Cardiac power as an integrative hemodynamic marker of risk stratification and ventricular dysfunction following acute myocardial infarction
M Merry, G N Gamela Nasr, I Z Islam Zakaria, E M Eman RamadanAbstract
Background
Cardiac power (CP), calculated from mean arterial pressure and cardiac output, reflects global cardiac pumping capability. Its prognostic role in relation to infarct-related artery and contemporary echocardiographic parameters after acute myocardial infarction (MI) remains incompletely defined.
Purpose
To determine whether early post-revascularization CP predicts left ventricular (LV) dysfunction and adverse clinical outcomes at 6 months following acute MI.
Methods
In this prospective study, 99 consecutive patients with acute MI undergoing percutaneous coronary intervention were enrolled. CP was measured 24–48 hours post-procedure. LV ejection fraction (LVEF) and global longitudinal strain (GLS) were assessed by transthoracic echocardiography. Patients were followed for 6 months. The primary adverse outcome was a composite of “Very low” or “Bad” clinical status at 3 or 6 months, based on a pre-specified scale integrating symptoms, functional class, and echocardiographic findings. Multivariable linear and logistic regression models adjusted for age, sex, Killip class, and time to revascularization. Discriminative performance was assessed using receiver operating characteristic (ROC) analysis.
Results
Patients with left anterior descending (LAD) culprit artery had lower CP compared with non-LAD infarctions (0.76±0.19 vs 0.91±0.24 W, p<0.001). CP correlated with LVEF (r=0.59, p<0.001) and GLS (r=0.64, p<0.001). CP remained independently associated with LVEF (β=2.3 per 0.1 W, p<0.001) and GLS (β=−0.8 per 0.1 W, p<0.001). Eighteen patients (18.2%) experienced adverse outcomes and had lower baseline CP than event-free patients (0.62±0.15 vs 0.86±0.21 W, p<0.001). CP independently predicted adverse outcomes (OR 0.68 per 0.1 W, p<0.001). ROC analysis showed AUC 0.82 for predicting LVEF <40% and 0.80 for adverse outcomes. CP improved from baseline to 6 months (0.82±0.23 to 0.90±0.20 W, p<0.001), with attenuated recovery in patients with adverse outcomes (interaction p=0.04).
Conclusions
Early cardiac power measurement after acute MI independently predicts LV dysfunction and 6-month adverse clinical outcomes. CP provides integrated hemodynamic information beyond conventional parameters and may assist in early risk stratification.CP Correlation with Key VariablesMultivariable Predictors