Pulmonary endarterectomy

Pulmonary endarterectomy: the potentially curative treatment for patients with chronic thromboembolic pulmonary hypertension

Pulmonary endarterectomy (PEA) is the treatment of choice to relieve pulmonary artery obstruction in patients with chronic thromboembolic pulmonary hypertension (CTEPH). It is a complex surgical procedure with a simple principle: removal of obstructive thromboembolic material from the pulmonary arteries in order to reduce pulmonary vascular resistance, relieve pulmonary hypertension (PH) and alleviate right ventricular dysfunction. In the majority of patients there is symptomatic and prognostic benefit. However, not all patients with CTEPH are suitable for treatment with PEA. Operability assessment is not always easy, being largely subjective and based on experience. It is therefore important that all patients are referred to an experienced CTEPH centre for careful evaluation of suitability for surgery. The most common reason for inoperability is distal vasculopathy accounting for a high proportion of the vascular resistance. Surgery requires cardiopulmonary bypass and periods of deep hypothermic circulatory arrest. Complications include reperfusion lung injury and persistent PH. However, with careful patient selection, surgical technique and post-operative management, PEA is a highly effective treatment with mortality rates <5% at experienced centres. Patients who are unsuitable for surgery may be candidates for medical therapy.

A review of pulmonary endarterectomy as a CTEPH treatment, including patient assessment, risks and outcomeshttp://ow.ly/L82F7

Imaging pulmonary arterial thromboembolism: challenges and opportunities

Magnetic resonance (MR) angiography of the pulmonary arteries is a rapidly evolving technique with proven clinical usefulness. Multiple-step protocols, such as MR perfusion followed by high-spatial resolution MR angiography, seem to be a good approach for the assessment of different vascular diseases affecting the pulmonary arteries. In combination with other imaging sequences, MR imaging is one of the most comprehensive potential noninvasive imaging techniques available.

A global perspective on the epidemiology of pulmonary hypertension

The epidemiology of pulmonary hypertension (PH) is not fully determined worldwide but is believed to vary in different regions of the world, with differences determined by genetic, geographic, environmental, and socioeconomic factors, as well as sex-related practices and inequities in access to health care. This article reviews the global epidemiology of PH, with emphasis on the prevalence, causes, forms, and underlying factors in the developing world. Left ventricular heart disease is the most common cause worldwide, but the main contributors in developing countries are chronic infectious diseases, hypertensive heart disease, cardiomyopathy, and rheumatic heart disease. Despite data suggesting a high prevalence in Sub-Saharan Africa, the available literature is very limited. International registries like the Pan African Pulmonary Hypertension Cohort are essential to provide information about the causes, comorbidities, and diagnostic classification, therapeutic management, and the natural course of PH worldwide. Moreover, there is a need to track diagnostic and management practices and challenges to identify the gaps and gradients between different regions of the world. The information gained will pinpoint areas for improvement, aiming at bridging the current divide between low-income and high-income countries.

Pulmonary thromboendarterectomy in 106 patients with chronic thromboembolic pulmonary hypertension

INTRODUCTION

Pulmonary thromboendarterectomy is the treatment of choice in chronic thromboembolic pulmonary hypertension. We report our experience with this technique.

METHODS

Between February 1996 and June 2014, we performed 106 pulmonary thromboendarterectomies. Patient population, morbidity and mortality and the long-term results of this technique (survival, functional improvement and resolution of pulmonary hypertension) are described.

RESULTS

Subjects' mean age was 53±14 years. A total of 89% were WHO functional class III-IV, presurgery mean pulmonary pressure was 49±13mmHg and mean pulmonary vascular resistance was 831±364 dynes.s.cm(-5). In-hospital mortality was 6.6%. The most important post-operative morbidity was reperfusion pulmonary injury, in 20% of patients; this was an independent risk factor (p=0.015) for hospital mortality. With a 31-month median follow-up (interquartile range: 50), 3- and 5-year survival was 90 and 84%. At 1 year, 91% were WHO functional class I-II; mean pulmonary pressure (27±11mmHg) and pulmonary vascular resistance (275±218 dynes.s.cm(-5)) were significantly lower (p<0.05) than before the intervention. Although residual pulmonary hypertension was detected in 14 patients, their survival at 3 and 5 years was 91 and 73%, respectively.

CONCLUSIONS

Pulmonary thromboendarterectomy offers excellent results in chronic thromboembolic pulmonary hypertension. Long-term survival is good, functional capacity improves, and pulmonary hypertension is resolved in most patients.

Right ventricular adaptation to pulmonary pressure load in patients with chronic thromboembolic pulmonary hypertension before and after successful pulmonary endarterectomy--a cardiovascular magnetic resonance study

BACKGROUND

The aim of the study was to characterize RV adaptation to varying loading conditions in patients with chronic thromboembolic hypertension (CTEPH) before and after pulmonary endarterectomy (PEA). Nearly 4% of patients with pulmonary embolism develop CTEPH. PEA offers a cure with excellent outcome. By use of cardiovascular magnetic resonance (CMR) combined with hemodynamic measurements pulmonary arterial elastance (Ea-pulm_i), end-systolic right ventricular elastance (Ees-RV_i) and ventriculo-arterial coupling (Ea-pulm_i/Ees-RV_i) can be studied before and after PEA.

METHODS

Sixty-five patients (mean age 41±12 years, 28 female) underwent CMR pre- and post-PEA. Ejection fraction (EF), end-diastolic (EDVi), end-systolic (ESVi), and stroke (SVi) volumes were indexed for body surface area. Ea-pulm_i was calculated as pulmonary artery mean pressure (mPAP)/SVi, and Ees-RV_i as mPAP/ESVi.

RESULTS

mPAP decreased from 47±12 to 25±9 mmHg, p=0.0001. Ea-pulm_i was increased before PEA and normalized afterwards (2.8±2.1 vs. 0.85±0.4 mmHg/ml/m2, p=0.0001). Ees-RV_i was depressed before and after PEA (0.72±0.27 vs. 0.66±0.3 mmHg/ml/m2, p=0.13). EF improved from 25±12% to 46±10%, p=0.0001, because ventriculo-arterial coupling was restored (4.2±3 vs. 1.4±0.6, p=0.0001). EDVi and ESVi mproved significantly (EDVi 92±32 to 72±23 ml, p=0.0001; ESVi 69±31 to 41±18 ml, p=0.0001).

CONCLUSION

RV function is largely determined by afterload and returns to normal once afterload is normalized. This is paralleled by a significant improvement of CMR indices of right ventricular remodelling.

Pulmonary Endarterectomy

Chronic thromboembolic pulmonary hypertension (CTEPH) results from recurrent or incomplete resolution of pulmonary embolism. CTEPH is much more common than generally appreciated. Although pulmonary embolism (PE) affects a large number of Americans, chronic pulmonary thromboembolic hypertension remains underdiagnosed. It is imperative that all patients with pulmonary hypertension (PH) be screened for the presence of CTEPH since this form of PH is potentially curable with pulmonary endarterectomy (PEA) surgery. The success of this procedure depends greatly on the collaboration of a multidisciplinary team approach that includes pulmonary medicine, cardiothoracic surgery, and cardiac anesthesiology. This review, based on the experience of more than 3000 pulmonary endarterectomy surgeries, is divided into 2 parts. Part I focuses on the clinical history and pathophysiology, diagnostic workup, and intraoperative echocardiography. Part II focuses on the surgical approach, anesthetic management, postoperative care, and complications.

Effect of pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension on stroke volume response to exercise

In pulmonary hypertension, exercise is limited by an impaired right ventricular (RV) stroke volume response. We hypothesized that improvement in exercise capacity after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) is paralleled by an improved RV stroke volume response. We studied the extent of PEA-induced restoration of RV stroke volume index (SVI) response to exercise using cardiac magnetic resonance imaging (cMRI). Patients with CTEPH (n = 18) and 7 healthy volunteers were included. Cardiopulmonary exercise testing and cMRI were performed before and 1 year after PEA. For cMRI studies, pre- and post-operatively, all patients exercised at 40% of their preoperative cardiopulmonary exercise testing-assessed maximal workload. Post-PEA patients (n = 13) also exercised at 40% of their postoperative maximal workload. Control subjects exercised at 40% of their predicted maximal workload. Preoperatively, SVI (n = 18) decreased during exercise from 35.9 ± 7.4 to 33.0 ± 9.0 ml·m(2) (p = 0.023); in the control subjects, SVI increased (46.6 ± 7.6 vs 57.9 ± 11.8 ml·m(-2), p = 0.001). After PEA, the SVI response (ΔSVI) improved from -2.8 ± 4.6 to 4.0 ± 4.6 ml·m(2) (p <0.001; n = 17). On exercise at 40% of the postoperative maximal workload, SVI did not increase further and was still significantly lower compared with controls. Moreover, 4 patients retained a negative SVI response, despite (near) normalization of their pulmonary hemodynamics. The improvement in SVI response was accompanied by an increased exercise tolerance and restoration of RV remodeling. In conclusion, in CTEPH, exercise is limited by an impaired stroke volume response. PEA induces a restoration of SVI response to exercise that appears, however, incomplete and not evident in all patients.

Pulmonary endarterectomy - an example of treatment of right ventricular after load failure

The treatment of choice for patients with chronic thromboembolic pulmonary hypertension is pulmonary endarterectomy to reduce pulmonary vascular resistance with significant symptomatic and prognostic benefit. The fundamental aim of the surgery is to perform a full endarterectomy (not embolectomy or thrombectomy) in both pulmonary arteries. The operation is performed via a median sternotomy with hypothermic cardiopulmonary bypass (CPB) at 20 °C. Pulmonary arteriotomies are performed within the pericardium and periods of circulatory arrest are necessary to reduce collateral blood flow from bronchial arteries and allow a clear field for dissection distally. The endarterectomy plane is raised carefully as it is essential the correct layer be identified. The dissection proceeds within the superficial media into all the affected segmental and sub-segmental vessels. A cast of the inner layer of the pulmonary arterial tree is then dissected free by eversion moving towards the periphery. After completion of the endarterectomies, and the patient is rewarmed slowly on full CPB. During weaning from CPB the right-sided filling pressures should be kept low, guided by invasive haemodynamic monitoring. Survival to hospital discharge is ≫95% in experienced centres with outcome dependent on the disease pattern and pulmonary vascular resistance pre- and post-surgery.

Recent progress in the diagnosis and management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a form of pulmonary hypertension caused by non-resolving thromboembolisms of the pulmonary arteries. In Japan, in contrast to Western countries, CTEPH is more prevalent in women. A Japanese multicenter study reported that a form of CTEPH unrelated to deep vein thrombosis is associated with HLA-B⁎5201, suggesting that this form of CTEPH may be associated with vasculopathy. CTEPH can be cured by pulmonary endarterectomy, provided that the thrombi are surgically accessible; thus, early diagnosis is important, and all patients with exertional dyspnea should be evaluated for pulmonary hypertension. Ventilation/perfusion scans provide an excellent non-invasive means to distinguish CTEPH from pulmonary arterial hypertension. Similarly, computed tomographic pulmonary angiograms allow for the detection of thrombi and evaluation of pulmonary hemodynamics in a minimally invasive manner. Importantly, the absence of subpleural perfusion on pulmonary angiograms can suggest the presence of small vessel disease. Small vessel disease might be involved in the pathogenesis of CTEPH, and its detection is essential in preventing operative death. Although no modern therapies for pulmonary arterial hypertension have been approved for treatment of CTEPH, a recent randomized control trial of riociguat in patients with CTEPH demonstrated that riociguat significantly improved 6-min walking distance. Further investigations into treatments that target endothelial dysfunction and hyperproliferative CTEPH cells are needed. Recently, balloon pulmonary angioplasty has emerged as a promising treatment modality in Japan. A specialized medical team, including at least one expert surgeon, should make decisions regarding patients' candidacy for pulmonary endarterectomy and/or balloon pulmonary angioplasty.

Pulmonary Hypertension due to a Pulmonary Artery Leiomyosarcoma: A Case Report

Background. Primary pulmonary artery sarcomas are very rare and their histologic type, called leiomyosarcoma, is even rarer. Case Report. A 64-year-old woman presented with progressive weakness, fatigue, malaise, and dyspnea, and a marked elevation of pulmonary artery pressure was admitted. She was initially diagnosed with chronic pulmonary thromboembolism and chest computed tomography (CT) scan revealed that lobulated heterogeneous left hilar mass extended to precarinal and subcarinal space. MRI demonstrated a polypoid lesion at trunk with extension to left main pulmonary artery and its first branch. She was operated, a yellowish-shiny solid mass in pulmonary trunk was seen intraoperatively, and pulmonary endarterectomy was performed. Her tumor was pathologically diagnosed as pulmonary artery leiomyosarcoma. She died 3 months later after one chemotherapy course. Conclusion. Initially, the patient underwent surgery due to pulmonary embolism but, during the operation, the observed mass increased the probability of pulmonary artery neoplasm. Clinicians must consider pulmonary artery sarcoma when making the differential diagnosis for patients with pulmonary arteries masses. In addition to clinical prediction scores and CT and MRI findings to identify the patients with pulmonary artery sarcoma, PET scanning is the diagnosis of choice in differentiating embolism and neoplasm and is strongly recommended in these patients.

Factors associated with elevated pulmonary arterial pressure levels on the echocardiographic assessment in patients with prior pulmonary embolism

BACKGROUND

Factors associated with the detection of raised systolic pulmonary artery pressure (sPAP) levels in patients with a prior episode of pulmonary embolism (PE) are not well known.

METHODS

We used the RIETE Registry database to identify factors associated with the finding of sPAP levels ≥50 mm Hg on trans-thoracic echocardiography, in 557 patients with a prior episode of acute, symptomatic PE.

RESULTS

Sixty-two patients (11.1%; 95% CI: 8.72-14.1) had sPAP levels ≥50 mm Hg. These patients were more likely women, older, and more likely had chronic lung disease, heart failure, renal insufficiency or leg varicosities than those with PAP levels <50mm Hg. During the index PE event, they more likely had recent immobility, and more likely presented with hypoxemia, increased sPAP levels, atrial fibrillation, or right bundle branch block. On multivariate analysis, women aged ≥70 years (hazard ratio [HR]: 2.0; 95% CI: 1.0-3.7), chronic heart or chronic lung disease (HR: 2.4; 95% CI: 1.3-4.4), atrial fibrillation at PE presentation (HR: 2.8; 95% CI: 1.3-6.1) or varicose veins (HR: 1.8; 95% CI: 1.0-3.3) were all associated with an increased risk to have raised sPAP levels. Chronic heart disease, varicose veins, and atrial fibrillation were independent predictors in women, while chronic heart disease, atrial fibrillation, a right bundle branch block or an S1Q3T3 pattern on the electrocardiogram were independent predictors in men.

CONCLUSIONS

Women aged ≥70 years more likely had raised sPAP levels than men after a PE episode. Additional variables influencing this risk seem to differ according to gender.

Clinical outcomes of thromboendarterectomy for chronic thromboembolic pulmonary hypertension: 12-year experience

BACKGROUND

We present our 12-year experience of pulmonary thromboendarterectomy in patients with chronic thromboembolic pulmonary hypertension.

MATERIALS AND METHODS

Between January 1999 and March 2011, 16 patients underwent pulmonary thromboendarterectomy. Eleven patients (69%) were classified as functional class III or IV based on the New York Heart Association (NYHA) classification. Seven patients had a history of inferior vena cava filter insertion, and 5 patients showed coagulation disorders. Pulmonary thromboendarterectomy was performed during total circulatory arrest with deep hypothermia in 14 patients.

RESULTS

In-hospital mortality and late death occurred in 2 patients (12.5%) and 1 patient (6.3%), respectively. Extracorporeal membrane oxygenation support was required in 4 patients who developed severe hypoxemia after surgery. Thirteen of the 14 survivors have been followed up for 54 months (range, 2 to 141 months). The pulmonary arterial systolic pressure and cardiothoracic ratio on chest radiography was significantly decreased after surgery (76±26 mmHg vs. 41±17 mmHg, p=0.001; 55%±8% vs. 48%±3%, p=0.003). Tricuspid regurgitation was reduced from 2.1±1.1 to 0.7±0.6 (p=0.007), and the NYHA functional class was also improved to I or II in 13 patients (81%). These symptomatic and hemodynamic improvements maintained during the late follow-up period.

CONCLUSION

Pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension shows good clinical outcomes with acceptable early and long term mortality.

An Australian tertiary referral center experience of the management of chronic thromboembolic pulmonary hypertension

The objective of this study was to report the outcome of pulmonary endarterectomy (PEA) surgery performed for chronic thromboembolic pulmonary hypertension (CTEPH) at a single tertiary center. The prospective study consisted of 35 patients with surgically amenable CTEPH undergoing PEA between September 2004 and September 2010. The main outcome measures were Functional (New York Heart Association [NYHA] class, 6-Minute Walk Distance), hemodynamic (echocardiography, right heart catheterization, and cardiac MRI), and outcome data (morbidity and mortality). Following PEA, there were significant improvements in NYHA class (pre 2.9±0.7 vs. post 1.3±0.5, P < 0.0001), right ventricular systolic pressure (pre 77.4±24.8 mmHg vs. post 45.1±24.9 mmHg, P = 0.0005), 6-Minute Walk Distance (pre 419.6±109.4 m vs. post 521.6±83.5 m, P = 0.0017), mean pulmonary artery pressure (pre 41.8±15.3 mmHg vs. post 24.7±8.8 mmHg, P = 0.0006), and cardiac MRI indices (end diastolic volume pre 213.8±49.2 mL vs. post 148.1±34.5 mL, P < 0.0001; ejection fraction pre 40.7±9.8 mL vs. post 48.1±8.9 mL, P = 0.0069). The mean cardiopulmonary bypass time was 258.77±26.16 min, with a mean circulatory arrest time of 43.83±28.78 min, a mean ventilation time of 4.7±7.93 days (range 0.2-32.7), and a mean intensive care unit stay of 7.22±8.71 days (range 1.1-33.8). Complications included reperfusion lung injury (20%), persistent pulmonary hypertension (17.1%), slow respiratory wean (25.7%), pericardial effusion (11.4%), and cardiac tamponade (5.7%). 1-year mortality post-procedure was 11.4%. Pulmonary endarterectomy can be performed safely with relatively low mortality.

Clinical worsening after pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension

INTRODUCTION

Pulmonary endarterectomy (PEA) is the most effective treatment for chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this study is to evaluate long-term survival and freedom from clinical worsening after PEA.

METHODS

All patients who underwent PEA in our hospital between May 2000 and August 2009 were included. Follow-up parameters were all-cause mortality and time to clinical worsening, defined as a combination of death, need for pulmonary hypertension-specific medication or 15% decrease in six-minute walk distance without improvement in functional class. The Cox proportional hazard regression was used to identify predictors.

RESULTS

Seventy-four consecutive patients (mean age 55.9 ± 13.8 years, 51% female) underwent PEA. Prior to surgery, 55 patients were in NYHA functional class III or higher. The mean pulmonary artery pressure was 41.3 ± 11.9 mmHg with a mean pulmonary vascular resistance of 521 ± 264 dyn·s·cm(-5) (range 279-1331 dyn·s·cm(-5)). Five patients (6.8%) died in-hospital. Out of hospital, 5 out of 69 patients (7.2%) died during a median follow-up of 3.7 ± 2.2 years [range 0.1-8.5 years]). The one- and five-year survival rates were 93% and 89%, respectively. During follow-up, clinical worsening occurred in 13 out of 69 patients (18.8%). The one- and five-year rates of freedom from clinical worsening were 94% and 72%, respectively. The baseline NT-pro BNP level tended to be a predictor for occurrence of clinical worsening.

CONCLUSION

Pulmonary endarterectomy is associated with good long-term survival in patients with CTEPH. However, clinical worsening occurred in a substantial number of patients at long-term follow-up.

Circulatory arrest versus cerebral perfusion during pulmonary endarterectomy surgery (PEACOG): a randomised controlled trial

BACKGROUND

For some surgical procedures to be done, a patient's blood circulation needs to be stopped. In such situations, the maintenance of blood flow to the brain is perceived beneficial even in the presence of deep hypothermia. We aimed to assess the benefits of the maintenance of antegrade cerebral perfusion (ACP) compared with deep hypothermic circulatory arrest (DHCA).

METHODS

Patients aged 18-80 years undergoing pulmonary endarterectomy surgery in a UK centre (Papworth Hospital, Cambridge) were randomly assigned with a computer generated sequence to receive either DHCA for periods of up to 20 min at 20°C or ACP (1:1 ratio). The primary endpoint was change in cognitive function at 12 weeks after surgery, as assessed by the trail-making A and B tests, the Rey auditory verbal learning test, and the grooved pegboard test. Patients and assessors were masked to treatment allocation. Primary analysis was by intention to treat. The trial is registered with Current Controlled Trials, number ISRCTN84972261.

FINDINGS

We enrolled 74 of 196 screened patients (35 to receive DHCA and 39 to receive ACP). Nine patients crossed over from ACP to DHCA to allow complete endarterectomy. At 12 weeks, the mean difference between the two groups in Z scores (the change in cognitive function score from baseline divided by the baseline SD) for the three main cognitive tests was 0·14 (95% CI -0·14 to 0·42; p=0·33) for the trail-making A and B tests, -0·06 (-0·38 to 0·25; p=0·69) for the Rey auditory verbal learning test, and 0·01 (-0·26 to 0·29; p=0·92) for the grooved pegboard test. All patients showed improvement in cognitive function at 12 weeks. We recorded no significant difference in adverse events between the two groups. At 12 weeks, two patients had died (one in each group) [corrected].

INTERPRETATION

Cognitive function is not impaired by either ACP or DHCA. We recommend circulatory arrest as the optimum modality for patients undergoing pulmonary endarterectomy surgery.

FUNDING

J P Moulton Charitable Foundation.

Time course of restoration of systolic and diastolic right ventricular function after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

BACKGROUND

In chronic thromboembolic pulmonary hypertension, right ventricular (RV) pressure overload causes RV remodeling and dysfunction. Successful pulmonary endarterectomy (PEA) initiates restoration of RV remodeling and global function. Little is known on the restoration of systolic and diastolic RV function. Using transthoracic echocardiography, we studied the time course and extent of postoperative restoration of systolic and diastolic RV function.

METHODS

In chronic thromboembolic pulmonary hypertension (n = 55, 36 women, age 52 ± 14 years), transthoracic echocardiography was performed before PEA (pre-PEA) and 2 weeks, 3 months, and 1 year postoperatively.

RESULTS

Two weeks postoperatively, RV afterload and dimension had decreased significantly, without further improvement during follow-up. Global RV function, expressed by the myocardial performance index, showed a gradual improvement (from pre-PEA 0.58 ± 0.29 to 0.45 ± 0.38, 0.39 ± 0.19, and 0.37 ± 0.18). In contrast, 2 weeks after PEA systolic RV function, as assessed by tricuspid annular plane systolic velocity excursion and peak tricuspid annular systolic velocity of the RV, had worsened, with a subsequent incomplete restoration during follow-up: tricuspid annular plane systolic velocity excursion from 19.3 ± 5.0 to 12.4 ± 2.5, 15.3 ± 3.0, and 16.8 ± 2.9 mm and systolic velocity of the right ventricle from 11.4 ± 3.0 to 9.6 ± 2.0, 10.0 ± 1.8, and 10.3 ± 1.7 cm/s. Postoperative diastolic RV function also showed a biphasic response: tricuspid inflow-to-annulus ratio from 6.1 ± 3.0 to 9.5 ± 3.5, 6.8 ± 2.4, and 6.3 ± 2.2 cm/s. Dynamics and ultimate level of restoration of systolic and diastolic RV function were similar in patients with and without residual pulmonary hypertension.

CONCLUSIONS

Postoperative reduction in RV afterload caused an immediate improvement in RV dimension and global function. In contrast, systolic and diastolic RV function deteriorated after PEA with subsequently a gradual yet incomplete restoration during 1-year follow-up.

Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension: a scientific statement from the American Heart Association

Venous thromboembolism (VTE) is responsible for the hospitalization of >250 000 Americans annually and represents a significant risk for morbidity and mortality. Despite the publication of evidence-based clinical practice guidelines to aid in the management of VTE in its acute and chronic forms, the clinician is frequently confronted with manifestations of VTE for which data are sparse and optimal management is unclear. In particular, the optimal use of advanced therapies for acute VTE, including thrombolysis and catheter-based therapies, remains uncertain. This report addresses the management of massive and submassive pulmonary embolism (PE), iliofemoral deep vein thrombosis (IFDVT),and chronic thromboembolic pulmonary hypertension (CTEPH). The goal is to provide practical advice to enable the busy clinician to optimize the management of patients with these severe manifestations of VTE. Although this document makes recommendations for management, optimal medical decisions must incorporate other factors, including patient wishes, quality of life, and life expectancy based on age and comorbidities. The appropriateness of these recommendations for a specific patient may vary depending on these factors and will be best judged by the bedside clinician.

Improvement of Tricuspid Regurgitation after Pulmonary Thromboendarterectomy

Chronic thromboembolic pulmonary hypertension causes right ventricular dilation with various degrees of tricuspid regurgitation, leading to right heart failure. Pulmonary thromboendarterectomy can substantially improve pulmonary hemodynamics and right ventricular dilation. The aim of this study was to determine whether the reduction of tricuspid regurgitation persists during follow-up. We studied 26 patients undergoing pulmonary thromboendarterectomy without repair of tricuspid regurgitation; 24 were followed up for 7 to 59 months after surgery (mean, 33 months). Echocardiographic and right heart catheterization data were obtained before and early after surgery. Severity of tricuspid regurgitation and tricuspid pressure gradient were evaluated at follow-up. Two patients died early after surgery, but none died during follow-up. Pulmonary thromboendarterectomy substantially improved pulmonary hemodynamics and right ventricular dilation. Tricuspid regurgitation graded severe in 5 patients and moderate in another 5, improved to trivial or mild postoperatively. The decreases in tricuspid pressure gradient and regurgitation early after surgery persisted during follow-up.

Clinical and haemodynamic evaluation of chronic thromboembolic pulmonary hypertension patients scheduled for pulmonary thromboendarterectomy: Is schistosomiasis hypertension an important confounding factor?

INTRODUCTION

Chronic thromboembolic pulmonary hypertension is a disease affecting approximately 4,000 people per year in the United States. The incidence rate in Brazil, however, is unknown. The estimated survival for patients with chronic thromboembolic pulmonary hypertension without treatment is approximately three years. Pulmonary thromboendarterectomy for select patients is a potentially curative procedure when correctly applied. In Brazil, the clinical and hemodynamic profiles of chronic thromboembolic pulmonary hypertension patients have yet to be described.

OBJECTIVES

To evaluate the clinical and hemodynamic characteristics of chronic thromboembolic pulmonary hypertension patients scheduled for pulmonary thromboendarterectomy in a referral center for chronic thromboembolic pulmonary hypertension treatment in Brazil.

METHODS

From December 2006 to November 2009, patients were evaluated and scheduled for pulmonary thromboendarterectomy. The subjects were classified according to gender, age and functional class and were tested for thrombofilia and brain natriuretic peptide levels.

RESULTS

Thirty-five consecutive chronic thromboembolic pulmonary hypertension patients were evaluated. Two patients tested positive for schistosomiasis, and 31 were enrolled in the study (19 female, 12 male). The majority of patients were categorized in functional classes III and IV. Hemodynamic data showed a mean pulmonary vascular resistance (PVR) of 970.8 ± 494.36 dynas·s·cm-5 and a low cardiac output of 3.378 ± 1.13 L/min. Linear regression revealed a direct relation between cardiac output and pulmonary vascular resistance. Paradoxical septal movement was strongly correlated with pulmonary vascular resistance and cardiac output (p=0.001). Brain natriuretic peptide serum levels were elevated in 19 of 27 patients.

CONCLUSIONS

In a referral center for pulmonary hypertension in Brazil, chronic thromboembolic pulmonary hypertension patients evaluated for pulmonary thromboendarterectomy had a hemodynamically severe status and had elevated brain natriuretic peptide serum levels. There was a predominance of females in our cohort, and the prevalence of hematological disorders and schistosomiasis was low (less than 10%).

Brain natriuretic peptide as a preclinical marker of chronic pulmonary hypertension in patients with pulmonary embolism

Chronic thromboembolic pulmonary hypertension (CTPH) is a potential complication of pulmonary embolism (PE). Only few studies have assessed the role of brain natriuretic peptide (BNP) in patients with chronic pulmonary hypertension, and there are no data on the potential utility of BNP as a preclinical biomarker of CTPH. To assess the correlation between pulmonary artery systolic pressures (PAPs) and amino terminal proBNP (Nt-proBNP) and its value in the diagnosis of CTPH in patients with previous PE. Patients were evaluated with echocardiography at least 6 months after the index event. Pulmonary hypertension was defined as PAPs > or =40 mmHg at rest. Each subject underwent measurement of Nt-proBNP. Forty-nine patients were enrolled (mean age 64.5 +/- 13.1 years; 22 men). Seven patients had CTPH, and two were symptomatic. There was a good correlation between PAP on echocardiography and Nt-proBNP (r 0.64; P = 0.00003). Nt-proBNP was elevated in 6 of 7 patients [sensitivity: 85.7%; 95% confidence interval (CI): 48.7, 97.4] and it was normal in 35 of 42 patients without CTPH (specificity: 76.2%; 95% CI: 61.5, 86.5%). Six of the 13 patients with high Nt-proBNP levels had CTPH, whereas 1 of 36 patients with normal Nt-proBNP levels had pulmonary hypertension. The resulting positive predictive value was 46.1% (95% CI: 19.2, 74.9), and the negative predictive value was 97.2% (95% CI: 85.5-99.9). In conclusion, Nt-proBNP correlates with PAPs and may be used to exclude preclinical or symptomatic CTPH in patients with previous PE. Prospective studies on a larger population are warranted to confirm our preliminary findings.

Thromboendarterectomy for severe chronic thromboembolic pulmonary hypertension

Pulmonary thromboendarterectomy is a curative surgical procedure for chronic thromboembolic pulmonary hypertension. The aim of this study was to clarify whether severe hemodynamic compromise affects surgical outcome. We studied 19 patients who underwent pulmonary thromboendarterectomy and compared 11 with pulmonary vascular resistance < 1,000 dyne x s x cm(-5) (group 1) and 8 with pulmonary vascular resistance > 1,000 dyne x s x cm(-5) (group 2). Mean pulmonary artery pressure and pulmonary vascular resistance decreased significantly after surgery in both groups. The incidence of postoperative complications did not differ between groups; however, one patient in group 2 died of multiorgan failure. The overall mortality rate was 5.3%, and the rate in group 2 was 13%. Our results indicate that preoperative hemodynamic compromise does not affect surgical outcome. Patients with high pulmonary vascular resistance can be treated effectively by thromboendarterectomy, with acceptable morbidity and mortality.