Mid-term results of pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension

Pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension: a systematic review

BACKGROUND

Pulmonary thromboendarterectomy (PTE) is the gold standard treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, the results are poorly quantified outside a few registry reports and several individual centers.

METHODS

A systematic review was performed searching five electronic databases assessing the outcomes for adult patients undergoing PTE for CTEPH. All articles that reported mortality data were included. Primary outcome measures were early/inpatient mortality; secondary outcomes were survival, pulmonary haemodynamics, morbidity and functional status following PTE for CTEPH. Results were pooled via a meta-analysis of proportions and meta-regression.

RESULTS

A total of 5,717 studies were identified, yielding sixty-one relevant papers. Thirty-day mortality ranged from 0.8% to 24.4%, and on meta-analysis was 8.4% [95% confidence interval (CI): 7.2-9.6%]. Mortality was noted to decrease with increasing center volume of PTE cases (P<0.01). Residual pulmonary hypertension was reported in 8.2% to 44.5% of patients.

CONCLUSIONS

CTEPH is associated with acceptable short-term mortality and an improvement in pulmonary hemodynamics. With increasing volume of experience and ongoing developments over time peri-operative mortality continues to decrease.

Oxygen Pathway Limitations in Patients With Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

Exertional intolerance is a limiting and often crippling symptom in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Traditionally the pathogenesis has been attributed to central factors, including ventilation/perfusion mismatch, increased pulmonary vascular resistance, and right heart dysfunction and uncoupling. Pulmonary endarterectomy and balloon pulmonary angioplasty provide substantial improvement of functional status and hemodynamics. However, despite normalization of pulmonary hemodynamics, exercise capacity often does not return to age-predicted levels. By systematically evaluating the oxygen pathway, we aimed to elucidate the causes of functional limitations in patients with CTEPH before and after pulmonary vascular intervention.

METHODS

Using exercise cardiac magnetic resonance imaging with simultaneous invasive hemodynamic monitoring, we sought to quantify the steps of the O₂ transport cascade from the mouth to the mitochondria in patients with CTEPH (n=20) as compared with healthy participants (n=10). Furthermore, we evaluated the effect of pulmonary vascular intervention (pulmonary endarterectomy or balloon angioplasty) on the individual components of the cascade (n=10).

RESULTS

Peak Vo₂ (oxygen uptake) was significantly reduced in patients with CTEPH relative to controls (56±17 versus 112±20% of predicted; P<0.0001). The difference was attributable to impairments in multiple steps of the O₂ cascade, including O₂ delivery (product of cardiac output and arterial O₂ content), skeletal muscle diffusion capacity, and pulmonary diffusion. The total O₂ extracted in the periphery (ie, ΔAVo₂ [arteriovenous O₂ content difference]) was not different. After pulmonary vascular intervention, peak Vo₂ increased significantly (from 12.5±4.0 to 17.8±7.5 mL/[kg·min]; P=0.036) but remained below age-predicted levels (70±11%). The O₂ delivery was improved owing to an increase in peak cardiac output and lung diffusion capacity. However, peak exercise ΔAVo₂ was unchanged, as was skeletal muscle diffusion capacity.

CONCLUSIONS

We demonstrated that patients with CTEPH have significant impairment of all steps in the O₂ use cascade, resulting in markedly impaired exercise capacity. Pulmonary vascular intervention increased peak Vo₂ by partly correcting O₂ delivery but had no effect on abnormalities in peripheral O₂ extraction. This suggests that current interventions only partially address patients' limitations and that additional therapies may improve functional capacity.

Balloon pulmonary angioplasty vs. pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension: a systematic review and meta-analysis

Although balloon pulmonary angioplasty (BPA) and pulmonary endarterectomy (PEA) are effective in chronic thromboembolic pulmonary hypertension (CTEPH), the comparison of their efficacy and safety is still unclear. We identified studies through a systematic review of PubMed, Cochrane Library, and Embase and used a random effects meta-analysis model to synthesize estimates of weighted mean differences or combined effect size. In total, 54 studies were included in this meta-analysis. The survival rates at perioperative/in-hospital period, 2 years, and 3 years were 100%, 99%, and 97%, respectively, in BPA group and 93%, 90%, and 88%, respectively, in PEA group. The variation of 6-min walk distance was 141.80 m in BPA and 100.73 m in PEA when the follow-up was 1-6 months. At < 1-month, 1-6-month, and > 12-month follow-up, the changed results of mean pulmonary arterial pressure were - 18.31, - 17.00, and - 12.97 mmHg in BPA group and - 18.93, - 21.21, and - 21.35 mmHg in PEA group. At < 1-month and 1-6-month follow-up, the changed values of pulmonary vascular resistance were - 542.24 and - 599.77 dyne•s•cm^-5 in PEA group and - 443.49 and - 280.00 dyne•s•cm^-5 in BPA group. In addition, there was more wide variety of complications in PEA group than in BPA group. BPA might have higher survival rate (perioperative/in-hospital period, 2-year and 3-year follow-up) and fewer types of complications compared with PEA. The improvement in exercise capacity (1-6-month follow-up) in the BPA group might be more pronounced than in PEA group. Moreover, PEA might be superior in improvement of hemodynamic parameters (< 1-month, 1-6-month, and > 12-month follow-up).

Chronic thromboembolic pulmonary hypertension - still evolving

Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the leading causes of severe pulmonary hypertension (PH). The disease is still underdiagnosed, and the true prevalence is unknown. CTEPH is characterized by intraluminal non-resolving thrombus organization and fibrous stenosis, or complete obliteration of pulmonary arteries, promoted by progressive remodeling of the pulmonary vasculature. One consequence of this is an increase in pulmonary vascular resistance and pressure, resulting in PH and progressive right heart failure, leading to death if left untreated.

Endovascular disobliteration by pulmonary endarterectomy (PEA) is the preferred treatment for CTEPH patients. PEA surgery is the only technique that can potentially cure CTEPH disease, especially in patients with fresh or organized thrombi of the proximal branches of pulmonary arteries. However, not all patients are eligible for PEA surgery. Recent research has provided evidence suggesting balloon pulmonary angioplasty (BPA) and targeted medical therapy as additional promising available treatments options for inoperable CTEPH and recurrent/persistent PH after PEA surgery.

Studies on BPA have shown it to improve pulmonary hemodynamics, symptoms, exercise capacity and RV function in inoperable CTEPH. Subsequently, BPA has developed into an essential component of the modern era of CTEPH treatment. Large randomized controlled trials have demonstrated varying significant improvements with targeted medical therapy in technically inoperable CTEPH patients. Thus, treatment of CTEPH requires a comprehensive multidisciplinary assessment, including an experienced PEA surgeon, PH specialist, BPA interventionist and CTEPH-trained radiologist at expert centers. In this comprehensive review, we address the latest developments in the fast-evolving field of CTEPH. These include advancements in imaging modalities and developments in operative and interventional techniques, which have widened the range of patients who may benefit from these procedures. The efficacy and safety of targeted medical therapies in CTEPH patients are also discussed. As the treatment options for CTEPH improve, hybrid management involving multiple treatments in the same patient may become a viable option in the near future.

Practical echocardiographic approach for risk stratification of patients with acute pulmonary embolism

Acute pulmonary embolism remains a common cause of mortality. Early diagnosis and appropriate risk stratification is necessary to individualize treatment strategy. Computed tomography scan of the pulmonary arteries is routinely used to diagnose acute pulmonary embolism and in some cases is useful to assess right ventricular dilation. In patients with acute pulmonary embolism, right ventricular dilation and dysfunction indicates a high-risk situation where immediate administration of thrombolytic agent, catheter-directed thrombolysis, or surgical embolectomy could be considered. A bedside 2D echocardiogram at the time of presentation could provide additional morphological, functional, and hemodynamic parameters including right ventricular dilation, McConnell's sign, reduced tricuspid annular plane systolic excursion (TAPSE), interventricular septal flattening, abnormal right ventricular hemodynamics and in rare cases thrombi in the inferior vena cava, right atrium or ventricle en route to pulmonary arteries may also be visualized. This additional information is useful for selection of appropriate treatment modality. Thus, our objective is to provide a practical echocardiographic approach for risk stratification of patients with acute pulmonary embolism.

Pulmonary vascular and right ventricular reserve in patients with normalized resting hemodynamics after pulmonary endarterectomy

Background

Patients with normalized mean pulmonary artery pressure (mPAP) after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) do not always regain normal exercise capacity. We evaluated right ventricular function, its interaction with both pulsatile and resistive afterload, and the effect of sildenafil during exercise in these patients.

Methods and Results

Fourteen healthy controls, 15 CTEPH patients, and 7 patients with normalized resting mPAP (≤25 mm Hg) post‐PEA underwent cardiopulmonary exercise testing, followed by cardiac magnetic resonance imaging with simultaneous invasive mPAP measurement during incremental supine cycling exercise. Peak oxygen consumption and peak heart rate were significantly reduced in post‐PEA and CTEPH patients compared to controls. The mPAP–cardiac output slope was steeper in post‐PEA patients than in controls and similar to CTEPH. Relative to controls, resting right ventricular ejection fraction was reduced in CTEPH, but not in post‐PEA patients. In contrast, peak exercise right ventricular ejection fraction was reduced both in post‐PEA and CTEPH patients. Exercise led to reduction of pulmonary arterial compliance in all groups. Nevertheless, resting pulmonary arterial compliance values in CTEPH and post‐PEA patients were even lower than those in controls at peak exercise. In post‐PEA patients, sildenafil did not affect resting hemodynamics nor right ventricular function, but decreased the mPAP/cardiac output slope and increased peak exercise right ventricular ejection fraction.

Conclusions

Exercise intolerance in post‐PEA patients is explained by abnormal pulmonary vascular reserve and chronotropic incompetence. The mPAP/cardiac output slope and pulmonary arterial compliance are sensitive measures demonstrating abnormal resistive and pulsatile pulmonary vascular function in post‐PEA patients. These abnormalities are partially attenuated with sildenafil.

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.

Outcome of Medically Versus Surgically Treated Patients With Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is an ominous disease leading to progressive right heart failure. Selected patients can be treated by pulmonary endarterectomy (PEA). We assessed long-term clinical outcome of patients with CTEPH who underwent PEA and patients who remained on medical treatment alone. A total of 112 consecutive patients with CTEPH referred between 1998 and 2008 to one center were followed for a mean of 35 (range 0-128) months after diagnosis. All the patients had advanced pulmonary hypertension at baseline. The operated group had higher World Health Organization functional class compared to the nonoperated group. No other differences in hemodynamic, echocardiographic, or biochemical parameters were observed at baseline. Despite the perioperative mortality rate of 9.1%, patients who underwent PEA had significantly lower long-term mortality compared to nonoperated patients (12.7% vs 34.8%; P = .003), and PEA survivors showed sustained clinical improvement. All efforts should be undertaken to perform PEA in all patients with operable CTEPH.

Diagnostic evaluation and management of chronic thromboembolic pulmonary hypertension: a clinical practice guideline

BACKGROUND

Pulmonary embolism is a common condition. Some patients subsequently develop chronic thromboembolic pulmonary hypertension (CTEPH). Many care gaps exist in the diagnosis and management of CTEPH patients including lack of awareness, incomplete diagnostic assessment, and inconsistent use of surgical and medical therapies.

METHODS

A representative interdisciplinary panel of medical experts undertook a formal clinical practice guideline development process. A total of 20 key clinical issues were defined according to the patient population, intervention, comparator, outcome (PICO) approach. The panel performed an evidence-based, systematic, literature review, assessed and graded the relevant evidence, and made 26 recommendations.

RESULTS

Asymptomatic patients postpulmonary embolism should not be screened for CTEPH. In patients with pulmonary hypertension, the possibility of CTEPH should be routinely evaluated with initial ventilation/perfusion lung scanning, not computed tomography angiography. Pulmonary endarterectomy surgery is the treatment of choice in patients with surgically accessible CTEPH, and may also be effective in CTEPH patients with disease in more 'distal' pulmonary arteries. The anatomical extent of CTEPH for surgical pulmonary endarterectomy is best assessed by contrast pulmonary angiography, although positive computed tomography angiography may be acceptable. Novel medications indicated for the treatment of pulmonary hypertension may be effective for selected CTEPH patients.

CONCLUSIONS

The present guideline requires formal dissemination to relevant target user groups, the development of tools for implementation into routine clinical practice and formal evaluation of the impact of the guideline on the quality of care of CTEPH patients. Moreover, the guideline will be updated periodically to reflect new evidence or clinical approaches.

Surgical management and outcome of patients with chronic thromboembolic pulmonary hypertension: results from an international prospective registry

OBJECTIVE

Pulmonary endarterectomy is a curative surgical treatment option for the majority of patients with chronic thromboembolic pulmonary hypertension. The current surgical management and postoperative outcome of patients enrolled in an international registry on chronic thromboembolic pulmonary hypertension were investigated.

METHODS

The registry included newly diagnosed (≤6 months) consecutive patients with chronic thromboembolic pulmonary hypertension from February 2007 to January 2009.

RESULTS

A total of 679 patients were registered from 1 Canadian and 26 European centers, of whom 386 (56.8%) underwent surgery. The median age of patients undergoing surgery was 60 years, and 54.1% were male. Previous pulmonary embolism was confirmed for 79.8% of patients. Perioperative complications occurred in 189 patients (49.2%): infection (18.8%), persistent pulmonary hypertension (16.7%), neurologic (11.2%) or bleeding (10.2%) complications, pulmonary reperfusion edema (9.6%), pericardial effusion (8.3%), need for extracorporeal membrane oxygenation (3.1%), and in-hospital mortality due to perioperative complications (4.7%). Documented 1-year mortality was 7%. Preoperative exercise capacity was predictive of 1-year mortality. Postoperative pulmonary vascular resistance predicted in-hospital and 1-year mortality. In patients evaluated within 1 year after surgery, the median pulmonary vascular resistance had decreased from 698 to 235 dyn x s x cm(-5) (95% confidence limit, 640-874 and 211-255, respectively, n = 70) and the median 6-minute walk distance had increased from 362 to 459 m (95% confidence limit, 340-399 and 440-473, respectively, n = 168). New York Heart Association functional class improved with most patients progressing from class III/IV to class I/II.

CONCLUSIONS

Pulmonary endarterectomy is associated with a low in-hospital mortality rate and improvements in hemodynamics and exercise capacity.

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.

[Image-guided minimally invasive treatment of pulmonary arterial hypertension due to embolic disease]

OBJECTIVE

Although surgical pulmonary thromboendarterectomy is the treatment of choice for pulmonary hypertension due to chronic thrombotic and/or embolic disease, minimally invasive endovascular techniques such as angioplasty or placement of a metallic stent can provide acceptable results when surgery is not indicated or has been refused by the patient.

PATIENTS AND METHODS

Eight patients (5 men, 3 women; mean age, 62.6 years) were treated. The patients were in New York Heart Association (NYHA) class III or IV and had a mean pulmonary artery pressure of 40 mm Hg and more, a capillary wedge pressure of 15 mm Hg or less, or a Miller index greater than 0.5. In all cases, diagnosis was based on Doppler echocardiography, pulmonary angiography, hemodynamic evaluation, and ventilation-perfusion scintigraphy. All patients received fibrinolytic therapy and underwent angioplasty. A metallic stent was implanted in 3 patients. Follow-up echocardiographic assessment and ventilation-perfusion scans were scheduled at 1, 3, 6, and 12 months.

RESULTS

The procedures were technically successful in all cases. The mean follow-up period was 18.7 months. Minor complications were extrasystoles (3 cases), slight bruising at the site of puncture (1 case), and rectal bleeding that resolved without treatment (1 case). One patient died from an unknown cause 24 hours after the procedure. In all other cases, improvements were noted in NYHA functional class, in hemodynamics demonstrated by echocardiography, and in vascular structure as shown by arteriography and scintigraphy.

CONCLUSIONS

Minimally invasive endovascular interventions can help improve pulmonary arterial hypertension due to chronic thrombotic and/or embolic disease in patients for whom medical or surgical treatment is not possible.

Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC)

Non-thrombotic PE does not represent a distinct clinical syndrome. It may be due to a variety of embolic materials and result in a wide spectrum of clinical presentations, making the diagnosis difficult. With the exception of severe air and fat embolism, the haemodynamic consequences of non-thrombotic emboli are usually mild. Treatment is mostly supportive but may differ according to the type of embolic material and clinical severity.

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.

Chronic thromboembolic pulmonary hypertension

The description of organized thrombus in major pulmonary arteries can be found in autopsy reports dating back to the late nineteenth and early twentieth centuries. Not until the 1950s was the antemortem diagnosis and clinical syndrome of chronic thrombotic obstruction of the major pulmonary arteries better characterized. The first surgical attempt to remove the adherent thrombus from the vessel wall occurred in 1958. This operation provided the conceptual foundation for the distinction between acute and chronic thromboembolic disease of the pulmonary vascular bed, and established that an endarterectomy, and not an embolectomy, would be necessary if a surgical remedy for this disease was to be successful.

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.

Evaluation of patients for pulmonary endarterectomy

Chronic thromboembolic obstruction of the pulmonary vascular bed has been increasingly recognized as a treatable form of pulmonary hypertension, with surgery referred to as a pulmonary endarterectomy. Careful evaluation of patients with pulmonary hypertension and proper selection of those with surgically accessible, chronic thromboembolic disease are critical determinants for a successful outcome from this operation. This article describes the clinical presentation, appropriate evaluation, and an approach to surgical selection for patients with chronic thromboembolic pulmonary hypertension.

Six-minute walk distance as parameter of functional outcome after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

OBJECTIVES

In chronic thromboembolic pulmonary hypertension, objective data to assess the functional outcome after pulmonary endarterectomy are lacking. We studied the 6-minute walk distance in relation to the clinical and hemodynamic severity of disease, and assessed the effect of pulmonary endarterectomy on the 6-minute walk distance.

METHODS

A total of 50 consecutive patients with chronic thromboembolic pulmonary hypertension were studied. Subsequently, pulmonary endarterectomy was performed in 42 patients, 35 of whom underwent a 6-minute walk distance 1 year after surgery.

RESULTS

The mean +/- standard error of the mean 6-minute walk distance was 391 +/- 19 m. The 6-minute walk distance decreased in proportion to New York Heart Association functional class and correlated (all P < .0001) with mean pulmonary artery pressure (r = -0.62), cardiac output (r = 0.76), total pulmonary resistance (r = -0.75), mixed venous oxygen saturation (r = 0.77), and brain natriuretic peptide (r = -0.65). One year after pulmonary endarterectomy, the 6-minute walk distance increased from 417 +/- 19 m to 517 +/- 16 m (P < .0001). The change from baseline in 6-minute walk distance correlated with the changes after 1 year in New York Heart Association functional class (P < .01) and brain natriuretic peptide (r = 0.57, P < .002), and with the observed hemodynamic changes directly after pulmonary endarterectomy (change in mean pulmonary artery pressure: r = 0.52; change in cardiac output: r = 0.70; change in total pulmonary resistance r = 0.70; all P < .001). In patients with residual pulmonary hypertension after pulmonary endarterectomy, the 6-minute walk distance was significantly lower than in hemodynamically normalized patients. However, the absolute increase in the 6-minute walk distance was higher in patients with residual pulmonary hypertension (137 +/- 26 m and 82 +/- 20 m, respectively; P = .03).

CONCLUSIONS

The 6-minute walk distance was demonstrated to reflect the clinical and hemodynamic severity of disease in patients with chronic thromboembolic pulmonary hypertension. One year after pulmonary endarterectomy, the 6-minute walk distance had increased significantly, and the change in the 6-minute walk distance correlated with the observed clinical and hemodynamic improvement.

Reverse right ventricular remodeling after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension: Utility of magnetic resonance imaging to demonstrate restoration of the right ventricle

OBJECTIVES

Pulmonary arterial hypertension causes right ventricular remodeling; that is, right ventricular dilatation, hypertrophy, and leftward ventricular septal bowing. We studied the effect of pulmonary endarterectomy on the restoration of right ventricular remodeling in patients with chronic thromboembolic pulmonary hypertension by magnetic resonance imaging.

METHODS

In 17 patients with chronic thromboembolic pulmonary hypertension, before and at least 4 months after pulmonary endarterectomy, and in 12 healthy controls, right ventricular and left ventricular end-diastolic and end-systolic volumes (milliliters) and mass (grams per meter squared) and leftward ventricular septal bowing (1 divided by the radius of curvature in centimeters) were determined by magnetic resonance imaging.

RESULTS

Before pulmonary endarterectomy, right ventricular volumes, left ventricular end-diastolic volume, right ventricular mass, and leftward ventricular septal bowing differed significantly between patients with chronic thromboembolic pulmonary hypertension and healthy control subjects. After pulmonary endarterectomy, pulmonary hemodynamics improved, and right and left ventricular volumes and leftward ventricular septal bowing normalized; right ventricular mass decreased significantly (46 +/- 14 to 31 +/- 9 g x m(-2), P< .0005), but did not completely normalize. The change in total pulmonary resistance correlated with the change in right ventricular ejection fraction (r = 0.50, P < .05), right ventricular mass (r = 0.63, P < .01), and leftward ventricular septal bowing (r = 0.50, P < .05).

CONCLUSIONS

Right ventricular remodeling was observed in patients with chronic thromboembolic pulmonary hypertension and restored almost completely after a hemodynamically successful pulmonary endarterectomy. Magnetic resonance imaging is a valuable tool to evaluate cardiac remodeling and function in patients with chronic thromboembolic pulmonary hypertension, both before and after pulmonary endarterectomy.

Reverse right ventricular remodeling after pulmonary endarterectomy

OBJECTIVES

We sought to evaluate the capability of the right ventricle to regain normal morphology and function after pulmonary endarterectomy, to correlate right ventricular reverse remodeling with functional status, and to identify independent predictors of clinical failure after surgical intervention.

METHODS

From December 2000 through August 2003, 45 patients underwent isolated pulmonary endarterectomy. Morphology and function of the right ventricle were studied by using a combination of right heart catheterization, cardiac magnetic resonance, and transthoracic echocardiography. Functional status was evaluated by using New York Heart Association class. Full preoperative data were available for 37 candidates. All patients were evaluated before discharge, at 3 months, and at 1, 2, and 3 years postoperatively using the same modalities.

RESULTS

Immediately after surgical intervention, right ventricular cavitary dimensions decreased significantly, and tricuspid regurgitation radically improved. Right ventricular ejection fraction and functional status improved and right ventricular hypertrophy reversed over a longer time period. Higher ventricular dimensions and lower ejection fraction of the right ventricle were associated with poorer functional status at any time postoperatively. At discharge, pulmonary vascular resistance of greater than 509 dyne x sec x cm(-5) and right ventricular ejection fraction of 24% or less predicted clinical failure at 12 months' follow-up.

CONCLUSIONS

After pulmonary endarterectomy, the right ventricle recovers and maintains normal architecture and function over time, regardless of the severity of preoperative disease. Accurate preoperative evaluation of the hemodynamics and anatomy of the thromboembolic lesions are mandatory. If pulmonary endarterectomy is not expected to decrease pulmonary vascular resistance to less than 509 dyne x sec x cm(-5), indication for surgical intervention needs to be carefully evaluated.

Long-Term Recovery of Exercise Ability After Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

The exercise capacity of patients with thromboembolic pulmonary hypertension was investigated to clarify the long-term effects of pulmonary endarterectomy. This capacity was assessed by measuring cardiopulmonary factors during cardiopulmonary exercise testing at the maximal level of exercise and a 6-minute walk test at the submaximal level. Their survival rate was also determined.

METHODS

We conducted a retrospective review of the clinical records of 102 patients who underwent pulmonary endarterectomy (63 women; median age, 53 years).

RESULTS

Eight (7.8%) hospital mortalities were encountered. Three late mortalities due to fulminant hepatitis, breast cancer, and pneumonia in a patient under steroid therapy were unrelated to pulmonary endarterectomy. The actual survival rate including hospital mortalities was 90.9% at 3 years and 84.0% at 5 years. All hemodynamic measurements significantly improved and reached a plateau 1-month after endarterectomy. The cardiopulmonary exercise test at the maximal exercise level revealed that peak oxygen uptake (V(O2)) baseline was 13.8 +/- 3.2 mL/min/kg, and at 1-month was 16.2 +/- 4.2 mL/min/kg (p = 0.0015) and ventilatory response to carbon dioxide production (V(E)-V(CO2)) slope baseline was 46.5 +/- 8.4 mL/min/kg, and at 1-month was 39.9 +/- 7.4 (p = 0.0006), which gradually and significantly improved during the first year after endarterectomy (peak V(O2), 19.9 +/- 3.9 mL/min/kg [p < 0.0001] and V(E)-V(CO2) slope, 33.2 +/- 5.4 mL/min/kg [p <0.0001]). The 6-minute walk test, which reflects the systemic response at the submaximal level of functional capacity, showed that the walking distance gradually and significantly increased for up to 1 year after endarterectomy (baseline, 358 +/- 102 meters [m]; at 1-month, 433 +/- 105 m; and at 1-year, 490 +/- 80 m [p < 0.0001]) and then reached a plateau.

CONCLUSIONS

After pulmonary endarterectomy, the hemodynamic recovery occurred immediately, and the patients' exercise capacity improved during the year. The 6-minute walk test was a good indicator to assess the recovery of exercise capacity.

Technical Advances of Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension

Pulmonary endarterectomy is the definitive treatment for chronic pulmonary hypertension as the result of thromboembolic disease. Although significant progress has been made over the last decade in recognition, diagnostic modalities, and treatment of this disease, chronic thromboembolic pulmonary hypertension (CTEPH) continues to be severely underdiagnosed and as a consequence pulmonary endarterectomy remains an uncommon procedure. Patients with CTEPH may present with a variety of debilitating cardiopulmonary symptoms. However, once diagnosed, there is no curative role for medical management, and surgery remains the only option. Medical management in these patients is only palliative, and surgery by means of transplantation for this type of pulmonary hypertension is an inappropriate use of resources with less than satisfactory results. In this article we describe the technical advances of pulmonary endarterectomy and the current procedure as it is performed at University of California-San Diego Medical Center.

Chronic thromboembolic pulmonary hypertension — assessment by magnetic resonance imaging

Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe disease that has been ignored for a long time. However, with the development of improved therapeutic modalities, cardiologists and thoracic surgeons have shown increasing interest in the diagnostic work-up of this entity. The diagnosis and management of chronic thromboembolic pulmonary hypertension require a multidisciplinary approach involving the specialties of pulmonary medicine, cardiology, radiology, anesthesiology and thoracic surgery. With this approach, pulmonary endarterectomy (PEA) can be performed with an acceptable mortality rate. This review article describes the developments in magnetic resonance (MR) imaging techniques for the diagnosis of chronic thromboembolic pulmonary hypertension. Techniques include contrast-enhanced MR angiography (ce-MRA), MR perfusion imaging, phase-contrast imaging of the great vessels, cine imaging of the heart and combined perfusion-ventilation MR imaging with hyperpolarized noble gases. It is anticipated that MR imaging will play a central role in the initial diagnosis and follow-up of patients with CTEPH.

Hemodynamic Effects of Monomeric Nonionic Contrast Media in Pulmonary Angiography in Chronic Thromboembolic Pulmonary Hypertension

OBJECTIVE

The purpose of this study was to investigate the hemodynamic safety of the monomeric nonionic contrast agent iomeprol for selective pulmonary angiography in chronic thromboembolic pulmonary hypertension (CTPH), and to investigate the effect of periinterventional oxygen administration.

SUBJECTS AND METHODS

Selective pulmonary digital subtraction angiography was performed in 94 patients with CTPH using six bolus injections of iomeprol (posteroanterior, oblique, and lateral projections; both pulmonary arteries; iomeprol, 25 mL at 13 mL/s). Hemodynamics were obtained with Swan-Ganz catheters, and systolic pulmonary artery pressure (PAsyst) was classified into one of three groups: 30 mm Hg or less (control group), greater than 30 but less than or equal to 60 mm Hg (group 1, moderate pulmonary hypertension), and greater than 60 mm Hg (group 2, severe pulmonary hypertension).

RESULTS

At baseline, values for PAsyst were 21.4 +/- 2.3 (control group, n = 8), 49.8+/- 8.5 (group 1, n = 18), and 86.5 +/- 18.9 (group 2, n = 68) mm Hg (p < 0.001). Pulmonary vascular resistance indexes (PVRI) were 222 +/- 105 (control), 703 +/- 364 (group 1), and 1,582 +/- 562 (group 2) dyne x s x cm(-5) x m2 (p < 0.001). The mean cardiac indexes were 3.1 (control), 2.8 (group 1), and 2.3 (group 2) L/min/m2 (p < 0.05). Pulmonary capillary wedge pressure (PCw) indicated healthy left heart function. Periinterventional oxygen inhalation improved oxygen saturation in all groups and slightly reduced pulmonary artery pressure and heart rate. Online measurement of pulmonary artery pressure during contrast bolus injection for angiography showed only a minor increase, predominantly in severe pulmonary hypertension (triangle up [difference] PAsyst: 1.3 +/- 1.9 [control], 2.9 +/- 3.4 [group 1], and 3.8 +/- 4.5 [group 2] mm Hg [p < 0.001]). After completion of angiography, right atrial pressure (RAP) and PAsyst were moderately increased: triangle up RAP: 1.4 (control), 2.6 (group 1, p < 0.001), and 3.0 (group 2, p < 0.001) mm Hg; triangle up PAsyst: 3.2 (control), 7.7 (group 1, p < 0.01), and 8.5 (group 2) mm Hg (p < 0.001). PVRI was significantly higher in group 2 (triangle up PVRI: 188 dyne x s x cm(-5) x m2, p < 0.001).

CONCLUSION

Selective pulmonary angiography using iomeprol is safe without critical pressure peaks during selective contrast bolus injection or significant hemodynamic derangement in severe CTPH. Periinterventional oxygen inhalation improved pulmonary circulation.

Two Cases of Chronic Pulmonary Thromboembolism Saved by Postoperative Use of a Percutaneous Cardiopulmonary Support Device

We performed pulmonary thromboendarterectomy under deep hypothermic intermittent circulatory arrest in 18 patients with chronic pulmonary thromboembolism from August 2001 to January 2004. In some of these cases, reperfusion pulmonary edema prevented a satisfactory improvement in hemodynamic data soon after the surgery. Here we report two cases of chronic pulmonary thromboembolism in which we successfully prevented postoperative persistent pulmonary hypertension and hypoxia caused by severe reperfusion pulmonary edema by the use of a percutaneous cardiopulmonary support device.

Effects of pulmonary thromboendarterectomy on right-sided echocardiographic parameters in patients with chronic thromboembolic pulmonary hypertension

OBJECTIVE

To determine the echocardiographic changes in the heart at 3 months and 1 year after pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension (CTEPH).

PATIENTS AND METHODS

Thirty-two adult patients who underwent PTE for CTEPH at the Mayo Clinic in Rochester, Minn, from 1997 to 2003 were included in the study. All underwent transthoracic echocardiography before surgery. Follow-up echocardiography was performed within 3 months of surgery in 28 patients and 1 year postoperatively in 17 patients. The results were compared with baseline data.

RESULTS

Within 3 months after PTE, the right ventricular end-diastolic area decreased from 38.4 +/- 12.8 cm2 to 32.5 +/- 10.4 cm2 (mean difference, 5.8 +/- 10.4 cm2; P = .02). The right ventricular end-systolic area decreased from 30.4 +/- 12.1 cm2 to 24.1 +/- 8.6 cm2 (mean difference, 6.3 +/- 10.1 cm2; P = .008). The right ventricular systolic pressure decreased significantly from 92.6 +/- 22.0 mm Hg to 55.0 +/- 19.8 mm Hg (mean difference, 40.0 +/- 24.8 mm Hg; P < .001). Tricuspid regurgitation (TR) improved from a mean grade of 2.5 +/- 1.2 to 1.2 +/- 1.1 (mean difference, 1.5 +/- 1.0; P < .001). At 12 months, the right ventricular end-diastolic area, right ventricular end-systolic area, right ventricular systolic pressure, and TR also were significantly lower than baseline values.

CONCLUSION

In patients with CTEPH who undergo PTE, echocardiographic measurements of right ventricular size, systolic pressure, and TR show significant improvement immediately after surgery, which is sustained for up to 1 year after surgery.

Pulmonary Hypertension due to Isolated Metastatic Squamous Cell Carcinoma Thromboemboli

Pulmonary hypertension as the initial presentation of occult malignancy is extremely rare. The differential diagnosis of pulmonary hypertension due to arterial tumour embolism is often overlooked and deserves contemplation. Our case report details the presentation of cardiorespiratory decompensation from an assumed classic saddle pulmonary embolus in a previously fit, well 80-year-old gentleman. The patient underwent successful pulmonary thromboendarterectomy, however, intraoperatively the specimen was noted to be atypical. This resulted in the surprising definitive diagnosis of thromboembolic pulmonary hypertension secondary to laminated thrombi of metastatic squamous cell tumour emboli. The site of tumour origin was however not histologically apparent and was unable to be elucidated on extensive further investigation. Post-operatively the patient had considerable subjective and functional improvement returning to activities of daily living. He however passed away some 9 months later.

Pulmonary thromboendarterectomy surgery

Considerable progress has been made over the past decade in understanding the etiology, prevalence, natural history, and therapeutic approach to chronic thromboembolic pulmonary hypertension. Pulmonary endarterectomy is now widely recognized as the definitive treatment for chronic pulmonary hypertension resulting from thromboembolic disease. This article focuses on the surgical treatment of chronic thromboembolic pulmonary hypertension.

Chronic Thromboembolic Pulmonary Hypertension: Pre- and Postoperative Assessment with Breath-hold MR Imaging Techniques

PURPOSE

To evaluate the potential of breath-hold magnetic resonance (MR) imaging techniques in morphologic and functional assessment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after surgery.

MATERIALS AND METHODS

Thirty-four patients with CTEPH were examined before and after pulmonary thromboendarterectomy (PTE). For morphologic assessment, contrast material-enhanced MR angiography was used; for assessment of hemodynamics, velocity-encoded gradient-echo sequences and cine gradient-echo sequences along the short axis of the heart were performed. Contrast-enhanced MR angiography was compared with selective digital subtraction angiography (DSA) for depiction of central thromboembolic material and visualization of the pulmonary arterial tree. Functional analysis included calculation of left and right ventricular ejection fractions and peak velocities, net forward volumes per heartbeat, and blood volume per minute in the left and right pulmonary arteries and ascending aorta. Flow measurements were compared with invasively measured mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance (PVR) measurements. Nonparametric Wilcoxon and sign tests were used for statistical analysis.

RESULTS

MR angiography revealed typical findings of CTEPH (intraluminal webs and bands, vessel cutoffs, and organized central thromboemboli) in all patients. It depicted pulmonary vessels up to the segmental level in all cases. For subsegmental arteries, DSA revealed significantly more patent vessel segments than did MR angiography (733 versus 681 segments, P <.001). MR angiography revealed technical success of surgery in 33 of 34 patients. Patients had reduced right ventricular ejection fractions and pulmonary peak velocities that significantly increased after PTE (P <.001 for both). Right ventricular ejection fraction had good correlation with PVR (r = 0.6) and MPAP (r = 0.7). The postoperative decrease in MPAP correlated well with the increase in right ventricular ejection fraction (r = 0.8). Postoperatively, there was complete reduction of a preoperatively existing bronchosystemic shunt volume in 33 of 34 patients.

CONCLUSION

Breath-hold MR imaging techniques enable morphologic and semiquantitative functional assessment of patients with CTEPH.

Chronic thromboembolic pulmonary hypertension

During the past 2 decades, there has been a steady rise in the number of patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing surgery and in the number of programs worldwide dedicated to the diagnosis and management of this patient population. This article discusses the natural history and clinical presentation of CTEPH, the evaluation of patients for pulmonary thromboendarterectomy, and the outcomes following surgery, along with a brief review of the procedure as performed at the University of California, San Diego.

Interventional and surgical modalities of treatment for pulmonary arterial hypertension

Beyond medical therapy, different interventional and surgical approaches exist for treatment of pulmonary arterial hypertension (PAH). Atrial septostomy has been applied in patients with lack of response to medical therapy in the absence of other surgical treatment options. With growing experience, procedure-related death rates have been reduced to 5.4%, and the most suitable patient group has been identified among patients with a mean right atrial pressure between 10 and 20 mm Hg. Pulmonary endarterectomy is the accepted form of treatment for patients with chronic thromboembolic pulmonary hypertension. Establishing the diagnosis and the classification of the type of lesions by pulmonary angiography is crucial for optimal patient selection. Perioperative mortality rates have been reduced to <10% in experienced centers, and the hemodynamic improvement is dramatic and sustained. Lung and heart-lung transplantation remains the procedure of choice for patients unsuitable for other treatment modalities. Timing of the procedure is difficult because waiting times vary between centers and usually are in a high range. Early referral of patients unresponsive to other treatment forms is therefore of importance to avoid transplantation of patients with established significant comorbidity. The survival rate during the first five years after transplantation for PAH is intermediate among the lung diseases, lower than chronic obstructive pulmonary disease but higher than idiopathic pulmonary fibrosis.

Surgical Treatments/Interventions for Pulmonary Arterial Hypertension

While considerable advances have been achieved in the medical treatment of pulmonary arterial hypertension (PAH) over the past decade, surgical and interventional approaches continue to have important roles in those patients for whom medical therapy is unavailable or has been unsuccessful. These techniques include pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension, thoracic transplantation, and atrial septostomy. This chapter will provide evidence-based recommendations for the selection and timing of surgical and interventional treatments of PAH for physicians involved in the care of these complex patients.

Regression of postobstructive vasculopathy after revascularization of chronically obstructed pulmonary artery

OBJECTIVES

Pulmonary vascular resistance decreases dramatically after pulmonary thromboendarterectomy and further improves in time. This may reflect the slow regression of postobstructive pulmonary vasculopathy. We hypothesized that postobstructive pulmonary vasculopathy may regress after reperfusion in a piglet model of chronic (5 weeks) left pulmonary artery obstruction.

METHODS

The ligated left pulmonary artery was reimplanted into the pulmonary arterial trunk. Pulmonary artery blood flow and pressure were measured 2 days and 5 weeks after reperfusion. Pulmonary artery smooth muscle thickness, endothelium-dependent relaxation, and left lung endothelial nitric oxide synthase activity and expression were assessed 5 weeks after ligation (n = 10) and 5 weeks after reperfusion (n = 10), and compared with a sham group (n = 10). Patency of the anastomoses and systemic blood supply to the lung were assessed by pulmonary angiography and nonselective thoracic aortography, respectively.

RESULTS

Angiography showed that pulmonary artery anastomoses were patent in all animals. Five weeks after reperfusion, left pulmonary blood flows were similar to those in the sham animals, and systemic blood supply to the left lung decreased. Left pulmonary vascular resistance decreased by 50% at 5 weeks after reperfusion compared with 2 days after reperfusion (P =.0009). Medial muscle thickness of the left pulmonary artery greater than 600 microm increased 5 weeks after ligation and regressed to sham values 5 weeks after reperfusion (P =.001). Endothelium-dependent relaxation was only partially restored 5 weeks after reperfusion, whereas left lung endothelial nitric oxide synthase expressions and activities returned to sham values.

CONCLUSIONS

This study shows that postobstructive pulmonary vasculopathy induced by ligation of the pulmonary artery for 5 weeks regresses after reperfusion, accounting for the progressive improvement in hemodynamics after thromboendarterectomy.

Inhaled iloprost in patients with chronic thromboembolic pulmonary hypertension: effects before and after pulmonary thromboendarterectomy

BACKGROUND

In primary pulmonary hypertension, aerosolized prostanoids selectively reduce pulmonary vascular resistance and improve right ventricular function. In this study, hemodynamic effects of inhaled iloprost, a stable prostacyclin analogue, were evaluated in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and early after pulmonary thromboendarterctomy (PTE).

METHODS

Ten patients (mean age 49 years old [32 to 70 years old], New York Heart Association functional class III and IV) received a dose of 33 micro g aerosolized iloprost immediately before surgery (T1), after intensive care unit admission (T2), and 12-hours postoperatively (T3). Effects on pulmonary and systemic hemodynamics and gas exchange were recorded and compared with preinhalation baseline values.

RESULTS

Preoperatively, inhaled iloprost did not significantly change mean pulmonary artery pressure (mPAP), cardiac index (CI), or pulmonary vascular resistance (PVR). Postoperatively, inhaled iloprost induced a significant reduction of mPAP and PVR and a significant increase of CI at T2 and T3. Preinhalation versus postinhalation PVR was as follows: at T1, 847 versus 729 dynes. s. cm(-5), p = 0.45; at T2, 502 versus 316 dynes. s. cm(-5), p = 0.008; and at T3, 299 versus 227 dynes. s. cm(-5), p = 0.004.

CONCLUSIONS

In patients with CTEPH, inhalation of iloprost elicits no significant pulmonary vasodilation before surgery, and may have detrimental effects on systemic hemodynamics. Postoperatively, it significantly reduces mPAP and PVR, and enhances CI. Following PTE, inhalation of iloprost is useful to improve early postoperative hemodynamics.

Tricuspid valvular disease in the patient with chronic pulmonary thromboembolic disease

Chronic thromboembolic pulmonary hypertension is associated with right ventricular dilatation, high right-sided filling pressures, and functional tricuspid regurgitation. The tricuspid regurgitation resulting from this disease has been postulated to be caused by tricuspid annular dilatation with displacement of the papillary muscles. Pulmonary endarterectomy is an operation that corrects the pulmonary hypertension resulting from chronic thromboemboli. As a result of this operation, most patients show significant improvement in tricuspid valve function. Thus, pulmonary endarterectomy is one of the few cardiac operations in which surgery remote to a valve restores valve function. This review analyzes the factors responsible for changes in tricuspid valve regurgitation after pulmonary endarterectomy and provides a strategy to predict the small subset of patients who will not show improvement in tricuspid valve function after this operation.

Caught in the act: impending paradoxical embolism

In a 73-year-old woman admitted with pulmonary embolism, a thrombus wedged across a patent foramen ovale was revealed by transesophageal echocardiography. After systemic anticoagulation, cardiac embolectomy and closure of the atrial septal defect were considered. Before surgery, repeat transesophageal echocardiography revealed only a small patent foramen ovale with no residual thrombus. We assumed dissolution of the thrombus as the patient had no sign of systemic or recurrent pulmonary embolism.