Prognostic value of right atrial pressure-corrected cardiac power index in cardiogenic shock

The pulmonary artery catheter (PAC)-derived cardiac power index (CPI) has been found of prognostic value in cardiogenic shock (CS) patients. The original CPI equation included the right atrial pressure (RAP), accounting for heart filling pressure as a determinant of systolic myocardial work, but this term was subsequently omitted. We hypothesized that the original CPI formula (CPI_RAP ) is superior to current CPI for risk stratification in CS.

A single-centre cohort of 80 consecutive Society for Cardiovascular Angiography and Interventions (SCAI) B-D CS patients with available PAC records was included. Overall in-hospital mortality was 21.3%. Results showed CPI_RAP to be the strongest haemodynamic predictor of in-hospital death (p_adj  = 0.038), outperforming CPI [area under the receiver operating characteristic (ROC) curves: 0.726 and 0.673, P-for-difference = 0.025]. When the population was stratified according to the identified CPI_RAP (0.28 W/m² ) and accepted CPI (0.32 W/m² ) thresholds, the cohort with discordant indexes (low CPI_RAP and high CPI) comprised a group of 13 patients featuring a congested phenotype with frequent right ventricle or biventricular involvement. In this group, in-hospital mortality was high (30.8%) similar to those with concordant low CPI and CPI_RAP .

Incorporating RAP in CPI calculation (CPI_RAP ) improves the prognostic yield in patients with CS SCAI B-D. A cut-off of 0.28 W/m² identifies patients at higher risk of in-hospital mortality. The improved prognostic value of CPI_RAP may derive from identification of patients with more intravascular congestion who may experience substantial in-hospital mortality, uncaptured by the commonly used CPI equation.