The ambulatory arterial stiffness index (AASI) is a marker of arterial stiffness, and predicts cardiovascular morbidity and mortality in hypertensives patients. However, data is scarce regarding the prognostic role of AASI for future cardiovascular events in patients with acute myocardial infarction (AMI). We therefore evaluated the relationship between AASI and long-term cardiovascular outcomes in patients suffering an AMI.
We followed up 130 patients [78.7% male; mean age 62.4 years; 68.5% hypertensives; 27.9% with diabetes mellitus (DM)] who were hospitalized because of ST-elevation MI (STEMI, 50.3%) and Non-ST–elevation MI (NSTEMI), for a period of 12 months. All patients underwent baseline estimation of clinical and laboratory parameters during their hospitalization. Moreover, patients underwent 24-hour ambulatory blood pressure (BP) monitoring during the third day of hospital stay. AASI was calculated as 1- (slope of diastolic on systolic blood pressure (BP) during 24-h ambulatory BP monitoring). Endpoints of interest where death or hospitalization for congestive heart failure, acute coronary syndrome, stroke, ventricular tachycardia, atrial fibrillation and acute renal failure.
AASI failed to predict mortality or the composite endpoint of cardiovascular morbidity and mortality during the follow-up period either in the entire population or separately for each AMI type. However, AASI demonstrated a significant prognostic role for hospitalization for major cardiovascular events in the NSTEMI population after univariate regression analysis (HR, 0.109; CI, 0.033–0.184; p = 0.005). In a model of multivariate regression analysis in the same AMI group, this association was maintained (HR, 0.072; CI, 0.002–0.141; p = 0.043) after controlling for traditional risk factors and severity of coronary artery disease assessed by the number of affected main vessels.
According to our study, AASI is an independent predictor of one-year cardiovascular morbidity in patients with NSTEMI. In the setting of an acute coronary event, this non-invasive tool may prove useful in risk stratification of such patients when available.
First Cardiology Clinic, Medical School, National and Kapodistrian University of Athens, Hippokration Hospital, Athens, GREECE