The feasibility of the initial postsystolic to systolic strain rate ratio as a predictor of the viability of ischemic myocardium with acute myocardial infarction.

BACKGROUND: Investigations of a strain index for the viability of ischemic myocardium with acute myocardial infarction (AMI) have been challenging. Therefore, the aim of this study was to evaluate patients with AMI to determine an optimal strain index for predicting the viability of ischemic myocardium. METHODS AND RESULTS: A total of 57 patients with AMI were assessed according to two-dimensional (2D) speckle tracking imaging strain and strain rate (SR), measured during the acute phase before urgent revascularization and at a 1-year follow-up postrevascularization. During the acute phase, all the myocardial segments were classified according to the acute end-systolic strain (Ses) values as normal (Ses ≤ -13%), hypocontractile (-13% < Ses ≤ -7%), or having a severe contractile abnormality (Ses > -7%). At the 1-year follow-up, we reassessed the recovery of the segments with a severe contractile abnormality. The viability of these segments was defined as an improved Ses (≤ -7%) at follow-up postrevascularization. The Ses values, postsystolic strain index (PSI), and SR values were significantly better in the viable segments than in the nonviable segments at both the acute phase and at follow-up (P < 0.001). The initial postsystolic to systolic SR ratio (SRps/SRs) had the best area under the curve (AUC = 0.897). In addition, a cutoff value of 0.6 predicted recovery from a severe contractile abnormality with a sensitivity of 75% and a specificity of 88%. CONCLUSIONS: The initial SRps/SRs ratio identified the viability of ischemic myocardium with AMI; therefore, this novel index may be clinically useful in the treatment of patients with AMI.

One-year clinical outcomes in invasive treatment strategies for acute ST-elevation myocardial infarction complicated by cardiogenic shock in elderly patients.

OBJECTIVE: To investigate the clinical outcomes of an invasive strategy for elderly (aged ≥ 75 years) patients with acute ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock (CS). METHODS: Data on 366 of 409 elderly CS patients from a total of 6,132 acute STEMI cases enrolled in the Korea Acute Myocardial Infarction Registry between January 2008 and June 2011, were collected and analyzed. In-hospital deaths and the 1-month and 1-year survival rates free from major adverse cardiac events (MACE; defined as all cause death, myocardial infarction, and target vessel revascularization) were reported for the patients who had undergone invasive (n = 310) and conservative (n = 56) treatment strategies. RESULTS: The baseline clinical characteristics were not significantly different between the two groups. There were fewer in-hospital deaths in the invasive treatment strategy group (23.5% vs. 46.4%, P < 0.001). In addition, the 1-year MACE-free survival rate after invasive treatment was significantly lower compared with the conservative treatment (51% vs. 66%, P = 0.001). CONCLUSIONS: In elderly patients with acute STEMI complicated by CS, the outcomes of invasive strategy are similar to those in younger patients at the 1-year follow-up.