Browsing by Subject "Intramyocardial hemorrhage"
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Item Accurate Intramyocardial Hemorrhage Assessment with Fast, Free-running, Cardiac Quantitative Susceptibility Mapping(Radiological Society of North America, 2024) Huang, Yuheng; Guan, Xingmin; Zhang, Xinheng; Yoosefian, Ghazal; Ho, Hao; Huang, Li-Ting; Lin, Hsin-Yao; Anthony, Gregory; Lee, Hsu-Lei; Bi, Xiaoming; Han, Fei; Chan, Shing Fai; Vora, Keyur P.; Sharif, Behzad; Singh, Dhirendra P.; Youssef, Khalid; Li, Debiao; Han, Hui; Christodoulou, Anthony G.; Dharmakumar, Rohan; Yang, Hsin-Jung; Medicine, School of MedicinePurpose: To evaluate the performance of a high-dynamic-range quantitative susceptibility mapping (HDR-QSM) cardiac MRI technique to detect intramyocardial hemorrhage (IMH) and quantify iron content using phantom and canine models. Materials and Methods: A free-running whole-heart HDR-QSM technique for IMH assessment was developed and evaluated in calibrated iron phantoms and 14 IMH female canine models. IMH detection and iron content quantification performance of this technique was compared with the conventional iron imaging approaches, R2*(1/T2*) maps, using measurements from ex vivo imaging as the reference standard. Results: Phantom studies confirmed HDR-QSM’s accurate iron content quantification and artifact mitigation ability by revealing a strong linear relationship between iron concentration and QSM values (R2, 0.98). In in vivo studies, HDR-QSM showed significantly improved image quality and susceptibility homogeneity in nonaffected myocardium by alleviating motion and off-resonance artifacts (HDR-QSM vs R2*: coefficient of variation, 0.31 ± 0.16 [SD] vs 0.73 ± 0.36 [P < .001]; image quality score [five-point Likert scale:], 3.58 ± 0.75 vs 2.87 ± 0.51 [P < .001]). Comparison between in vivo susceptibility maps and ex vivo measurements showed higher performance of HDR-QSM compared with R2* mapping for IMH detection (area under the receiver operating characteristic curve, 0.96 vs 0.75; P < .001) and iron content quantification (R2, 0.71 vs 0.14). Conclusion: In a canine model of IMH, the fast and free-running cardiac QSM technique accurately detected IMH and quantified intramyocardial iron content of the entire heart within 5 minutes without requiring breath holding.Item Assessment of intramyocardial hemorrhage with dark-blood T2*-weighted cardiovascular magnetic resonance(Elsevier, 2021-07-15) Guan, Xingmin; Chen, Yinyin; Yang, Hsin‑Jung; Zhang, Xinheng; Ren, Daoyuan; Sykes, Jane; Butler, John; Han, Hui; Zeng, Mengsu; Prato, Frank S.; Dharmakumar, Rohan; Medicine, School of MedicineBackground: Intramyocardial hemorrhage (IMH) within myocardial infarction (MI) is associated with major adverse cardiovascular events. Bright-blood T2*-based cardiovascular magnetic resonance (CMR) has emerged as the reference standard for non-invasive IMH detection. Despite this, the dark-blood T2*-based CMR is becoming interchangeably used with bright-blood T2*-weighted CMR in both clinical and preclinical settings for IMH detection. To date however, the relative merits of dark-blood T2*-weighted with respect to bright-blood T2*-weighted CMR for IMH characterization has not been studied. We investigated the diagnostic capacity of dark-blood T2*-weighted CMR against bright-blood T2*-weighted CMR for IMH characterization in clinical and preclinical settings. Materials and methods: Hemorrhagic MI patients (n = 20) and canines (n = 11) were imaged in the acute and chronic phases at 1.5 and 3 T with dark- and bright-blood T2*-weighted CMR. Imaging characteristics (Relative signal-to-noise (SNR), Relative contrast-to-noise (CNR), IMH Extent) and diagnostic performance (sensitivity, specificity, accuracy, area-under-the-curve, and inter-observer variability) of dark-blood T2*-weighted CMR for IMH characterization were assessed relative to bright-blood T2*-weighted CMR. Results: At both clinical and preclinical settings, compared to bright-blood T2*-weighted CMR, dark-blood T2*-weighted images had significantly lower SNR, CNR and reduced IMH extent (all p < 0.05). Dark-blood T2*-weighted CMR also demonstrated weaker sensitivity, specificity, accuracy, and inter-observer variability compared to bright-blood T2*-weighted CMR (all p < 0.05). These observations were consistent across infarct age and imaging field strengths. Conclusion: While IMH can be visible on dark-blood T2*-weighted CMR, the overall conspicuity of IMH is significantly reduced compared to that observed in bright-blood T2*-weighted images, across infarct age in clinical and preclinical settings at 1.5 and 3 T. Hence, bright-blood T2*-weighted CMR would be preferable for clinical use since dark-blood T2*-weighted CMR carries the potential to misclassify hemorrhagic MIs as non-hemorrhagic MIs.Item Chronic heart failure following hemorrhagic myocardial infarction: mechanism, treatment and outlook(Shared Science Publishers, 2023-02-13) Chan, Shing Fai; Vora, Keyur; Dharmakumar, Rohan; Medicine, School of MedicineMyocardial infarction (MI), the blockage of arterial blood supply of the heart, is among the most common causes of death worldwide. Even when patients receive immediate treatment by re-opening blocked arteries, they often develop chronic heart failure (CHF) in the aftermath of MI events. Yet, the factors that contribute to the development of MI-associated CHF are poorly understood. In our recent study (Nat Commun 13:6394), we link intramyocardial hemorrhage, an injury which can occur during reperfusion of areas affected by MI, to an increased risk of CHF. Mechanistically, our data suggest that an iron-induced adverse cascade of events after hemorrhagic MI drives fatty degeneration of infarcted tissue, which ultimately contributes to negative cardiac remodeling. In this Microreview, we discuss the implications of our findings regarding the molecular mechanism, more targeted treatment options as well as perspectives in the clinical care of CHF after hemorrhagic MI.Item Impact of Intramyocardial Hemorrhage on Clinical Outcomes in ST-Elevation Myocardial Infarction: A Systematic Review and Meta-analysis(Elsevier, 2022-08-26) Vyas, Rohit; Changal, Khalid H.; Bhuta, Sapan; Pasadyn, Vanessa; Katterle, Konrad; Niedoba, Matthew J.; Vora, Keyur; Dharmakumar, Rohan; Gupta, Rajesh; Medicine, School of MedicineBackground: Intramyocardial hemorrhage (IMH) occurs after ST-elevation myocardial infarction (STEMI) and has been documented using cardiac magnetic resonance imaging. The prevalence and prognostic significance of IMH are not well described, and the small sample size has limited prior studies. Methods: We performed a comprehensive literature search of multiple databases to identify studies that compared outcomes in STEMI patients with or without IMH. The outcomes studied were major adverse cardiovascular events (MACE), infarct size, thrombolysis in myocardial infarction (TIMI) flow after percutaneous coronary intervention (PCI), left ventricular end-diastolic volume (LVEDV), left ventricular ejection fraction (LVEF), and mortality. Odds ratios (ORs) and standardized mean differences with corresponding 95% CIs were calculated using a random effects model. Results: Eighteen studies, including 2824 patients who experienced STEMI (1078 with IMH and 1746 without IMH), were included. The average prevalence of IMH was 39%. There is a significant association between IMH and subsequent MACE (OR, 2.63; 95% CI, 1.79-3.86; P < .00001), as well as IMH and TIMI grade <3 after PCI (OR, 1.75; 95% CI, 1.14-2.68; P = .05). We also found a significant association between IMH and the use of glycoprotein IIb/IIIa inhibitors (OR, 2.34; 95% CI, 1.42-3.85; P = .0008). IMH has a positive association with infarct size (standardized mean difference, 2.19; 95% CI, 1.53-2.86; P < .00001) and LVEDV (standardized mean difference, 0.7; 95% CI, 0.41-0.99; P < .00001) and a negative association with LVEF (standardized mean difference, -0.89; 95% CI, -1.15 to -0.63; P = .01). Predictors of IMH include male sex, smoking, and left anterior descending infarct. Conclusions: Intramyocardial hemorrhage is prevalent in approximately 40% of patients who experience STEMI. IMH is a significant predictor of MACE and is associated with larger infarct size, higher LVEDV, and lower LVEF after STEMI.Item Reperfused Myocardial Infarction: The Road to CCS Classification of Acute MI and Beyond(Elsevier, 2025) Dharmakumar, Rohan; Kloner, Robert A.; Fishbein, Michael; Heusch, Gerd; Vora, Keyur P.; Gropler, Robert; Henry, Timothy; Shing-Chan, Fai; Singh, Dhirendra; Jambunathan, Nithya; Subramanian, Ramesh; Kreutz, Rolf P.; Reed, Grant W.; Kovacs, Richard J.; Fry, Edward; Kalra, Ankur; Kumar, Andreas; Raman, Subha V.; Medicine, School of MedicineThe Canadian Cardiovascular Society recently put forth a new classification of acute reperfused myocardial infarction (MI) based on stages of myocardial injury. Backed by more than 5 decades of intense investigation in the field, the key message of this new classification is that not all MIs are the same and that the type and extent of myocardial injury should be considered in diagnosing and treating MI. We review the literature with the goal of highlighting the progressive advances that enabled the synthesis of the Canadian Cardiovascular Society classification into 4 distinct stages of tissue injury. We emphasize the major breakthroughs from insights gained from experimental, translational, and clinical studies to date. We also identify current gaps in knowledge and critical research directions that need to be pursued to improve patient care and reduce post-MI complications such as chronic heart failure and malignant arrhythmias, whose risk is linked to stage and extent of myocardial injury.