Improvement of right ventricular dysfunction after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension: Utility of echocardiography to demonstrate restoration of the right ventricle during 2-year follow-up

Update on the roles of imaging in the management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH), classified as group 4 pulmonary hypertension (PH), is caused by stenosis and obstruction of the pulmonary arteries by organized thrombi that are incompletely resolved after acute pulmonary embolism. The prognosis of patients with CTEPH is poor if untreated; however, in expert centers with multidisciplinary teams, a treatment strategy for CTEPH has been established, dramatically improving its prognosis. CTEPH is currently not a fatal disease and is the only curable form of PH. Despite these advances and the establishment of treatment approaches, early diagnosis is still challenging, especially for non-experts, for several reasons. One of the reasons for this is insufficient knowledge of the various diagnostic imaging modalities, which are essential in the clinical practice of CTEPH. Imaging modalities should detect the following pathological findings: lung perfusion defects, thromboembolic lesions in pulmonary arteries, and right ventricular remodeling and dysfunction. Perfusion lung scintigraphy and catheter angiography have long been considered gold standards for the detection of perfusion defects and assessment of vascular lesions, respectively. However, advances in imaging technology of computed tomography and magnetic resonance imaging have enabled the non-invasive detection of these abnormal findings in a single examination. Cardiac magnetic resonance (CMR) is the gold standard for evaluating the morphology and function of the right heart; however, state-of-the-art techniques in CMR allow the assessment of cardiac tissue characterization and hemodynamics in the pulmonary arteries. Comprehensive knowledge of the role of imaging in CTEPH enables appropriate use of imaging modalities and accurate image interpretation, resulting in early diagnosis, determination of treatment strategies, and appropriate evaluation of treatment efficacy. This review summarizes the current roles of imaging in the clinical practice for CTEPH, demonstrating the characteristic findings observed in each modality.

Is it time for a paradigm shift: Should double-lung transplant be considered the treatment of choice for idiopathic pulmonary arterial hypertension and giant pulmonary aneurysm?

Idiopathic pulmonary arterial hypertension is a rare condition, frequently complicated by pulmonary arteries' aneurysm. Aggressive medical therapy is often unsatisfactory and lung transplantation remains the only option. We report a unique case of severe idiopathic pulmonary arterial hypertension complicated by a giant pulmonary aneurism, massive pulmonary valve regurgitation, and right ventricle dysfunction. The patient was, as our first choice, listed for heart-lung transplantation and remained in emergency list for more than 7 months. Unfortunately, due to further clinical deterioration and the unavailability of a heart-lung bloc, plan B was mandatory. The patient underwent a combined procedure including: double lung transplant, pulmonary artery plasty, and sutureless pulmonary valve prosthesis with open deployment (first-in-man use in such scenario). Postoperative outcome was uneventful. Our thought is that double lung transplantation and conventional combined pulmonary artery/valve surgery should be considered as the first option avoiding excessive waiting times and potential further clinical deterioration.

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).

Supervised Exercise Training in Patients with Chronic Thromboembolic Pulmonary Hypertension as Early Follow-Up Treatment after Pulmonary Endarterectomy: A Prospective Cohort Study

BACKGROUND

Data on exercise training in chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary endarterectomy (PEA) as well as data on clinical and haemodynamic changes shortly after PEA are lacking.

OBJECTIVE

The objective of this prospective study was to analyse the safety, feasibility, and the effectiveness of combined supervised inpatient rehabilitation in patients with CTEPH directly after PEA.

METHODS

CTEPH patients started a 19-week rehabilitation program (3 weeks as inpatients and continued at home for another 16 weeks) with supervised exercise training as follow-up treatment shortly after PEA. Haemodynamics were assessed by right heart catheterisation before PEA and 22 weeks after PEA. Non-invasive assessments as transthoracic echocardiography and 6-min walking distance (6MWD) were performed before PEA and after 3 (that is, beginning of rehabilitation), 6, and 22 weeks following PEA. Adverse events were recorded throughout the study.

RESULTS

Forty-five CTEPH patients were included (49% female, 57.6 ± 12.4 years old, 60% WHO functional class III). Rehabilitation was started 3.3 ± 0.9 weeks after PEA. Exercise training was well tolerated in all patients without severe side effects. Haemodynamics measured by right heart catheterisation significantly improved from pre-PEA to 22 weeks post-PEA in cardiac output (+1.2 ± 1.5 L/min, 33.4%, p = 0.001) and mean pulmonary arterial pressure (-19 ± 13 mm Hg, -39.6%, p < 0.0001). Right heart size measured by echocardiography, 6MWD, quality of life, and oxygen saturation significantly improved not only within the first 3 weeks after PEA but also during the following 19 weeks of exercise training.

CONCLUSIONS

Supervised exercise training was feasible as early follow-up treatment after PEA. Further controlled studies are needed to discriminate the effects of PEA and early follow-up rehabilitation.

TRIAL REGISTRATION

The study was registered at clinicaltrials.gov (NCT01393327) on July 13, 2011. The study start date was January 2010, and completion date was December 2013.

Impact of pulmonary thromboendarterectomy on tricuspid regurgitation in patients with chronic thromboembolic pulmonary hypertension: a single-center prospective cohort experience

Background

For patients with chronic thromboembolic pulmonary hypertension (CTEPH) and tricuspid regurgitation (TR) undergoing pulmonary thromboendarterectomy (PTE), whether concomitant tricuspid annuloplasty should be carried out is still controversial.

Methods

The study population consisted of 45 consecutive patients with CTEPH who were scheduled to undergo PTE. All PTE surgeries were conducted with a median sternotomy and deep hypothermia circulatory arrest (DHCA). We collected and analyzed the demographics, surgical details, echocardiographic parameters, and right heart catheterization (RHC) results of these patients.

Results

Moderate to severe TR was documented in 48.9% (22/45) of the patients pre-operatively and 4.4% (2/45) of the patients post-operatively. In patients with grade 4 TR, severity decreased to grade 2 in 8 and to grade 1 in 1. In patients with grade 3 TR, severity decreased to grade 2 in 9, to grade 1 in 3, and 1 remained unchanged. In patients with grade 2 TR, severity decreased to grade 1 in 8, and 15 remained unchanged. The post-operative TR velocity was decreased significantly (431.9±53.4 vs. 196.5±154.0, P<0.001). Pulmonary artery systolic pressure was 84±17 mmHg pre-operatively and decreased to 38±14 mmHg post-operatively (P<0.001). The pre and post-operative pulmonary diastolic pressure was 29±9 and 17±7 mmHg, respectively (P<0.001). The pre and post-operative mean pulmonary pressure was 48±10 and 24±9 mmHg, respectively (P<0.001). The pulmonary vascular resistance (PVR) (1,025.4±465.0 vs. 476.6±181.2 dynes·sec·cm^-5, P<0.001) and pulmonary artery wedge pressure (PAWP) (9±4 vs. 5±2 mmHg, P<0.001) decreased significantly after operation. The cardiac index (CI) increased significantly (1.9±0.5 vs. 2.3±0.4, P=0.003) after operation.

Conclusions

In conclusion, functional TR could be alleviated after PTE even in patients with high PVR. However, the long-term results need to be further investigated.

High preoperative plasma endothelin-1 levels are associated with increased acute kidney injury risk after pulmonary endarterectomy

OBJECTIVES

The only curative treatment for chronic thromboembolic pulmonary hypertension (CTEPH) is pulmonary endarterectomy (PEA). PEA requires cardiopulmonary bypass (CPB) which is associated with a high acute kidney injury (AKI) risk. Circulating endothelin-1 (ET-1) levels are elevated in CTEPH, and ET-1 plays a pivotal role in AKI. Because AKI is burdened by high morbidity and mortality, we aimed to evaluate the association between preoperative ET-1 and the risk to develop AKI in CTEPH individuals who undergo PEA. We also evaluated the association of AKI and ET-1 with kidney function and mortality at 1 year after PEA.

METHODS

In 385 consecutive patients diagnosed with CTEPH who underwent PEA at the Foundation IRCC Policlinico San Matteo (Pavia, Italy) from January 2009 to April 2015, we assessed preoperative circulating ET-1 by ELISA and identified presence of AKI based on 2012 KDIGO criteria.

RESULTS

AKI occurred in 26.5% of the 347 patients included in the analysis, and was independently associated with preoperative ET-1 (p = 0.008), body mass index (BMI) (p = 0.022), male gender (p = 0.005) and duration of CPB (p = 0.002). At 1-year post PEA, estimated glomerular filtration rate (eGFR) significantly improved in patients who did not develop AKI [ΔeGFR 5.6 ml/min/1.73 m² (95% CI 3.6-7.6), p < 0.001] but not in those with perioperative AKI. AKI (p < 0.001), age (p < 0.001), preoperative eGFR (p < 0.001) and systemic hypertension diagnosis (p = 0.015) were independently associated with 1-year ΔeGFR. Neither perioperative AKI nor preoperative ET-1 was associated with 1-year survival.

CONCLUSION

Perioperative AKI is associated with higher preoperative circulating ET-1 and it negatively influences long-term kidney function in patients with CTEPH who undergo PEA.

Long-term outcomes of surgery for chronic thromboembolic pulmonary hypertension compared with medical therapy at a single Korean center

BACKGROUND/AIMS

Pulmonary endarterectomy (PEA) is the gold standard for treating chronic thromboembolic pulmonary hypertension (CTEPH) in Western countries. The aim of this study was to investigate the long-term outcomes of performing PEA on CTEPH patients in comparison with medical therapy at a single Korean center.

METHODS

This retrospective study included 88 CTEPH patients. These patients were classified into the PEA group (n = 37) or non-PEA group (i.e., medical therapy; n = 51). The clinical characteristics, hemodynamic data, and long-term survival rates were compared. Independent prognostic factors for CTEPH were also investigated.

RESULTS

CTEPH was not associated with either gender, and the mean age at diagnosis was 53.3 ± 13.7 years. Echocardiography revealed that the mean peak velocity of the tricuspid regurgitation jet was 4.2 ± 0.7 m/sec and the mean pulmonary arterial pressure was 51.7 ± 15.1 mmHg. The PEA and non-PEA groups demonstrated no significant differences, except in terms of the right ventricular end-diastolic diameter. The survival rates of the PEA group were significantly higher than the non-PEA group at 1, 3, 5, and 10 years (p = 0.032). Multivariate analyses indicated that World Health Organization class IV and PEA were significant predictors of poorer and better outcomes, respectively.

CONCLUSIONS

PEA demonstrates more favorable effects on long-term survival than medical therapy in Korean CTEPH patients who were considered operable.

Chronic Thromboembolic Pulmonary Hypertension: Pearls and Pitfalls of Diagnosis

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by chronic obstruction of major pulmonary arteries by organized thromboembolic material. Untreated CTEPH can result in pulmonary hypertension and eventually right heart failure, yet it is the only form of pulmonary hypertension that is potentially curable with surgical or catheter-based intervention. While early diagnosis is key to increasing the likelihood of successful treatment, CTEPH remains largely underdiagnosed. This article reviews the role of echocardiogram, ventilation/perfusion scan, and other available modalities in the diagnosis of CTEPH.

Echocardiographic evidence of right ventricular functional improvement after balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) induces right ventricular (RV) adaptive changes but often results in RV failure and death. Balloon pulmonary angioplasty (BPA) is a treatment option in patients in whom pulmonary endarterectomy is contraindicated and in patients with residual pulmonary hypertension after pulmonary endarterectomy. We hypothesized that RV reverse remodeling and improved RV function would occur after BPA in patients with CTEPH.

METHODS

In 26 patients with CTEPH (59 ± 12 years old; 11 men), echocardiography, cardiopulmonary exercise testing, blood samples, and right-sided cardiac catheterization were performed before and after 4 ± 2 BPA procedures. Echocardiography images were analyzed off-line with particular focus on RV function according to current recommendations. Differences from baseline to follow-up were analyzed by paired samples t tests.

RESULTS

Significant improvements in hemodynamics, peak oxygen consumption, and levels of N-terminal pro-B-type natriuretic peptide were detected after BPA. All measures of RV function improved considerably, including fractional area change (+6%; p = 0.003), tricuspid annular plane systolic excursion (+3 mm; p < 0.001), and RV free wall peak strain (-4.4; p = 0.002). RV end-diastolic diameter, area, and free wall thickness decreased significantly, whereas left ventricular diameter and stroke volume increased.

CONCLUSIONS

After BPA, a significant improvement in RV functional parameters could be observed by echocardiography, adding credibility to this form of treatment in patients with CTEPH.

Right ventricle in acute and chronic pulmonary embolism (2013 Grover Conference series)

Venous thromboembolism (VTE) encompasses deep-vein thrombosis and pulmonary embolism (PE). It is the third-most-frequent cardiovascular disease, with an overall annual incidence of 1-2 per 1,000 population. Chronic thromboembolic pulmonary hypertension (CTEPH) is regarded as a late sequela of PE, with a reported incidence varying between 0.1% and 9.1% of those surviving acute VTE. Right ventricular (RV) function is dependent on afterload. The most precise technique to describe RV function is invasive assessment of the RV-to-pulmonary vascular coupling. However, assessments of RV afterload (i.e., steady and pulsatile flow components and their product, the RC-time) may be useful hemodynamic surrogates of coupling. RV load is different in acute and chronic PE. In acute PE, more than 60% occlusion of the cross-sectional area of the pulmonary artery within a short period of time leads to abrupt hemodynamic collapse. If the time of occlusion is limited to ∼15 seconds, significant decreases in fractional area change, tricuspid annulus systolic excursion, and RV free-wall deformation (strain) occur, with the latter showing significant postsystolic shortening. These changes have similarities to ischemic stunning, and they recover within minutes. In CTEPH, studies of pulmonary vascular resistance (PVR) and pulmonary arterial compliance demonstrated low RC-times that were further lowered after pulmonary endarterectomy (PEA). Immediate postoperative PVR was the only predictor of long-term survival/freedom from lung transplantation, suggesting that the effect of PEA on opening vascular territories to flow outweighs its effect on proximal stiffness. This review summarizes the current knowledge on vascular and intrinsic RV adaptation to VTE, including CTEPH, and the role of imaging.

Relationship between echocardiographic and cardiac magnetic resonance imaging-derived measures of right ventricular function in patients with chronic thromboembolic pulmonary hypertension

BACKGROUND

Echocardiography is widely used to evaluate right ventricular (RV) function. However, the value of echocardiographic parameters to assess RV function in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is unknown. In this study, we analyzed the correlations between echocardiographic parameters and the RV ejection fraction (RVEF) as measured by cardiac magnetic resonance (CMR) imaging to systematically elucidate the role of echocardiographic parameters in the assessment of RV function in patients with CTEPH.

METHODS

Echocardiography was used to measure the tissue Doppler-derived tricuspid lateral annular systolic velocity (S'), fractional area change (FAC), myocardial performance index (MPI), and tricuspid annular plane systolic excursion (TAPSE). CMR was used to measure the RV end-diastolic volume (RVEDV) and end-systolic volume (RVESV), and the RVEF was calculated.

RESULTS

A significant positive correlation was found between S' and RVEF (r=0.689, P<0.0001) and between FAC and RVEF (r=0.423, P=0.022), a significant negative correlation was found between MPI and RVEF (r=-0.387, P=0.048), and no correlation was found between TAPSE and RVEF (r=0.451, P=0.22).

CONCLUSION

Echocardiography can be routinely used in the clinical setting to measure S', FAC, and MPI for the evaluation of right heart function in patients with CTEPH.