Hemodynamic assessment and risk classification for successful weaning of Impella in patients with cardiogenic shock.

Abstract

Clinical predictors for successful weaning of patients from Impella heart pump have not been clarified. We aimed to elucidate the relationship between pulmonary artery catheter (PAC) parameters at the time of Impella weaning and subsequent outcomes. We enrolled consecutive patients who had received Impella for cardiogenic shock. PAC data were collected immediately before Impella weaning. Patients were classified as non-survivors if they died or required any mechanical circulatory support reintroduction within 30days of weaning. Of 81 patients enrolled, 61 underwent Impella weaning. Of these, 16 were non-survivors. Predictive indicators of non-survival were high pulmonary artery wedge pressure (PAWP; hazard ratio [HR] per 5mmHg 1.97, 95% CI 1.35-2.80; p<0.001), high mean pulmonary artery pressure (MPAP; HR per 5mmHg 1.90, 1.38-2.58; p<0.001), and low cardiac power output (CPO; HR per 0.1 Watts 0.71, 0.52-0.92; p=0.006). Cutoff values of PAWP 20mmHg, MPAP 22mmHg, and CPO 0.59 Watts showed strong associations with 30-day non-survival risk (low risk 8% in patients with low PAWP and high CPO or 4% in patients with low MPAP and high CPO; high risk 100% in patients with high PAWP and low CPO or 82% in patients with high MPAP and low CPO). PAWP or MPAP higher than the cutoff with CPO below the cutoff at Impella weaning were associated with worse outcomes. We proposed a risk classification model for successful Impella weaning using PAC.