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Background: Susceptibility-weighted imaging (SWI) and T1/T2 mapping can be used to detect reperfusion intramyocardial hemorrhage (IMH) in ST-segment elevation myocardial infarction (STEMI) patients. However, the sensitivity and accuracy of the SWI and T1/T2 mapping sequences were not systematically compared. The study aimed to evaluate image quality and diagnostic performance of SWI in patients with IMH, compared with T1/T2 mapping. Methods: A prospective study was conducted on consecutive acute STEMI patients who were recruited from January to July 2022. Within 2-6 days after reperfusion treatment, all patients underwent a 3T cardiac magnetic resonance (CMR) examination, including T2-weighted short-tau inversion recovery (T2W-STIR), T1/T2 mapping, and SWI. A total of 36 patients [age, 56.50±17.25 years; males, 83.33% (30/36)] were enrolled. The relative infarct-remote myocardium signal intensity ratio (SIinfarct-remote) and contrast-to-noise ratio (CNR) were calculated for each patient on T1/T2 mapping and SWI, and the difference between relative signal intensity-to-noise ratio (rSNR) in the IMH (rSNRIMH) was measured for IMH patients on T1/T2 mapping and SWI. SIinfarct-remote, CNR, and rSNRIMH were compared among the three sequences. Receiver operating characteristic (ROC) analyses were used to evaluate the diagnostic performance of three sequences by SIinfarct-remote and visual assessment. Results: A total of 26 (72.22%) patients had IMH. Quantitatively, the SIinfarct-remote of three sequences had excellent diagnostic performance for detecting IMH [SWI area under the curve (AUC) =1.000, 95% confidence interval (CI): 1.000-1.000 vs. T1 mapping AUC =0.954, 95% CI: 0.885-1.000 vs. T2 mapping AUC =0.985, 95% CI: 0.955-1.000; SWI vs. T1 mapping, P=0.300; SWI vs. T2 mapping, P=0.188; T1 mapping vs. T2 mapping, P=0.302). Qualitatively, three sequences had similar performance on detecting IMH (SWI AUC =0.895, 95% CI: 0.784-1.000; T1 mapping AUC =0.835, 95% CI: 0.711-0.958; and T2 mapping AUC =0.855, 95% CI: 0.735-0.974; SWI vs. T1 mapping, P=0.172; SWI vs. T2 mapping, P=0.317; T1 mapping vs. T2 mapping, P=0.710). The rSNRIMH was highest in T1 mapping, followed by T2 mapping and SWI, but SWI had the highest CNR. Conclusions: SWI, as well as T1/T2 mapping, is a feasible and accurate approach for clinical diagnosis of IMH with excellent performance.
ABSTRACT
Background: Intramyocardial hemorrhage (IMH) is a result of ischemia-reperfusion injury in ST-segment elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (PPCI). Despite patients with IMH show poorer prognoses, studies investigating predictors of IMH occurrence are scarce. This study firstly investigated the effectiveness of regulatory T cell (Treg), peak value of Creatine Kinase MB (pCKMB), high-sensitivity C-reactive protein (hsCRP), and left ventricular end-systolic diameter (LVESD) as predictors for IMH. Methods: In 182 STEMI patients received PPCI, predictors of IMH were analyzed by logistic regression analysis. The predictive ability of risk factors for IMH were determined by receiver operating characteristic curves, net reclassification improvement (NRI), integrated discrimination improvement (IDI) and C-index. Results: Overall, 80 patients (44.0%) developed IMH. All 4 biomarkers were independent predictors of IMH [odds ratio [OR] (95% confidence interval [CI]): 0.350 (0.202-0.606) for Treg, 1.004 (1.001-1.006) for pCKMB, 1.060 (1.022-1.100) for hsCRP, and 3.329 (1.346-8.236) for LVESD]. After propensity score matching (PSM), the biomarkers significantly predicted IMH with areas under the curve of 0.750 for Treg, 0.721 for pCKMB, 0.656 for hsCRP, 0.633 for LVESD, and 0.821 for the integrated 4-marker panel. The addition of integrated 4-marker panel to a baseline risk model had an incremental effect on the predictive value for IMH [NRI: 0.197 (0.039 to 0.356); IDI: 0.200 (0.142 to 0.259); C-index: 0.806 (0.744 to 0.869), all p < 0.05]. Conclusions: Treg individually or in combination with pCKMB, hsCRP, and LVESD can effectively predict the existence of IMH in STEMI patients received PPCI. Clinical Trial Registration: NCT03939338.
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Objective • To investigate the influence of smoking on acute myocardial injury and long-term prognosis in the patients with ST-segment elevation myocardial infraction (STEMI) by cardiac magnetic resonance (CMR). Methods • Three hundred and forty-nine STEMI patients were retrospectively selected from a prospective cohort from May 2012 to August 2017, and were followed up for at least 2 years. The primary endpoint was a composite of all-cause death, reinfarction and stroke. The secondary endpoint was heart failure rehospitalization. The patients were divided into smoker group and non-smoker group according to the baseline status of smoking which was recorded at admission. The difference in the incidence of endpoint events was further analyzed in combination with the presence or absence of intramyocardial hemorrhage (IMH) between the two groups. Results • There were 221 patients in the smoker group, accounting for 63.3% of the total sample. The average age of onset in smokers were 4.66 years earlier than nonsmokers. However, smokers showed a lower incidence of left ventricular thrombosis and lower levels of brain natriuretic peptide than non-smokers (P=0.023, P=0.000). There was no difference in the left ventricular ejection fraction between the two groups (P>0.05), but the smokers had a better endsystolic and end-diastolic volume index (P=0.019, P=0.007). Smokers and non-smokers had similar clinical outcomes of all-cause death, reinfarction and stroke (P>0.05). The incidence of heart failure rehospitalization in smokers was quite lower than that of the non-smokers, but this kind of protective effect disappeared after differences in baseline being adjusted (P=0.167). In the patients with IMH, smoking had a protective effect on primary endpoints (HR=0.266, P=0.008), but in the patients without IMH, smokers had a worse outcome of all-cause death and reinfarction than non-smokers (P=0.024). Conclusion • In patients with STEMI, smoking has no protective effect on long-term prognosis. When IMH appears in STEMI patients, smoking has a protective effect on all-cause death, reinfarction and stoke. However, in patients without IMH, smokers have a worse prognosis than non-smokers.
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BACKGROUND: Intramyocardial hemorrhage (IMH) and microvascular obstruction (MVO) are two major mechanisms of reperfusion injury of the left ventricle after acute ST-segment elevation myocardial infarction (STEMI). The aim of this study was to assess the impact of IMH and MVO on left ventricular (LV) cardiac mechanics using two-dimensional speckle-tracking echocardiography during the acute phase of STEMI and on LV functional recovery. METHODS: Eighty-one patients with STEMI who received primary reperfusion therapy were prospectively studied. Infarct segments were classified by cardiac magnetic resonance according to infarct transmurality and the presence or absence of IMH and/or MVO. Segmental systolic longitudinal strain, circumferential strain (CS), and radial strain were measured by two-dimensional speckle-tracking echocardiography. Adverse LV remodeling and major adverse cardiovascular events were assessed at 1 year. RESULTS: MVO without IMH was much less frequent in nontransmural infarct segments than in transmural infarct segments (6.0% vs 19.1%, P = .000), while IMH was present only in transmural infarct segments. In nontransmural infarct segments, MVO was not associated with any significant changes in strain (P > .5). In transmural infarct segments, there were no differences in all types of strain between segments without reperfusion injury and those with MVO alone (P > .20). IMH was evident in the midmyocardial layer within the infarct zone in 196 segments (46.1%). The presence of IMH in addition to MVO decreased CS significantly (P = .004), but not longitudinal and radial strain (P > .5). A receiver operating characteristic curve analysis with cross-validation by k-folding showed that the sensitivity and specificity of CS using a cutoff of >-11.66% to diagnose IMH were 78.00% and 79.45%, respectively (area under the curve = 0.86; P = .0001). At 1 year, patients with major adverse cardiovascular events and LV remodeling had significantly lower baseline measurements of all types of global strain (P < .05). CONCLUSIONS: In the acute phase of STEMI, reperfusion MVO and IMH injury have differential effects on cardiac mechanics. IMH preferentially affects CS, presumably related to its location in the midmyocardial layer.