Pulmonary angiography in severe chronic pulmonary hypertension

The role of imaging in pulmonary hypertension

Pulmonary hypertension (PH) is a debilitating and potentially life threatening condition in which increased pressure in the pulmonary arteries may result from a variety of pathological processes. These can include disease primarily involving the pulmonary vasculature, but more commonly PH may result from left-sided heart disease, including valvular heart disease. Chronic thromboembolic pulmonary hypertension (CTEPH) is an important disease to identify because it may be amenable to surgical pulmonary artery endarterectomy or balloon pulmonary angioplasty. Parenchymal lung diseases are also widespread in the community. Any of these disease processes may result in adverse remodeling of the right ventricle and progressive right heart (RH) failure as a common final pathway. Because of the breadth of pathological processes which cause PH, multiple imaging modalities play vital roles in ensuring accurate diagnosis and classification, which will lead to application of the most appropriate therapy. Multimodality imaging may also provide important prognostic information and has a role in the assessment of response to therapies which ultimately dictate clinical outcomes. This review provides an overview of the wide variety of established imaging techniques currently in use, but also examines many of the novel imaging techniques which may be increasingly utilized in the future to guide comprehensive care of patients with PH.

Chronic Thromboembolic Pulmonary Hypertension: Evolving Therapeutic Approaches for Operable and Inoperable Disease

Chronic thromboembolic pulmonary hypertension (CTEPH), a rare consequence of an acute pulmonary embolism, is a disease that is underdiagnosed, and surgical pulmonary thromboendarterectomy (PTE) remains the preferred therapy. However, determination of operability is multifactorial and can be challenging. There is growing excitement for the percutaneous treatment of inoperable CTEPH with data from multiple centers around the world showing the clinical feasibility of balloon pulmonary angioplasty. Riociguat remains the only approved medical therapy for CTEPH patients deemed inoperable or with persistent pulmonary hypertension after PTE. We recommend that expert multidisciplinary CTEPH teams be developed at individual institutions. Additionally, optimal and standardized techniques for balloon pulmonary angioplasty need to be developed along with dedicated interventional equipment and appropriate training standards. In the meantime, the percutaneous revascularization option is appropriate for patients deemed inoperable in combination with targeted medical therapy, or those who have failed to benefit from surgery.

Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is associated with several risk factors but is most frequently seen as a rare consequence of an acute pulmonary embolism. Surgical pulmonary thromboendarterectomy (PTE) is potentially curative for CTEPH with the best outcomes seen for the treatment of primarily proximal, accessible lobar or segmental disease. For surgically inoperable patients, percutaneous balloon pulmonary angioplasty (BPA) is feasible and has good short- to mid-term efficacy outcomes. This review focuses on the technique and outcomes associated with BPA which has emerged as a new therapeutic option for CTEPH.

Chronic thromboembolic pulmonary hypertension from the perspective of patients with pulmonary embolism

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but feared long-term complication of acute pulmonary embolism (PE), although CTEPH may occur in patients with no history of symptomatic venous thromboembolism. It represents the most severe presentation of the so-called 'post-PE syndrome', a phenomenon of permanent functional limitations after PE caused by deconditioning after PE or ventilatory or circulatory impairment as a result of unresolved pulmonary artery thrombi. Because the post-PE syndrome may occur in up to 50% of PE survivors, and CTEPH tends to have an insidious and non-specific clinical presentation, CTEPH is often not diagnosed or diagnosed after a very long delay. Once the diagnosis is confirmed, the treatment of choice is pulmonary endarterectomy which effectively lowers the pulmonary vascular resistance and normalizes resting pulmonary artery pressures, leading to recovery of the right ventricle. When pulmonary endarterectomy is not technically feasible, balloon pulmonary angioplasty may be a potential acceptable alternative. Also, medical treatment may help to improve patient's symptoms and hemodynamics. Current studies are focusing on strategies for earlier CTEPH diagnosis after acute PE, as well as the most optimal treatment of inoperable patients. This review will focus on the epidemiology, risk factors, diagnosis and treatment of CTEPH from the perspective of the PE patient.

Diagnostic Evaluation of Chronic Thromboembolic Pulmonary Hypertension

Pulmonary hypertension is defined by a mean pulmonary artery pressure greater than 25 mm Hg. Chronic thromboembolic pulmonary hypertension (CTEPH) is defined as pulmonary hypertension in the presence of an organized thrombus within the pulmonary vascular bed that persists at least 3 months after the onset of anticoagulant therapy. Because CTEPH is potentially curable by surgical endarterectomy, correct identification of patients with this form of pulmonary hypertension and an accurate assessment of surgical candidacy are essential to provide optimal care. Patients most commonly present with symptoms of exertional dyspnea and otherwise unexplained decline in exercise capacity. Atypical chest pain, a nonproductive cough, and episodic hemoptysis are observed less frequently. With more advanced disease, patients often develop symptoms suggestive of right ventricular compromise. Physical examination findings are minimal early in the course of this disease, but as pulmonary hypertension progresses, may include nonspecific finding of right ventricular failure, such as a tricuspid regurgitation murmur, pedal edema, and jugular venous distention. Chest radiographs may suggest pulmonary hypertension, but are neither sensitive nor specific for the diagnosis. Radioisotopic ventilation-perfusion scanning is sensitive for detecting CTEPH, making it a valuable screening study. Conventional catheter-based pulmonary angiography retains an important role in establishing the presence and extent of chronic thromboembolic disease. However, computed tomographic and magnetic resonance imaging are playing a growing diagnostic role. Innovative technologies such as dual-energy computed tomography, dynamic contrast-enhanced magnetic resonance imaging, and optical coherence tomography show promise for contributing diagnostic information and assisting in the preoperative characterization of patients with CTEPH.

Imaging in Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the potentially curable causes of pulmonary hypertension and is definitively treated with pulmonary thromboendartectomy. CTEPH can be overlooked, as its symptoms are nonspecific and can be mimicked by a wide range of diseases that can cause pulmonary hypertension. Early diagnosis of CTEPH and prompt evaluation for surgical candidacy are paramount factors in determining future outcomes. Imaging plays a central role in the diagnosis of CTEPH and patient selection for pulmonary thromboendartectomy and balloon pulmonary angioplasty. Currently, various imaging tools are used in concert, with techniques such as computed tomography (CT) and conventional pulmonary angiography providing detailed structural information, tests such as ventilation-perfusion (V/Q) scanning providing functional data, and magnetic resonance imaging providing a combination of morphologic and functional information. Emerging techniques such as dual-energy CT and single photon emission computed tomography-CT V/Q scanning promise to provide both anatomic and functional information in a single test and may change the way we image these patients in the near future. In this review, we discuss the roles of various imaging techniques and discuss their merits, limitations, and relative strengths in depicting the structural and functional changes of CTEPH. We also explore newer imaging techniques and the potential value they may offer.

Chronic Thromboembolic Pulmonary Hypertension and Pulmonary Thromboendarterectomy

Chronic thromboembolic pulmonary hypertension results from incomplete resolution of a pulmonary embolus or from recurrent pulmonary emboli. Its incidence is underappreciated, and it is currently an undertreated phenomenon. Pulmonary thromboendarterectomy is currently the safest and most effective treatment for this condition. The surgery involves midline sternotomy, profound hypothermic circulatory arrest, and complete endarterectomy of the pulmonary vascular tree. Success depends on effective coordination of multiple medical teams, including pulmonary medicine, anesthesiology, and surgery. This review, based on the past 30 years of experience at University of California San Diego Medical Center, includes information about the clinical history, diagnostic workup, anesthesia, surgical approach, and postoperative care. Outcome data are discussed, as are avenues for future research.

[Surgical treatment of chronic thromboembolic pulmonary hypertension]

Chronic thromboembolic pulmonary hypertension is a rare but underdiagnosed disease. The development of imaging played a crucial role for the screening and the decision of operability over the past few years. Indeed, chronic thromboembolic pulmonary hypertension is the only type of pulmonary hypertension with a potential curative treatment: pulmonary endarterectomy. It is a complexe surgical procedure performed under cardiopulmonary bypass with deep hypothermia and circulatory arrest. The aim of the procedure is to completely remove the scar tissue inside the pulmonary arteries down to the segmental and sub-segmental levels. Compared to lung transplantation, which carries a postoperative mortality of 15-20% and a 5-year survival of 50%, pulmonary endarterectomy is a curative treatment with a postoperative mortality of less than 3%. However, lung transplantation remains an option for young patients with inoperable distal disease or after pulmonary endarterectomy failure. Considering that medical history of deep venous thrombosis or pulmonary embolism is lacking in 25 to 50%, the diagnosis of chronic thromboembolic pulmonary hypertension remains challenging. The lung V/Q scan is useful for the diagnosis showing ventilation and perfusion mismatches. Lesions located at the level of the pulmonary artery, the lobar or segmental arteries may be accessible to surgical removal. The pulmonary angiogram with the lateral view and the pulmonary CT scan help to determine the level of the intravascular lesions. If there is a correlation between the vascular obstruction assessed by imaging and the pulmonary resistance, pulmonary endarterectomy carries a postoperative mortality of less than 3% and has a high rate of success. If the surgery is performed at a later stage of the disease, pulmonary arteriolitis developed mainly in unobstructed territories and participated in the elevated vascular resistance. At this stage, postoperative risk is higher.

Chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a potentially life-threatening condition characterized by obstruction of pulmonary arterial vasculature by acute or recurrent thromboemboli with subsequent organization, leading to progressive pulmonary hypertension and right heart failure. Until relatively recently, CTEPH was a diagnosis made primarily at autopsy, but advances made in diagnostic modalities and surgical pulmonary endarterectomy techniques have made this disease treatable and even potentially curable. Although published guidelines are available, in the absence of randomized controlled trials regarding CTEPH there is a lack of standardization, and treatment options have to be individualized.

Pulmonary hypertension: newer concepts in diagnosis and management

Pulmonary hypertension comprises a family of disorders occurring as a primary disease or as a complication of a large number of respiratory and cardiac diseases. Pulmonary hypertension is present when pulmonary artery pressure or mean pressure exceeds 30 mmHg or 20 mmHg, respectively. Underlying the hemodynamic changes that result in pulmonary hypertension, whether from hypoxia, acidosis, increased pulmonary blood flow, increased shear stress, or idiopathic causes, is a dysfunctional vascular endothelium. In this review, the role of the history and physical examination in the initial assessment is emphasized. Newer diagnostic modalities, such as subselective pulmonary angiography and ultrafast computed tomography scanning, are reviewed. Low-flow oxygen, anticoagulation, and calcium-channel blockade are presented as accepted therapeutic modalities. Inhaled nitric oxide and prostacyclin infusion are presented as newer therapies that may be useful given the limited availability of donor organs for hear-lung transplantation. Future therapeutic strategies are likely to develop from advances in vascular biology.

Hypertension pulmonaire postembolique

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease characterized by the persistence of thromboemboli obstructing the pulmonary arteries as an organized tissue. The consequence is an increase in pulmonary vascular resistance resulting in pulmonary hypertension (PH) and progressive right heart failure.

BACKGROUND

It is difficult to recognize the postembolic nature of PH because there is no known history of thromboembolic disease in more than 50% of cases. Diagnosis is based on the presence of mismatched segmental defects in the ventilation-perfusion scanning. When CTEPH is suspected, pulmonary angiography and high-resolution CT scan are required to establish the diagnosis and to assess the operability. Pulmonary angiography is always performed in conjunction with a diagnostic right heart catheterization, which is required to confirm the diagnosis of PH and to determine the degree of hemodynamic impairement. If there is a good correlation between the pulmonary vascular resistance and the anatomical obstruction, pulmonary endarterectomy (PEA) must be proposed. Otherwise, vasodilator and antiproliferative treatments and lung transplantation represent interesting alternatives.

VIEWPOINT AND CONCLUSION

PEA remains the treatment of choice for eligible patients. Nevertheless, there is a need to conduct randomized trials to assess the efficacy of novel medical therapies in some situations: (1) in inoperable CTEPH due to distal lesions, (2) before PEA (therapeutic bridge) in patients who are considered "high risk" due to extremely poor hemodynamics, (3) in patients with persistent pulmonary hypertension after surgery.

Pulmonary Arterial Hypertension

The first description of the circulation of blood through the lungs has been attributed to Ibn Nafis (1210–1288).1 The concept was rediscovered by Michael Servetus, a Spanish physician during the Renaissance (1511–1553) and recorded, oddly enough, in two pages of his religious treatise, Christianismi Restitutio (1553).2 The definitive exposition of the pulmonary circulation was made by William Harvey in DeMotu Cordis (1628).3 The first observation of the pulmonary capillaries was first reported by Marcellus Malpighi (1661).4 Heart catheterization in humans, driven by a desire to obtain the perfect mixed venous specimen and measure cardiac output, was first performed in 1929 by the German urologist Forssmann,5 using a ureteral catheter to access his own right atrium. Over a decade later, Cournand and Richards at Columbia University in New York subsequently used right heart catheterization to record pulmonary artery pressure (PAP) in patients with shock and secondary forms of pulmonary hypertension (PHT). For these accomplishments, which were inspired by an interest in the pulmonary circulation and PHT related to mitral stenosis, Forssmann, Cournand, and Richards received the Nobel Prize in 1956.

Complications of right heart catheterization procedures in patients with pulmonary hypertension in experienced centers

OBJECTIVES

This study sought to assess the risks associated with right heart catheter procedures in patients with pulmonary hypertension.

BACKGROUND

Right heart catheterization, pulmonary vasoreactivity testing, and pulmonary angiography are established diagnostic tools in patients with pulmonary hypertension, but the risks associated with these procedures have not been systematically evaluated in a multicenter study.

METHODS

We performed a multicenter 5-year retrospective and 6-month prospective evaluation of serious adverse events related to right heart catheter procedures in patients with pulmonary hypertension, as defined by a mean pulmonary artery pressure >25 mm Hg at rest, undergoing right heart catheterization with or without pulmonary vasoreactivity testing or pulmonary angiography.

RESULTS

During the retrospective period, 5,727 right heart catheter procedures were reported, and 1,491 were reported from the prospective period, for a total of 7,218 right heart catheter procedures performed. The results from the retrospective and the prospective analyses were almost identical. The overall number of serious adverse events was 76 (1.1%, 95% confidence interval 0.8% to 1.3%). The most frequent complications were related to venous access (e.g., hematoma, pneumothorax), followed by arrhythmias and hypotensive episodes related to vagal reactions or pulmonary vasoreactivity testing. The vast majority of these complications were mild to moderate in intensity and resolved either spontaneously or after appropriate intervention. Four fatal events were recorded in association with any of the catheter procedures, resulting in an overall procedure-related mortality of 0.055% (95% confidence interval 0.01% to 0.099%).

CONCLUSIONS

When performed in experienced centers, right heart catheter procedures in patients with pulmonary hypertension are associated with low morbidity and mortality rates.

Pulmonary endarterectomy

Chronic thromboembolic pulmonary hypertension is a condition that is recognised in an increased percentage of patients. Pulmonary endarterectomy is recognised as being the only curative option for a subgroup of those patients, but anaesthesiologists and intensivists face many challenges in how they manage these patients perioperatively. Ultimately, it is the combination of skills in a multidisciplinary team that leads to a successful procedure and dramatically improves patient's quality of life and life expectancy.

Traitement chirurgical de la maladie thromboembolique pulmonaire chronique

Chronic thromboembolic pulmonary hypertension is a condition that has long remained in the shadows, a kind of orphan disease, because of the lack of any curative treatment. The renewal of interest by pulmonary specialists, cardiologists and thoracic surgeon is due to the development over the past 20 years of major new treatments: lung transplantation, continuous prostacyclin infusion, and pulmonary endarterectomy, in chronological order. Most patients with postembolic pulmonary arterial hypertension (PEPAH) in a sufficiently proximal location can benefit from curative surgical treatment by bilateral endarterectomy of the pulmonary arteries. This complex surgery, performed under deep hypothermic circulatory arrest, clears out the pulmonary vascular bed down through its subsegmental branches and results in a frank reduction in pulmonary vascular resistance and normalization of cardiopulmonary function. It is a curative procedure with a perioperative mortality rate less than 7% and a definitive result, unlike pulmonary and cardiopulmonary transplantation, which have a postoperative mortality rate of 20% and a 5-year survival rate of 50%. It is difficult to recognize the postembolic nature of pulmonary hypertension because there is no known history of venous thrombosis or embolic phenomena in more than 50% of cases. Diagnosis is based on the presence of mismatched segmental defects in the radioisotopic ventilation-perfusion scanning. To be accessible to endarterectomy, lesions must involve the main, lobar, or segmental arteries. When conducted by experienced operators according to specific protocols, pulmonary (frontal and lateral views of each lung) and multislice CT angiography optimize assessment of the lesion site. When the pulmonary vascular resistance evaluated by catheterization is correlated with the anatomical obstruction visible on the images, pulmonary endarterectomy has a mortality rate below 4% and offers the patient a substantial chance to regain normal cardiorespiratory function. In cases of pulmonary arterial hypertension due to older embolisms, major arteriolitis occurs in the nonobstructed areas and aggravates the pulmonary hypertension, which may become suprasystemic. The endarterectomy mortality rate is then higher, and in specific cases justifies preoperative medical treatment. Pulmonary or cardiopulmonary transplantation is indicated in this disease only when the lesions are too distal and thus inaccessible to endarterectomy.

Cardiac catheterization techniques in pulmonary hypertension

Once considered dangerous and potentially life threatening, cardiac catheterization of the patient with pulmonary hypertension can be performed safely and provides essential information in the diagnosis and management of pulmonary hypertension. This article summarizes the modern techniques used for right-heart catheterization, selective pulmonary angiography, and pulmonary angioscopy in the evaluation of the patient with pulmonary hypertension or suspected chronic thromboembolic disease.

Safety and Hemodynamic Effects of Pulmonary Angiography in Patients with Pulmonary Hypertension: 10-Year Single-Center Experience

OBJECTIVE

We sought to examine the incidence of complications and change in pulmonary artery pressure in patients with pulmonary hypertension who were undergoing pulmonary angiography.

MATERIALS AND METHODS

A retrospective review was performed for all patients who underwent pulmonary angiography over a 10-year period at a single institution. Patients with moderate pulmonary hypertension (pulmonary artery pressure, 30-59 mm Hg) and severe pulmonary hypertension (pulmonary artery pressure, >/= 60 mm Hg) served as the study population. Demographic data, clinical indication, pre- and postcontrast pulmonary artery pressure measurements, type of pulmonary hypertension, contrast agent volume, complications, and American Society of Anesthesiologists (ASA) classification were recorded for all patients and compared.

RESULTS

Two hundred two of 612 patients who underwent pulmonary angiography had pulmonary hypertension. Moderate pulmonary hypertension was present in 155 patients (77%) and severe pulmonary hypertension, in 47 patients (23%). Three (2.0%) of four complications were fatal. The complication rate was higher in patients with severe pulmonary hypertension compared with patients with moderate pulmonary hypertension but not statistically significant (6.3% vs 0.6%, p = 0.63). Patients with complications had a higher mean ASA score than those without complications (4.0 vs 3.0, p = 0.03). Patients with lung transplants had the greatest increase in pulmonary artery pressure after pulmonary angiography compared with all other clinical indications (16.75 +/- 12.97 mm Hg vs 5.46 +/- 6.86 mm Hg, p = 0.003).

CONCLUSION

The complication rate of pulmonary angiography in patients with pulmonary hypertension is low. However, in severely ill patients with acute pulmonary hypertension, pulmonary angiography should be undertaken with extreme caution.

Quand, comment et pourquoi réaliser une imagerie des artères pulmonaires ?

For several years, catheter angiography was the standard imaging technique used for evaluating the pulmonary arteries. Technical advances with computed tomography have had a significant impact on chest imaging, especially the increasing availability of multidetector row CT units. CT pulmonary angiography (CTPA) is now the first line imaging technique to evaluate pulmonary arterial diseases, including pulmonary embolus. Pulmonary angiography is now essentially limited to the endovascular management of pulmonary arteriovenous malformations, pulmonary arteriovenous fistulas or pulmonary arterial aneurysms. Gadolinium enhanced MR angiography of the pulmonary arteries may be helpful in patients with contraindications to the use of iodinated contrast material.

[Surgical treatment of post-embolism pulmonary hypertension]

Pulmonary hypertension is a serous condition which, after a long history as an orphan disease, has raised renewed interest due to the development of efficacious therapeutic options including lung transplantation and continuous infusion of prostacycline. Bilateral endarteriectomy of the pulmonary arteries is another possibility for post-embolism pulmonary hypertension. The procedure is complex and must be performed in conditions of cardiac arrest and deep hypothermia but, unlike transplantation, provides definitive cure. Recognizing the post-embolic nature of pulmonary hypertension is not simple because old episodes of venous thrombosis or embolus migration are not found in 50% of patients. Segmentary defects on the perfusion scintigraphy contrasting with the homogeneous respiratory scintigraphy is the primary diagnostic feature. Lesions must be located in a main trunk or at the origin of lobular or segmentary branches to be accessible to endarteriectomy. An antero-posterior and lateral angiogram of each lung and a multiple-array helicoidal angioscan performed with a precise protocol by an experienced team are needed to identify the localization of the lesions. If the pulmonary resistance determined at right catheterism is correlated with anatomic obstruction, the risk of mortality of pulmonary endarteriectomy is low, offering patients a significant chance for normal or nearly normal cardiorespiratory function.

Primary pulmonary hypertension

Primary pulmonary hypertension (PPH) is a rare disorder characterised by raised pulmonary-artery pressure in the absence of secondary causes. Precapillary pulmonary arteries are affected by medial hypertrophy, intimal fibrosis, microthrombosis, and plexiform lesions. Most individuals present with dyspnoea or evidence of right heart failure. Echocardiography is the best non-invasive test to screen for suspected pulmonary hypertension. The discovery of mutations in the coding region of the gene for bone morphogenetic protein receptor 2 in patients with familial and sporadic PPH may help not only to elucidate pathogenesis but also to direct future treatment options. The pathogenesis is not completely understood, but recent investigations have revealed many possible candidate modifier genes. Without treatment, the disorder progresses in most cases to right heart failure and death. With current therapies such as epoprostenol, progression of disease is slowed, but not halted. Many promising new therapeutic options, including prostacyclin analogues, endothelin-1-receptor antagonists, and phosphodiesterase inhibitors, improve clinical function and haemodynamic measures and may prolong survival.

Review article: Effects of radiographic contrast media on the lung

The pulmonary adverse effects of intravascular use of water soluble radiographic contrast media (RCM) include bronchospasm, pulmonary oedema and increase in the pulmonary arterial blood pressure (Ppa). Symptomatic bronchospasm is rare but subclinical increase in airways resistance is common after intravascular injection of RCM. Experimental studies have demonstrated that the low osmolar ionic dimer ioxaglate can induce significant bronchospasm in comparison with other types of RCM. Histamine and endothelin, which are potent bronchoconstrictors and released in response to the administration of RCM, do not seem to mediate the bronchospastic effect of RCM. Pretreatment with corticosteroids or antihistamine does not appear to prevent RCM induced bronchospasm, but the administration of beta(2) adrenergic agonist can abolish this adverse effect. RCM induced pulmonary oedema can be secondary to endothelial injury causing an increase in the permeability of the microcirculation. It may also occur in patients with incipient cardiac failure, when large doses of RCM particularly of the high osmolar type are used. A rise in Ppa induced by RCM seems to be secondary to an increase in pulmonary vascular resistance through direct effects on the pulmonary circulation. Low osmolar non ionic monomers induce the least changes in the pulmonary circulation and should be the contrast media of choice for intravascular use in patients with pulmonary hypertension. The mechanisms responsible for the effects of RCM on airway resistance and pulmonary circulation remain unclear. Intrabronchial administration of high osmolar water soluble RCM is dangerous and can induce severe bronchial irritation and pulmonary oedema. Low osmolar RCM are well tolerated by the lungs following aspiration with minimal histological reaction.

Overview of Prospective Investigation of Pulmonary Embolism Diagnosis II

The Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II) is a prospective multicenter study funded by the National Heart, Lung, and Blood Institute which began recruiting patients in the fall of 2001. It was designed to assess the efficacy of the spiral computed tomographic pulmonary angiogram in patients suspected of having acute pulmonary embolism (PE). In contrast to the original PIOPED study, which used contrast pulmonary angiography as the primary reference test for PE, PIOPED II will use a composite reference test for venous thromboembolism that is based on the ventilation/perfusion lung scan, venous compression ultrasound of the lower extremities, digital subtraction pulmonary angiography, and contrast venography in various combinations to establish the PE status of the patient. New criteria for ventilation/perfusion lung scan diagnosis have been developed for PIOPED II. This article describes the various techniques that will be used, the combination of the composite reference tests that will be used to determine the PE status of the patient, and the PIOPED II diagnostic criteria that will be used for the ventilation/perfusion scan diagnosis of PE in the study.

[Clinico-hemodynamic study and treatment of 44 patients with primary pulmonary hypertension]

BACKGROUND

Primary pulmonary hypertension is a poorly understood disease with a difficult treatment.

PATIENTS AND METHOD

Retrospective study of a series of 44 patients suffering from pulmonary hypertension who were studied in our center between 1992 and 2000.

RESULTS

At diagnosis, 6 (13%) patients were classified as having NYHA functional class I, 11 (25%) had class II, 25 (57%) had class III, and 2 had class IV. Mean pulmonary artery systolic pressure by echo-doppler was 92 (range: 43-154) mmHg. Basal right catheterization showed a mean (SD) pulmonary artery pressure of 58 (18) mmHg, total basal pulmonary resistances of 1679 (1,071) din/cm2 and cardiac index of 2.2 (1) 1/minute/m2. Five patients improved with anticoagulation and calcium channel blockers therapy. Since 1998, 11 patients had been treated with continuous endovenous epoprostenol, yet only 3 (27%) had significant clinical improvement. Survival at 5 years after diagnosis was 56%. At the end of study, 7 (70%) out of 10 patients who underwent pulmonary transplantation were alive (mean: 34, range: 3-62 months).

CONCLUSIONS

Pulmonary hypertension is a disease with a poor prognosis. However, treatment with prostaglandins and pulmonary transplantation may lead to encouraging results.

Current management of primary pulmonary hypertension

Primary pulmonary hypertension (PPH) is a rare disorder of the lung vasculature characterised by an increase in pulmonary artery pressure. Although the aetiology of this disease remains unknown, knowledge of the pathophysiology of the disease has advanced considerably. Diagnosis of PPH is largely by exclusion. The clinical symptoms associated with PPH are aspecific and similar to those seen in other cardiovascular and pulmonary diseases. Electrocardiography, echocardiography, pulmonary function tests, and a lung perfusion scan are necessary to exclude secondary forms of pulmonary hypertension and also help to confirm the diagnosis of PPH. A definite diagnosis of PPH is established by right-heart catheterisation which gives a precise measure of the blood pressure in the right side of the heart and the pulmonary artery, right ventricular function and cardiac output. Once a diagnosis of PPH is established, treatment involving drug therapy or surgery is commenced on the basis of the New York Heart Association functional class. Conventional treatment consists of lifetime administration of anticoagulants, oxygen, diuretics, and digoxin. Vasodilator therapy with calcium channel antagonists is indicated in patients who are 'vasoreactive' to acute vasodilator challenge as assessed by right-heart catheterisation. Promising results are obtained by continuous intravenous administration of epoprostenol (prostacyclin). Newer therapies for PPH include prostacyclin analogues, endothelin receptor antagonists, nitric oxide, phosphodiesterase-5 inhibitors, elastase inhibitors, and gene therapy. Surgical treatment consists of atrial septostomy, thromboendarterectomy, and lung or heart-lung transplantation.

Effects of radiographic contrast media on pulmonary vascular resistance of normoxic and chronically hypoxic pulmonary hypertensive rats

Intravascular radiographic contrast media (RCM) can be associated with significant morbidity in patients with pulmonary hypertension (PH). This study investigated the direct effect of the four main classes of RCM (high osmolar ionic monomer "diatrizoate"; low osmolar ionic dimer "ioxaglate"; low osmolar non-ionic monomer "iopromide"; and iso-osmolar non-ionic dimer "iotrolan") in ex vivo isolated rat lungs perfused with blood at 20 ml min(-1) under basal conditions (air + 5% CO2 ventilation, pulmonary artery pressure (Ppa) 16-20 mmHg) and when Ppa was raised by hypoxic vasoconstriction in normal rats (2-3% O2+5% CO2 ventilation, Ppa increased by 4-14 mmHg). The effects of low osmolar RCM (ioxaglate, iopromide and iotrolan) were also studied in rats with PH induced by chronic hypoxia (3 weeks 10% O2, Ppa 26-36 mmHg). Increasing volumes (0.05 ml, 0.1 ml, 0.3 ml, and 0.5 ml) of RCM, mannitol (osmolar and pH control) or normal saline (volume control) were added to the 10 ml blood reservoir (n=4-9 per group). In normal rats, RCM caused a dose-dependent slow rise in Ppa. The maximum rise in mean+/-SEM Ppa at the cumulative dose of 0.95 ml was ioxaglate 13.8+/-1.6 mmHg>iotrolan 7.3+/-1.7 mmHg=diatrizoate 9.8+/-2.2 mmHg>iopromide 3.0+/-0.8 mmHg (p<0.05). The rise in Ppa induced by ioxaglate and iotrolan was significantly greater than in the mannitol and saline controls (p<0.05). Pre-treatment with endothelin receptor A/B blockade (SB209670) did not abolish the rise in Ppa induced by diatrizoate (0.95 ml) in the normal rat (3.8+/-1.3 mmHg diatrizoate alone and 3.4+/-1.1 mmHg in the presence of 40 microM SB209670, n=5 per group). When Ppa was raised by acute hypoxia, ioxaglate and diatrizoate (0.5 ml) caused a fall in Ppa (percentage fall -53+/-23 and -118+/-10, respectively, p<0.001) while iotrolan and iopromide caused a small further rise in Ppa, which was significant with iotrolan at a dose of 0.3 ml (percentage rise in pressure 14.2+/-2.3, p<0.05). In chronic pulmonary hypertensive rats, RCM (0.95 ml) caused an overall slow progressive rise in Ppa (iopromide 6.8+/-1.7 mmHg< ioxaglate 11.6+/-2.5 mmHg=iotrolan 12.7+/-1.1 mmHg). However, ioxaglate initially induced an acute fall of Ppa (maximum fall 4.22+/-0.9 mmHg, p<0.05) for almost 20 min. In summary, iopromide induced the least change in Ppa of normal and pulmonary hypertensive rats. The pathophysiology of the effects of RCM on the pulmonary circulation remains uncertain.

Chronic thromboembolic pulmonary hypertension

Remarkable advances have occurred over the past 2 decades in the diagnostic approach, surgical management, and postoperative care of patients afflicted with chronic thromboembolic pulmonary hypertension. Despite these advances, a great deal needs to be achieved if the morbidity and mortality of the disease process are to be reduced further. First, the preliminary insights that have been achieved into the natural history of the disease must be defined further. The level of pulmonary hypertension encountered in most patients with chronic thromboembolic pulmonary hypertension at the time of initial clinical recognition cannot be reached on an acute basis. Gradual hemodynamic progression, therefore, must occur over time. The basis for this progression, why it occurs in certain patients and not others, following an acute thromboembolic event and why it seems to occur over months in certain patients and over decades in others, remain entirely speculative. It is possible that the overall extent of central pulmonary vascular obstruction represents the primary pathophysiologic determinant of disease progression. Given the lack of correlation between the degree of central thromboembolic obstruction and hemodynamic impairment in certain patients, however, it is also possible that other factors, such as the circulating vasoconstrictors, the development of a hypertensive pulmonary arteriopathy, an individual genetic predisposition to pulmonary hypertension, or the compensatory adaptations of the right ventricle, contribute to the extent and rate of disease progression. By identifying and sequentially evaluating patients with persistent pulmonary vascular obstruction or pulmonary hypertension following an acute thromboembolic event, valuable insights into the natural history of thromboembolic pulmonary hypertension and other variants of pulmonary hypertension might be achieved. It is also important to recognize that the development of chronic thromboembolic pulmonary hypertension represents a failure in the long-term management or follow-up surveillance of those with documented acute thromboembolic disease. Recent insights into the recurrent nature of acute thromboembolic disease and its potential for only partial resolution in a number of afflicted individuals suggest that a repeat perfusion scan and, if abnormal, an echocardiogram be performed at the time of anticipated discontinuation of anticoagulation in patients with documented pulmonary embolic disease. Although the cost-effectiveness of this approach has been questioned in the past, recent data suggest that doing so would help identify that subset of patients with unresolved embolism, provide additional information regarding the optimal duration of anticoagulation, and provide a new baseline study for patients in whom anticoagulation is discontinued and who subsequently present with suspected embolic recurrence. Improved diagnostic techniques are also necessary if the mortal risk of thromboendarterectomy is to be reduced. Even in the setting of a broad experiential base, prognostic uncertainty exists in approximately 10% of patients before operative intervention. Because many of these patients will benefit from the procedure, and because many are ineligible for transplantation for reason of age or other restriction, it has been the authors' practice to offer surgery to these patients, although at an assumed higher risk. To not do so would be to deny a potentially lifesaving procedure to many who would benefit and who might be left without an effective therapeutic alternative. The ability to better define the group of patients who will not benefit from surgery, however, would spare those patients the morbid and mortal risks of the procedure and provide a basis for the investigation of other therapeutic alternatives such as pulmonary vasodilating agents. Finally, this patient population offers a unique opportunity to enhance understanding of the pathophysiologic mechanisms involved in acute lung injury. The population involved is uniform, the predisposing event is consistent, the time of onset is predictable, and, compared with other populations at risk for acute lung injury, the presence of confounding variables is negligible. It also provides a unique opportunity to evaluate pharmacologic interventions designed to prevent or diminish the occurrence of acute lung injury and postoperative management strategies designed to minimize its impact.

Radionuclide imaging of acute pulmonary embolism

From the prospective and outcome-based studies that have been carried out in the past few years, the following conclusions regarding the diagnostic evaluation of patients with suspected PE can be made: 1. A normal V/Q scan interpretation excludes the diagnosis of clinically significant PE. 2. Patients with a very-low- or low-probability V/Q scan interpretation and a low clinical likelihood of PE do not require angiography or anticoagulation. 3. Patients with a very-low- or low-probability V/Q scan interpretation, an intermediate or high clinical likelihood of PE, and negative serial noninvasive venous studies of the lower extremities do not require anticoagulation or angiography. If serial noninvasive venous studies of the lower extremities are positive, patients should be treated. 4. Clinically stable patients with an intermediate-probability V/Q scan interpretation require noninvasive venous studies of the legs and, if negative, require CT angiography or pulmonary angiography for a definite diagnosis. 5. Clinically stable patients with a high-probability V/Q scan interpretation and a high clinical likelihood of PE require treatment and need no further diagnostic tests to confirm the diagnosis. 6. Clinically stable patients with a high-probability V/Q scan interpretation and a low or intermediate clinical likelihood of PE require noninvasive venous studies of the legs and, if negative, often require CT angiography or pulmonary CT for a definitive diagnosis.

Magnetic resonance imaging of the thorax. Past, present, and future

Magnetic resonance imaging is a valuable modality of extreme flexibility for specific problem-solving capability in the thorax. This article reviews MR applications in the imaging of great vessels, which are currently the most important applications in the thorax; other established applications in the thorax; and pulmonary functional MR imaging.

Intravascular ultrasound imaging of the pulmonary arteries in primary pulmonary hypertension

OBJECTIVE

Intravascular ultrasound has the unique ability to provide cross-sectional images of the arterial wall. This study examined intravascular ultrasound (IVUS) images of the proximal pulmonary arteries in primary pulmonary hypertension (PPH).

METHODOLOGY

Study 1: Specimens from four patients who had died of PPH (in vitro PPH group) were compared with those of three patients who had died of subarachnoid haemorrhage but had no evidence of cardiopulmonary disease (in vitro control group). Three-centimetre segments of the following levels were examined by IVUS: pulmonary trunk, eight secondary branch arteries of the upper, middle, and lower lobes of both lungs, and the thoracic descending aorta. Study 2: Four patients with PPH (in vivo PPH group) and five patients without pulmonary hypertension and no evidence of cardiopulmonary disease (in vivo control group) were examined. The IVUS images of the apical segmental artery of the right upper lobe and the descending branch of the right pulmonary artery were studied.

RESULTS

Echographic examination of formalin-fixed preparations of secondary branch sections of the pulmonary artery failed to show a clear three-layer structure in the in vitro control group (24 preparations), but a distinct three-layer structure and increased vessel wall thickness were observed in the in vitro PPH group (32 preparations). Similar findings were obtained in the in vivo study. The mean echo density of the proximal pulmonary arterial wall correlated well with the mean pulmonary arterial pressure (mPA) in the in vitro PPH, and also correlated with the mPA in the in vivo study (r = 0.960, P < 0.0001). The echo intensity of secondary branch sections of the pulmonary artery was higher in the in vitro PPH group than in the in vitro control group (180.5 +/- 27.0 vs 132.5 +/- 26.7 counts, P < 0.001); similar results were obtained in the in vivo study (144.7 +/- 23.4 vs 85.0 +/- 14.3 counts, P < 0.01).

CONCLUSIONS

These results suggest that the histological changes detected in the pulmonary artery walls in the PPH group were responsible for the increased echo intensity.

From the archives of the AFIP: pulmonary vasculature: hypertension and infarction

Pulmonary hypertension is the hemodynamic consequence of vascular changes within the precapillary (arterial) or postcapillary (venous) pulmonary circulation. These changes may be idiopathic, as in primary pulmonary hypertension or pulmonary veno-occlusive disease, but more commonly they represent a secondary response to alterations in pulmonary blood flow. The pulmonary and systemic bronchial circulations form broad anastomoses that largely prevent infarction except in settings of markedly elevated pulmonary venous pressure, underlying malignancy, or excessive embolic burden. Causes of precapillary pulmonary hypertension include long-standing cardiac left-to-right shunt, chronic thromboembolic disease, and widespread pulmonary embolism arising from intravascular malignant cells, parasites, or foreign materials. The classic radiologic features of precapillary pulmonary hypertension are central arterial enlargement, sharply pruned peripheral vascularity, and right-sided heart hypertrophy and chamber dilatation. Postcapillary pulmonary hypertension may develop secondary to focal venous constriction or to compromised pulmonary venous drainage due to left atrial neoplasia, mitral stenosis, or left ventricular failure. Radiologic manifestations of postcapillary pulmonary hypertension include prominent septal lines, small pleural effusions, and occasionally air-space opacities. In addition, radiologic evaluation of postcapillary pulmonary hypertension may demonstrate evidence of pulmonary arterial hypertension, secondary to the retrograde transmission of elevated pulmonary venous pressure across the capillary bed.

Magnetic resonance imaging of the thorax. Past, present, and future

Magnetic resonance is a valuable modality of extreme flexibility for specific problem-solving capability in the thorax. This article reviews MR applications in the imaging of great vessels, which are currently the most important applications in the thorax; other established applications in the thorax; and pulmonary functional MR imaging.

Pulmonary hypertension in collagen vascular disease

Pulmonary hypertension associated with collagen vascular disease often eludes diagnosis, sometimes causing considerable morbidity or even death before being identified. This review details its characteristic clinical features, appropriate diagnostic and treatment approaches, and expected outcomes.

How to manage secondary pulmonary hypertension

Establishing an underlying cause and treatment plan for patients with pulmonary hypertension presents a significant challenge to practicing physicians. Doppler echocardiography is a simple, cost-effective tool for detecting pulmonary hypertension and evaluating right ventricular function. Nonspecific therapy (use of digoxin and diuretics, anticoagulation) for pulmonary hypertension and right ventricular failure achieves a degree of symptomatic improvement and should be considered in patients with moderate to severe disease. CTEPH should be considered in patients with dyspnea. Because severs forms of pulmonary hypertension usually are not discovered until late in the disease course, a high level of suspicion is required when evaluating symptoms and risk factors consistent with pulmonary vascular disease. Pulmonary hypertension is classified as idiopathic, or primary, when no secondary cause can be identified. Primary pulmonary hypertension is a devastating disease that largely affects young women. Significant advances in treatment have been made and will be discussed in detail in part 2 of this article.

[Pulmonary thromboendarterectomy with video-angioscopy and circulatory arrest: an alternative to cardiopulmonary transplantation and post-embolism pulmonary artery hypertension]

The best predictor of poor or suboptimum outcome from pulmonary thromboendarterectomy (PTE) is insufficient relief of obstruction, especially in the lower lobes. The aim of this study is to emphasize that the use of video-assisted angioscopy may increase the quality of PTE and thus improve outcome. PTE included a median sternotomy, intrapericardial dissection limited to the superior vena cava, institution of cardiopulmonary bypass, deep hypothermia and sequential circulatory arrest periods. PTE was always bilateral and performed through two separate arteriotomies of both main intrapericardial pulmonary arteries. A rigid 5 mm angioscope connected to a video camera was introduced through the arteriotomy into the lumen to increase the visibility and perform the video-assisted endarterectomies of all obstructed segmental branches, including normally inaccessible anterior segmental branches. Between January 1996 and December 1997, 48 patients with severe postembolic pulmonary hypertension had PTE. Patients were in New York Heart Association (NYHA) class II (n = 2), III (n = 28) or IV (n = 18) with the following hemodynamics: mean pulmonary arterial pressure (PAP) 53 +/- 13 mmHg, cardiac index 2.16 +/- 0.5 L/min/m2, pulmonary vascular resistances (PVR): 1,152 +/- 414 dyne.s-1.cm-5. Six patients died from alveolar hemorrhage (n = 1), high residual pulmonary pressure and rethrombosis (n = 4) and hypoxic cardiac arrest (n = 1). The functional outcome in surviving patients was as follows: (NYHA) class I (n = 24), II (n = 16) or III (n = 2) with improved hemodynamics: mean pulmonary arterial pressure: 30 +/- 9 mmHg, cardiac index: 2.78 +/- 0.5 L/min/m2, pulmonary vascular resistances (PVR): 484 +/- 159 dynes.s-1.cm-5. Video-assisted angioscopy allows much improved quality and degree of pulmonary endarterectomy. This expands the indications to include patients with previously inaccessible distal disease and candidates for heart-lung transplantation.

MR pulmonary angiography and perfusion imaging: recent advances

Recent advances in MR pulmonary angiography and MR perfusion imaging are reviewed, focusing on two principal areas of technical development: (1) the availability of MR scanners equipped with enhanced gradient systems; and (2) new trends in MR angiography using gadolinium contrast agents or labeling of blood with an inversion recovery radiofrequency pulse in place of the more traditional methods using naturally flowing spins as the source of intravascular signal. These recent developments in MR have significant potential for clinical imaging of the pulmonary vasculature, particularly for the diagnosis of pulmonary embolism, and are now opening windows to functional MR imaging of the lung.

Therapeutic options for severe pulmonary hypertension

Pulmonary hypertension occurs as a consequence of numerous and varied conditions, all of which result in an elevation of pulmonary vascular resistance. Over the past decade, significant progress has been made in understanding the factors which contribute to the progressive nature of pulmonary vascular disease, and in identifying new treatments for pulmonary hypertension. The majority of these therapeutic options are pharmacologic, but for specific circumstances, surgical therapy may be a consideration. This article discusses nonspecific therapies for all patients with pulmonary hypertension, vasodilator therapy (including screening for vasodilator responsiveness, standard oral agents, and newer intravenous or inhalational therapies) and surgical options applicable to specific situations.

Comparison of bronchopulmonary collaterals and collateral blood flow in patients with chronic thromboembolic and primary pulmonary hypertension

OBJECTIVE

To compare the visualisation of bronchopulmonary collaterals and bronchopulmonary collateral blood flow in patients with chronic thromboembolic pulmonary hypertension 2nd primary pulmonary hypertension.

SETTING

Referral centre for cardiology at an academic hospital.

PATIENTS

Nine patients with chronic thromboembolic pulmonary hypertension and 17 with primary pulmonary hypertension.

INTERVENTIONS

Bronchopulmonary collaterals were visualised by selective bronchial arteriography or thoracic aortography. Bronchopulmonary collateral blood flow was estimated by injecting indocyanine green into the ascending aorta and sampling below the mitral valve from the left ventricle.

RESULTS

The degree of pulmonary hypertension was comparable in the two groups. Large bronchopulmonary collaterals were visualised in all the patients with thromboembolic pulmonary hypertension who had bronchial arteriography or aortography or both. None of the primary pulmonary hypertension group studied by aortography had bronchopulmonary collaterals (P < < 0.001). All the patients with chronic thromboembolic pulmonary hypertension had significant bronchopulmonary collateral blood flow, which was (mean (SD)) 29.8 (18.6)% of the systemic blood flow. There was no recordable collateral blood flow in 11 of 15 patients with primary pulmonary hypertension. In the remaining four patients the mean value was 1.1 (1.8)% of the systemic blood flow (P < < 0.001).

CONCLUSIONS

Visualisation of bronchopulmonary collaterals by thoracic aortography or by bronchial arteriography, or the demonstration of an increased bronchopulmonary collateral flow, helps to distinguish patients with chronic thromboembolic pulmonary hypertension from those with primary pulmonary hypertension.

Pulmonary hypertension in systemic autoimmune disease

Rare in occurrence, insidious in onset, and relentless in its course, pulmonary hypertension in systemic autoimmune disease remains one of the most challenging entities to diagnose and treat today. The subtlety and nonspecificity of its symptoms and signs, the lack of availability of sensitive, noninvasive, accurate diagnostic tests, the rudimentary understanding we have of its pathogenesis, the multiplicity of findings on histopathologic survey, and the paucity of data from large-scale therapeutic trials in this population all pose many frustrations for patient and physician. Although supportive, symptomatic therapy remains the mainstay of treatment, we continue to await the results of carefully conducted clinical trials investigating antiinflammatory drugs and vasodilators. Careful scrutiny of the histologic lesions seen in pulmonary hypertension has shown striking similarity with the changes of PPH in some patients, and close follow-up of patients diagnosed with PPH has shown that some of them later develop evidence of a specific autoimmune disease like scleroderma. A natural tendency to extrapolate the use of therapeutic modalities of PPH to patients with autoimmune disease-associated pulmonary hypertension then results. We are thus encouraged by the lessons learned from the past about PPH; studies of patients with PPH have identified a subset of them who enjoy a distinct survival advantage with use of vasodilators or transplantation. We remain hopeful that future investigations in the treatment of autoimmune disease-associated pulmonary hypertension will yield similar information, and that we will be able to provide afflicted individuals some long-awaited improvements in quality and duration of life.

Prospective evaluation of pulmonary artery pressures during pulmonary angiography performed with low-osmolar nonionic contrast media

PURPOSE

To determine the effects of pulmonary angiography performed with low-osmolar, nonionic contrast media on pulmonary artery pressures.

PATIENTS AND METHODS

In a prospective, uncontrolled clinical trial, pulmonary artery pressures (systolic, diastolic, mean) of 116 patients referred for pulmonary angiography were recorded before and 1 and 5 minutes after injection of contrast material.

RESULTS

There was a statistically significant rise in systolic, diastolic, and mean pulmonary artery pressure at 1 minute (4.6, 3.4, 4.1 mm Hg, respectively) and 5 minutes (3.8, 2.7, 3.4 mm Hg, respectively) after the initial contrast material injection (P < .05). Increases were smaller with additional injections. Systolic pressure changes at 1 and 5 minutes after the first injection were linearly dependent on the volume of contrast material injected (P < .05). There was no statistically significant difference in the increase in pulmonary artery pressure between patients with pulmonary embolus or pulmonary arterial hypertension and those without.

CONCLUSION

There is a small but statistically significant rise in pulmonary artery pressure after injection of low-osmolar, nonionic contrast material for pulmonary angiography; it is unlikely to be of clinical significance.

Safety of pulmonary angiography in the 1990s

PURPOSE

To examine the safety of pulmonary angiography with low-osmolar contrast material and modern angiographic techniques and to analyze periprocedural complications with respect to potential predictors.

PATIENTS AND METHODS

A retrospective review was conducted of data from 547 consecutive patients who underwent pulmonary angiography. Minor and major complications were analyzed by using several clinical parameters.

RESULTS

There were five major (0.9%) and 26 minor complications (4.8%). Eleven of the 26 minor complications were contrast-induced nephrotoxicity. There were no periprocedural deaths. Patients with complications had an increased incidence of coexistent pulmonary morbidities and were of a poorer physical status according to the American Society of Anesthesiology criteria. Moderate to severe pulmonary hypertension was correlated with major complications. Age, volume of contrast material used, and presence of pulmonary embolism were not correlated with complications.

CONCLUSION

Pulmonary angiography is a safe procedure with an acceptable complication rate. These findings should be considered in the selection of an imaging method for the diagnosis of pulmonary embolism.

Hemodynamic effects and image quality of low-osmolar ionic and nonionic contrast media during pulmonary angiography

RATIONALE AND OBJECTIVES

We compared the hemodynamic responses to ionic and nonionic low-osmolar contrast media of patients who underwent pulmonary angiography.

METHODS

Ninety-nine consecutive patients with suspected pulmonary emboli were randomly assigned to receive either 40 ml iohexol or 40 ml ioxaglate in 2 sec at 600 psi (0.17 kg/m2). Mean pulmonary arterial pressure, pulse rate, and blood pressure were recorded before, immediately after, and 2, 5, and 10 min following injection. Image quality was assessed by readers who were unaware of drug assignment.

RESULTS

Pulmonary arterial pressure increased to a maximum at 2 min and was higher in patients with pulmonary emboli (p = .06). There were no significant differences between the two contrast media used. The systolic blood pressure and pulse rate in patients with pulmonary emboli increased significantly more in the ioxaglate group (ps = .03 and .04, respectively). Image quality was excellent in 90% of both groups.

CONCLUSION

Both contrast agents are safe for pulmonary angiography and yield similar image quality. There appears to be a positive inotropic effect of ioxaglate.