4 Efficacy

4 Efficacy

This section describes efficacy outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview.

4.1 In a case series of 18 patients treated by balloon pulmonary angioplasty (BPA) for chronic thromboembolic pulmonary hypertension, the survival rate was 89% (16/18) after a mean follow‑up of 34 months.

4.2 In a non-randomised retrospective comparative study of 53 patients treated by BPA (n=29) or pulmonary endarterectomy (PEA; n=24), the mean pulmonary arterial pressure decreased from 39.4 mmHg to 21.3 mmHg (p<0.001) in the BPA group at 1‑week follow‑up and from 44.4 mmHg to 21.6 mmHg (p<0.001) in the PEA group at 2‑week follow‑up. In the same study, the mean right atrial pressure decreased from 5.5 mmHg to 2.6 mmHg (p=0.013) in the BPA group at 1‑week follow‑up and from 10.2 mmHg to 6.0 mmHg (not significant) in the PEA group at 2‑week follow‑up. Also, the mean cardiac index increased from 2.2 litre/min/m2 to 2.7 litre/min/m2 (p<0.001) in the BPA group at 1‑week follow‑up and from 2.1 litre/min/m2 to 2.8 litre/min/m2 (p=0.005) in the PEA group at 2‑week follow‑up.

4.3 In a case series of 68 patients with a mean follow‑up of 2.2 years after the last BPA session, the mean pulmonary arterial pressure decreased from 45.4 mmHg to 24.0 mmHg (p<0.01). In the same study, the mean right atrial pressure decreased from 8.1 mmHg to 1.9 mmHg (p<0.01), and the mean cardiac index increased from 2.2 litre/min/m2 to 3.2 litre/min/m2 (p<0.01). In the case series of 18 patients with a mean follow‑up of 3 years, the mean pulmonary arterial pressure decreased from 42 mmHg to 33 mmHg (p=0.002) and the mean cardiac index changed from 2.0 litre/min/m2 to 2.1 litre/min/m2 (not significant).

4.4 In the case series of 18 patients, the mean New York Heart Association class (range from I to IV: I indicating no limitation of physical activity because of heart failure and IV indicating severe limitation of physical activity because of heart failure) improved from 3.3 to 1.8 (p<0.001) at a mean follow‑up of 3 years after the last BPA session. In the case series of 68 patients, all patients were categorised as having World Health Organization (WHO) Class III or IV pulmonary hypertension (marked or severe limitation of physical activity because of pulmonary hypertension) before treatment. At a mean follow‑up of 2.2 years after the last BPA session, 96% (64/67) of patients were categorised as having WHO functional class I or II pulmonary hypertension (no or slight limitation of physical activity because of pulmonary hypertension) and 5% (3/67) of patients were categorised as having WHO functional class III pulmonary hypertension.

4.5 In the non‑randomised retrospective comparative study of 53 patients treated by BPA (n=29) or PEA (n=24), the mean 6‑minute walking test distance increased from 295 m to 397 m in the BPA group (p<0.001; follow‑up period not reported). No results were reported for the PEA group. In the case series of 18 patients, the mean 6‑minute walking test distance increased from 191 m to 454 m (p<0.0001) at a mean follow‑up of 3 years after the last BPA session.

4.6 In a case series of 20 patients, the mean time that patients were able to carry out cardiopulmonary exercise tests increased from 6.5 minutes to 9.2 minutes (p=0.017) 3 months after the last BPA session. The mean total workload (peak watts) reached during cardiopulmonary exercise testing increased from 86 watts to 111 watts (p=0.001) and the mean peak oxygen consumption during cardiopulmonary exercise testing increased from 13.6 ml/kg/ml to 17.0 ml/kg/ml (p<0.01).

4.7 In the non‑randomised retrospective comparative study of 53 patients treated by BPA (n=29) or PEA (n=24), mean B‑type natriuretic peptide levels decreased from 210 pg/ml to 41 pg/ml (p=0.01) in the BPA group and from 263 pg/ml to 74 pg/ml (p=0.022; follow‑up period not reported) in the PEA group. In the case series of 68 patients, mean B‑type natriuretic peptide levels decreased from 330 pg/ml to 35 pg/ml (p<0.01) at a mean follow‑up of 2.2 years after the last BPA session. In the case series of 20 patients, the proportion of patients who were Troponin T positive decreased from 60% (12/20) to 15% (3/20) 3 months after the last BPA session (p=0.001).

4.8 In the case series of 68 patients, the proportion of patients who used endothelin receptor agonists decreased from 52% (35/68) to 37% (25/67) and the proportion of patients who used phosphodiesterase‑5 inhibitor decreased from 40% (27/68) to 28% (19/67) at a mean follow‑up of 2.2 years after the last BPA session (p<0.05 for both drug groups).

4.9 The specialist advisers listed the following key efficacy outcomes: symptomatic improvement; improved functional status (WHO classification, 6‑minute walk test); improved haemodynamics; improved tissue perfusion and increased rapidity of pulmonary venous phase during angiography; improved quality of life; improved cardiopulmonary exercise testing; and improved survival.

  • National Institute for Health and Care Excellence (NICE)