Inhaled nitric oxide therapy is effective in improving right ventricular function in patients receiving ECPELLA support.

Abstract

Objectives: ECPELLA, which uses veno-arterial extracorporeal membrane oxygenation (V-A ECMO) and the Impella percutaneous ventricular assist device, is effective for patients with cardiogenic shock. However, patients with severe right heart dysfunction frequently have difficulty weaning off V-A ECMO. Inhaled nitric oxide (iNO) therapy may induce pulmonary artery pressure while improving right ventricular function. The goal of this study is to determine whether iNO improves right and left ventricular function in patients on ECPELLA.

Methods: This retrospective study, conducted at a single-center, involved 44 ECPELLA-supported patients diagnosed with cardiac shock from January 2019 to August 2024. After applying exclusion criteria, 16 cases who received iNO therapy for right heart failure were analyzed (n = 16). Patients without evidence of right ventricular dysfunction or with incomplete data were excluded. iNO was initiated at 20 ppm when the pulmonary artery pulsatility index (PAPi) was < 1.0 during data collection, the ECMO flow rate was maintained at 2 L/min, and the pulmonary artery catheter measurements were taken before starting iNO and 24 h later.

Results: The median age of the patients was 66 years, with an interquartile range of 59-72, and 11 of the patients (69%) were male. Acute myocardial infarction was the primary diagnosis in eight patients, followed by dilated cardiomyopathy in four, ischemic cardiomyopathy in two, arrhythmogenic right ventricular cardiomyopathy in one, and pulmonary embolism in one. The average duration of iNO therapy was 8 ± 6 days, with 12 patients (75%) successfully weaning off ECPELLA. The 30-day mortality rate was 38% (6/16), with an in-hospital mortality rate of 50% (8/16). Hemodynamic parameters improved significantly after receiving iNO therapy. The PAPi rose from 0.96 ± 0.54 to 1.94 ± 1.7, and the right ventricular fractional area change improved from 24 ± 7.6 to 32 ± 9.5%. In addition, cardiac power output increased from 0.33 ± 0.07 Watt (W) to 0.73 ± 0.21 W, while left ventricular ejection fraction improved from 19 ± 7.6 to 31 ± 16%. Impella flow increased significantly following iNO therapy, and V-A extracorporeal membrane oxygenation-assisted flow decreased. Patients with PAPi levels below 1.0 after iNO therapy had significantly lower ECMO weaning rates and higher 30-day mortality rates.

Conclusions: iNO significantly enhanced both right and left ventricular function in patients undergoing ECPELLA. However, it was also indicated that severe right ventricular dysfunction, which did not respond to iNO, was linked to poor outcomes in patients supported by ECPELLA.