Clinical impact of mean pulmonary arterial pressure after balloon pulmonary angioplasty for inoperable chronic thromboembolic pulmonary hypertension.

BACKGROUND

Balloon pulmonary angioplasty (BPA) improves haemodynamics in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Previous studies on BPA have set the treatment objective to achieve a mean pulmonary arterial pressure (mPAP) of <30 mm Hg. However, the clinical impact of mPAP after BPA remains unclear. This study aimed to stratify patients according to their mPAP after BPA and evaluate its association with clinical status and long-term outcomes.

METHODS

We retrospectively reviewed 304 patients with inoperable CTEPH (median age, 72 (61 to 79) years) who underwent BPA and follow-up right heart catheterisation. Patients were categorised by mPAP after BPA: ≤20, >20-<30 and ≥30 mm Hg groups.

RESULTS

The WHO functional classification, 6 min walk distance and right ventricular ejection fraction were significantly better in the group with a lower mPAP (trend test p=0.007, p<0.001 and p=0.002, respectively). Additionally, the proportions of patients who required pulmonary vasodilators or oxygen therapy were significantly lower in the group with a lower mPAP (trend test p<0.001 and p<0.001, respectively). Across all multivariable models, the mPAP ≥30 mm Hg group had a significantly poorer prognosis compared with the mPAP ≤20 mm Hg group. In contrast, no significant difference was observed between the mPAP ≤20 mm Hg and >20-<30 mm Hg groups.

CONCLUSIONS

In patients with CTEPH after BPA, an mPAP of <30 mm Hg was associated with a favourable prognosis, and patients with an mPAP of ≤20 mm Hg presented with better symptoms, exercise capacity, right ventricular function and more withdrawal from oxygen therapy and pulmonary vasodilators. The BPA treatment goal may require individual adaptation.