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.
CONCLUSION: Cardiac magnetic resonance evaluation of pre-contrast T1 values revealed no difference between NSTEMI and STEMI patients in terms of tissue characterisation post-myocardial infarction. However, pre-contrast T1 of infarcted tissue is significantly correlated with regional diastolic circumferential strain rate.
PATIENTS AND METHODS: Fourteen patients with normal ejection fraction and 16 patients with reduced ejection fraction were compared with 20 healthy individuals. Phase-contrast MRI was used to assess intraventricular flow variables and speckle-tracking echocardiography to assess myocardial strain and left ventricular (LV) dyssynchrony. Infarct size was acquired using delayed-enhancement MRI.
RESULTS: The results obtained showed no significant differences in intraventricular flow variables between the healthy group and the patients with normal ejection fraction group, whereas considerable reductions in kinetic energy (KE) fluctuation index, E' (P<0.001) and vortex KE (P=0.003) were found in the patients with reduced ejection fraction group. In multivariate analysis, only vortex KE and infarct size were significantly related to LV ejection fraction (P<0.001); furthermore, vortex KE was correlated negatively with energy dissipation, energy dissipation index (r=-0.44, P=0.021).
CONCLUSION: This study highlights that flow energetic indices have limited applicability as early predictors of LV progressive dysfunction, whereas vortex KE could be an alternative to LV performance.
METHODS: We conducted a systematic review and meta-analysis of prospective observational studies that have investigated the relationship of door-to-balloon delay and clinical outcomes. The main outcomes include mortality and heart failure.
RESULTS: 32 studies involving 299 320 patients contained adequate data for quantitative reporting. Patients with ST-elevation MI who experienced longer (>90 min) door-to-balloon delay had a higher risk of short-term mortality (pooled OR 1.52, 95% CI 1.40 to 1.65) and medium-term to long-term mortality (pooled OR 1.53, 95% CI 1.13 to 2.06). A non-linear time-risk relation was observed (P=0.004 for non-linearity). The association between longer door-to-balloon delay and short-term mortality differed between those presented early and late after symptom onset (Cochran's Q 3.88, P value 0.049) with a stronger relationship among those with shorter prehospital delays.
CONCLUSION: Longer door-to-balloon delay in primary percutaneous coronary intervention for ST-elevation MI is related to higher risk of adverse outcomes. Prehospital delays modified this effect. The non-linearity of the time-risk relation might explain the lack of population effect despite an improved door-to-balloon time in the USA.
CLINICAL TRIAL REGISTRATION: PROSPERO (CRD42015026069).
DESIGN: This is a retrospective analysis of women with ST-elevation MI (STEMI) and non-STEMI (NSTEMI) from 18 hospitals across Malaysia using the Malaysian National Cardiovascular Database registry-acute coronary syndrome (NCVD-ACS).
PARTICIPANTS: Women patients diagnosed with acute MI from year 2006 to 2013 were identified and divided into young (age ≤ 45, n=292) and older women (age >45, n=5580).
PRIMARY OUTCOME MEASURE: Comparison of demographics, clinical characteristics and in-hospital management was performed between young and older women. In-hospital and 30-day all-cause mortality were examined.
RESULTS: Young women (mean age 39±4.68) made up 5% of women with MI and were predominantly of Malay ethnicities (53.8%). They have a higher tendency to present as STEMI compared with older women. Young women have significantly higher rates of family history of premature coronary artery disease (CAD) (20.5% vs 7.8% p<0.0001). The prevalence of risk factors, such as hypertension, diabetes and dyslipidaemia was high in both groups. The primary reperfusion strategy was thrombolysis with no significant differences observed in the choice of intervention for both groups. Other than aspirin, rates of prescriptions for evidence-based medications were similar with >80% prescribed statins and aspirin. The all-cause mortality rates of young women were lower for both in-hospital and 30 days, especially in those with STEMI with adjusted mortality ratio to the older group, was 1:9.84.
CONCLUSION: Young women with MI were over-represented by Malays and those with a family history of premature CAD. Preventive measures are needed to reduce cardiovascular risks in young women. Although in-hospital management was similar, short-term mortality outcomes favoured young compared with older women.