Normal CMR Research Articles

Myocardial strain analysis by feature tracking cardiac magnetic resonance to identify subclinical cardiac dysfunction in patients with MINOCA

BackgroundTo investigate whether feature tracking cardiac magnetic resonance (FT-CMR) can identify subclinical myocardial dysfunction in patients with myocardial infarction with non-obstructed coronary arteries (MINOCA).MethodsClinical data and CMR images of MINOCA patients (N = 46) and control individuals (N = 12) were compared. The infarct and edema volume to total myocardium, peak global longitudinal strain (GLS), global longitudinal strain rate (GLSR), peak global circumferential strain (GCS), global circumferential strain rate, peak global radial strain, and global radial strain rate were measured. Diagnostic performances of strain parameters for MINOCA were evaluated by logistic regression and receiver operating characteristics analysis.ResultsExcept smoking history, the two groups showed no significant differences in cardiovascular risk factors and traditional heart function. GLS (-14.67 ± 1.96% vs. -19.19 ± 2.05%), GLSR (-0.94 ± 0.16 S− 1 vs. -1.23 ± 0.14 S− 1) and GCS (-17.59 ± 1.81% vs. -19.22 ± 1.76%) were impaired in MINOCA patients compared with the control group. MINOCA patients with normal routine CMR showed abnormalities in GLS (-16.23 ± 1.16%) and GLSR (-1.04 ± 0.16 S− 1). GLS and GLSR were predictive for MINOCA diagnosis (P = 0.002 vs. P = 0.033). GLS correlated strongly with myocardial infarction and edema. The optimal diagnostic threshold for GLS was <-16.9% for MINOCA diagnosis (sensitivity 87.1%, specificity 92.9%); the area under the receiver operating characteristic curve was 0.968.ConclusionsMyocardial strain by FT-CMR may effectively detect early myocardial impairment with MINOCA, especially in patients with normal routine MRI.

A fully automated stress regional strain score as a prognostic marker of cardiovascular events in patients with normal CMR.

A fully automated stress regional strain score as a prognostic marker of cardiovascular events in patients with normal CMR.

Kiosk 1R-TA-07 - Microvascular Dysfunction Assessed by Quantitative Perfusion CMR Is a Common Condition in Patients with MINOCA (myocardial Infarction with Non-obstructive Coronary Arteries) and Otherwise Normal CMR

Kiosk 1R-TA-07 - Microvascular Dysfunction Assessed by Quantitative Perfusion CMR Is a Common Condition in Patients with MINOCA (myocardial Infarction with Non-obstructive Coronary Arteries) and Otherwise Normal CMR

Kiosk 10R-TB-01 - Fully Automated Assessment of Global Longitudinal Strain by Machine Learning Predicts Death in Patients with a Normal Stress CMR

Kiosk 10R-TB-01 - Fully Automated Assessment of Global Longitudinal Strain by Machine Learning Predicts Death in Patients with a Normal Stress CMR

Reduced stress perfusion in myocardial infarction with nonobstructive coronary arteries

Myocardial infarction with nonobstructive coronary arteries (MINOCA) has several possible underlying causes, including coronary microvascular dysfunction (CMD). Early cardiovascular magnetic resonance imaging (CMR) is recommended, however cannot provide a diagnosis in 25% of cases. Quantitative stress CMR perfusion mapping can identify CMD, however it is unknown if CMD is present during long-term follow-up of MINOCA patients. Therefore, this study aimed to evaluate presence of CMD during long-term follow-up in MINOCA patients with an initial normal CMR scan. MINOCA patients from the second Stockholm myocardial infarction with normal coronaries study (SMINC-2), with a normal CMR scan at median 3 days after hospitalization were investigated with comprehensive CMR including stress perfusion mapping a median of 5 years after the index event, together with age- and sex-matched volunteers without symptomatic ischemic heart disease. Cardiovascular risk factors, medication and symptoms of myocardial ischemia measured by the Seattle Angina Questionnaire 7 (SAQ-7), were registered. In total, 15 patients with MINOCA and an initial normal CMR scan (59 ± 7 years old, 60% female), and 15 age- and sex-matched volunteers, underwent CMR. Patients with MINOCA and an initial normal CMR scan had lower global stress perfusion compared to volunteers (2.83 ± 1.8 vs 3.53 ± 0.7 ml/min/g, p = 0.02). There were no differences in other CMR parameters, hemodynamic parameters, or cardiovascular risk factors, except for more frequent use of statins in the MINOCA patient group compared to volunteers. In conclusion, global stress perfusion is lower in MINOCA patients during follow-up, compared to age- and sex-matched volunteers, suggesting that CMD may be a possible pathophysiological mechanism in MINOCA.Clinical Trial Registration: Clinicaltrials.gov identifier NCT02318498. Registered 2014-12-17.

Ai-based fully automated left atrioventricular coupling index as a prognostic marker in patients undergoing stress-CMR

Abstract Background The left atrioventricular coupling index (LACI) is a strong and independent predictor of heart failure (HF) in individuals without clinical cardiovascular disease. Its prognostic value is not established in patients with cardiovascular disease. Purpose To determine in patients undergoing stress CMR whether fully automated artificial intelligence-based LACI can provide incremental prognostic value to predict HF. Methods Between 2016 and 2018, we conducted a longitudinal study including all consecutive patients with abnormal (inducible ischemia or late gadolinium enhancement (LGE)) vasodilator stress CMR. Control subjects with normal stress CMR were selected using propensity score-matching. LACI was defined as the ratio of LA to LV end-diastolic volumes. The primary outcome included hospitalization for acute HF or cardiovascular death. Cox regression was used to evaluate the association of LACI with the primary outcome after adjustment for traditional risk factors. Results In 2,134 patients [65±12 years, 77% men, 1:1 matched patients (1,067 with normal and 1,067 with abnormal CMR)], LACI was positively associated with the primary outcome (median follow-up 5.2 (4.8-5.5) years) before and after adjustment for risk factors in the overall propensity-matched population (adjusted hazard ratio [HR], 1.18 [95%CI, 1.13-1.24] per 0.1% increment), patients with abnormal (adjusted HR, 1.22 [95%CI, 1.14-1.30] per 0.1% increment), and normal CMR (adjusted HR, 1.12 [95%CI, 1.05-1.20] per 0.1% increment; all p&amp;lt;0.001). After adjustment, a higher LACI of ≥25% showed the greatest improvement in model discrimination and reclassification over and above traditional risk factors and stress CMR findings (C-statistic improvement: 0.16; NRI=0.388; IDI=0.153, all p&amp;lt;0.001; LR-test p&amp;lt;0.001). Conclusion LACI is independently associated with hospitalization for HF and cardiovascular death in patients undergoing stress CMR, with an incremental prognostic value over traditional risk factors including inducible ischemia and LGE.LACI measurement method using CMRKaplan-Meier curves by LACI value

Predictors for and the role of abnormal mapping values at cardiac magnetic resonance in myocardial infarction with non-obstructive coronary arteries

Abstract Background Cardiovascular magnetic resonance (CMR) plays a crucial role in the diagnostic approach of Myocardial infarction with non-obstructive coronary arteries (MINOCA), as a result of its ability to perform myocardial tissue characterization using mapping sequences. Purpose To analyze clinical and prognostic differences in MINOCA patients with and without abnormal mapping values when early CMR is performed. Methods We assessed all MINOCA cases from January 2017 to October 2021 in our Center. MINOCA was defined according to current European guidelines criteria. Acute myocarditis, Tako-tsubo syndromes and cardiomyopathies were excluded. CMR protocol included cine images, T1 and T2 mapping and late gadolinium enhancement (LGE). Abnormal mapping was considered as the presence of prolonged native T1 and T2 mapping with a specific pattern suggestive of ischemic myocardial injury. The receiver operating characteristics curve (ROC) for the detection of abnormal mapping was derivate. Multivariate logistic regression analysis was used to determine predictors of abnormal mapping. The primary outcome of major adverse cardiovascular events (MACE) in patients with and without abnormal mapping was evaluated. Results The final cohort included 198 MINOCA, 161 (81.3%) of which constituted the abnormal mapping group (M+) while the remaining 37 consisted of MINOCA without either abnormal mapping values or presence of late gadolinium enhancement (normal CMR findings, m-). The mean time delay between acute clinical presentation and CMR was 4.8 ± 1.5 days. Among the M+ group, patients were older and presented familiarity for cardiovascular disease and hypercholesterolemia more frequently compared to the m- group. At admission, the M+ group more frequently presented ST segment alterations, wall motion abnormalities (WMA) and greater left ventricular (LV) volumes, compared to the m- ones. Furthermore, the M+ group exhibit greater peak high sensitivity-Troponin I (hs-TnI) values. The ROC curve for the detection of abnormal mapping showed that peak Tn values had an excellent area under the curve (AUC) of 0.935 (95%CI 0.902-0.968), p&amp;lt;0.001. At multivariable analyses, adjusted for confounding factors, the strongest predictor of abnormal mapping was the peak hs-TnI values (OR 1.02, 95% CI 1.01-1.03, p&amp;lt;0.001). Finally, MINOCA M+ had more MACE compared to MINOCA m- (16.8% vs 2.7%, p&amp;lt;0.001) at a mean follow up time of 33.7 ± 12.0 months. Conclusion Among selected MINOCA, abnormal mapping values when early CMR is performed identify a subgroup of patients with worse clinical presentation and outcome. Some baseline characteristics (such as ST alterations, WMA and LV volumes) may support the detection of abnormal mapping. Overall, peak hs-TnI values have an excellent diagnostic performance to predict abnormal mapping values and could be useful in identifying high-risk MINOCA and the consequent need for a CMR evaluation.

Abstract 14282: Electrocardiography Rules out Myocardial Abnormalities on Cardiac Magnetic Resonance Imaging in Post-Hospitalized COVID-19 Patients: A Multicenter Observational Study

Introduction: The diagnostic performance of EKG in ruling out myocardial abnormalities following COVID-19 is unclear. Aim: To assess the ability of EKG to exclude cardiac abnormalities on cardiac magnetic resonance imaging (CMR) in post-hospitalised COVID-19 patients. Methods: Post-hospitalized patients (n=212) &amp; comorbidities matched controls (n=38) underwent CMR and 12-lead EKG. EKG assessments included depolarization &amp; repolarization abnormalities [ QTc , corrected QT dispersion ( QTc disp ), JT ( JTc ) &amp; T peak-end ( cTPe ) intervals]. CMR abnormalities were defined as reduced left ventricular ejection fraction (LVEF), high T1 &amp; T2 Z scores and high extracellular volume and pathological late gadolinium enhancement. Results: At 5.6 months post-discharge, patients had a higher burden of EKG abnormalities vs controls (72.2% vs 42.1%, p=0.001 ) (Figure A) . CMR abnormalities were comparable despite patients having lower LVEF. Abnormal EKG findings and prolonged repolarization were more common in patients with CMR abnormalities vs patients with normal CMR and controls ( Figure A &amp; B ). Area-under-the-receiver-operating curve (AUROC) of routine EKG abnormalities to discriminate abnormal CMR was 0.56 (95% CI 0.47-0.65), p=0.185. Inclusion of JTc &amp; QTc disp improved the AUROC to 0.64 (95% CI 0.55-0.74), p=0.002. Inclusion of JTc ≥340ms &amp; QTc disp ≥40ms improved the sensitivity from 81.6% to 99.9% with higher negative predictive value (84.7% to 99.9%) ( Figure A ). Conclusions: Post-hospitalized COVID-19 patients have more EKG abnormalities than comorbidities-matched controls. A normal EKG with normal repolarization is effective in ruling out significant CMR abnormalities.

Cardiac magnetic resonance in suspected MINOCA patients, clinical and imaging profile, diagnostic performance and 1 year clinical follow up

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance (CMR) is fundamental at the evaluation of patients with differential diagnosis of myocardial infarction with non-obstructive coronary arteries (MINOCA) due to its tissue characterization potential to exclude non-ischaemic causes such as myocarditis and Takotsubo syndrome and better stratify ischaemic disease in acute and chronic disease. Purpose To describe the clinical profile, cardiac magnetic resonance findings, final clinical and CMR diagnosis and clinical 1-year follow-up in patients with a working diagnosis of MINOCA evaluated with a CMR. Methods All patients who underwent a CMR for suspected MINOCA during a period of 1 year from June 2021 to June 2022 were retrospectively evaluated, past medical history, clinical characteristics, CMR reports and 1 year follow up were obtained. Myocarditis was defined by modified Lake Louise criteria. Patients were stratified following CMR diagnosis, accurate CMR diagnosis was considered when matched clinical final diagnosis. Results A total of 107 patients were evaluated with a CMR for a suspected MINOCA from June 2021 to June 2022, of whom CMR classified 51 (47.7%) as myocarditis, 11 (10.3%) as Takotsubo syndromes, 13 (12.2%) as acute ischaemic etiology, 3 (2.8%) as chronic ischaemic etiology, 24 (22.4%) as normal CMR and 5 (4.7%) had other diagnoses (cardiomyopathies and type II myocardial infarctions). Myocarditis patients were younger and more frequently males, ischaemic etiologies were older, had more comorbidities and were more frequently males, Takotsubo syndromes were more frequently females and were frequently hypertense. (Table 1) The final clinical diagnosis corresponded to the diagnosis provided by CMR in 92.2% of myocarditis, 100% of Takotsubo syndromes, 84.6% in acute ischaemic etiologies and 100% of chronic ischaemic etiologies. Patients with a normal CMR or other diagnosis had significantly lower correspondence between final and CMR diagnosis, in this setting CMR was still useful to rule out ischaemic etiology, myocarditis and Takotsubo syndrome. During follow-up there were no clinical differences between groups in terms of deaths, readmissions myocardial infarction and visits for recurrent chest pain. Patients with myocarditis CMR diagnosis were more likely to be followed up with CMR than other groups. (Table 2). Conclusions The final diagnosis of the patient studied for suspected MINOCA was given or facilitated by CMR in most cases, being of clinical use in the diagnostic and the follow up strategy of patients.

Diagnostic and Prognostic Value of Stress Cardiovascular Magnetic Resonance Imaging in Patients With Known or Suspected Coronary Artery Disease

The clinical utility of stress cardiovascular magnetic resonance imaging (CMR) in stable chest pain is still debated, and the low-risk period for adverse cardiovascular (CV) events after a negative test result is unknown. To provide contemporary quantitative data synthesis of the diagnostic accuracy and prognostic value of stress CMR in stable chest pain. PubMed and Embase databases, the Cochrane Database of Systematic Reviews, PROSPERO, and the ClinicalTrials.gov registry were searched for potentially relevant articles from January 1, 2000, through December 31, 2021. Selected studies evaluated CMR and reported estimates of diagnostic accuracy and/or raw data of adverse CV events for participants with either positive or negative stress CMR results. Prespecified combinations of keywords related to the diagnostic accuracy and prognostic value of stress CMR were used. A total of 3144 records were evaluated for title and abstract; of those, 235 articles were included in the full-text assessment of eligibility. After exclusions, 64 studies (74 470 total patients) published from October 29, 2002, through October 19, 2021, were included. This systematic review and meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Diagnostic odds ratios (DORs), sensitivity, specificity, area under the receiver operating characteristic curve (AUROC), odds ratio (OR), and annualized event rate (AER) for all-cause death, CV death, and major adverse cardiovascular events (MACEs) defined as the composite of myocardial infarction and CV death. A total of 33 diagnostic studies pooling 7814 individuals and 31 prognostic studies pooling 67 080 individuals (mean [SD] follow-up, 3.5 [2.1] years; range, 0.9-8.8 years; 381 357 person-years) were identified. Stress CMR yielded a DOR of 26.4 (95% CI, 10.6-65.9), a sensitivity of 81% (95% CI, 68%-89%), a specificity of 86% (95% CI, 75%-93%), and an AUROC of 0.84 (95% CI, 0.77-0.89) for the detection of functionally obstructive coronary artery disease. In the subgroup analysis, stress CMR yielded higher diagnostic accuracy in the setting of suspected coronary artery disease (DOR, 53.4; 95% CI, 27.7-103.0) or when using 3-T imaging (DOR, 33.2; 95% CI, 19.9-55.4). The presence of stress-inducible ischemia was associated with higher all-cause mortality (OR, 1.97; 95% CI, 1.69-2.31), CV mortality (OR, 6.40; 95% CI, 4.48-9.14), and MACEs (OR, 5.33; 95% CI, 4.04-7.04). The presence of late gadolinium enhancement (LGE) was associated with higher all-cause mortality (OR, 2.22; 95% CI, 1.99-2.47), CV mortality (OR, 6.03; 95% CI, 2.76-13.13), and increased risk of MACEs (OR, 5.42; 95% CI, 3.42-8.60). After a negative test result, pooled AERs for CV death were less than 1.0%. In this study, stress CMR yielded high diagnostic accuracy and delivered robust prognostication, particularly when 3-T scanners were used. While inducible myocardial ischemia and LGE were associated with higher mortality and risk of MACEs, normal stress CMR results were associated with a lower risk of MACEs for at least 3.5 years.

AI-based fully automated left atrioventricular coupling index as a prognostic marker in patients undergoing stress-CMR

The left atrioventricular coupling index (LACI) is a strong and independent predictor of heart failure (HF) in individuals without clinical cardiovascular disease. To determine in patients undergoing stress CMR whether fully automated artificial intelligence-based LACI can provide incremental prognostic value to predict HF. Between 2016 and 2018, we conducted a study including all consecutive patients with abnormal vasodilator stress CMR [inducible ischemia or late gadolinium enhancement (LGE)]. Control subjects with normal CMR were selected using propensity score-matching. LACI was defined as the ratio of LA to LV end-diastolic volumes. The primary outcome included hospitalization for acute HF or cardiovascular death using Cox regression. In 2662 patients [65 ± 12 years, 68% men, 1:1 matched patients (1331 with normal and 1331 with abnormal CMR)], LACI was positively associated with the primary outcome [median follow-up 5.2 (4.8–5.5) years] before and after adjustment for risk factors in the overall propensity-matched population [adjusted hazard ratio (HR), 5.94 (95%CI, 3.74–9.45) per 0.1% increment], patients with abnormal [adjusted HR, 6.38 (95%CI, 3.77–10.8) per 0.1% increment], and normal CMR [adjusted HR, 6.15 (95%CI, 2.97–12.7) per 0.1% increment; all P < 0.001]. After adjustment, a higher LACI of ≥ 25% showed the greatest improvement in model discrimination and reclassification over and above traditional risk factors and stress CMR findings (C-statistic improvement: 0.15; NRI = 0.705; IDI = 0.398, all P < 0.001; LR-test P < 0.001). LACI is independently associated with hospitalization for HF and cardiovascular death in patients undergoing stress CMR, with an incremental prognostic value over traditional risk factors including inducible ischemia and LGE (Fig. 1).

Utility of cardiovascular magnetic resonance in patients with stable troponin elevation.

Cardiovascular magnetic resonance (CMR) imaging has a potential role in the evaluation of symptomatic patients with stable troponin elevation; however, its utility remains unexplored. We sought to determine the incremental diagnostic value of CMR in this unique cohort and assess the long-term clinical outcomes. Two hundred twenty-five consecutive patients presenting with cardiac chest pain/dyspnoea, stable troponin elevation, and undergoing CMR assessment were identified retrospectively from registry database. The study cohort was prospectively followed for major adverse cardiac events (MACEs) (defined as composite of all-cause mortality and cardiovascular readmissions). The primary outcome measure was the diagnostic utility of CMR, i.e. percentage of patients for whom CMR identified the cause of stable troponin elevation. Secondary outcome measures included the incremental value of CMR and occurrence of MACE. CMR was able to identify the cause for stable troponin elevation in 160 (71%) patients. A normal CMR was identified in 17% and an inconclusive CMR in 12% of the patients. CMR changed the referral diagnosis in 59 (26%) patients. Utilizing a baseline prediction model (pre-CMR referral diagnosis), the net reclassification index was 0.11 and integrated discriminatory improvement index measured 0.33 following CMR. Over a median follow-up of 4.3 years (interquartile range 2.8-6.3), 72 (32%) patients experienced MACE. CMR identified a cause for stable troponin elevation in 7 of 10 cases, and a new diagnosis was evident in 1 of 4 cases. CMR improved the net reclassification of patients with stable troponin elevation.

Lower stress perfusion in patients with myocardial infarction with non-obstructive coronary arteries compared to controls in long-term follow-up with quantitative perfusion mapping

Abstract Introduction Myocardial infarction with non-obstructive coronary arteries (MINOCA) constitutes a heterogenous condition with different coronary, cardiac and non-cardiac etiologies. Cardiovascular magnetic resonance imaging (CMR) has emerged as an important diagnostic tool in recent years and is now recommended in patients with MINOCA as a working diagnosis. However, despite early CMR following admission for MINOCA, no cause can be found in around 25% of all patients. A pathophysiological mechanism may be diffuse global coronary microvascular dysfunction (CMD) which has emerged as an important cause of myocardial ischemia. Quantitative adenosine stress CMR perfusion mapping allows for absolute quantification of myocardial perfusion, reflecting CMD in the absence of obstructive coronary disease in MINOCA patients. Purpose To study the presence of CMD in MINOCA patients with an initial normal CMR scan compared to healthy controls. Methods Patients from the multicenter myocardial infarction in our city with normal Coronaries 2 (SMINC-2) study, with a normal CMR scan 2–4 days after hospitalization, and healthy age- and sex-matched controls underwent stress perfusion at 1.5T (MAGNETOM Aera). Native rest T1 and T2 short-axis maps were acquired. Quantitative perfusion maps were acquired during adenosine stress (140 micrograms/kg/min) and at rest following an intravenous contrast bolus (0.05 mmol/kg of gadoteric acid, Gd-DOTA). Post contrast T1 maps were acquired after intravenous contrast (total dose 0.2 mmol/kg) rendering extracellular volume (ECV) maps. Global native T1, T2, ECV and rest and stress perfusion values were acquired by averaging segmental values per patient. Myocardial perfusion reserve (MPR) was calculated as perfusion in stress divided by rest. Values were presented as mean±standard deviation and compared with the independent t-test in normally distributed data, and with the Mann-Whitney U test in non-normally distributed data. Clinical data regarding cardiovascular risk factors, smoking and medications were presented as numbers (percentages) and compared with Fisher's exact test. Rate pressure product (RPP) was calculated as systolic blood pressure multiplied by heart rate in rest and stress. Results In total, 15 patients (59±16 years old, 60% female), and 15 healthy age- and sex-matched controls, were included. There was a trend towards higher incidence of hypertension in patients compared to controls, however no difference in other risk factors (Table 1). Compared to controls, MINOCA patients had lower perfusion in stress (Figure 1). There was no difference in global native T1, T2, ECV, rest perfusion, MPR or hemodynamic parameters between the MINOCA patients and the controls (p&amp;gt;0.05 for all, Table 1). Conclusions Myocardial stress perfusion is lower in MINOCA patients with a normal initial CMR scan compared to age- and sex-matched controls suggesting CMD as a possible pathophysiological mechanism in MINOCA. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Swedish Heart and Lung Foundation

The challenging management of cardiac involvement in systemic sarcoidosis

A 34 year-old young man came to our attention after an occasional finding of complete AV block. We made the diagnosis of systemic sarcoidosis with cardiac involvement through an FDG-PET even with a normal CMR. We started corticosteroid therapy and we decided to follow-up the patient through an implantable loop recorder (ILR). Beyond an initial regression of the AV block, after 8 months the ILR revealed AV block and pauses more than 3 s during the day; a new FDG-PET evidenced FDG uptake in new areas of left ventricle. Hence we started infliximab and implanted a dual chamber ICD.

Abstract 10785: Cardiac Magnetic Resonance Imaging and Optical Coherence Tomography in Patients with a Clinical Diagnosis of Myocardial Infarction with Non-Obstructive Coronary Arteries - A Systematic Review and Meta-Analysis

Background: Myocardial Infarction with Non-Obstructive Coronary arteries (MINOCA) is defined as acute Myocardial Infarction (MI) despite the absence of severe coronary artery stenosis on angiography (i.e., stenosis severity &lt;50%) and no specific alternative diagnosis (e.g., sepsis, pulmonary embolism). MINOCA remains a serious diagnostic and therapeutic challenge given the various possible underlying etiologies. Cardiac Magnetic Resonance Imaging (CMR) can distinguish between acute myocarditis (AM), MI, and Takotsubo cardiomyopathy (TCM) which are some of the commonest causes of MINOCA. Hence, The European Society of Cardiology (ESC) recommend CMR in all MINOCA patients with an unclear etiology. Intracoronary Optical coherence tomography (OCT) is a high-resolution imaging modality that allows for assessment of the integrity of the atheroma. We aimed to study the efficacy of CMR and OCT in detecting the etiology in MINOCA patients, which has the potential to guide medical therapy. Methods: A systematic search was made in PubMed, Medline and Cochrane database. Search terms used: Myocardial infarction, Coronary angiography, Normal coronary arteries, CMR, and OCT. Inclusion criteria was fulfilled by 18 studies. Meta-analysis and meta-regression was performed with 14 studies due to increased heterogeneity. Results: A total of 2474 patients were included in the meta-analysis. The mean age of all the patients was 51.5 and 56.4% were men. CMR was able to establish diagnosis in 74% of the patients; 30.4% had AM, 21.3% had true MI and 12% had TCM. Upon meta-regression the demographic variables, cardiovascular risk factors, troponin levels and C-reactive protein levels did not have any association with AM or MI. Incorporation of OCT with CMR was better at finding the etiology than either modalities individually. Conclusion: CMR is integral in finding the cause of MINOCA. Coupling coronary OCT and CMR is better than either techniques alone at identifying the etiology.

Myocardial deformation assessed by CMR in children after multisystem inflammatory syndrome (MIS-C)

BackgroundShort-term sequelae of Multisystem Inflammatory Syndrome in Children (MIS-C), recently published by our institution, showed rapid improvement of the cardiac abnormalities within a few weeks after the onset of the disease. However, subtle residual abnormalities, affecting mainly the myocardial interstitium, were shown in some of the patients. The current study aimed to assess myocardial deformation with CMR shortly after MIS-C. MethodsSixty children were included into the study; 30 following MIS-C (onset-to-scan mean 27 days, SD 11) and 30 controls. Strain values were compared between patients and controls and additionally to published paediatric normal CMR values. U-Mann Whitney test was used for comparison of the myocardial deformation between patients and controls. ResultsMedian age of the patients was 9.0 years (range 0.99–14.4) and controls 9.8 years (range 4.7–14.9). All conventional CMR parameters in patients were in normal range. Strain values were significantly lower in patients than in controls. When compared to published centile graphs, radial and circumferential global strain was within 2.5th and 97.5th centile in all patients. Eleven patients had global longitudinal strain between 2.5th centile and 50th centile, 1 patient was below 2.5th centile and all the others above 50th centile. Only 3 controls had global longitudinal strain between 2.5th centile and 50th centile, all other had higher strain. ConclusionsThis study demonstrates that myocardial deformation indices measured by CMR are within normal range in the vast majority of the patients within a few weeks after the onset of MIS-C. However, when compared to healthy controls, all strain parameters were lower in patients.

Cardiac magnetic resonance in COVID-19 positive and probable cases: A report from a high volume CMR centre in Ireland

Funding AcknowledgementsType of funding sources: None.IntroductionCoronavirus disease 2019 (COVID-19) infection can have multisystem involvements. The inflammation sequelae can cause myocarditis. The COVID-19 pandemic has impacted Ireland significantly. Understanding of myocardial involvement in COVID-19 is not fully elucidated but has been reported. The Centre for Cardiovascular Magnetic Resonance, Blackrock Clinic in Ireland is a high volume CMR centre with approximately 4500 cases per year and accepting referral from all hospital in Ireland. These analyses are to describe the CMR findings in COVID-19 positive and probable cases attending the centre.MethodsConsecutive 65 referrals with mention of "COVID-19" from March 2020 to December 2020 was assessed. 56 cases were included in this analysis. Cases were categorised as COVID-19 positive cases or probable (viral illness like symptoms) cases. The demography and CMR parameters were collected. Serial imaging of selected cases was included. Descriptive analyses methods were applied.ResultsIn the period of 10 months, there was 49 COVID-19 positive cases (65.3% male; median age 49 [32 : 61] years) and 7 COVID-19 probable cases (42.9% male; median age 39 [37 : 59] years). In the COVID-19 positive cases, 25 had normal CMR, 11 has evidence of myocarditis, 1 with pericarditis, 2 with infarction/ischaemia, 3 with dilated cardiomyopathy, 2 with hypertrophic cardiomyopathy and 5 with other findings. There were 3 COVID-19 positive cases with serial imaging showing resolving myocarditis (100% female; median age 41 [30 : 47] years). 2 professional athletes with COVID-19 positive test showed no evidence of myocarditis. There are no significant differences in the age of male COVID-19 positive versus female group (p= 0.0752). Different demography and CMR parameters and tissue characterisation are described in Table 1 and Table 2.ConclusionsThe prevalence of myocarditis in this cohort is approximately 1 in 5 (21.4%). Within the COVID-19 positive cases, the prevalence is 22.4%. These observations may reflect selection bias for CMR referral in those with cardiac symptoms or cardiac enzymes leak. Table 1 Table 2

Clinical value of left ventricular strain analysis by cardiovascular magnetic resonance in patients with coronary chronic total occlusion

Objective: To explore the clinical value of quantitatively assessment of left ventricular strain in patients with coronary chronic total occlusion (CTO) by cardiac magnetic resonance imaging (CMR)-feature tracking (CMR-FT) technique. Methods: In this retrospective and observation study, patients with single CTO, who underwent CMR examination in Beijing Anzhen Hospital from November 2014 to January 2019, were selected as case group (CTO group), and those without cardiovascular diseases defined by echocardiography, electrocardiogram (ECG) and clinical history and with normal CMR results were selected as healthy control group (control group). General clinical data including age, gender, discharge diagnosis, and the examination results of echocardiography and ECG were obtained from the electronic medical record system. Two-dimensional CMR-FT was applied to measure left ventricle (LV) global peak radial, circumferential, and longitudinal strains (GPRS, GPCS and GPLS, respectively), and the regional myocardial strain in the target vessel area of CTO was analyzed. Grayscale thresholds of 5 standard deviations (SDs) were used to quantify late gadolinium enhancement (LGE). Patients with CTOs were divided into infract size>10% group and infarct size≤10% group, and left ventricular ejection fraction (LVEF)≥50% group and LVEF<50% group, respectively. The differences between various groups were compared. Results: There were 52 patients in CTO group (34 males, age (54.1±11.7) years, body mass index (BMI) (26.2±2.5)kg/m2) and 30 patients in control group (14 males, age(51.6±12.3)years, BMI (25.6±3.3)kg/m2). There was no significant difference in age, gender, and BMI between the two groups (all P>0.05). LVEF, GPRS, GPCS and GPLS were significantly lower in CTO group than in control group (all P<0.05), left ventricular volume (LVEDV) was similar between the two groups (P>0.05). Among the patients with CTO, there were 26 patients with infarct size>10% and 26 patients with infarct size≤10%. GPRS, GPCS and GPLS were significantly lower (all P<0.05), while LVEF and LVEDV were similar in CTO patients with infarct size≤10% as compared to control group (both P>0.05). LVEF, GPRS, GPCS and GPLS were significantly lower (all P<0.05), while LVEDV was similar in CTO patients with infarct size>10% (P>0.05) as compared to control group. GPRS and GPCS were significantly lower (both P<0.05), while LVEF, LVEDV and GPLS were similar in CTO patients with infarct size>10% as compared to infarct size≤10% group. There were 40 subjects in LVEF≥50% group and 12 subjects in LVEF<50% group. Compared with the control group, GPCS and GPLS of CTO patients were significantly lower in LVEF≥50% group and LVEF<50% group (all P<0.01), LVEF and LVEDV was similar in CTO patients with LVEF≥50% (both P>0.05), but LVEF was lower and LVEDV was larger in LVEF<50% group (both P<0.05). The GPRS, GPCS, GPLS and LVEF of CTO patients in LVEF ≥ 50% group were higher than those in LVEF<50% group (all P<0.0l), and the myocardial infarction size was smaller than that in LVEF reduced group (P<0.0l), but there was no significant difference in LVEDV between the two groups (P=0.07). In the CTO group, there were 21 patients with left anterior descending artery (LAD) occlusion and 126 segments supplied by the target vessels. The peak radial strain (PRS), circumferential strain (PCS) and longitudinal strain (PLS) in the blood supply area were lower than those in the control group (all P<0 01). In 7 patients with left circumflex artery (LCX) occlusion, the number of myocardial segments supplied by the target vessels was 35, and the PRS, PCS and PLS in the target vessel supply area were lower than those in the control group (all P<0 05). In 24 patients with right coronary artery (RCA) occlusion, the number of myocardial segments supplied by the target vessels was 120, and the PRS, PCS and PLS in the target vessel supply area were lower than those in the control group (all P<0.01). Among the 126 segments in 21 patients with LAD CTO, 91 (72.2%) segments had infarct size≤25%, 17 (13.5%) segments had infarct size between 26%-50%, 11 segments (8.7%) had infarct size between 51%-75%, and 7 (5.6%) segments had infarct size between 76%-100%. Among the 35 segments in 7 patients with LCX CTO, 31 (88.6%) segments had infarct size≤25%, and 4 (11.4%) segments had infarct size between 26%-75%. Among the 120 segments in 24 patients with RCA CTO, 96 (80.0%) segments had infarct size≤25%, 11 (9.2%) segments had infarct size between 26%-50%, 8 (6.7%) segments had infarct size between 51%-75%, and 5 segments (4.2%) had infarct size between 76%-100%. Conclusions: In this study with single CTO, although the LVEF is preserved in the majority of the patients, the left ventricular global and regional strain values are significantly decreased. The larger the infarct size, the greater the impact on radial and circumferential motion, reflecting the early impairment of left ventricular function in these patients.

Native T1 mapping and extracellular volume fraction for differentiation of myocardial diseases from normal CMR controls in routine clinical practice

BackgroundThis study aimed to determine native T1 and extracellular volume fraction (ECV) in distinct types of myocardial disease, including amyloidosis, dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), myocarditis and coronary artery disease (CAD), compared to controls.Methods We retrospectively enrolled patients with distinct types of myocardial disease, CAD patients, and control group (no known heart disease and negative CMR study) who underwent 3.0 Tesla CMR with routine T1 mapping. The region of interest (ROI) was drawn in the myocardium of the mid left ventricular (LV) short axis slice and at the interventricular septum of mid LV slice. ECV was calculated by actual hematocrit (Hct) and synthetic Hct. T1 mapping and ECV was compared between myocardial disease and controls, and between CAD and controls. Diagnostic yield and cut-off values were assessed.ResultsA total of 1188 patients were enrolled. The average T1 values in the control group were 1304 ± 42 ms at septum, and 1294 ± 37 ms at mid LV slice. The average T1 values in patients with myocardial disease and CAD were significantly higher than in controls (1441 ± 72, 1349 ± 59, 1345 ± 59, 1355 ± 56, and 1328 ± 54 ms for septum of amyloidosis, DCM, HCM, myocarditis, and CAD). Native T1 of the mid LV level and ECV at septum and mid LV with actual and synthetic Hct of patients with myocardial disease or CAD were significantly higher than in controls.ConclusionsAlthough native T1 and ECV of patients with cardiomyopathy and CAD were significantly higher than controls, the values overlapped. The greatest clinical utilization was found for the amyloidosis group.

Three-dimensional late gadolinium enhancement increases the diagnostic yield of cardiovascular magnetic resonance to detect low voltage in the right ventricular outflow tract

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance (CMR) using late gadolinium enhancement (LGE) fails to detect scar tissue in patients with electroanatomical abnormalities and biopsy-proven structural heart disease. It has shown conflicting data regarding existence of structural abnormalities in patients with idiopathic premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT). Three- dimensional (3D) LGE enables high-spatial resolution more appropriate to the thin-walled right ventricle than two-dimensional (2D) LGE. Objective Our aim was to evaluate if the use of 3D-LGE would improve the performance of CMR to detect low voltage areas in the RVOT of patients with PVCs. Methods Since May 2020 we performed 3D-LGE CMR in 11 consecutive patients that underwent ablation of frequent PVCs. A control group of 11 consecutive patients that underwent catheter ablation by the same operator and had a 2D-LGE CMR performed before ablation was also studied. All patients had normal 2D-LGE CMR. A 3D electroanatomical bipolar voltage map of the RVOT was performed in sinus rhythm (0.5 mV-1.5 mV colour display). Areas with electrograms &amp;lt;1.5 mV represented the LVA. The area adjacent to the pulmonary valve usually displays voltage between 0.5 and 1.5 mV and is classified as transitional-voltage zone. Presence of LVAs outside this transitional-voltage zone were estimated. We compared the accuracy of CMR for detecting LVA in the two groups: 3D LGE and 2D LGE. Results The median number of points used for the voltage map was 344 (242-450). 18 patients (82%) displayed LVAs. The site of origin of the PVCs was the RVOT in 17 patients and the left ventricular outflow tract (LVOT) in 5. Comparison between groups is displayed in the table. 2D LGE CMR failed to demonstrate abnormalities of the RVOT in any of the patients that presented with LVAs. 3D CMR showed presence of fibrosis (Figure) in 3 out of 9 patients with LVAs (33%). Conclusion CMR using 3-D LGE techniques showed an increased power to diagnose structural abnormalities. This technique may be a better choice in initial stages of RVOT disease. All sampleN = 223D-LGE CMRN = 112D-LGE CMRN = 11p-valueAge in years, median (Q1-Q3)47 (35-68)62 (34-55)42 (34-55)0.243Male gender, n (%)8 (36)3 (27)5 (46)0.330PVCs RVOT/LVOT17/59/28/30.500Nº points in the map, median (Q1-Q3)344 (242-450)350 (259-450)300 (158-345)0.076Low voltage areas, n (%)18 (82)9 (82)9 (82)0.707Abstract Figure.