Abstract
BACKGROUND: Synchronization between 0.1-Hz rhythms in cardiovascular system is deteriorated at acute myocardial infarction (AMI) leading to a disruption of natural functional couplings within the system of autonomic regulation. OBJECTIVE: This study evaluates the prognostic value of autonomic regulation indices for the 5-year risk of fatal and nonfatal cardiovascular events in patients after AMI. METHODS AND RESULTS: We studied 125 patients (53 [42%] female) after AMI aged between 30 and 83 years. The period of observation was 5 years with checkpoints at the first week after AMI and after each year after AMI. We compared the prognostic value of established clinical characteristics and degree S of synchronization between 0.1-Hz rhythms in heart rate and microcirculation for evaluation of the 5-year risk of mortality and recurrent myocardial infarction (MI) in patients after AMI. Acute heart failure Killip 2-4 at AMI and S < 20% at the first week after AMI were identified as the most important factors for evaluation of the risk of 5-year mortality in patients after AMI (χ(2) = 14.2, P = 0.003). Sensitivity and specificity of low S (<20%) at the first week after AMI were 76% and 43%, respectively. For evaluation of the 5-year risk of recurrent MI index S had no advantage over established clinical characteristics. CONCLUSION: The value of S below 20% in patients with AMI is a sensitive marker of high risk of mortality during the subsequent five years. It is characterized by better prognostic value than most of established clinical characteristics.