Initial Cardiac Magnetic Resonance Research Articles

Predictive value of cardiac magnetic resonance imaging for adverse left ventricular remodeling after acute ST-segment elevation myocardial infarction

To assess the value of cardiac magnetic resonance (CMR) imaging for predicting adverse left ventricular remodeling in patients with ST-segment elevation myocardial infarction (STEMI). We retrospectively analyzed the clinical data and serial CMR (cine and LGE sequences) images of 86 STEMI patients within 1 week and 5 months after percutaneous coronary intervention (PCI), including 25 patients with adverse LV remodeling and 61 without adverse LV remodeling, defined as an increase of left ventricular end-systolic volume (LVESV) over 15% at the second CMR compared to the initial CMR. The CMR images were analyzed for LV volume, infarct characteristics, and global and infarct zone myocardial function. The independent predictors of adverse LV remodeling following STEMI were analyzed using univariate and multivariate Logistic regression methods. The initial CMR showed no significant differences in LV volume or LV ejection fraction (LVEF) between the two groups, but the infarct mass and microvascular obstructive (MVO) mass were significantly greater in adverse LV remodeling group (P < 0.05). Myocardial injury and cardiac function of the patients recovered over time in both groups. At the second CMR, the patients with adverse LV remodeling showed a significantly lower LVEF, a larger left ventricular end-systolic volume index (LVESVI) and a greater extent of infarct mass (P < 0.001) with lower global peak strains and strain rates in the radial, circumferential, and longitudinal directions (P < 0.05), infarct zone peak strains in the 3 directions, and infarct zone peak radial and circumferential strain rates (P < 0.05). The independent predictors for adverse LV remodeling following STEMI included the extent of infarct mass (AUC=0.793, 95% CI: 0.693-0.873; cut-off value: 30.67%), radial diastolic peak strain rate (AUC=0.645, 95% CI: 0.534-0.745; cut-off value: 0.58%), and RAAS inhibitor (AUC= 0.699, 95% CI: 0.590-0.793). The extent of infarct mass, peak radial diastolic strain rate, and RAAS inhibitor are independent predictors of adverse LV remodeling following STEMI.

The association of myocardial strain with cardiac magnetic resonance and clinical outcomes in patients with acute myocarditis.

The role of myocardial strain in risk prediction for acute myocarditis (AMC) patients, measured by cardiac magnetic resonance (CMR), deserves further investigation. Our objective was to evaluate the association between myocardial strain measured by CMR and clinical events in AMC patients. This was a prospective single-center study of patients with AMC. We included 100 patients with AMC with CMR confirmation. The primary outcome was the composite of all-cause mortality, heart failure and AMC recurrence in 24 months. A subgroup analysis was performed on a sample of 36 patients who underwent a second CMR between 6 and 18 months. The association between strain measures and clinical events or an increase in left ventricular ejection fraction (LVEF) was explored using Cox regression analysis. Global peak radial, circumferential and longitudinal strain in the left and right ventricles was assessed. ROC curve analysis was performed to identify cutoff points for clinical event prediction. The mean follow-up was 18.7 ± 2.3 months, and the composite primary outcome occurred in 26 patients. The median LVEF at CMR at baseline was 57.5% (14.6%). LV radial strain (HR = 0.918, 95% CI: 0.858-0.982, p = 0.012), LV circumferential strain (HR = 1.177, 95% CI: 1.046-1.325, p = 0.007) and LV longitudinal strain (HR = 1.173, 95% CI: 1.031-1.334, p = 0.015) were independently associated with clinical event occurrence. The areas under the ROC curve for clinical event prediction were 0.80, 0.79 and 0.80 for LV radial, circumferential, and longitudinal strain, respectively. LV longitudinal strain was independently correlated with prognosis (HR = 1.282, CI 95%: 1.022-1.524, p = 0.007), even when analyzed together with ejection fraction and delayed enhancement. LV and right ventricle (RV) strain were not associated with an increase in LVEF. Finally, when the initial CMR findings were compared with the follow-up CMR findings, improvements in the measures of LV and RV myocardial strain were observed. Measurement of myocardial strain by CMR can provide prognostic information on AMC patients. LV radial, circumferential and longitudinal strain were associated with long-term clinical events in these patients.

Cardiac magnetic resonance for the early prediction of reverse left ventricular remodeling in patients with ST-segment elevation myocardial infarction.

To evaluate the changes in cardiac magnetic resonance (CMR) characteristics and investigate the predictors of reverse left ventricular remodeling (r-LVR) in ST-segment elevation myocardial infarction (STEMI) patients. Eighty-six STEMI patients (median 56 years) were retrospectively studied. The patients were divided into r-LVR and without r-LVR groups. CMR analysis included LV volume, infarct characteristics, and global and regional myocardial function. The strain and displacement were assessed by CMR-feature tracking. The predictors of r-LVR were analyzed by the logistic regression method. There were 37 patients in the r-LVR group and 49 patients in the without r-LVR group. At initial CMR, there was no difference in LV volume and global cardiac function between the two groups. However, the infarct zone radial and longitudinal displacements were higher in the r-LVR group (p< 0.05, respectively). At the second CMR, the r-LVR group showed higher LVEF, lower LV volume, and total enhanced mass (all p< 0.05). The infarct zone radial and circumferential strains and radial displacement were higher in the r-LVR group (all p< 0.05). The r-LVR group had better recovery of myocardial injury and function. Of note, microvascular obstruction (MVO) mass (odds ratio: 0.779 (0.613-0.989), p= 0.041) and infarct zone peak longitudinal displacement (PLD) (odds ratio: 1.448 (1.044-2.008), p= 0.026) were independent predictors of r-LVR. At initial CMR, there were no differences in global cardiac function between the two groups, but infarct zone displacements were higher in the r-LVR group. The r-LVR group had better recovery of cardiac function. In addition, MVO mass and infarct zone PLD were independent predictors of r-LVR. Our study assessed changes in cardiac structure, function, and tissue characteristics after STEMI by CMR, investigated the best predictors of r-LVR in STEMI patients, and laid the foundation for the development of new parameter-guided treatment strategies for STEMI patients. • At initial CMR, the reverse left ventricular remodeling (r-LVR) group had less myocardial damage and higher infarct zone displacement, but there were no differences in global function between the two groups. • Both groups showed recovery of myocardial injury and cardiac function over time, but the r-LVR group had less enhanced mass and better cardiac function compared to the without r-LVR group at the second CMR. • Microvascular obstruction mass and infarct zone peak longitudinal displacement by cardiac magnetic resonance feature-tracking were significant predictors of r-LVR in STEMI patients.

C65 POST–DISCHARGE ARRHYTHMIC RISK STRATIFICATION OF PATIENTS WITH ACUTE MYOCARDITIS AND LIFE–THREATENING VENTRICULAR TACHYARRHYTHMIAS

Abstract Aims The outcomes of patients presenting with acute myocarditis and life–threatening ventricular arrhythmias (LT–VA) are unclear. The aim of this study was to assess the incidence and predictors of recurrent major arrhythmic events (MAEs) after hospital discharge in this patient population. Methods and Results We retrospectively analysed 156 patients (median age 44 years; 77% male) discharged with a diagnosis of acute myocarditis and LT–VA from 16 hospitals worldwide. Diagnosis of myocarditis was based on histology or the combination of increased markers of cardiac injury and cardiac magnetic resonance (CMR) Lake Louise criteria. MAEs were defined as the relapse, after discharge, of sudden cardiac death or successfully defibrillated ventricular fibrillation, or sustained ventricular tachycardia (sVT) requiring implantable cardioverter–defibrillator therapy or synchronized external cardioversion. Median follow–up was 23months [first to third quartile (Q1–Q3) 7–60]. Fifty–eight (37.2%) patients experienced MAEs after discharge, at a median of 8 months (Q1–Q3 2.5–24.0 months; 60.3% of MAEs within the first year). At multivariable Cox analysis, variables independently associated with MAEs were presentation with sVT [hazard ratio (HR) 2.90, 95% confidence interval (CI) 1.38–6.11]; late gadolinium enhancement involving ≥2 myocardial segments (HR 4.51, 95% CI 2.39–8.53), and absence of positive short–tau inversion recovery (STIR) (HR 2.59, 95% CI 1.40–4.79) at first CMR. Conclusions In this international multicentre study, patients discharged free from HTx or LVAD after an acute myocarditis complicated by LT–VA had a recurrence of MAEs during follow–up of 37.2%, after a median time of 8 months. Initial CMR pattern and sVT at presentation stratify the risk of arrhythmia recurrence.

Follow-up cardiac magnetic resonance in children with vaccine-associated myocarditis.

Myocarditis is a rare complication of the COVID-19 mRNA vaccine. We previously reported a case series of 15 adolescents with vaccine-associated myocarditis, 87% of whom had abnormalities on initial cardiac magnetic resonance (CMR), including late gadolinium enhancement (LGE) in 80%. We performed follow-up CMRs to determine the trajectory of myocardial recovery and better understand the natural history of vaccine-associated myocarditis. Case series of patients age < 19 years admitted to Boston Children’s Hospital with acute vaccine-associated myocarditis following the BNT162b2 vaccine who had abnormal CMR at the time of initial presentation, and underwent follow-up testing. CMR assessment included left ventricular (LV) ejection fraction, T2-weighted myocardial imaging, LV global native T1, LV global T2, extracellular volume (ECV), and late gadolinium enhancement (LGE). Ten patients (9 male, median age 15 years) with vaccine-associated myocarditis underwent follow-up CMR at a median of 92 days (range 76–119) after hospital discharge. LGE was persistent in 80% of patients, though improved from prior in all cases. Two patients (20%) had abnormal LV global T1 at presentation, which normalized on follow-up. ECV decreased between acute presentation and follow-up in 6/10 patients; it remained elevated at follow-up in 1 patient and borderline in 3 patients.Conclusion: CMR performed ~3 months after admission for COVID-19 vaccine-associated myocarditis showed improvement of LGE in all patients, but persistent in the majority. Follow-up CMR 6–12 months after acute episode should be considered to better understand the long-term cardiac risks. What is Known:• Myocarditis is a rare side effect of COVID-19 mRNA vaccine.•Late gadolinium enhancement is present on most cardiac magnetic resonance at the time of acute presentation.What is New:•Late gadolinium enhancement improved on all repeat cardiac magnetic resonance at 3-month follow-up.•Most patients still had a small amount of late gadolinium enhancement, the clinical significance of which is yet to be determined.Supplementary informationThe online version contains supplementary material available at 10.1007/s00431-022-04482-z.

COVID-19-Vaccination-Induced Myocarditis in Teenagers: Case Series with Further Follow-Up.

Presently, the whole globe is struggling the tough challenge of the COVID-19 pandemic. Vaccination remains the most effective and safe COVID-19 weapon for adults and in the paediatric population. Aside from possible mild and moderate post-vaccination side effects, more severe side effects may occur. We retrospectively analysed a group of 5 teenagers aged from 15 to 17 years with obesity/overweight (BMI ranging from 24.8 to 30) who presented typical myocarditis symptoms following the first or second dose (3 and 2 patients, respectively) of the COVID-19 vaccine. In the whole study group, a significant increase in troponin serum concentration was observed (1674–37,279.6 ng/L) with a further quick reduction within 3–4 days. In all patients, ST segments elevation or depression with repolarisation time abnormalities in electrocardiography were noticed. Chest X-ray results were within normal limits. Echocardiography showed normal left ventricular diameter (47–56.2 mm) with ejection fraction between 61–72%. All patients were diagnosed with myocarditis based on cardiac magnetic resonance (CMR) imaging. During further hospitalisation, swift clinical improvement was notable. Follow-up in the whole study group was obtained after 106–134 days from initial CMR, revealing no myocarditis symptoms, proper troponin level, and no ECG or echocardiographic abnormalities. At the same time, persistent myocardium injury features were detected in the whole study group, including ongoing myocarditis. COVID-19-vaccine-induced myocarditis seems to be a mild disease with fast clinical recovery, but the complete resolution of the inflammatory process may last over 3 months. Further follow-up and investigation for assessing subsequent implications and long-term COVID-19-vaccine-induced myocarditis is required.

Post-discharge arrhythmic risk stratification of patients with acute myocarditis and life-threatening ventricular tachyarrhythmias.

The outcomes of patients presenting with acute myocarditis and life-threatening ventricular arrhythmias (LT-VA) are unclear. The aim of this study was to assess the incidence and predictors of recurrent major arrhythmic events (MAEs) after hospital discharge in this patient population. We retrospectively analysed 156 patients (median age 44 years; 77% male) discharged with a diagnosis of acute myocarditis and LT-VA from 16 hospitals worldwide. Diagnosis of myocarditis was based on histology or the combination of increased markers of cardiac injury and cardiac magnetic resonance (CMR) Lake Louise criteria. MAEs were defined as the relapse, after discharge, of sudden cardiac death or successfully defibrillated ventricular fibrillation, or sustained ventricular tachycardia (sVT) requiring implantable cardioverter-defibrillator therapy or synchronized external cardioversion. Median follow-up was 23 months [first to third quartile (Q1-Q3) 7-60]. Fifty-eight (37.2%) patients experienced MAEs after discharge, at a median of 8months (Q1-Q3 2.5-24.0months; 60.3% of MAEs within the first year). At multivariable Cox analysis, variables independently associated with MAEs were presentation with sVT [hazard ratio (HR) 2.90, 95% confidence interval (CI) 1.38-6.11]; late gadolinium enhancement involving ≥2 myocardial segments (HR 4.51, 95% CI 2.39-8.53), and absence of positive short-tau inversion recovery (STIR) (HR 2.59, 95% CI 1.40-4.79) at first CMR. Among patients discharged with a diagnosis of myocarditis and LT-VA, 37.2% had recurrences of MAEs during follow-up. Initial CMR pattern and sVT at presentation stratify the risk of arrhythmia recurrence.

Introduction of Cardiac Magnetic Resonance Imaging in Kosovo: First Fifty Consecutive Patients Registry Report

BACKGROUND: Cardiac magnetic resonance (CMR) as advanced diagnostic tool for the heart has been introduced in our institution since September 2019. AIM: We report on the first fifty consecutive patients using this imaging modality. METHODS AND MATERIALS: Strict protocol for CMR procedure, imaging quality assessment, contraindications, and informed consent were established. Patients selected for CMR were enrolled in a prospective registry. Visualizing the heart chambers, heart muscle and heart valves, resulted in acquiring complex imaging of the heart structure and function. When applicable, patients received gadolinium contrast agent for Late Gadolinium Enhancement (LGE). Adenosine was used for stress induced myocardial perfusion study. In this study, we report on the initial CMR procedures in the first 15 months. RESULTS: The age of the patients ranges from 17 to 82 and the number of male and female patients was well balanced. No absolute contraindications were met in any patient. Relative contraindications were noted but did not prevent from performing the scan. Different cardiac pathologies were encountered in the examined patients. Most common was the ischemic heart disease – 19 (38%). We had 15 (30%) out of 46 (92%) CMR procedures with LGE showing fibrotic scaring. Quality image assessment was scaled from poor to excellent. Most of the assessments were graded very good and good (46% and 48%), no poor, and very poor noted. CONCLUSION: CMR has been successfully introduced in Kosovo as excellent imaging tool for diagnosing and characterizing a nearly exhaustive spectrum of heart diseases.

Persistence of Late Gadolinium Enhancement on Follow-Up CMR Imaging in Children with Acute Myocarditis.

Cardiac magnetic resonance (CMR) imaging is the gold standard non-invasive test for the diagnosis of acute myocarditis. Late gadolinium enhancement (LGE) on CMR imaging signifies myocardial fibrosis or scar but information on long-termfollow-up in pediatric patients is limited. The aim of this study is to evaluate the persistence of LGE in follow-up CMR imaging and highlight the need for serially following LGE after acute myocarditis in children. A retrospective review of the CMR images in pediatric patients less than 18years of age at Children's Memorial Hermann Hospital was performed from October 31, 2010, to December 31, 2017. The ages of the patients included in the study ranged from 10 to 17years. Out of 34 subjects, 12 subjects had a follow-up CMR imaging after the initial CMR imaging. Cardiac enzymes and inflammatory markers were elevated in all patients on initial presentation with normalization seen for all patients on follow-up testing. Baseline CMR imaging demonstrated depressed function in 50% of patients (6/12) with recovery of biventricular function seen in all except for one patient. LGE was detected in 10 out of 12 patients on baseline CMR and persisted in all on follow--up CMR imaging. Two patients did not have LGE at baseline CMR and had no evidence of LGE at follow-up CMR. Despite resolution of acute myocardial inflammation, LGE persisted in all of our study subjects. There is neither an agreement on time interval to perform follow-up CMR, nor on duration of follow-up. We recommend large-scale prospective CMR study for long-term follow-up evaluation of children after acute myocarditis.

Serial Magnetic Resonance Imaging to Identify Early Stages of Anthracycline-Induced Cardiotoxicity

BackgroundAnthracycline-induced cardiotoxicity is a major clinical problem, and early cardiotoxicity markers are needed. ObjectivesThe purpose of this study was to identify early doxorubicin-induced cardiotoxicity by serial multiparametric cardiac magnetic resonance (CMR) and its pathological correlates in a large animal model. MethodsTwenty pigs were included. Of these, 5 received 5 biweekly intracoronary doxorubicin doses (0.45 mg/kg/injection) and were followed until sacrifice at 16 weeks. Another 5 pigs received 3 biweekly doxorubicin doses and were followed to 16 weeks. A third group was sacrificed after the third dose. All groups underwent weekly CMR examinations including anatomical and T2 and T1 mapping (including extracellular volume [ECV] quantification). A control group was sacrificed after the initial CMR. ResultsThe earliest doxorubicin-cardiotoxicity CMR parameter was T2 relaxation-time prolongation at week 6 (2 weeks after the third dose). T1 mapping, ECV, and left ventricular (LV) motion were unaffected. At this early time point, isolated T2 prolongation correlated with intracardiomyocyte edema secondary to vacuolization without extracellular space expansion. Subsequent development of T1 mapping and ECV abnormalities coincided with LV motion defects: LV ejection fraction declined from week 10 (2 weeks after the fifth and final doxorubicin dose). Stopping doxorubicin therapy upon detection of T2 prolongation halted progression to LV motion deterioration and resolved intracardiomyocyte vacuolization, demonstrating that early T2 prolongation occurs at a reversible disease stage. ConclusionsT2 mapping during treatment identifies intracardiomyocyte edema generation as the earliest marker of anthracycline-induced cardiotoxicity, in the absence of T1 mapping, ECV, or LV motion defects. The occurrence of these changes at a reversible disease stage shows the clinical potential of this CMR marker for tailored anthracycline therapy.

IDENTIFYING RISK FACTORS FOR MASSIVE RIGHT VENTRICULAR DILATION IN PATIENTS WITH REPAIRED TETRALOGY OF FALLOT

In repaired tetralogy of Fallot (rTOF), pulmonary insufficiency and volume overload result in varying degrees of right ventricular (RV) dilation. A subset of patients are diagnosed at initial cardiac magnetic resonance (CMR) with a massively dilated RV, far beyond published pulmonary valve

A retrospective study: cardiac MRI of fulminant myocarditis in children—can we evaluate the short-term outcomes?

BackgroundFulminant myocarditis (FM) is an inflammatory disease of the myocardium that results in ventricular systolic dysfunction and causes acute-onset heart failure. Cardiac magnetic resonance (CMR) has become the primary noninvasive tool for the diagnosis and evaluation of myocarditis. The aim of our study was to assess the CMR findings at different course of FM and the short-term outcomes of fulminant myocarditis (FM) in children.MethodsEight FM children with CMR examinations were included in our study. Initial baseline CMR was performed 10 days (range, 7–20 days) after onset of FM and follow-up CMR after 55 days (range, 33–75 days). Cardiac morphology and function and myocardial tissue characterization at baseline and follow-up CMR were compared using paired T-test and Mann–Whitney U test. The clinical data and initial CMR findings were also compared to predict short-term outcomes.ResultsThe median age of eight FM children was 8.5 years old (range, 3–14). The initial CMR findings were most common with early gadolinium enhancement (EGE, 100%), followed by signal increasing on T2WI and late gadolinium enhancement (LGE, 87.5%), increased septal thickness (75.0%) and increased left ventricle ejection fraction (LVEF, 50.0%). Only three LGE (37.5%), one signal increasing on T2WI (12.5%) and one increased LVEF (12.5%) were found at follow-up. Statistically significant differences were found between initial and follow-up CMR abnormalities in the septal thickness, left ventricular end-diastolic diameter (LVEDD), end-systolic volume (ESV), LVEF, left ventricular mass, T2 ratio and LGE area (P = 0.011, P = 0.042, P = 0.016, P = 0.001, P = 0.003, P = 0.011, P = 0.020). The children with full recovery performed higher incidence of III° atrioventricular block (AVB, five cases VS 0 case) and smaller LGE area (104.0 ± 14.5 mm2 VS 138.0 ± 25.2 mm2) at baseline CMR.DiscussionThe CMR findings of FM in children were characteristic and useful for early diagnosis. Full recovery of clinical manifestations, immunological features and CMR findings could be found in most FM children. The presence of III° AVB and smaller LGE area at baseline CMR might indicate better short-term outcomes.

Abstract 13289: Reduction in Extracellular Volume Fraction After Mitral Valve Repair of Chronic Mitral Regurgitation: A Cardiac MRI Pilot Study

Background: Global extracellular volume fraction (ECV) assessed with cardiac magnetic resonance (CMR) has been shown to be elevated in patients with chronic mitral regurgitation compared with healthy controls. Limited work has been published on ECV changes following reduction in chronic volume overload with mitral valve intervention. We examined changes in ECV in patients with chronic mitral valve regurgitation after surgical mitral valve repair (SMVR). Methods: All patients underwent CMR studies before and after SMVR. CMR studies were performed with cine, phase contrast, T1 maps, and late gadolinium enhancement (LGE) imaging. Mid, short axis T1 maps were divided into 6 cardiac segments, each classified as LGE absent or present. ECV was derived from T1 maps using area-weighted averages of only segments where LGE was absent, by a reader blinded to study date, clinical history and valve status. Results: Fifteen patients underwent SMVR a median of 1.4 (interquartile range [IQR] 0.8, 2.3) months after an initial CMR study (Table). Repeat CMR was performed a median 12.4 (IQR 7.2, 19.2) months after SMVR. None were on calcium channel blockers, nitrates, or direct arterial vasodilators. Following SMVR, significant reverse remodeling was seen with reductions in indexed left atrial volume and left ventricular parameters except end systolic volume (Table). ECV decreased from a mean 28.3% to 26.0% (p=0.01) (Table). No significant correlation was seen between changes in left sided CMR parameters and ECV (p=NS). Conclusion: In this pilot study of patients with significant chronic mitral regurgitation undergoing valve repair, a reduction in extracellular volume fraction was seen after 6 months or more, suggesting a decrease in myocardial fibrosis alongside reverse structural remodeling. Larger studies are needed to substantiate these findings and evaluate the clinical significance of ECV changes beyond cardiac reverse remodeling in patients undergoing mitral valve repair.

Prognostic value of MRI T2 quantification in heart transplant patients: a 5-year outcome study

Background Endomyocardial biopsy (EMB) is the current gold standard to monitor patients for heart transplant rejection. Quantification of myocardial T2 relaxation time using cardiac magnetic resonance (CMR) has been shown to have high sensitivity and specificity to detect rejection episodes. In this study, we evaluated the prognostic value of myocardial T2 to predict adverse cardiovascular outcomes during 5-year follow-up after initial CMR.

Abstract 16194: Prognostic Value of Cardiac Magnetic Resonance T2 Quantification in Heart Transplant Patients: A 5-year Outcome Study

Background: Endomyocardial biopsy (EMB) is the current gold standard to monitor patients for heart transplant rejection. Quantification of myocardial T2 relaxation time using cardiac magnetic resonance (CMR) has been shown to have high sensitivity and specificity to detect rejection episodes. In this study, we evaluated the prognostic value of myocardial T2 to predict adverse cardiovascular outcomes during 5-year follow-up after initial CMR. Methods: 49 cardiac transplant patients (mean age, 48 ± 14 years; 65% male) were recruited from a single institution. CMR at 1.5T was performed in all patients, with subsequent quantifications of regional and global myocardial T2. Clinical data was gathered post-CMR over a 5-year period. EMBs were graded according to the International Society of Heart &amp; Lung Transplantation criteria. Rejection episodes were defined by EMB ≥ 2R, new onset heart failure (HF), LV ejection fraction &lt; 40%, or death. Adverse cardiovascular events gathered included coronary artery disease, cardiomyopathies, arrhythmias, and different types of HFs. Multivariable logistic regression and Kaplan-Meier analysis was performed to measure the prognostic value of myocardial T2. Results: Myocardial T2 was found to increase with worsening EMB grade from 53.0 ms (0R, no rejection) to 59.9 ms (3R, severe rejection). ROC analysis using two groups (EMBs ≤ 1R and ≥ 2R) showed T2 = 55.0 ms to have the highest specificity and sensitivity. In multivariable analysis that considered T2 measures, age, length of surgery, donor ischemic time, and BMI, both peak T2 (p = 0.038) and septal T2 (p = 0.035) were significant predictors of EMB grade ≥ 2R. Kaplan-Meier analysis showed a significant higher probability of developing EMB ≥ 2R, new onset HF, or death with a global T2 ≥ 55 (p = 0.02). Adverse cardiovascular outcomes of systolic HF, acute systolic HF, and chronic diastolic HF had a higher probability of developing in patients with global T2 ≥ 55 (p = 0.01, p = 0.01, and p &lt; 0.01, respectively). Conclusions: CMR T2 quantification demonstrated prognostic value for all-cause rejection and various types of HFs in cardiac transplant patients. These findings suggest that CMR may be a suitable modality to non-invasively monitor cardiac transplant patients for rejection.

Mitral regurgitation recovery and atrial reverse remodeling following pulmonary vein isolation procedure in patients with atrial fibrillation: a clinical observation proof-of-concept cardiac MRI study

Reverse remodeling of the left atrium (LA) following successful pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) has been well documented. However, mitral regurgitation (MR) recovery after successful PVI has never been demonstrated systematically. The objective of our study was to retrospectively analyze the effectiveness of PVI in patients with AF on recovery of MR using cardiac magnetic resonance (CMR) imaging. Prior to PVI, patients underwent a clinically indicated CMR imaging. Post-PVI (6 ± 2months), patients underwent a follow-up MRI and were classified into two groups-responders (R) and non-responders (NR) to PVI-as assessed by cessation of AF at the end of the prespecified 6-month (14-day "P" sensitive event monitor defined) follow-up period. Furthermore, CMR was used to evaluate the severity of MR (0 to 4+) and to relate changes in MR to LA volumes as well as mitral apparatus geometry. Patients who had mild and higher MR (2+) on baseline CMR and had a post-PVI CMR were selected for final analysis. Out of the consecutive 122 patients with AF who underwent PVI, 74 patients that had mitral regurgitation on initial CMR were included in the study. Of these74 patients with AF with MR, 52 (70%) were classified as R and 22 (30%) were classified as NR. Baseline demographics were similar between the groups. In the subgroup with mild to severe MR, pre vs. post in the R group MR severity significantly improved (mean = 2.3, median = 2.0 vs. mean = 1.0, median = 1.0, p < 0.0001) and was matched by favorable reverse remodeling of the mitral apparatus geometry (annulus = 35 ± 4 vs. 33 ± 3mm, p < 0.002; tenting area = 175 ± 56 vs.137 ± 37mm(2), p < 0.003; tenting height = 8 ± 2 vs.7 ± 2mm, p < 0.02; and tenting angle = 129 ± 10° vs. 131 ± 11°, p = 0.1). However, in the NR subgroup, MR failed to improve (mean = 2.2, median = 2.0 vs. mean = 1.5, median = 1.0, p = NS) and paralleled general failure of mitral geometry reverse remodeling (annulus = 35 ± 4 vs. 35 ± 4mm, p = 0.2; tenting area = 153 ± 39 vs. 152 ± 34mm(2), p = NS; tenting height = 7 ± 1 vs. 7.0 ± 2, p = 0.1; and tenting angle = 131 ± 11° vs. 133 ± 10°, p = NS). In those with lesser degrees of MR, favorable remodeling was predicated on responder status to PVI. Similarly, other cardiac dimensions pre- to post-PVI favorably improved in the R group, but not in the NR group. In those with durable maintenance of normal sinus rhythm (NSR), cardiac reverse remodeling demonstrated by 3D CMR occurs and is matched by marked improvements in MR and mitral apparatus, likely contributing to continued maintenance of NSR.

Noncardiac Findings in Clinical Cardiac Magnetic Resonance

To assess the prevalence of noncardiac findings (NCFs) in a consecutive series of 300 cardiac magnetic resonance (CMR) studies. We retrospectively evaluated CMRs of 192 males and 108 females (42 ± 22 years), comparing findings included in reports to those detected after focused reassessment of CMR images. Noncardiac findings were classified as relevant if additional workup was required. We found 19 NCFs, 14 (4.7%) tagged as nonrelevant and 5 (1.7%) as relevant. Images' reassessment presented 45 NCFs, 26 (8.7%) nonrelevant and 16 (5.3%) relevant (P < 0.003). Cardiac magnetic resonance involves the study of areas larger than the heart alone, and NCFs are found in 1 of 7 patients; more than a half of them are not included in the initial CMR report. A small part is relevant, but detection can be unnecessarily stressful and harmful for patients and could increase costs. Risks of overdiagnosis or underreporting are to be taken into account.

Abstract 18476: Are Cardiac Magnetic Resonance Patterns Associated with Adverse 18-Month Outcome in Patients with Acute Myocarditis?

Introduction: Cardiac Magnetic Resonance (CMR) is a fundamental tool in the diagnosis of Acute Myocarditis (AM). However, its prognostic value is not well established. Hypothesis: CMR findings in patients with AM may predict functional/clinical outcome. Methods: We studied consecutive pts diagnosed with AM by CMR between 2008 and 2011. All pts underwent initial clinical assessment and CMR was performed at a mean of 11±12 days after acute clinical presentation. Black-blood T2-CMR was used for myocardial edema assessment and contrast-enhanced CMR was performed 3 (early gadolinium enhancement, EGE) and 10 (late gadolinium enhancement, LGE) min after gadolinium chelates. Images were analysed dividing the myocardium into 17 segments and 3 myocardial sectors (subepicardium, midwall, and subendocardium), allowing quantification of lesions extent as percent of LV myocardium. Presence of pericardial effusion and LV segmental wall motion was assessed. Adverse cardiac events including recurrence of symptoms, congestive heart failure, ventricular arrhythmias, heart transplantation, or death, were carefully recorded at clinical follow-up (FU) performed 19±8 months after indexed CMR. Results: The patient population comprised 203 pts (43±17 year-old, 76% males) with AM. A total of 22/203 patients (10.8% of the whole population) experienced adverse cardiac events. By univariate analysis, the extent of EGE was inversely correlated with the presence of clinical events at FU (2.2±4.1 vs. 5.1±6.0% of LV myocardial mass, for pts with and without adverse cardiac events, respectively, p=0.005). Additionally, pts with altered EF on initial CMR examination had worse myocardial function at FU. In contrast, presence of hyper-T2 signal (p=0.68), extent (p=0.72) and distribution (p=0.09) of LGE, presence of pericardial effusion p=0.18), were not associated with adverse clinical outcome. Multivariate analysis showed no CMR predictors of adverse clinical outcome. Conclusions: In this large cohort of patients with AM, there were no CMR predictors of adverse clinical outcome. A significant association was found between initial LV function and impaired LVEF at FU, as well as between EGE and adverse clinical events.

Apicobasal gradient of left ventricular myocardial edema underlies transient T-wave inversion and QT interval prolongation (Wellens’ ECG pattern) in Tako-Tsubo cardiomyopathy

Tako-Tsubo cardiomyopathy (TTC) presents with chest pain, ST-segment elevation followed by T-wave inversion and QT interval prolongation (Wellens' electrocardiographic [ECG] pattern), and left ventricular dysfunction, which may mimic an acute coronary syndrome. To assess the pathophysiologic basis of the Wellens' ECG pattern in TTC by characterization of underlying myocardial changes by using cardiac magnetic resonance (CMR). The study population included 20 consecutive patients with TTC (95% women; mean age 65.3 ± 10.4 years) who underwent CMR studies both in the initial phase and after 3-month follow-up by using a protocol that included cine images, T2-weighted sequences for myocardial edema, and post-contrast sequences for late gadolinium enhancement. Quantitative ECG indices of repolarization, such as maximal amplitude of negative T waves, sum of the amplitudes of negative T waves, and maximum corrected QT interval (QTc max), were correlated to CMR findings. At the time of initial CMR study, there was a significant linear correlation between the apicobasal ratio of T2-weighted signal intensity for myocardial edema and the maximal amplitude of negative T waves (ρ = 0.498; P = .02), sum of the amplitudes of negative T waves (ρ = 0.483; P = .03), and maximum corrected QT interval (ρ = 0.520; P = .02). Repolarization indices were unrelated to either late gadolinium enhancement or quantitative cine parameters. Wellens' ECG abnormalities and myocardial edema showed a parallel time course of development and resolution on initial and follow-up CMR studies. Our study results show that the ischemic-like Wellens' ECG pattern in TTC coincides and quantitatively correlates with the apicobasal gradient of myocardial edema as evidenced by using CMR. Dynamic negative T waves and QTc prolongation are likely to reflect the edema-induced transient inhomogeneity and dispersion of repolarization between apical and basal left ventricular regions.

Evaluating Microvascular Obstruction After Acute Myocardial Infarction Using Cardiac Magnetic Resonance Imaging and 201-Thallium and 99m-Technetium Pyrophosphate Scintigraphy

Few studies have compared the ability of cardiac magnetic resonance (CMR) with that of scintigraphy using 201-thallium (201-Tl) and 99m-technetium pyrophosphate (99m-Tc PYP) to evaluate microvascular obstructions (MOs). In the present study the relationship between the scintigraphic and CMR characteristics of MOs after acute myocardial infarction (MI) was examined. The 14 patients (age 69±8 years, 11 males) underwent 201-Tl/99m-Tc PYP SPECT 7±3 days, initial CMR 16±12 days, and follow-up CMR 193±20 days after a reperfused first acute MI. Each image was analyzed using a 17-segment model. Segmental extent of delayed enhancement (DE), wall motion (WM) and degree of 201-Tl uptake were scored in 238 segments. Of 91 MI segments, MO was recognized in 22 (25%) segments on CMR. WM was significantly better in proportion to 201-Tl uptake (P=0.01) in MO segments. All 8 MO segments with WM improvement at follow-up had 99m-Tc PYP uptake, although only 3 (21%) of 14 MO segments that did not show WM improvement at follow-up had 99m-Tc PYP uptake (P=0.001). 99m-Tc PYP and 201-Tl scintigraphy have the potential to predict WM status and improvement of the MO region after reperfused acute MI.