Impact of Systemic-to-Pulmonary Artery Shunt Embolization on Right Heart Hemodynamics in Patients with Bronchiectasis

To explore whether right heart hemodynamics improve after embolization of systemic-to-pulmonary artery shunt (SPS), a common vascular abnormality associated with bronchiectasis.

This study enrolled patients with bronchiectasis diagnosed with SPS. Stroke volume (SV), cardiac index (CI), cardiac output (CO), pulmonary artery pressure, pulmonary artery wedge pressure (PAWP), and shunt oxygen saturation (SO2) were assessed by right heart catheterization. Cardiac magnetic resonance (MR) imaging was also performed in patients who tolerated it. Both were performed before and within 24-48 hours after SPS embolization.

Twenty patients were enrolled, with a mean age of 56.2 years (SD ± 9.3), including 6 males (30%). Shunt PAWP and SO2 significantly decreased after embolization (P = .004 and P = .009, respectively). SV significantly increased (64.8 mL [24.3 mL] to 76.8 mL [23.3 mL], P = .048) after embolization. Postembolization CO and CI numerically increased but did not reach statistical significance (5.0 L/min [1.6 L/min] to 5.9 L/min [2.0 L/min], P = .139; 3.3 L/min/m² [1.3 L/min/m²] to 3.8 L/min/m² [1.0 L/min/m²], P = .211, respectively). Pre-embolization N-terminal pro-brain natriuretic peptide elevation was correlated with postembolization SV improvement (r = 0.457, P = .043). Cardiac MR imaging demonstrated a significant increase in postembolization right ventricular (RV) ejection fraction, rising from 43.00% (SD ± 10.90 to 48.83% [SD ± 6.59%], P = .034). The postembolization shunt volume between the left ventricle and RV significantly decreased (20.67 mL [SD ± 9.52] to 9.50 mL [SD ± 6.47], P = .017).

Embolization of SPS might improve right heart hemodynamics in patients with bronchiectasis; however, larger controlled studies with longer follow-up are needed.