Florence Parent

A Clinical Trial of Vena Caval Filters in the Prevention of Pulmonary Embolism in Patients with Proximal Deep-Vein Thrombosis

BACKGROUND The efficacy and safety of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis is still a matter of debate. METHODS Using a two-by-two factorial design, we randomly assigned 400 patients with proximal deep-vein thrombosis who were at risk for pulmonary embolism to receive a vena caval filter (200 patients) or no filter (200 patients), and to receive low-molecular-weight heparin (enoxaparin, 195 patients) or unfractionated heparin (205 patients). The rates of recurrent venous thromboembolism, death, and major bleeding were analyzed at day 12 and at two years. RESULTS At day 12, two patients assigned to receive filters (1.1 percent), as compared with nine patients assigned to receive no filters (4.8 percent), had had symptomatic or asymptomatic pulmonary embolism (odds ratio, 0.22; 95 percent confidence interval, 0.05 to 0.90). At two years, 37 patients assigned to the filter group (20.8 percent), as compared with 21 patients assigned to the no-filter group (11.6 percent), had had recurrent deep-vein thrombosis (odds ratio, 1.87; 95 percent confidence interval, 1.10 to 3.20). There were no significant differences in mortality or the other outcomes. At day 12, three patients assigned to low-molecular-weight heparin (1.6 percent), as compared with eight patients assigned to unfractionated heparin (4.2 percent), had had symptomatic or asymptomatic pulmonary embolism (odds ratio, 0.38; 95 percent confidence interval, 0.10 to 1.38). CONCLUSIONS In high-risk patients with proximal deep-vein thrombosis, the initial beneficial effect of vena caval filters for the prevention of pulmonary embolism was counterbalanced by an excess of recurrent deep-vein thrombosis, without any difference in mortality. Our data also confirmed that low-molecular-weight heparin was as effective and safe as unfractionated heparin for the prevention of pulmonary embolism.

Long-term intravenous epoprostenol infusion in primary pulmonary hypertension: Prognostic factors and survival

OBJECTIVES We sought to determine the factors associated with long-term survival in patients with primary pulmonary hypertension (PPH) treated with continuous epoprostenol infusion. BACKGROUND Epoprostenol improves survival in patients with PPH in New York Heart Association (NYHA) functional class III or IV. However, some patients do not benefit from epoprostenol and must be considered for lung transplantation. The best timing for listing these patients on a lung transplantation program is currently unknown. METHODS Between December 1992 and January 2001, 178 patients with PPH in NYHA functional class III or IV were treated with epoprostenol. The 6-min walk test (WT) and right-sided heart catheterization were performed at baseline, after three months on epoprostenol and thereafter once a year. RESULTS Overall survival rates at one, two, three, and five years were 85%, 70%, 63%, and 55%, respectively. On univariate analysis, the baseline variables associated with a poor outcome were a history of right-sided heart failure, NYHA functional class IV, 6-min WT <or=250 m (median value), right atrial pressure >or=12 mm Hg, and mean pulmonary artery pressure <65 mm Hg. On multivariate analysis, including both baseline variables and those measured after three months on epoprostenol, a history of right-sided heart failure, persistence of NYHA functional class III or IV at three months, and the absence of a fall in total pulmonary resistance of >30%, relative to baseline, were associated with poor survival. CONCLUSIONS Survival of patients with PPH treated with epoprostenol depends on the severity at baseline, as well as the three-month response to therapy. These findings suggest that lung transplantation should be considered in a subset of patients who remain in NYHA functional class III or IV or in those who cannot achieve a significant hemodynamic improvement after three months of epoprostenol therapy, or both.

Long-Term Response to Calcium Channel Blockers in Idiopathic Pulmonary Arterial Hypertension

Background—Characteristics of patients with idiopathic pulmonary arterial hypertension (IPAH) who benefit from long-term calcium channel blockers (CCB) are unknown. Methods and Results—Acute pulmonary vasodilator testing with epoprostenol or nitric oxide was performed in 557 IPAH patients. Acute responders, defined by a fall in both mean pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) >20%, received long-term oral CCB. Patients who benefit from long-term CCB were defined as those being in New York Heart Association (NYHA) functional class I or II after at least 1 year on CCB monotherapy. Among the 70 patients who displayed acute pulmonary vasoreactivity (12.6%; 95% CI, 9.8% to 15.3%) and received CCB therapy, only 38 showed long-term improvement (6.8%; 95% CI, 4.7% to 8.9%). Long-term CCB responders had less severe disease at baseline than patients who failed. During acute vasodilator testing, long-term CCB responders displayed a more pronounced fall in mean PAP (−39±11% versus −26±7%; P<0.0001), reaching an absolute value of mean PAP lower than that measured in patients who failed (33±8 versus 46±10 mm Hg; P<0.0001). After 7.0±4.1 years, all but 1 long-term CCB responders were alive in NYHA class I or II, with a sustained hemodynamic improvement. In the group of patients who failed on CCB, the 5-year survival rate was 48%. Conclusions—Long-term CCB responders represent <10% of IPAH patients evaluated in a pulmonary vascular referral center. During acute vasodilator testing, these patients showed significantly lower levels of both mean PAP and PVR, which reached near-normal values.

Diagnostic strategy for patients with suspected pulmonary embolism: a prospective multicentre outcome study

BACKGROUND We designed a prospective multicentre outcome study to evaluate a diagnostic strategy based on clinical probability, spiral CT, and venous compression ultrasonography of the legs in patients with suspected pulmonary embolism (PE). The main aim was to assess the safety of withholding anticoagulant treatment in patients with low or intermediate clinical probability of PE and negative findings on spiral CT and ultrasonography. METHODS 1041 consecutive inpatients and outpatients with suspected PE were included. Patients with negative spiral CT and ultrasonography and clinically assessed as having a low or intermediate clinical probability were left untreated. Those with high clinical probability underwent lung scanning, pulmonary angiography, or both. All patients were followed up for 3 months. FINDINGS PE was diagnosed in 360 (34.6%) patients; 55 had positive ultrasonography despite negative spiral CT. Of 601 patients with negative spiral CT and ultrasonography, 76 were clinically assessed as having a high probability of PE; lung scanning or angiography showed PE in four (5.3% [95% CI 1.5-13.1]). The remaining 525 patients were assessed as having low or intermediate clinical probability, and 507 of them were not treated. Of these patients, nine experienced venous thromboembolism during follow-up (1.8% [0.8-3.3]). The diagnostic strategy proved inconclusive in 95 (9.1%) patients, and pulmonary angiography was done in 74 (7.1%). INTERPRETATION Withholding of anticoagulant therapy is safe when the clinical probability of PE is assessed as low or intermediate and spiral CT and ultrasonography are negative.

A Hemodynamic Study of Pulmonary Hypertension in Sickle Cell Disease

BACKGROUND The prevalence and characteristics of pulmonary hypertension in adults with sickle cell disease have not been clearly established. METHODS In this prospective study, we evaluated 398 outpatients with sickle cell disease (mean age, 34 years) at referral centers in France. All patients underwent Doppler echocardiography, with measurement of tricuspid-valve regurgitant jet velocity. Right heart catheterization was performed in 96 patients in whom pulmonary hypertension was suspected on the basis of a tricuspid regurgitant jet velocity of at least 2.5 m per second. Pulmonary hypertension was defined as a mean pulmonary arterial pressure of at least 25 mm Hg. RESULTS The prevalence of a tricuspid regurgitant jet velocity of at least 2.5 m per second was 27%. In contrast, the prevalence of pulmonary hypertension as confirmed on catheterization was 6%. The positive predictive value of echocardiography for the detection of pulmonary hypertension was 25%. Among the 24 patients with confirmed pulmonary hypertension, the pulmonary-capillary wedge pressure was 15 mm Hg or less (indicating precapillary pulmonary hypertension) in 11 patients. Patients with confirmed pulmonary hypertension were older and had poorer functional capacity and higher levels of N-terminal pro-brain natriuretic peptide than other patients. In contrast, patients who had a tricuspid regurgitant jet velocity of at least 2.5 m per second without pulmonary hypertension and patients with a tricuspid regurgitant jet velocity of less than 2.5 m per second had similar clinical characteristics. CONCLUSIONS In this study of adults with sickle cell disease, the prevalence of pulmonary hypertension as confirmed on right heart catheterization was 6%. Echocardiographic evaluation alone had a low positive predictive value for pulmonary hypertension. (Funded by the French Ministry of Health and Assistance Publique-Hôpitaux de Paris; ClinicalTrials.gov number, NCT00434902.).

Pulmonary veno-occlusive disease

Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary hypertension (PH) characterised by preferential remodelling of the pulmonary venules. In the current PH classification, PVOD and pulmonary capillary haemangiomatosis (PCH) are considered to be a common entity and represent varied expressions of the same disease. The recent discovery of biallelic mutations in the EIF2AK4 gene as the cause of heritable PVOD/PCH represents a major milestone in our understanding of the molecular pathogenesis of PVOD. Although PVOD and pulmonary arterial hypertension (PAH) share a similar clinical presentation, with features of severe precapillary PH, it is important to differentiate these two conditions as PVOD carries a worse prognosis and life-threatening pulmonary oedema may occur following the initiation of PAH therapy. An accurate diagnosis of PVOD based on noninvasive investigations is possible utilising oxygen parameters, low diffusing capacity for carbon monoxide and characteristic signs on high-resolution computed tomography of the chest. No evidence-based medical therapy exists for PVOD at present and lung transplantation remains the preferred definitive therapy for eligible patients. Recent advances such as discovery of the genetic basis of PVOD will pave way for future translational research http://ow.ly/YldhC

Inhaled nitric oxide as a screening agent for safely identifying responders to oral calcium-channel blockers in primary pulmonary hypertension

In a subset of patients with primary pulmonary hypertension (PPH), high doses of oral calcium-channel blockers (CCB) produce a sustained clinical and haemodynamic improvement. However, significant side-effects have been reported during acute testing with CCB. Therefore, to identify accurately patients who may benefit from long-term CCB therapy, there is a need for a safe, potent and short-acting vasodilator. The aim of this study was to compare the acute response to inhaled nitric oxide (NO) and oral high doses of CCB in 33 consecutive patients with PPH. A significant acute vasodilator response was defined by a fall in both mean pulmonary artery pressure and total pulmonary resistance by >20%. Ten patients responded acutely to NO, nine of whom responded acutely to CCB, without any complications. The 23 other patients failed to respond to NO and CCB. In these nonresponders, nine serious adverse events were observed with CCB (38%). There was no clinical or baseline haemodynamic feature predicting acute vasodilator response. Long-term oral treatment with CCB was restricted to the nine acute responders and a sustained clinical and haemodynamic improvement was observed in only six patients. In primary pulmonary hypertension, the acute response rate to high doses of calcium-channel blockers is low (27%). Serious adverse reactions to high doses of calcium-channel blockers during acute testing are frequently observed in nonresponders. It is concluded that nitric oxide may be used as a screening agent for safely identifying patients with primary pulmonary hypertension who respond acutely to calcium-channel blockers and may benefit from long-term treatment with these agents.

Pulmonary hypertension in patients with human immunodeficiency virus infection. Comparison with primary pulmonary hypertension.

BACKGROUND Previously reported cases of patients with pulmonary hypertension (PH) and human immunodeficiency virus (HIV) infection are poorly documented regarding baseline hemodynamics and potential for pulmonary vasodilatation. The purpose of this report was to compare HIV-infected patients who had PH with non-HIV-infected patients who had primary pulmonary hypertension (PPH) in terms of (1) clinical characteristics, (2) hemodynamics in baseline conditions and during a short-term vasodilator trial with epoprostenol, and (3) survival. METHODS AND RESULTS Between April 1987 and August 1992, 20 HIV-infected patients with PH and 93 non-HIV-infected patients with PPH were referred to our department. At the time of referral, baseline right-side heart hemodynamics were obtained in addition to demographic variables and medical history. A short-term vasodilator trial with epoprostenol was performed in 19 of 20 HIV-infected and 86 of 93 non-HIV-infected patients. Outcome and survival were analyzed and compared for both groups (22 transplant recipients were excluded from the group of patients with PPH). At the time of diagnosis of PH, HIV-infected patients significantly differed from non-HIV-infected patients in age (32 +/- 5 versus 42 +/- 13 years; P < .05) and degree of disability (New York Heart Association functional class III or IV, 50% versus 75%; P < .01). The proportion of disease states known to be associated with PPH (Raynauds phenomenon, migraine, collagen disease without overt symptoms and signs, or a positive family history of PPH) was similar in the two groups. HIV-infected patients had a severe but significantly lower level of PH than patients with PPH. The percentage of responders to epoprostenol and the level achieved in pulmonary vasodilatation were similar in the two groups. PH was the cause of death in 8 of the 10 HIV-infected patients who died within 1 year after the diagnosis of PH. Overall survival was poor and not significantly different between the two groups. Pathological findings in lung tissue obtained from 3 HIV-infected patients were close to those seen in most of the lung specimens available from 27 patients with PPH and resembled plexogenic pulmonary arteriopathy. CONCLUSIONS These results support the view that HIV infection may now be regarded as another common disease state that can be associated with PPH development. The lower initial severity in HIV-infected patients may be due to the close medical attention usually devoted to such patients, who may account for an earlier diagnosis. However, the overall survival rate of HIV-infected patients with PH appeared to be as poor as in non-HIV-infected patients with PPH.

Prognostic factors for pulmonary embolism: the prep study, a prospective multicenter cohort study.

RATIONALE The short-term prognosis of pulmonary embolism (PE) depends on hemodynamic status and underlying disease. The prognostic value of right ventricular dysfunction and injury is less well established. OBJECTIVES To evaluate prognostic factors of PE in a multicenter prospective cohort study. METHODS Echocardiography, brain natriuretic peptide (BNP), N-terminal-proBNP and cardiac troponin I measurements were done on admission of 570 consecutive patients with an acute PE. A predictive model was based on independent predictors of 30-day adverse events defined as death, secondary cardiogenic shock, or recurrent venous thromboembolism. MEASUREMENTS AND MAIN RESULTS At 30 days, 42 patients (7.4%; 95% confidence interval [CI], 5.5-9.8%) had adverse events. On multivariate analysis, altered mental state (odds ratio [OR] 6.8; 95% confidence interval [CI], 2.0-23.3), shock on admission (OR 2.8; 95% CI, 1.1-7.5), cancer (OR 2.9; 95% CI, 1.2-6.9), BNP (OR 1.3 for an increase of 250 ng/L; 95% CI, 1.1-1.6) and right to left ventricle diameter ratio (OR 1.2 for an increase of 0.1; 95% CI, 1.1-1.4) were associated with 30-days of adverse events. The predictive performance of the model was good (area under receiver operating characteristics curve 0.84 [95% CI, 0.78-0.90]), making it possible to develop a bedside prognostic score. CONCLUSIONS BNP and echocardiography may be useful determinants of the short-term outcome for patients with PE, together with clinical findings. Patients with PE can be stratified according to the initial risk of adverse outcome, using a simple score based on clinical, echocardiographic, and biochemical variables.

Pathobiology of pulmonary hypertension. The role of platelets and thrombosis.

With the rare exceptions of PAH associated with antiphospholipid antibodies, genetic platelet dysfunction, or inherited deficiencies of antithrombotic pathways, the thrombotic lesions are secondary, but frequently occurring, in most cases of primary or secondary PAH. Pulmonary arterial hypertension is associated with thrombotic lesions and persistent vasoconstriction and structural remodeling of PA. Activated platelets interact with the PA wall and may contribute to the functional and structural alterations of pulmonary vessels by releasing vasoactive factors and mitogenic mediators.