Strain analysis is superior to wall thickening in discriminating between infarcted myocardium with and without microvascular obstruction

Objectives: The aim of the present study was to evaluate the diagnostic performances of strain and wall thickening analysis in discriminating among three types of myocardium after acute myocardial infarction: non-infarcted myocardium, infarcted myocardium without microvascular obstruction (MVO) and infarcted myocardium with MVO. Methods: Seventy-one patients with a successfully treated ST-segment elevation myocardial infarction underwent cardiovascular magnetic resonance imaging at 2-6 days after reperfusion. The imaging protocol included conventional cine imaging, myocardial tissue tagging and late gadolinium enhancement. Regional circumferential and radial strain and associated strain rates were analyzed in a 16-segment model as were the absolute and relative wall thickening. Results: Hyperenhancement was detected in 418 (38%) of 1096 segments and was accompanied by MVO in 145 (35%) of hyperenhanced segments. Wall thickening, circumferential and radial strain were all significantly diminished in segments with hyperenhancement and decreased even further if MVO was also present (all p < 0.001). Peak circumferential strain (CS) surpassed all other strain and wall thickening parameters in its ability to discriminate between hyperenhanced and non-enhanced myocardium (all p < 0.05). Furthermore, CS was superior to both absolute and relative wall thickening in differentiating infarcted segments with MVO from infarcted segments without MVO (p = 0.02 and p = 0.001, respectively). Conclusions: Strain analysis is superior to wall thickening in differentiating between non-infarcted myocardium, infarcted myocardium without MVO and

Discrepancy between short-term and long-term effects of bone marrow-derived cell therapy in acute myocardial infarction: a systematic review and meta-analysis

Abstract Background Bone marrow-derived cell therapy has been used to treat acute myocardial infarction. However, the therapeutic efficacy of this approach remains controversial. Here, we performed a systematic review and meta-analysis to evaluate short-term and long-term effectiveness of bone marrow-derived therapy. Methods We searched eight databases (Ovid-Medline, Ovid-EMBASE, Cochrane Library, KoreaMed, KMBASE, KISS, RISS, and KisTi) up to December 2014. Demographic characteristics, clinical outcomes, and adverse events were analyzed. We identified 5534 potentially relevant studies; 405 were subjected to a full-text review. Forty-three studies with 2635 patients were included in this review. Results No safety issues related to cell injection were reported during follow-up. At 6 months, cell-injected patients showed modest improvements in left ventricular ejection fraction (LVEF) compared with the control group. However, there were no differences between groups at other time points. In the cardiac MRI analysis, there were no significant differences in infarct size reduction between groups. Interestingly, mortality tended to be reduced at the 3-year follow-up, and at the 5-year follow-up, cell injection significantly decreased all-cause mortality. Conclusions This meta-analysis demonstrated discrepancies between short-term LV functional improvement and long-term all-cause mortality. Future clinical trials should include long-term follow-up outcomes to validate the therapeutic efficacy of cell therapy

Dynamic changes of injured myocardium very early after acute myocardial infarction quantified using T1 mapping cardiovascular magnetic resonance technique

Background It has recently been suggested that myocardial oedema follows a bimodal pattern early post ST-segment elevation myocardial infarction (STEMI). Yet, water content, quantified using tissue desiccation, did not return to normal values unlike oedema quantified by cardiovascular magnetic resonance (CMR) imaging. We studied the temporal changes in the extent and intensity of injured myocardium using T1-mapping technique within the first week after STEMI. Methods A first group (n = 31) underwent 3 acute 3 T CMR scans (time-point (TP) and#60; 3 h, 24 h and 6 days), including cine, native shortened modified look-locker inversion recovery T1 mapping, T2* mapping and late gadolinium enhancement (LGE). A second group (n = 17) had a single scan at 24 h with an additional T2-weighted sequence to assess the difference in the extent of area-at-risk (AAR) compared to T1-mapping. Results The mean T1 relaxation time value within the AAR of the first group was reduced after 24 h (P and#60; 0.001 for TP1 vs.TP2) and subsequently increased at 6 days (P = 0.041 for TP2 vs.TP3). However, the extent of AAR quantified using T1-mapping did not follow the same course, and no change was detected between TP1andTP2 (P = 1.0) but was between TP2 andTP3 (P = 0.019). In the second group, the extent of AAR was significantly larger on T1-mapping compared to T2-weighted (42 ± 15% vs. 39 ± 15%, P = 0.025). No change in LGE was detected while microvascular obstruction and intra-myocardial haemorrhage peaked at different time points within the first week of reperfusion. Conclusion The intensity of oedema post-STEMI followed a bimodal pattern; while the extent of AAR did not track the same course. This discrepancy has implications for use of CMR in this context and may explain the previously reported disagreement between oedema quantified by imaging and tissue desiccation