Simvastatin treatment of pulmonary hypertension: an observational case series

BACKGROUND: Statins confer cardiovascular benefits beyond the reduction of serum cholesterol through antiproliferative and antiinflammatory mechanisms and induction of endothelial nitric oxide expression. In pneumonectomized rats injected with monocrotaline, simvastatin reversed established pulmonary hypertension and conferred a 100% survival advantage. STUDY OBJECTIVES: To evaluate the safety and efficacy of simvastatin for treatment of patients with pulmonary arterial hypertension (PAH). DESIGN: Open-label observational study performed at Stanford University Medical Center. Sixteen patients with primary and secondary causes of PAH, World Health Organization (WHO) classes I (n = 2), II (n = 4), III (n = 3), IV (n = 7), are described. Simvastatin was prescribed at 20 to 80 mg/d and continued in the absence of adverse effects. MEASUREMENTS AND RESULTS: Serial measurements of 6-min walk (6MW) performance, hemodynamics, and echocardiographic estimates of right ventricular systolic pressures (RVSPs) were recorded on each patient. Simvastatin treatment was not associated with hepatic dysfunction, muscle necrosis, or other adverse events. Individual patients demonstrated improvements in 6MW performance, improvements in cardiac output, or decreases in RVSP that may be attributable to simvastatin treatment. Overall, the rate of disease progression appeared to be attenuated, and WHO class IV patients demonstrated improved survival. CONCLUSIONS: Simvastatin treatment appears safe in patients with PAH.     

Endothelin-1/endothelin-3 ratio: a potential prognostic factor of pulmonary arterial hypertension

BACKGROUND: Pulmonary arterial hypertension (PAH) is a rare condition characterized by elevated pulmonary artery pressure leading to right-heart failure and death. Endothelin (ET)-1 has been shown to play a significant pathogenic role in PAH. ET-3 has not yet been investigated in PAH. METHODS: ET-1 and ET-3 plasma concentrations were measured in 33 PAH patients prior to any specific PAH therapy and in 9 control subjects. In PAH patients, hemodynamic parameters measured by right-heart catheterization, 6-min walk distance (6MWD), New York Heart Association (NYHA) functional class, and time until lung transplantation or death were recorded. RESULTS: In patients with PAH, levels of ET-1 were increased while those of ET-3 were decreased, as compared to control subjects (p < 0.005 for both comparisons). ET-1/ET-3 ratio varied little in control subjects, while it increased threefold in PAH patients (p < 0.0001). ET-1 correlated positively with right atrial pressure (RAP), indexed total pulmonary resistance, and negatively with cardiac index and venous saturation of oxygen (Svo(2)). ET-3 correlated positively with 6MWD. ET-1/ET-3 ratio correlated positively with RAP, negatively with Svo(2) and 6MWD, and was also associated with NYHA functional class. ET-1/ET-3 ratio was associated with prognosis in this sample of PAH patients treated with specific therapies. CONCLUSIONS: PAH is characterized by elevated ET-1 and ET-1/ET-3 ratio and decreased ET-3 plasma concentrations. All of them correlate with hemodynamic and clinical markers of disease severity. ET-1/ET-3 ratio might be a novel prognostic factor in PAH. These preliminary data should be validated in a large prospective multicenter cohort of PAH patients.     

Predictors of nocturnal oxygen desaturation in pulmonary arterial hypertension

Background:Sleep may be associated with significant respiratory compromise in patients with lung disease and can result in hypoxia. In patients with pulmonary arterial hypertension (PAH), nocturnal desaturation may not be reflected in daytime evaluations of oxygenation and can lead to worsening pulmonary hemodynamics. The study was conducted to determine the prevalence and significance of nocturnal oxygen desaturation in patients with PAH.Methods:A cross-sectional study conducted at the Cleveland Clinic. Patients were followed up at our institution except for the overnight oximetry study done at home. Data regarding degree of nocturnal desaturation, demographics, hemodynamics, pulmonary function, and functional capacity were collected.Results:Forty-three patients (mean age, 47.9 ± 13.5 years [± SD]; 36 women and 7 men) underwent nocturnal oximetry. The etiology of PAH included idiopathic PAH (88%) and PAH associated with connective tissue diseases (12%). The majority of patients were New York Heart Association functional class II (42%) or III (53%). Thirty patients (69.7%) spent > 10% of sleep time with oxygen saturation by pulse oximetry < 90%. Desaturators were older (p = 0.024) and had higher hemoglobin (p = 0.002). Sixteen of 27 patients (59%) without desaturation < 90% during a 6-min walk test were nocturnal desaturators. Nocturnal desaturators had higher brain natriuretic protein (p = 0.004), lower cardiac index (p = 0.03), and higher mean right atrial pressure (p = 0.09), mean pulmonary artery pressure, and pulmonary vascular resistance. On echocardiography, desaturators were more likely to have moderate or severe right ventricular dilation (p = 0.04) and pericardial effusion. Only one patient had significant sleep apnea.Conclusions:Nocturnal hypoxemia is common in PAH patients and correlates with advanced pulmonary hypertension and right ventricular dysfunction. Approximately 60% patients without exertional hypoxia had nocturnal desaturation. Overnight oximetry should be considered in the routine workup of PAH patients who do not demonstrate exertional desaturation.     

Atrial septostomy decreases sympathetic overactivity in pulmonary arterial hypertension

BACKGROUND: We have reported previously that the sympathetic nervous system is activated in patients with pulmonary arterial hypertension (PAH), and that this is only partly explained by a decrease in arterial oxygenation. Possible causes for increased muscle sympathetic nerve activity (MSNA) in patients with PAH include right atrial distension and decreased cardiac output. Both may be improved by atrial septostomy, but this intervention also further decreases arterial oxygenation. In the present study, we wanted to investigate the effect of atrial septostomy on MSNA in patients with PAH. METHODS: We recorded BP, heart rate (HR), arterial O2 saturation (SaO2), and MSNA before and after atrial septostomy in PAH patients (mean [+/- SE] age, 48 +/- 5 years) and in closely matched control subjects. Measurements were also performed after septostomy, while SaO2 was brought to the preprocedure level by supplemental O2 therapy. RESULTS: Compared to the control subjects (n = 10), the PAH patients (n = 11) had a lower mean BP (75 +/- 2 vs 96 +/- 3 mm Hg, respectively; p < 0.001), lower mean SaO2 (92 +/- 1% vs 97 +/- 0%, respectively; p < 0.001), increased mean HR (84 +/- 4 vs 68 +/- 3 beats/min; p < 0.01), and markedly increased mean MSNA (76 +/- 5 vs 29 +/- 2 bursts per minute; p < 0.001). Atrial septostomy decreased mean SaO2 (to 85 +/- 2%; p < 0.001) and mean MSNA (to 69 +/- 4 bursts per minute; p < 0.01), but did not affect HR or BP. Therapy with supplemental O2 did not affect MSNA, BP, or HR. The decrease in MSNA was correlated to the decrease in right atrial pressure (r = 0.62; p < 0.05). CONCLUSIONS: Atrial septostomy in PAH patients decreases sympathetic hyperactivity despite an associated decrease in arterial oxygenation, and this appears to be related to decreased right atrial distension.     

Pulmonary hemodynamics in advanced COPD candidates for lung volume reduction surgery or lung transplantation

STUDY OBJECTIVES: To assess the pulmonary hemodynamic characteristics in COPD candidates for lung volume reduction surgery (LVRS) or lung transplantation (LT). DESIGN: Retrospective study. SETTING: One center in France. PATIENTS: Two hundred fifteen patients with severe COPD who underwent right-heart catheterization before LVRS or LT. RESULTS: Mean age was 54.6 years. Pulmonary function test results were as follows: FEV(1), 24.3% predicted; total lung capacity, 128.3% predicted; residual volume, 259.7% predicted. Mean pulmonary artery pressure (PAPm) was 26.9 mm Hg. Pulmonary hypertension (PAPm > 25 mm Hg) was present in 50.2% and was moderate (PAPm, 35 to 45 mm Hg) or severe (PAPm > 45 mm Hg) in 9.8% and in 3.7% of patients, respectively. Cardiac index was low normal. PAPm was related to Pao(2) and alveolar-arterial oxygen gradient in multivariate analysis. Cluster analysis identified a subgroup of atypical patients (n = 16, 7.4%) characterized by moderate impairment of the pulmonary mechanics (mean FEV(1), 48.5%) contrasting with high level of pulmonary artery pressure (PAPm, 39.8 mm Hg), and severe hypoxemia (mean Pao(2), 46.2 mm Hg). CONCLUSION: While pulmonary hypertension is observed in half of the COPD patients with advanced disease, moderate-to-severe pulmonary hypertension is not a rare event in these patients. We individualized a subgroup of patients presenting with a predominant vascular disease that could potentially benefit from vasodilators.     

Medical therapy for pulmonary arterial hypertension: updated ACCP evidence-based clinical practice guidelines

A consensus panel convened by the American College of Chest Physicians developed guidelines for the treatment of pulmonary arterial hypertension (PAH) that were published in 2004. Subsequently, several important clinical trials have been published, and new treatments have received regulatory approval. In addition, add-on and combination therapy are being explored, which promise to open new therapeutic avenues. This article, taking into consideration studies published prior to September 1, 2006, provides an update to the previously published guidelines. The original guidelines have been summarized, a discussion of new studies has been added, and the treatment algorithm has been revised to take into account recent developments in therapy. This update provides evidence-based treatment recommendations for physicians involved in the care of patients with PAH. Due to the complexity of the diagnostic evaluation required and the treatment options available, referral of patients with PAH to a specialized center continues to be strongly recommended.     

Dramatic functional improvement following bariatric surgery in a patient with pulmonary arterial hypertension and morbid obesity

Pulmonary arterial hypertension (PAH) and morbid obesity both dramatically impair functional capacity. New therapies have emerged for both conditions, including pharmaceutical agents for the former and bariatric surgery for the latter. The presence of both conditions simultaneously, however, may limit the applicability and effectiveness of these therapies. We report a case of a morbidly obese patient with severe PAH and functional impairment. A three-drug combination regimen consisting of oral bosentan and sildenafil, and inhaled iloprost produced sufficient hemodynamic improvement to allow for the performance of bariatric surgery. Over the subsequent 7 months, body weight, oxygen requirement, functional class, and 6-min walk distance all improved dramatically despite the persistence of PAH. While such surgery is typically denied to patients with PAH, we suggest that aggressive medical therapy for patients with PAH may allow for its safe performance, and that the clinical improvement resulting from the subsequent weight loss may be quite dramatic.     

Pericardial abnormalities predict the presence of echocardiographically defined pulmonary arterial hypertension in systemic sclerosis-related interstitial lung disease

OBJECTIVES: To determine the prevalence and significance of pericardial abnormalities in systemic sclerosis (SSc)-related interstitial lung disease (ILD). METHODS: Retrospective study of 41 subjects with SSc-related ILD who underwent evaluation including thoracic high-resolution CT (HRCT) imaging, transthoracic echocardiography (TTE), and pulmonary function testing. HRCT review evaluated the pericardium for the presence of pericardial effusion (PEf), thickness of the anterior pericardial recess (APR) [abnormal defined as > 10 mm], and pericardial thickening as calculated by total pericardial score (TPS) [abnormal defined as > 8 mm]. Pulmonary arterial hypertension (PAH) was defined as a pulmonary artery pressure > 35 mm Hg estimated by TTE. RESULTS: Fifty-nine percent had an abnormal pericardium, 49% had a PEf, 56% had an abnormal APR, and 49% had an abnormal TPS. An abnormal pericardium was more common in men than women. Subjects with and without pericardial abnormalities were otherwise similar with respect to age, SSc classification, autoantibodies, ILD radiographic pattern, and presence of esophageal dilation. Both groups had similar median percentage of predicted total lung capacity, percentage of predicted FVC, percentage of predicted FEV(1), and percentage of predicted diffusion capacity of the lung for carbon monoxide. Subjects with pericardial abnormalities were more likely to have coexistent PAH (35% vs 75%; p = 0.02) and a higher median right ventricular systolic pressure (31 mm Hg vs 44 mm Hg; p = 0.03). Multiple logistic regression revealed that TPS was the best individual predictor of the presence of TTE-defined PAH. CONCLUSIONS: In patients with SSc-related ILD, pericardial abnormalities are commonly seen on HRCT, and their presence is strongly associated with echocardiographically defined PAH, with abnormal TPS as the best individual predictor.     

Pulmonary Artery Denervation Attenuates Pulmonary Arterial Remodeling in Dogs With Pulmonary Arterial Hypertension Induced by Dehydrogenized Monocrotaline

ObjectivesThis study aimed to investigate sympathetic nerve (SN) ultrastructural changes and hemodynamic and pulmonary artery (PA) pathological improvements by pulmonary arterial denervation (PADN) in animals with pulmonary arterial hypertension (PAH), as well as the underlying mechanisms.BackgroundSN overactivity plays a role in PAH. Previous studies have reported short-term improvements in pulmonary arterial pressure (PAP) and cardiac function by PADN, but PA remodeling and the associated mechanisms remain unclear.MethodsForty dogs were randomly (ratio of 1:3) assigned to the control (intra-atrial injection of N-dimethylacetamide, 3 mg/kg) and test (intra-atrial injection of dehydrogenized-monocrotaline, 3 mg/kg) groups. After 8 weeks, the animals in the test group with a mean PAP >25 mm Hg (n = 20) were randomized (ratio of 1:1) into the sham and PADN groups. At 14 weeks, the hemodynamics, medial wall thickness and PA muscularization, and messenger ribonucleic acid expression of genes in lung tissues were measured. Another 35 PAH dogs were used to measure the SN conduction velocity, electron microscopic assessment, and nerve distribution.ResultsPADN induced significant SN demyelination and axon loss and slowed SN conduction velocity over time, with resulting profound reductions in the mean PAP (23.5 ± 2.3 mm Hg vs. 33.7 ± 5.8 mm Hg), pulmonary vessel resistance (3.5 ± 2.3 Wood units vs. 7.7 ± 1.7 Wood units), medial wall thickness (22.3 ± 3.3% vs. 30.4 ± 4.1%), and full muscularization (40.3 ± 9.3% vs. 57.1 ± 5.7%) and increased nonmuscularization (29.8 ± 6.1% vs. 12.9 ± 4.9%) compared with the Sham group (all p < 0.001). PADN inhibited the messenger ribonucleic acid expression of genes correlated with inflammation, proliferation, and vasoconstriction.ConclusionsPADN induces permanent SN injury and subsequent improvements in hemodynamics and PA remodeling in animals with PAH through mechanisms that may be experimentally and clinically beneficial.     

Pulmonary hypertension due to a retained totally implantable venous access device fragment

Pulmonary hypertension can occur from obstruction of the distal pulmonary arteries by thrombus, ova and parasites, and foreign material. We report a 62-year-old patient who had fatal pulmonary hypertension from an 8-cm fragment of a totally implantable venous access device (TIVAD) retained in the pulmonary artery. Despite long-term therapeutic anticoagulation, pulmonary angiography showed chronic occlusion of the posterior branch of the superior right pulmonary artery with paucity of distal vasculature consistent with an old right upper lobe pulmonary embolus. Retrieval of the fragment was attempted via pulmonary artery catheterization techniques but was unsuccessful. In conclusion, progressive pulmonary hypertension may result from retention of a TIVAD fragment in a central pulmonary artery despite therapeutic anticoagulation. Worsening pulmonary hypertension may have been due to partial obstruction of the main pulmonary arteries, resulting in recurrent thromboembolism or in situ thrombosis, and remodeling of small distal pulmonary arteries.     

Improvement of pulmonary hypertension after liver transplantation.

Pulmonary hypertension at the end stage of chronic liver disease is not an uncommon situation. This association termed portopulmonary hypertension raises the question of the feasibility of performing orthotopic liver transplantation (OLT). In the case reported herein, there was a favorable outcome after OLT, even though the mean pulmonary artery pressure (MPAP) before transplantation was increased to 45 mm Hg. Before OLT, the cardiac index (CI) was considerably elevated (7.69 L/min/m2), giving evidence of a marked hyperdynamic circulatory state. The CI decreased significantly after OLT (3.38 L/min/m2), and this produced a significant decrease in the MPAP. Our observation suggests that portopulmonary hypertension due to a marked increase in the CI can be managed successfully by OLT.     

Sildenafil improves walk distance in idiopathic pulmonary fibrosis

Pulmonary hypertension is a common finding in patients with idiopathic pulmonary fibrosis (IPF), and is associated with increased morbidity and mortality. Therapy with sildenafil has been shown to decrease pulmonary vascular resistance in patients with pulmonary fibrosis and may improve functional status. Patients with IPF and documented pulmonary hypertension were followed up in an open-label study of sildenafil. The 6-min walk test distance (6MWD) was obtained before and after 3 months of sildenafil therapy. Fourteen patients were followed up in the study; 11 patients completed both 6-min walk tests. The mean improvement in walk distance was 49.0 m (90% confidence interval, 17.5 to 84.0 m). When all 14 patients were dichotomized into groups of "responders" (ie, >/= 20% improvement in 6MWD) or "nonresponders" (ie, < 20% change or unable to complete), 57% were classified as responders. Sildenafil is a promising and well-tolerated therapeutic agent for use in patients with IPF and pulmonary hypertension, and should be studied in a large, well-controlled trial.     

LGE Patterns in Pulmonary Hypertension Do Not Impact Overall Mortality

ObjectivesThe goal of this study was to determine the prognostic value of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) features in patients with pulmonary hypertension.BackgroundThe prognostic significance of LGE in the clinical assessment of patients with pulmonary hypertension remains uncertain.MethodsConsecutive patients with suspected pulmonary hypertension seen at a specialist pulmonary hypertension referral center who underwent right heart catheterization and CMR with LGE imaging within 48 h were identified. Short-axis late-enhancement imaging was performed using a 3-dimensional gradient spoiled echocardiography sequence on a 1.5-T scanner. Three groups were identified: 1) no late enhancement of the myocardium; 2) late enhancement at the right ventricular insertion points (LGE-IP); and 3) late enhancement involving the right ventricular insertion points and the interventricular septum (LGE-S).ResultsOf 194 patients, 162 had pulmonary hypertension. LGE was identified in 135 of 162 (83%) patients with pulmonary hypertension, and 47 (29%) of patients demonstrated LGE-S. Patients with LGE-S had significantly higher right ventricular end-diastolic volume index (p = 0.013) and lower mixed venous oxygen saturation (p = 0.045) than patients with LGE-IP alone. The presence of LGE-S (p = 0.022), but not LGE-IP alone, right ventricular end-systolic volume (p = 0.045), right ventricular ejection fraction (p = 0.034), mixed venous oxygen saturation (p = 0.021), mean right atrial pressure (0.027), and male sex (p = 0.002) predicted mortality. At multivariate analysis, male sex was the only significant predictor of mortality independent of covariate predictors (p = 0.027).ConclusionsThe presence of LGE at the right ventricular insertion points is suggestive of the presence of pulmonary hypertension. LGE may also be more extensive, involving the septum; however, after multivariable analysis including other factors associated with pulmonary hypertension, septal LGE was not associated with an increase in overall mortality.     

Sildenafil improves health-related quality of life in patients with pulmonary arterial hypertension

BACKGROUND: Sildenafil inhibits phosphodiesterase-5, enhancing cyclic guanosine monophosphate- mediated relaxation of pulmonary vasculature and is effective in treating patients with pulmonary arterial hypertension (PAH). METHODS: Patients with PAH (n = 278) received oral sildenafil (20, 40, or 80 mg three times daily) in a 12-week, double-blind, placebo-controlled study and an open-label extension. Health-related quality of life (HRQoL) was recorded by patients using the Medical Outcomes Study 36-item short form (SF-36) and EuroQol 5D (EQ-5D) questionnaires at baseline and after 12 and 24 weeks of therapy. Data are presented for patients who received sildenafil for up to 24 weeks. RESULTS: Sildenafil-treated patients, compared with placebo-treated patients, exhibited significant improvement in exercise capacity at week 12 (p < 0.001). Increases from baseline to week 12 were observed in all SF-36 domains for sildenafil-treated patients, with statistically significant improvements, compared with placebo-treated control subjects, in physical functioning (p < 0.001), general health (p < 0.001), and vitality (p < 0.05). Statistically significant improvements were also observed for the EQ-5D current health status (p < 0.01) and utility index (p < 0.01). These benefits were maintained for 24 weeks. Treatment groups were pooled for analyses as the results for the 6-min walk distance, SF-36, and EQ-5D were not dose dependent. CONCLUSIONS: Sildenafil improves HRQoL of PAH patients. These improvements appear to be maintained for at least 24 weeks. The effects are strongest in domains addressing the physical impact of health on daily activities and patients' overall perception of health.     

Clinical application of tissue Doppler imaging in patients with idiopathic pulmonary hypertension

BACKGROUND: Tissue Doppler (TD) echocardiographic imaging of mitral and tricuspid annulus has been applied to assess right ventricular (RV) and left ventricular (LV) function in many cardiac diseases, but its clinical application, including response to long-term targeted therapy in patients with idiopathic pulmonary hypertension (PH), has not been addressed. METHODS: Seventy patients with idiopathic PH were compared with 35 age-matched control subjects to examine myocardial velocities by TD. Of these, 35 patients underwent repeat imaging after long-term targeted therapy. In addition, 50 consecutive patients with idiopathic PH with simultaneous right-heart catheterization and echocardiography were examined. RESULTS: No significant differences were noted between PH patients and the control group in lateral mitral annulus systolic velocity and early diastolic velocity (Ea) by TD, but septal velocities were significantly lower (p < 0.01). With targeted therapy, myocardial velocities at the septum and RV free wall increased significantly (p < 0.05). Likewise, E/Ea ratio increased, albeit still in the normal range. In all 50 patients with invasive measurements, lateral E/Ea ratio readily identified normal mean pulmonary capillary wedge pressure (PCWP). CONCLUSIONS: TD imaging of the lateral mitral annulus can reliably predict the presence of normal/reduced mean PCWP in patients with idiopathic PH, and track the improvement in RV function and LV filling with long-term targeted therapy.     

Long-term follow-up of a fenestrated Amplatzer atrial septal occluder in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease, with right-heart failure being the main cause of death. In patients refractory to conventional drug therapy, atrial septostomy can serve as palliative treatment or as a bridge to transplantation. A 41-year-old woman with a 15-year history of PAH associated with a corrected atrial septal defect presented with severe deterioration of symptoms. Echocardiography confirmed reocclusion of an atrial septal stoma that had been created several months before. After performing a repeat atrial septostomy, we implanted a custom-made atrial septostomy device, an Amplatzer septal occluder that had been fenestrated to serve as a custom-made atrial septostomy device. This resulted in an improvement in cardiac output and a marked symptomatic relief. During the 6-year follow-up, the patient was clinically stable with limited but constant exercise tolerance, under specific medical therapy. Repeated echocardiography confirmed long-term patency of the device.     

Unexplained pulmonary hypertension in elderly patients

BACKGROUND: Idiopathic pulmonary arterial hypertension (IPAH) preferentially affects young women. However, a subset of patients with IPAH is elderly. Our objective was to compare elderly (age >/= 65 years) vs younger persons with unexplained pulmonary hypertension (PH) and a presumptive diagnosis of IPAH. METHODS: Clinical, echocardiographic, hemodynamic, and survival data were collected on consecutive patients with suspected IPAH after evaluation in a large tertiary center PH clinic. RESULTS: Of 197 patients (mean age +/- SD, 52 +/- 16 years; 80% female), 48 patients (24%) were elderly. Elderly and younger patients had similar symptom severity, systolic pulmonary artery (PA) pressure (82.7 +/- 20.3 mm Hg vs 86.9 +/- 18.8 mm Hg, respectively; p = 0.21), and severity of right ventricular enlargement and dysfunction. Elderly patients had higher pulmonary capillary wedge pressure (PCWP) [15.3 +/- 7.3 mm Hg vs 11.1 +/- 5.3 mm Hg; p < 0.0001] and more frequently failed (56%) to meet hemodynamic criteria for IPAH (PH with PCWP < 15 mm Hg) than did younger patients (19%). Elderly patients also had higher systemic systolic (p < 0.0001) and pulse (p < 0.0001) pressures and more cardiovascular disease. Among those patients with normal PCWP, elderly patients had worse survival than young patients (p = 0.007). Among those patients with elevated PCWP, elderly patients had lower PA pressures (p = 0.04) and better survival (p = 0.02). CONCLUSIONS: Elderly patients with clinically suspected IPAH often fail to meet hemodynamic criteria for IPAH due to elevated PCWP. Studies to define the proper diagnostic strategy and the safety and efficacy of pulmonary vasodilators in elderly patients with unexplained PH are needed.     

Large and medium-sized pulmonary artery obstruction does not play a role of primary importance in the etiology of sickle-cell disease-associated pulmonary hypertension

BACKGROUND: Pulmonary hypertension (PHT) occurs in approximately 30% of adult patients with sickle-cell disease (SCD) and is a risk factor for early death. The potential role of pulmonary artery obstruction, whether due to emboli or in situ thrombosis, in the etiology of SCD-related PHT is unknown. METHODS: Consecutive SCD patients were screened for PHT (defined as a tricuspid regurgitant jet flow velocity > or = 2.5 m/s) employing echocardiography and were evaluated for pulmonary artery obstruction with ventilation-perfusion (VQ) scintigraphy. RESULTS: Fifty-three HbSS, 6 HbSbeta(0)-thalassemia, 20 HbSC, and 6 HbSbeta(+)-thalassemia patients were included. The overall prevalence of PHT was 41% in HbSS/HbSbeta(0)-thalassemia patients and 13% in HbSC/HbSbeta(+)-thalassemia patients. High-probability VQ defects (Prospective Investigation of Pulmonary Embolism Diagnosis criteria) were detected in two patients, one of whom had PHT. In HbSS/HbSbeta(0)-thalassemia patients with PHT, 19 patients (86%), 2 patients (9%), and 1 patient (5%) had low-, intermediate-, or high-probability scan results as compared to 30 patients (97%), 1 patient (3%), and 0 patients (0%) in HbSS/HbSbeta(0)-thalassemia patients without PHT (p = 0.31). In HbSC/HbSbeta(+)-thalassemia patients with PHT, 3 patients (100%), 0 patients (0%), and 0 patients (0%) had low-, intermediate-, and a high-probability scan as compared to 19 patients (90%), 1 patient (5%), and 1 patient (5%) in HbSC/HbSbeta(+)-thalassemia patients without PHT (p = 0.86). There were no statistical differences in irregular distribution of the radiopharmaceutical or nonspecific signs associated with PHT between patients with and without PHT. CONCLUSIONS: Although small pulmonary artery obstruction cannot be excluded, large to medium-sized pulmonary artery obstruction is an unlikely primary causative factor in SCD-related PHT.     

Thalassemia heart disease: a comparative evaluation of thalassemia major and thalassemia intermedia

BACKGROUND: Heart disease represents the main determinant of survival in beta-thalassemia, but its particular features in the two clinical forms of the disease, thalassemia major (TM) and thalassemia intermedia (TI), are not completely clarified. METHODS: We compared clinical and echocardiographic global parameters in 131 TM patients who received regular chelation transfusions and were highly compliant with treatment (mean age, 28 +/- 6 years [+/- SD]), and 74 age-matched, TI patients who did not receive chelation transfusions. RESULTS: Congestive heart failure was encountered in five patients with TM (3.8%; age range, 25 to 29 years) and in two patients with TI (2.7%; age range, 37 to 40 years). Systolic left ventricular (LV) dysfunction (ejection fraction < 55% or shortening fraction < 35%) was only encountered in patients with TM (8.4%). Considerable pulmonary hypertension (systolic tricuspid gradient > 35 mm Hg) was only present in TI (23.0%). In the remaining patients without evident heart disease, cardiac dimensions, LV mass, LV shortening and ejection fractions, and cardiac output were significantly higher in patients with TI. LV afterload was higher in patients with TM. LV diastolic early transmitral diastolic peak flow velocity (E)/late transmitral diastolic peak flow velocity (A) ratio was also higher in TM. Systolic and mean pulmonary artery pressures and total pulmonary resistance were higher in both young and old TI patients. CONCLUSION: Regular lifelong transfusion and chelation therapy in TM prevented premature heart disease and pulmonary hypertension, although LV dysfunction still occurred and led to heart failure. The absence of regular therapy in TI, in contrast, preserved systolic LV function but allowed pulmonary hypertension development, which also led to heart failure, starting within the fourth decade of life, a decade later compared to TM.