3D echocardiography derived cardiac power output as an independent prognostic marker for heart failure in young patients with STEMI

Abstract Background Cardiac power output (CPO) is a measurement of cardiac performance and one of the hemodynamic predictors of adverse outcomes in cardiogenic shock1. However, its prognostic role in earlier stages of heart failure (HF) or pre HF remains unclear. Purpose This study aimed to assess the prognostic value of CPO determined by 3D echocardiography, in a cohort of young patients with ST-elevation myocardial infarction (STEMI). Patients and methods: We enrolled 85 consecutive, hemodynamically stable patients aged between 18 and 50 years old (mean age 44.6 years) who presented with an index STEMI treated by primary PCI. All patients underwent both standard and 3D echocardiography. CPO was estimated as the product of mean arterial pressure (MAP) and cardiac output (CO) divided by 451 (CPO=MAP*CO/451), where CO was measured by 3D echocardiography and MAP was calculated using the dedicated formula: (systolic blood pressure − diastolic blood pressure)/3 + diastolic blood pressure. Patients were followed up for one year after STEMI and the primary endpoint was the occurrence of HF, defined according to the latest ESC guidelines 2. Results Out of 85 patients, 12.9% developed post-STEMI heart failure during the follow up period. Patients who reached the endpoint had lower baseline 3D CPO (0,6 Watts vs 0,78 Watts, p0.001), 3D left ventricular ejection fraction (3D LVEF) 34.4% vs 43.6%, p0.001 and left ventricular global longitudinal strain (LVGLS) values (-9.6 vs -13.7, p0.001), as assessed during their index hospitalization. No significant differences in MAP values (84 mmHg vs 87 mmHg, p=0.325) or 3D CO (3.2 l/min vs 4.6 l/min, p=0.39) were observed between the groups. Receiver operating characteristic (ROC) analysis demonstrated that 3D CPO yielded a higher area under the curve (AUC= 0.884, 95%CI 0.791-0.977,p0.0001) indicating superior predictive accuracy for HF compared to 3D CO (AUC 0.794, 95%CI 0.664-0.923, p=0.002), MAP (AUC=616, 95% CI 0.431-0.802, p=0.217), 3D LVEF (AUC=829, 95% CI 0.726-0.932, p0.0001), and LVGLS (AUC=817, 95% CI 0.689-0.944, p=0.001) - Figure 1. A 3D CPO value below 0.65 predicted the development of HF with 72% sensitivity and 91% specificity. Cox regression analysis demonstrated that CPO remained an independent predictor for heart failure after adjustment for age, CO, 3D LVEF, and LVGLS (95% CI, HR 7.3, p 0.005). Kaplan-Meier analysis revealed that patients with 3D CPO values lower than the cut off (0.65 Watts) were at significantly higher risk for HF hospitalization (Log-rank p 0.0001) - Figure 2. Conclusion CPO, noninvasively assessed using 3D echocardiography, emerged as an independent predictor of HF at one-year follow-up in a cohort of young patients with STEMI. It holds potential as a clinically applicable marker for risk stratification in this specific patient cohort. However, larger-scale studies are necessary to validate these findings.Figure 1 - ROC curves Figure 2 - Kaplan Meier analysis