Inhaled Nitric Oxide in Patients with Cardiogenic Shock Treated with Veno-arterial Extracorporeal Membrane Oxygenation and Impella

Abstract

Background: Inhaled nitric oxide (iNO) is a pulmonary vasodilator that can reduce the right ventricular afterload. We aimed to determine the clinical significance of iNO on right ventricular function in patients with cardiogenic shock (CS) treated with combined veno-arterial extracorporeal membrane oxygenation and Impella (ECPELLA). Methods: Pulmonary artery (PA) catheter parameters were obtained before and 24 hours after iNO introduction for eight CS patients receiving ECPELLA and three patients receiving Impella. The causes of CS were MI in six patients, heart failure deterioration in three patients, and myocarditis in two patients. An Impella CP was mainly used (n=9). Results: Before iNO introduction, the mean ± SD PA pulsatility index (0.83 ± 0.56 versus 2.73 ± 1.00; p=0.002) and Impella flow rate (2.0 ± 1.1 versus 3.1 ± 0.1 l/min; p=0.038) were lower in patients receiving ECPELLA than in those receiving Impella. Both the PA pulsatility index (+0.81 ± 0.82; p=0.013) and Impella flow rate (+0.65 ± 0.58 l/min; p=0.008) increased 24 hours after iNO introduction without a worsening of pulmonary congestion in patients receiving ECPELLA. A reduction in pulmonary vascular resistance was the only characteristic haemodynamic change in patients receiving Impella. Conclusion: Right ventricular-specific haemodynamics and Impella flows were improved during iNO treatment. Therefore, the addition of iNO for CS patients with right ventricular dysfunction supported with ECPELLA can be a useful therapeutic option.