[Update in the management of chronic thrombo-embolic pulmonary hypertension]

Chronic thrombo-embolic pulmonary hypertension (CTEPH) is a potentially curable form of pulmonary hypertension (PH) that develops in up to 3% of patients after pulmonary embolism (PE). In these patients, PE does not resolve, leading to organized fibrotic clots, with the development of precapillary PH as a result of the proximal obstruction of the pulmonary arteries. In addition, a distal microvasculopathy may also develop, contributing to the increase of pulmonary vascular resistance. Transthoracic echocardiography is the diagnostic tool that allows to establish the suspicion of PH. Ventilation-perfusion lung scintigraphy is the fundamental tool in the study of patients with suspected CTEPH; if it is normal, virtually rules out the diagnosis. Right heart catheterization is mandatory for the diagnosis of these patients. CTEPH is defined as the existence of symptoms, residual perfusion defects and precapillary PH after a minimum period of three months of anticoagulation. Pulmonary angiography helps determine the extent and surgical accessibility of thromboembolic lesions. CTEPH patients are candidates for long-term anticoagulation. Pulmonary endarterectomy is the treatment of choice, resulting in significant clinical and hemodynamic improvement. About 25% of patients have residual PH post-endarterectomy. Balloon pulmonary angioplasty is an endovascular technique that targets more distal lesions, being potentially useful for patients with inoperable CTEPH or persistent/recurrent PH post-endarterectomy. Both types of patients may also benefit from pharmacological treatment for PH. These three therapies are the cornerstone of CTEPH treatment, which has evolved towards a multimodal approach.

Progress in the treatment of acute pulmonary embolism and chronic thrombo-embolic pulmonary hypertension/disease

The combination of an initial clinical approach aimed at evaluating the early risk of mortality with subsequent diagnostic and therapeutic approaches articulated on the overall patient's profile is recommended in acute pulmonary embolism (PE). The presence of pulmonary hypertension associated with the persistence of chronic vascular obstructions in the pulmonary arteries after one or more acute thrombo-embolic events identifies a condition defined as chronic thrombo-embolic pulmonary hypertension (CTEPH). The evolution of technology and knowledge in the field of imaging has allowed us to qualify the computed tomography angiography of the pulmonary arteries as the gold standard for the diagnostic confirmation of both acute PE and CTEPH. In both these conditions, the first therapeutic step is the immediate initiation of anticoagulant therapy. In acute high-risk PE, in addition to anticoagulant therapy, thrombolytic therapy is recommended; in the event of contraindications to thrombolysis, surgical embolectomy or percutaneous catheter-directed treatment represents viable treatment options. In CTEPH, the combination of data collected from cardiac catheterization, computed tomography angiography, and conventional angiography of pulmonary arteries allows a team of experts to identify candidates for pulmonary endarterectomy surgery. Inoperable patients should be considered for percutaneous balloon angioplasty of the pulmonary arteries which can improve patients' symptoms, quality of life, and prognosis.

Comprehensive evaluation of the effectiveness and safety of balloon pulmonary angioplasty for inoperable chronic thrombo-embolic pulmonary hypertension: long-term effects and procedure-related complications

Aims

Although balloon pulmonary angioplasty (BPA) improves haemodynamics and short-term prognosis in patients with inoperable chronic thrombo-embolic pulmonary hypertension (CTEPH), the long-term effects of BPA, and procedure-related complications remain to be fully elucidated.

Methods and results

From July 2009 to October 2016, we performed a total of 424 BPA sessions in 84 consecutive patients with inoperable CTEPH. We used 3D reconstructed computed tomography to determine target lesions of pulmonary arteries and optical computed tomography to select balloon size, if needed. In 77 patients (92%) who completed the BPA treatment [65 ± 14 (SD) years-old, male/female 14/63], haemodynamics and exercise capacity were examined at 6 months after last BPA and in the chronic phase [>12 months after first BPA, 31 (20, 41) months]. The BPA treatment significantly improved mean pulmonary arterial pressure (38 ± 10 to 25 ± 6 mmHg), pulmonary vascular resistance (7.3 ± 3.2 to 3.8 ± 1.0 Wood units), and 6-minute walk distance (380 ± 138 to 486 ± 112 m) (all P < 0.01), and the improvements persisted throughout the follow-up period (43 ± 27 months) (N = 53). In the 424 sessions, haemoptysis was noted in 60 sessions (14%), and non-invasive positive pressure ventilation (NPPV) was used to treat haemoptysis and/or hypoxemia in 33 sessions (8%). Furthermore, 5-year survival was 98.4% (only one patient died of colon cancer) with no peri-procedural death.

Conclusion

These results indicate that BPA improves haemodynamics and exercise capacity in inoperable CTEPH patients with acceptable complication rate and that the beneficial haemodynamic effects of BPA persist for years with resultant good long-term prognosis.

Pulmonary endarterectomy for chronic thrombo-embolic pulmonary hypertension: an institutional experience

OBJECTIVE

Pulmonary endarterectomy (PEA) is the treatment of choice for patients with chronic thrombo-embolic pulmonary hypertension (CTEPH). The aim of this study was to review our initial experience since the implementation of our program.

METHODS

Data were collected prospectively on all patients who underwent PEA between March 2011 and March 2012.

RESULTS

Forty-nine patients (20 male, 29 female, mean age 47.7 years) underwent surgery. The preoperative New York Heart Association class distribution showed the majority to be in class III or IV (n = 40). Mortality rate was 14.2% (n = 7) and the morbidity rate was 26.5% (n = 13). After PEA, the durations of mechanical ventilation, intensive care stay and hospital stay before discharge were 49.7 ± 46.1 h, 6.5 ± 5.0 days and 12.9 ± 7.5 days, respectively. The systolic and mean pulmonary artery pressure (PAP) fell significantly from 87.0 ± 26.6 mmHg and 53.8 ± 14.5 before, to 41.5 ± 12.4 mmHg and 28.5 ± 10.5 after surgery (P < 0.001 and P < 0.001, respectively). Pulmonary vascular resistance (PVR) also improved significantly from 808 ± 352.0 to 308 ± 91 dyn•s•cm(-5) (P < 0.001). Univariate analysis showed that preoperative systolic PAP, tricuspid annular plane systolic excursion, right atrial volume, right atrial pressure, forced expiratory volume in 1 s, forced vital capacity, preoperative PVR, postoperative PVR, the duration of circulatory arrest and postoperative use of extracorporeal membrane oxygenation were risk factors for mortality (P < 0.05). According to multivariate analyses, only prolonged mechanical ventilation was selected as predictive risk factor for morbidity (P = 0.005). After a median follow-up of 6.1 months, two patients died due to cerebrovascular disease and one patient needed targeted pulmonary hypertension therapy. The rest of the 39 patients showed marked improvements in their clinical status.

CONCLUSIONS

Starting a pulmonary endarterectomy program with acceptable mortality and morbidity rates and satisfactory early-term outcomes increases awareness of the CTEPH and surgery. Preoperative factors can primarily predict postoperative outcome after PEA. Identifying the risk factors in order to achieve a good result is important for the success of a PEA program. Therefore all patients diagnosed with CTEPH should be referred for consideration of PEA in a specialized centre.

Residual pulmonary hypertension after retrograde pulmonary embolectomy: long-term follow-up of 30 patients with massive and submassive pulmonary embolism

OBJECTIVES

Pulmonary hypertension is a major cause of morbidity and mortality in patients following acute pulmonary embolism. Although thrombolytic therapy decreases pulmonary arterial pressure, compared with anticoagulation alone, it has the propensity for haemorrhagic complications, distal embolization and incomplete recanalization, with the potential risk of late pulmonary hypertension. Surgical embolectomy-once performed solely on critically-ill patients-has now gained favour in a wider range of patients. In this paper we present the outcomes of patients who underwent surgical embolectomy complemented with retrograde technique and follow-up systolic pulmonary arterial pressure (SPAP).

METHODS

From January 2004 to December 2010, 30 consecutive patients with a mean age of 58±15 years underwent pulmonary embolectomy at our centre. The patients were followed for a mean period of 30.5±12 months. Their New York Heart Association (NYHA) classifications were assessed and their SPAPs were measured by echocardiography.

RESULTS

The overall mortality rate was 13.2% (4/30). Of the remaining patients, 19 patients (73.1%) were in NYHA classes I and II, 7 patients (26.9%) in class III and no patient in class IV. The patients' preoperative and postoperative mean SPAPs were 44.9±5.7 and 34.9±7.1 mmHg, respectively, which showed a significant reduction (P<0.001). The mean SPAP in the follow-up was 29.4±11.5 mmHg, which again showed significant reduction compared with early postoperation values (P<0.001). No significant correlations were found between the level of SPAP reduction in patients' follow-up with age (P=0.727) and total days of ICU admission (P=0.700), but weak correlations with sex (P=0.016) and total intubation time were noticed (P=0.035).

CONCLUSIONS

This is the first series reporting the long-term outcome of patients undergoing surgical embolectomy complemented by retrograde embolectomy technique, demonstrating the safety and favourable long-term outcome of this technique. It is also a new element in the growing body of evidence regarding the relevance of surgical embolectomy in patients with acute pulmonary embolism. We concluded that, following surgery, not only does the pulmonary arterial pressure drop immediately, but also the trend toward normalization continues long after operation.