METHODS: Revascularised acute myocardial infarction patients with normal left ventricular (LV) systolic function on TTE were assessed by 1.5T CMR. Acute regional diastolic wall motion abnormalities, global diastolic function measurements, acute segmental damage fraction with LGE and mean segmental pre-contrast T1 values were assessed on matching short axis slices.

RESULTS: Forty-four patients were analysed. Mean LVEF was 62.1±9.4%. No difference between NSTEMI (22/44) and STEMI in mean pre-contrast T1 values of infarcted (1025.0±109.2 vs 1011.0±81.6ms, p=0.70), adjacent (948.3±45.3 vs 941.1±46.6ms, p=0.70) and remote (888.8±52.8 vs 881.2±54.5ms, p=0.66) segments was detected. There was no correlation between pre-contrast T1 of infarcted segments with global diastolic dysfunction (E/A, r(2)=0.216, p=0.06; S/D, r(2)=0.243, p=0.053; E/E', r(2)=0.240, p=0.072), but there was significantly positive, moderate correlation with circumferential diastolic strain rate, (r(2)=0.579, p<0.01) with excellent agreement and reproducibility.

CASE SUMMARY: We report a case of late presenting MI, where on initial echocardiogram had what was thought to be an intraventricular clot. However, upon further evaluation, the patient actually had an intramyocardial haematoma, with the supporting echocardiographic features to distinguish it from typical left ventricular (LV) clot. While this prevented the patient from receiving otherwise unnecessary anticoagulation, this diagnosis also put him at a much higher risk of mortality. Despite exhaustive medical and supportive management, death as consequence of pump failure occurred after 2 weeks.

PATIENTS AND METHODS: This was a single-center cohort study. 46 patients with TACI were enrolled and followed up for 30 days, discharged, or death; whichever earlier. The National Institutes of Health Stroke Scale (NIHSS) was performed daily by investigators who are NIHSS certified and radiological findings were confirmed by a certified radiologist. Neurological deterioration was defined by a drop in NIHSS by 2 points or Glasgow Coma Scale (GCS) by 1 point. Clinical, laboratory and radiological variables were evaluated. Significant predictive variables were given a score based on its co-efficient values in multivariate analysis.

METHOD: We will search PubMed/MEDLINE, EMBASE, ClinicalTrials.gov, WHO International Clinical Trials Registry, CINAHL Database, and the Cochrane Library using a predefined search strategy. Other sources of literature will include proceedings from the European Society of Cardiology, the American College of Cardiology, the American Heart Association, the EUROPCR, and the ProQuest Dissertations and Theses Database. We will include data from observational studies (case-control and cohort study design) and randomized control trials (that have investigated the relationship of D2B time and clinical outcome(s) in an adult (older than 18) STEMI population). Mortality (cardiac related and all-cause) and incidence heart failure (HF) have been prioritized as the primary outcomes. All eligible studies will be assessed for risk of bias using the Risk Of Bias in Non-randomized Studies - of Interventions tool. The Grading of Recommendations, Assessment, and Evaluation (GRADE) framework will be used to report the quality of evidence and strength of recommendations. We will proceed to analyze the data quantitatively if the pre-specified conditions are satisfied.

DISCUSSION: Recent discussion on the negative findings of improved D2B delay over time being unrelated to better STEMI outcomes at the population level has reminded us of an important knowledge gap we have on this domain. This systematic review will serve to address some of these key questions not previously examined. Answers to these questions could clarify the controversies and offer empirical support for or against the suggested hypotheses.