Published online Dec 26, 2015. doi: 10.4330/wjc.v7.i12.948
Peer-review started: May 30, 2015
First decision: August 25, 2015
Revised: September 22, 2015
Accepted: October 12, 2015
Article in press: October 13, 2015
Published online: December 26, 2015
Processing time: 210 Days and 23.5 Hours
AIM: To conduct a systematic review relating myocardial strain assessed by different imaging modalities for prognostication following ST-elevation myocardial infarction (STEMI).
METHODS: An online literature search was performed in PubMed and OVID® electronic databases to identify any studies that assessed global myocardial strain parameters using speckle-tracking echocardiography (STE) and/or cardiac magnetic resonance imaging (CMR) techniques [either myocardial tagging or feature tracking (FT) software] in an acute STEMI cohort (days 0-14 post-event) to predict prognosis [either development of major adverse cardiac events (MACE)] or adverse left ventricular (LV) remodelling at follow-up (≥ 6 mo for MACE, ≥ 3 mo for remodelling). Search was restricted to studies within the last 20 years. All studies that matched the pre-defined search criteria were reviewed and their results interpreted. Due to considerable heterogeneity between studies, meta-analysis was not performed.
RESULTS: A total of seven studies (n = 7) were identified that matched the search criteria. All studies used STE to evaluate strain parameters - five (n = 5) assessed global longitudinal strain (GLS) (n = 5), one assessed GLS rate (GLS-R) (n = 1) and one assessed both (n = 1). Three studies showed that GLS independently predicted the development of adverse LV remodelling by multivariate analysis - odds ratio between 1.19 (CI: 1.04-1.37, P < 0.05) and 10 (CI: 6.7-14, P < 0.001) depending on the study. Four studies showed that GLS predicted the development of MACE - hazard ratio (HR) between 1.1 (CI: 1-1.1, P = 0.006) and 2.34 (1.10-4.97, P < 0.05). One paper found that GLS-R could significantly predict MACE - HR 18 (10-35, P < 0.001) - whilst another showed it did not. GLS < -10.85% had sensitivity/specificity of 89.7%/91% respectively for predicting the development of remodelling whilst GLS < -13% could predict the development of MACE with sensitivity/specificity of 100%/89% respectively. No suitable studies were identified that assessed global strain by CMR tagging or FT techniques.
CONCLUSION: GLS measured acutely post-STEMI by STE is a predictor of poor prognosis. Further research is needed to show that this is true for CMR-based techniques.
Core tip: Global myocardial strain is an objective measure of cardiac function. It can be assessed using post-processing analysis on different imaging modalities such as speckle-tracking echocardiography (STE) and cardiac magnetic resonance imaging (CMR) - tagging and feature tracking. We performed a systematic review that showed global longitudinal strain (GLS) measured acutely by STE following ST-elevation myocardial infarction (STEMI) predicted clinical outcomes and adverse left ventricular remodelling, a surrogate marker of poor prognosis. No relevant studies were found for CMR techniques. GLS may refine risk stratification in the STEMI population but further work is needed to support this.