Impact of time to reperfusion after acute myocardial infarction on myocardial damage assessed by left ventricular longitudinal strain.

The relation between cardiac troponin T (cTnT) and regional strain in patients with acute myocardial infarction (AMI) was investigated. Furthermore, the effect of symptoms-to-balloon time on impairment in regional strain after AMI was evaluated. A total of 157 consecutive patients with AMI who underwent primary percutaneous coronary intervention were included. Two-dimensional echocardiography soon after percutaneous coronary intervention was performed. Speckle-tracking analysis was applied to assess left ventricular global and regional longitudinal peak systolic strain (LPSS). Infarcted area was defined based on the culprit vessel. Mean left ventricular ejection fraction was 47 +/- 7%. Global LPSS was -14.4 +/- 3.2%. The infarcted area LPSS was significantly decreased compared with global LPSS (-11.3 +/- 4.5%, p <0.001). The major reflector of cTnT was infarcted area LPSS (beta 0.47, p <0.001). Mean symptoms-to-balloon time was 212 +/- 92 minutes. Based on this time, the study population was divided in tertiles. In the group with the shortest symptoms-to-balloon time, global LPSS and infarcted area LPSS were less impaired compared with groups with longer symptoms-to-balloon time (p <0.01 for the 2 comparisons). In conclusion, myocardial strain was related to peak levels of cTnT, thus reflecting damage after AMI. Early reperfusion resulted in decreased myocardial damage in the infarcted area as quantified with strain.