A pilot study of prognostic value of non-invasive cardiac parameters for major adverse cardiac events in patients with acute coronary syndrome treated with percutaneous coronary intervention.

The objective of this study was to determine the combination of left ventricular ejection fraction (LVEF) and individual electrocardiographic parameters related to abnormal depolarization/repolarization or baroreceptor sensitivity that had the best predictive value for major adverse cardiac events (MACE) in patients with acute coronary syndrome (ACS). Patients with ACS who underwent coronary angiography and percutaneous coronary intervention (PCI) were included in this prospective study. Ventricular late potential (VLP), heart rate turbulence (HRT), heart rate variability (HRV), and T wave alternans (TWA) parameters were measured using 24 h Holter monitoring 2-4 weeks after onset of ACS. Initial and follow-up LVEF was measured by ultrasound. Patients were followed for at least 6 months to record the occurrence of MACE. Models using combinations of the individual independent prognostic factors found by multivariate analysis were then constructed to use for estimation of risk of MACE. In multivariate analysis, VLP measured as QRS duration, HRV measured as standard deviation of normal RR intervals, and followup LVEF, but none of the other parameters studied, were independent risk factors for MACE. Areas under ROC curve (AUCs) for combinations of 2 or all 3 factors ranged from 0.73 to 0.76. Combinations of any of the three independent risk factors for MACE in ACS patients with PCI improved prediction and, because these risk factors were obtained non-invasively, may have future clinical usefulness.