Time course of aortic stiffness changes after acute myocardial infarction

Abstract

Our aim was to study aortic wall properties at comparable blood pressures for a follow-up period of 30 days after acute myocardial infarction (AMI). We performed ultrasound aortic wall and non-invasive pressure measurements to determine, at the level of the ascending aorta, changes in stiffness index β (days 1, 2, 4, 7, 15 and 30). Forty patients (31 men and 9 women) with mean age 69.1±4.4 years were included. Twenty more age-matched patients, with the same risk factors for coronary artery disease, served as controls. The patients were divided into two groups according to the pattern of β changes during the follow-up period. Dippers consisted of 27 patients who showed an initial increase in β, from the first to the seventh day (from 14.9±2.1 to 19.5±2.9, p<0.001) and a gradual decrease thereafter. Non-dippers consisted of 13 patients who showed a continuous increase in β from the first to the thirtieth day (from 16.5±2.4 to 24.4±3.3, p<0.001). Intravenous or oral nitroglycerin, β-blockers, and angiotensin-converting-enzyme inhibitors abolished any difference in blood pressure and heart rate between patients. Peak serum creatine kinase was increased while ejection fraction decreased in non-dippers more than in dippers, p<0.001. All other recorded variables were similar between the two groups. After multivariate adjustment peak creatine kinase levels (OR, 1.0036, CI=1.0002–1.0070) and ejection fraction (OR, 0.6231, CI=0.4300–0.9030) were significantly associated with the presence of the nondipper pattern. Ejection fraction was significantly correlated with β in all measurements, p<0.001. These may represent the first findings concerning increased aortic stiffness in patients with AMI. There are two patterns of changes in aortic stiffness during a 30-day follow-up after AMI. Nondippers may have adversely affected cardiac function in the long run.