Impact of Right Ventricular Dysfunction on Outcomes in Acute Myocardial Infarction and Cardiogenic Shock: Insights from the National Cardiogenic Shock Initiative

Abstract

Background: Right ventricular dysfunction (RVD) complicates 30%-40% of cases in acute myocardial infarction (AMI) and cardiogenic shock (CS). There are sparse data on the effects of RVD on outcomes and the impact of providing early left ventricular (LV) mechanical circulatory support (MCS) on RV function and hemodynamics.

Methods and results: Between July 2016 and December 2020, 80 sites participated in the study. All centers agreed to treat patients with AMI-CS using a standard protocol emphasizing invasive hemodynamic monitoring and rapid initiation of LV-MCS. RVD was defined as a right atrial (RA) pressure of >12 mm Hg and a pulmonary artery pulsatility index (PAPI) of <1 within 24 hours of the index procedure. The primary outcome was survival to discharge. In a subgroup analysis, data available from the Automated Impella Controller console was used to analyze diastolic suction alarms from LV placement signal and its relation to RVD. A total of 361 patients were included in the analysis, of whom 28% had RVD. The median age was 64 years (interquartile range 55-72 years), 22.7% were female and 75.7% were White. There was no difference in age, sex, or comorbidities between those with or without RVD. Patients with RVD had a higher probability of active CPR during LV-MCS implant (14.7% vs 6.3%), Society for Cardiovascular Angiography and Interventions stage E shock (39.2% vs 23.2%), and higher admission lactate levels (5.1 mg/dL vs 3.0 mg/dL). Survival to discharge was significantly lower among those with RVD (61.8% vs 73.4%, odds ratio 0.89, 95% confidence interval 0.36-0.95, P = .031). This association remained significant in the multivariate analysis. There was no significant difference in hemodynamic variables within 24 hours of LV-MCS support among those with or without RVD. At 24 hours, patients with a CPO of >0.6 W and a PAPi of >1 had a trend toward better survival to discharge compared with those with a CPO of ≤0.6 W and a PAPi of ≤1 (77.1% vs 54.6%, P = .092). Patients with RVD were significantly more likely to have diastolic suction alarms within 24 hours of LV-MCS initiation.

Conclusions: RVD in AMI-CS is common and associated with worse survival to discharge. Early LV-MCS decreases filling pressures rapidly within the first 24 hours and decreases the rate of RVD. Achieving a CPO of >0.6 W and a PAPi of >1 within 24 hours is associated with high survival. Diastolic suction alarms may have usefulness as an early marker of RVD.

Keywords: Impella; Right ventricular dysfunction; cardiogenic shock; diastolic suction alarm; mechanical circulatory support.