ≤36.5 mm: 15.9 (95% confidence interval 9.4 to 26.8) vs 6.6 (95% confidence interval 3.3 to 13.2) events per 100-person years (p = 0.0442). In contrast, the death rate was similar in patients with RV wall thickness above or below the median value. However, among the patients with a RV wall thickness >6.6 mm, a RV diameter >36 mm was not associated with a poorer prognosis (p = 0.6837). In conclusion, in patients with idiopathic pulmonary arterial hypertension, a larger RV diameter is a marker of a poor prognosis but a greater RV wall thickness reduces the risk of death associated with a dilated right ventricle.

Mid term effects of pulmonary thromboendarterectomy on clinical and cardiopulmonary function status

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) can be successfully treated surgically by pulmonary thromboendarterectomy (PTE) but there are few data on mid-term cardiopulmonary function, particularly on exertion, and clinical benefits following pulmonary PTE. Methods: A 2 year follow up study was undertaken of clinical status, haemodynamic and lung function indices, gas exchange, and exercise tolerance in 38 patients of mean (SD) age 50 (15) years who had undergone PTE. Results: In-hospital mortality was about 10%. Before PTE all the patients were severely impaired (NYHA classes III–IV). There was no time difference in the improvement in the parameters: nearly all the improvement in cardiac output, gas exchange, and clinical status was achieved in the first 3 months as a result of the relief of pulmonary obstruction. At 3 months the percentage of patients with normal cardiac output and Pao2 and of those with reduced clinical impairment increased to 97%, 59%, and 87%, respectively, without any further change. Only mean pulmonary artery pressure (mPAP), carbon monoxide transfer factor (Tlco), and exercise tolerance improved gradually during the second year, probably due to the recovery of the damaged small vessels. Tlco was overestimated before PTE but afterwards the trend was similar to that of mPAP. Conclusions: At mid term only a few patients did not have a satisfactory recovery because of lack of operative success, hypertension relapse, or the effect of preoperative hypertension on vessels in non-obstructed segments. Most of the patients, even the more compromised ones, had excellent long lasting results.