Balloon Pulmonary Angioplasty as a Treatment in Chronic Thromboembolic Pulmonary Hypertension: Past, Present, and Future

Effectiveness and Safety of Balloon Pulmonary Angioplasty for the Treatment of Patients with Persistent Pulmonary Hypertension after Pulmonary Endarterectomy

(1) Background: Pulmonary endarterectomy (PEA) is the "gold standard" treatment for operable patients with chronic thromboembolic pulmonary hypertension (CTEPH). Persistent pulmonary hypertension (PH) after PEA confers a worse prognosis. Balloon pulmonary angioplasty (BPA) could represent a useful therapy in this setting, but evidence about its effectiveness and safety in patients with previous PEA is limited. (2) Methods: A total of 14 patients with persistent PH after PEA were treated with BPA in a single PH center. Hemodynamic and clinical effects of BPA and complications of the procedure were retrospectively collected. (3) Results: After BPA, the mean pulmonary arterial pressure fell from 50.7 ± 15.3 mmHg to 38.0 ± 7.9 mmHg (25.0% decrease; 95% confidence interval (CI) 14.0-35.5%; p = 0.01). Pulmonary vascular resistances were reduced from 8.5 ± 3.6 WU to 5.3 ± 2.2 WU (37.6% decrease; 95% CI 18.8-56.5%; p = 0.01). WHO functional class was also improved with BPA. Severe BPA-related complications were infrequent and no periprocedural deaths were observed. (4) Conclusions: BPA is an effective and safe therapy for patients with CTEPH and persistent PH after PEA.

Right ventricular end-systolic remodeling index on cardiac magnetic resonance imaging: comparison with other functional markers in patients with chronic thromboembolic pulmonary hypertension

BACKGROUND

Cardiac magnetic resonance imaging (CMR) can provide important metrics of pulmonary hypertension. In the current study, we investigated whether the CMR-derived right ventricular end-systolic remodeling index (RVESRI) could be a metric in assessing the function and hemodynamics of chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS

A total of 64 patients (45±14 years, 37 males), including 46 patients with CTEPH and 18 patients with chronic pulmonary thromboembolism (CTE), were retrospectively enrolled. All patients underwent right heart catheterization and CMR within 7 days. RVESRI, right ventricular eccentricity index, right ventricular end-diastolic and end-systolic volume index, right ventricular ejection fraction, right ventricular cardiac output, and strain were analyzed on cine images of CMR. Hemodynamic parameters including mean pulmonary arterial pressure, pulmonary vascular resistance, and cardiac output were obtained from right heart catheterization.

RESULTS

RVESRI of all patients was 1.50 (IQR, 1.26-1.90). Compared with CTE patients, RVESRI in patients with CTEPH was significantly increased (U=27.5, P<0.001). The interclass correlation coefficients of intra-observer reproducibility and inter-observer reproducibility for RVESRI measurement were 0.96 (95% CI, 0.93-0.97) and 0.99 (95% CI, 0.98-0.99), respectively. RVESRI positively correlated with right ventricular end-diastolic and end-systolic volume index and right ventricular global longitudinal strain (r=0.79, 0.83, 0.62, P<0.001), while it was negatively correlated with right ventricular ejection fraction (r=-0.64, P<0.001), right ventricular cardiac output (r=-0.50, P<0.001), and right ventricular eccentricity index (r=-0.81, P<0.001). RVESRI had a positive correlation with mean pulmonary arterial pressure (r=0.65, P<0.001) and pulmonary vascular resistance (r=0.69, P<0.001), while it was negatively correlated with cardiac output (r=-0.64, P<0.001). The receiver operating characteristic curve indicated that RVESRI >1.35 had a sensitivity of 97.8% and specificity of 83.3% in predicting mean pulmonary arterial pressure ≥25 mmHg, and its area under the curve (AUC) was 0.96±0.02. Meanwhile, the AUC of RVESRI was similar to RVEI (Z=1.635, P=0.102) and was more than the diameter of the main pulmonary artery (MPA) (Z=2.26, P=0.02) and the ratio of the MPA and ascending aorta diameter (MPA/AAo) (Z=3.826, P<0.001) in predicting mean pulmonary arterial pressure ≥25 mmHg.

CONCLUSIONS

RVESRI measured on CMR is a simple and reproducible metric in assessing right ventricular function and hemodynamics in CTEPH patients.

Balloon Pulmonary Angioplasty in Patients With Inoperable or Recurrent/Residual Chronic Thromboembolic Pulmonary Hypertension: A Single-Centre Initial Experience

BACKGROUND

Patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) are often treated with pulmonary arterial hypertension-specific drugs. However, most of these patients remain symptomatic, despite medical treatment. Balloon pulmonary angioplasty (BPA) is an emerging therapeutic intervention for patients with inoperable CTEPH. This study aimed to report the initial experience of BPA in a tertiary referral centre for CTEPH.

METHODS

A total of 26 consecutive patients, who underwent 91 BPA sessions, were included in the study. All patients underwent a detailed examination, including 6-minute walking distance (6MWD), and right heart catheterisation at baseline and 3 months after the last BPA session.

RESULTS

The mean age of the patients was 51±17 years. Fifteen (15) patients had inoperable CTEPH and 11 patients had residual or recurrent CTEPH post pulmonary endarterectomy (PEA). Functional class improved in 17 of 26 (65%) patients. The 6MWD increased from a mean 315±129 to 411±140 m (p<0.001), and NT pro-BNP reduced from a median 456 to 189 pg/mL (p=0.001). The number of patients who required supplemental oxygen decreased from 11 (42.3%) to five (19%) (p=0.031) after BPA treatment. The mean pulmonary artery pressure decreased from a mean 47.5±13.4 to 38±10.9 mmHg (p<0.001), the pulmonary vascular resistance decreased from a mean 9.3±4.7 to 5.8±2.8 Wood units (p<0.001), and the cardiac index increased from a mean 2.4±0.7 to 2.9±0.6 L/min/m² (p=0.008).

CONCLUSIONS

Balloon pulmonary angioplasty improved haemodynamics, 6MWD, and functional class, and reduced the requirement for supplemental oxygen, with an acceptable risk-benefit ratio in patients with inoperable CTEPH and with residual/recurrent CTEPH.

Epidemiology and Management of Chronic Thromboembolic Pulmonary Hypertension in Greece. Real-World Data from the Hellenic Pulmonary Hypertension Registry (HOPE)

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) is a rare disease with poor prognosis if left untreated, characterized by pulmonary vascular bed obstruction due to unresolving thromboembolic material. The Hellenic pulmonary hypertension registry (HOPE) was launched in Greece in early 2015 and enrolls patients from all pulmonary hypertension subgroups in Greece. In total, 98 patients with CTEPH were enrolled from January 2015 until November 2019. Of these patients, 55.1% represented incident population, 50% were classified in the World Health Organization functional class II and 49% had a history of acute pulmonary embolism. The median values of pulmonary vascular resistance (PVR) and cardiac index were 7.4 (4.8) WU and 2.4 (1.0) L/min/m², respectively, the mean diffusing capacity for carbon monoxide was 74.8 ± 20.6%, the median 6-minute walk distance was 347 (220) meters and the median value of N Terminal-pro brain natriuretic peptide was 506.0 (1450.0) pg/mL. In total, 60.2% of the patients were under pulmonary arterial hypertension-targeted therapy at the time of enrolment; specifically, riociguat was received by 35.7% of the patients and combination therapy was the preferred strategy for 16% of the patients. In total, 74 patients were evaluated for pulmonary endarterectomy (PEA), 34 (45.9%) were assessed as operable but only 23 of those (31.1%) finally underwent PEA. The remaining 40 patients were ineligible for PEA according to the operability assessment and 13 (17.6%) of them underwent balloon pulmonary angioplasty. The age of the non-operable patients was significantly higher than the operable patients (p < 0.001), while there was no significant difference with regard to the history of coagulopathies between the operable and non-operable patients (p = 0.33).

Efficacy and safety of balloon pulmonary angioplasty for residual pulmonary hypertension after pulmonary endarterectomy

BACKGROUND

Pulmonary endarterectomy (PEA) is the standard treatment for chronic thromboembolic pulmonary hypertension (CTEPH), although some patients may experience residual pulmonary hypertension (PH). It is unclear whether balloon pulmonary angioplasty (BPA) is effective for residual PH after PEA. This study aimed to compare the BPA outcomes between patients with residual PH after PEA and those with inoperable CTEPH.

METHODS

This retrospective study compared BPA for residual PH after PEA (25 patients, 101 BPA sessions) and BPA alone for inoperable CTEPH (21 patients, 89 BPA sessions). All patients underwent right heart catheterisation and functional and laboratory tests before PEA or before and after BPA.

RESULTS

There was no difference in the number of BPA sessions per patient (4.0 ± 1.9 vs. 4.2 ± 1.9, p = 0.671). No significant differences were observed with respect to the mean pulmonary artery pressure (23.6 ± 9.1 vs. 21.9 ± 5.7 mmHg, p = 0.44), pulmonary vascular resistance (3.7 ± 0.5 vs. 2.8 ± 1.2 Wood units, p = 0.14), 6-min walking distance (392.1 ± 117.7 vs. 452.4 ± 90.1 m, p = 0.096), and World Health Organization functional class (I/II/III/IV: 14/11/0/0 vs. 9/12/0/0, p = 0.375). Severe haemoptysis requiring embolisation was more common in the PH after PEA group (16.0% vs. 5.4%, p = 0.018). However, no patients required mechanical ventilation or extracorporeal membrane oxygenation, and there were no procedural deaths.

CONCLUSION

Although BPA might be effective for residual PH after PEA, it was associated with a high rate of haemoptysis.