Chronic thromboembolic pulmonary hypertension is believed to be rare after an episode of acute pulmonary embolism. This study showed that the incidence of this serious complication was nearly 4 percent — substantially higher than previously reported — and was associated with previous pulmonary embolism, large perfusion defects, and an idiopathic presentation. Possible approaches to prevention are discussed. The incidence of this serious complication was nearly 4 percent. Chronic pulmonary hypertension is considered a relatively rare complication of pulmonary embolism but is associated with considerable morbidity and mortality. 1 – 3 It is commonly believed that symptoms become manifest only several years after the initial episode of pulmonary embolism. However, the true frequency (estimated at 0.1 percent among patients who survive a pulmonary embolism) and timing are not well established, and there is limited documentation concerning predisposing factors that could be addressed in an effort to prevent this feared complication. It has been hypothesized that in situ thrombosis and pulmonary arteriopathy are common causes of vascular occlusion leading to chronic . . .
This study showed that sickle cell disease is complicated by pulmonary hypertension in about one third of adult patients. Even more important, patients with pulmonary hypertension have a much higher mortality rate than those without pulmonary hypertension. Pulmonary hypertension can be diagnosed noninvasively and indicates a poor prognosis. Pulmonary hypertension develops in most forms of hereditary and chronic hemolytic anemia, including sickle cell disease, 1 thalassemia, 2 hereditary spherocytosis, 3 and paroxysmal nocturnal hemoglobinuria, 4 suggesting that there is a clinical syndrome of hemolysis-associated pulmonary hypertension. This complication has been reported with increasing frequency in patients with sickle cell disease. 1 , 5 – 11 Retrospective studies from tertiary care referral centers suggest a prevalence of pulmonary hypertension ranging from 20 to 40 percent. 9 , 11 , 12 Although these studies have demonstrated that patients with sickle cell disease have lower pulmonary pressures and higher cardiac output than patients with primary pulmonary hypertension, the two-year mortality rates . . .
The aim of this study was to investigate the potential role of brain natriuretic peptide (BNP) levels in the assessment of functional status and right heart performance in primary pulmonary hypertension (PPH). Primary pulmonary hypertension is a progressive disease leading to right heart failure and death. Right heart catheterization and maximal or submaximal exercise tests are employed to assess the course of the disease and the effect of therapeutic interventions. Additional noninvasive and reproducible parameters would be helpful to assess the status of patients with PPH. The natriuretic peptide system is up-regulated in PPH patients. Brain natriuretic peptide (BNP) is produced from the cardiac ventricles and elevated in PPH. The aim of our study was to evaluate the clinical significance of BNP in PPH patients. Correlation analysis was performed for plasma BNP levels of 28 PPH patients and World Health Organization (WHO) functional class (WHO-class), distance walked in 6 min, peak oxygen uptake (peak V ), and oxygen pulse during spiroergometry and various hemodynamic parameters, including pulmonary vascular resistance (PVR), pulmonary artery pressure (PAP), right atrial pressure (RAP), and cardiac index. The BNP levels were inversely correlated with the 6-min walk (r = −0.70; p < 0.001) and peak V (r = −0.61; p < 0.01), and positive correlation was observed with WHO-class (r = 0.79; p < 0.001). Moreover, BNP levels were also correlated to PVR (r = 0.61; p < 0.01), PAP (r = 0.48; p < 0.05), and RAP (r = 0.78; p < 0.01), and were inversely related to cardiac index (r = −0.48; p < 0.05). Our data suggest that plasma BNP levels are closely related to the functional impairment of PPH patients and parallel the extent of pulmonary hemodynamic changes and right heart failure. Serial measurements of plasma BNP concentrations may help improve the management of PPH patients.
Recurrent vaso-occlusive episodes lead to progressive end-organ damage in patients with sickle cell disease. We sought to determine the prevalence of pulmonary hypertension in adult patients with sickle cell disease and to identify factors associated with this life-threatening complication. Sixty patients (≥18 years of age; mean [± SD] age, 37 ± 13 years) followed at a University Medical Center were evaluated. They were selected by a systematic sampling of patients presenting to the clinic for routine follow-up visits. All enrolled subjects underwent a clinical examination, Doppler echocardiography, pulmonary function tests, and hematologic tests during a single visit. Pulmonary hypertension was defined using an age- and body mass index–adjusted nomogram. The prevalence of pulmonary hypertension was 30% (18/60). Ten patients had mild pulmonary hypertension (up to 44 mm Hg), 5 had moderate pulmonary hypertension (45 to 74 mm Hg), and 2 had severe pulmonary hypertension (≥75 mm Hg). In a logistic regression model, both lower fetal hemoglobin level and lower systolic blood pressure were associated with the presence of pulmonary hypertension. We found that the prevalence of pulmonary hypertension in adult patients with sickle cell disease was substantial, particularly in those with lower levels of fetal hemoglobin and lower systolic blood pressure.
Sickle cell disease was first described in 1910 by Herrick and Irons. The irregularly shaped blood cells observed by Irons were those of Walter Clement Noel, a dental student with symptoms that included joint pain and shortness of breath. After graduation, Dr. Noel returned to his native Grenada, where he died suddenly at 32 years of age. Although the cause of death was recorded as pneumonia, his death was most likely the result of sudden, undetected pulmonary hypertension. Today, we know that pulmonary hypertension and chronic lung disease are two of the most common causes of death among patients with . . .
PURPOSE: To evaluate the potential of breath-hold magnetic resonance (MR) imaging techniques in morphologic and functional assessment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after surgery. MATERIALS AND METHODS: Thirty-four patients with CTEPH were examined before and after pulmonary. thromboendarterectomy (PTE). For morphologic assessment, contrast material-enhanced MR angiography was used; for assessment of hemodynamics, velocity-encoded gradient-echo sequences and cine gradient-echo sequences along the short axis of the heart were performed. Contrast-enhanced MR angiography was compared with selective digital subtraction angiography (DSA) for depiction of central thromboembolic material and visualization of the pulmonary arterial tree. Functional analysis included calculation of left and right ventricular ejection fractions and peak velocities, net forward volumes per heartbeat, and blood volume per minute in the left and right pulmonary arteries and ascending aorta. Flow measurements were compared with invasively measured mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance (PVR) measurements. Nonparametric Wilcoxon and sign tests were used for statistical analysis. RESULTS: MR angiography revealed typical findings of CTEPH (intraluminal webs and bands, vessel cutoffs, and organized central thromboemboli) in all patients. It depicted pulmonary vessels up to the segmental level in all cases. For subsegmental arteries, DSA revealed significantly more patent vessel segments than did MR angiography (733 versus 681 segments, P < .001). MR angiography revealed technical success of surgery in 33 of 34 patients. Patients had reduced right ventricular ejection fractions and pulmonary peak velocities that significantly increased after PTE (P < .001 for both). Right ventricular ejection fraction had good correlation with PVR (r = 0.6) and MPAP (r = 0.7). The postoperative decrease in MPAP correlated well with the increase in right ventricular ejection fraction (r = 0.8). Postoperatively, there was complete reduction of a preoperatively existing bronchosystemic shunt volume in 33 of 34 patients. CONCLUSION: Breath-hold MR imaging techniques enable morphologic and serniquantitative functional assessment of patients with CTEPH. (C) RSNA, 2004.
Right ventricular (RV) afterload is best described by a pulmonary arterial impedance (PVZ) spectrum, which integrates pulmonary vascular resistance (PVR), elastance, and wave reflection. We evaluated the feasibility of PVZ determinations in patients with pulmonary arterial hypertension (PAH) during routine right heart catheterization and Doppler echocardiography. Prospective study. Academic hospital. Twenty-two patients with PAH. Right heart catheterization with a fluid-filled Swan-Ganz catheter, Doppler echocardiography, and administration of inhaled nitric oxide (NO) [10 to 20 ppm; 17 patients], maximum tolerated dose of IV epoprostenol (average, 8.5 ng/kg/min; 5 patients), and IV dobutamine (8 μg/kg/min; 8 patients). PVZ was calculated from the spectral analysis of synchronized pulmonary artery pressure (Ppa) and flow waves. The mean (± SE) Ppa was 63 ± 3 mm Hg, and the mean PVR was 16 ± 2 Wood units. The PVZ spectrum was markedly shifted to higher than normal pressures and frequencies, with a mean 0-Hz impedance (Z ) of 1,506 ± 138 dyne · s · cm , and a mean characteristic impedance (Zc) of 124 ± 11 dyne · s · cm , which are in keeping with data from previous studies. Inhaled NO levels decreased Ppa, PVR, Z , and Zc without a change in cardiac output. Epoprostenol administration did not affect Ppa, increased cardiac output, and decreased Z and Zc. Dobutamine administration increased cardiac output and Ppa, and decreased PVR and Z , without changing Zc. The determination of PVZ to quantify RV afterload is feasible during routine right heart catheterization and Doppler echocardiography. The measurement is sensitive to pharmacologic interventions.