Baseline Cardiac Magnetic Resonance Research Articles

Biventricular pacing during cardiac magnetic resonance imaging.

We aimed to assess the effect of cardiac resynchronization on left ventricular (LV) function, volumes, geometry, and mechanics in order to demonstrate reverse remodelling using cardiac magnetic resonance (CMR) with resynchronization on. New York Heart Association (NYHA) Class II-III patients on optimal medical therapy with LV ejection fraction (LVEF) ≤35%, and complete LBBB with broad QRS (>150 ms) were prospectively recruited. Cardiac magnetic resonance examination was performed at baseline and at 6-month follow-up, applying both biventricular and AOO pacing. The following data were measured: conventional CMR parameters, remodelling indices, global longitudinal, circumferential, radial strain, global dyssynchrony [mechanical dispersion (MD) defined as the standard deviation of time to peak longitudinal/circumferential strain in 16 LV segments], and regional dyssynchrony (maximum differences in time between peak septal and lateral transversal displacement). Thirteen patients (64 ± 7 years, 38% male) were enrolled. Comparing the baseline and follow-up CMR parameters measured during biventricular pacing, significant increase in LVEF, and decrease in LV end-diastolic volume index (LVEDVi) and LV end-systolic volume index (LVESVi) were found. Left ventricular remodelling indices, global longitudinal, circumferential, and radial strain values showed significant improvement. Circumferential MD decreased (20.5 ± 5.5 vs. 13.4 ± 3.4, P < 0.001), while longitudinal MD did not change. Regional dyssynchrony drastically improved (362 ± 96 vs. 104 ± 66 ms, P < 0.001). Applying AOO pacing resulted in an immediate deterioration in LVEF, LVESVi, circumferential strain, global and regional dyssynchrony. Cardiac magnetic resonance imaging during biventricular pacing is feasible and enables a more precise quantification of LV function, morphology, and mechanics. As a result, it may contribute to a better understanding of the effects of resynchronization therapy and might improve responder rate in the future.

4936Cardiac magnetic resonance strain analysis predicts functional recovery following acute ST-segment elevation myocardial infarction

Abstract Background Late gadolinium enhancement (LGE) is the clinical reference standard for estimation of infarct extension and prediction of functional recovery following reperfused acute ST-segment elevation myocardial infarction (STEMI). Nevertheless, myocardial edema, microvascular obstruction and intramyocardial hemorrhage as well as the timing of image acquisition after contrast administration may influence the extent of LGE and underestimate the potential for recovery. Dobutamine stress testing has been recommended to more accurately predict functional recovery when infarct transmurality is between 25 to 75%. We hypothesized that cardiac magnetic resonance (CMR) tissue tracking strain analysis may provide additional value to LGE for the prediction of functional recovery. Methods In 370 patients with STEMI who underwent successful primary percutaneous revascularization and were studied with CMR within 3–5 days of the event, peak systolic longitudinal (LS), circumferential (CS) and radial (RS) strain were analyzed with routine SSFP images of 3 long-axis and a stack of short-axis slices (Tissue Tracking, CVI42®, Figure panel A and B). Inversion-recovery echogradient sequences were analyzed 20 minutes after contrast administration for LGE transmurality (Panel C). All per-segment analysis was performed according to the AHA 16-segment model. CMR was repeated at 6 months and functional recovery was defined as persistent normokinesia or improvement of wall motion score from baseline to 6-month CMR. Results At baseline CMR, of a total of 5920 segments 70.4% were normokinetic, 7.2% were hypokinetic, 21.9% were akinetic and 0.6% were dyskinetic. All strain parameters decreased significantly with worsening wall motion. At follow-up, 81.5% of the segments showed functional recovery. All strain parameters were significantly associated with functional recovery (p&lt;0.001) and showed higher predictive value for improvement of wall motion than LGE transmurality (ROC AUC 0.713 LS, 0.710 CS, 0.683 RS and 0.660 LGE). For basal CMR dysfunctional segments, a CS &lt;−10.7% showed the highest accuracy (66%) to predict wall motion improvement, with 58% sensitivity, 76% specificity, 75% positive predictive value (PPV) and 59% negative predictive value (NPV). These results were comparable to LGE transmurality &lt;50% (65% accuracy, 59% sensitivity, 73% specificity, 74% positive predictive value and 58% negative predictive value). Nevertheless, adding CS analysis to a 50% LGE transmurality cutoff was the best combination for prediction of functional recovery and increased the overall accuracy to 70%, with 76% sensitivity, 64% specificity, 65% PPV and 75% NPV. CS analysis in an inferior STEMI Conclusions Acute CMR tissue tracking strain analysis complements LGE assessment for prediction of functional recovery following an STEMI. The combination of LGE infarct transmurality under 50% and a CS strain higher than −10.7% showed the highest accuracy for prediction of recovery of function.

Clinical and cardiac magnetic resonance features of apical hypertrophic cardiomyopathy patients complicating with left ventricular apical aneurysm

Objective: To evaluate the clinical and cardiac magnetic resonance (CMR) features of apical hypertrophic cardiomyopathy (ApHCM) patients complicating with left ventricular apical aneurysm (LVAA). Methods: CMR confirmed 25 ApHCM patients complicating with LVAA from January 2010 to December 2017 in Fuwai hospital were included in this study, and the baseline clinical data and CMR characteristics were retrospectively analyzed. There were 14 pure ApHCM (hypertrophy limited at the apical segments) complicating with LVAA patients and 11 mixed ApHCM (predominantly apical hypertrophy along with thickening of contiguous non-apical left ventricular region) with LVAA patients. Results: In this patient cohort,age of 84% (21/25) patients ranged between 20-70 years old, and 68% (17/25) were male. There were 68% (17/25) patients with complaint of chest distress symptom, 56% (14/25) with complaint of chest pain, 32% (8/25) with complaint of palpitation,16% (4/25) with complaint of dyspnea, and 12% (3/25) presented as syncope. ST-T segment changes of electrocardiogram were observed in all patients, and giant negative T waves were detected in 80% patients (20/25). The rate of missed diagnosis by echocardiography for detecting ApHCM and LVAA was 16% (4/25) and 68% (17/25), respectively. CMR showed discrete thin-walled dyskinetic or akinetic segment of the most distal portion of the left ventricular chamber in ApHCM patients with LVAA. Transmural late gadolinium enhancement of the aneurysmal rim was detected in 76% (19/25) patients, and the maximum transverse dimension of aneurysm was bigger in patients with transmural late gadolinium enhancement than in patients without transmural late gadolinium enhancement ((22.0±10.8)mm vs. (11.7±4.0) mm, P=0.033). Conclusion: ApHCM with LVAA patients have distinct cardiac clinical features, and CMR is the most useful tool for the accurate and objective evaluation of this disease.

Acute impact of an endurance race on cardiac function and biomarkers of myocardial injury in triathletes with and without myocardial fibrosis.

AimsThe aim of this study was to investigate the occurrence of myocardial injury and cardiac dysfunction after an endurance race by biomarkers and cardiac magnetic resonance in triathletes with and without myocardial fibrosis.Methods and resultsThirty asymptomatic male triathletes (45 ± 10 years) with over 10 training hours per week and 55 ± 8 ml/kg per minute maximal oxygen uptake during exercise testing were studied before (baseline) and 2.4 ± 1.1 hours post-race. Baseline cardiac magnetic resonance included cine, T1/T2, late gadolinium enhancement (LGE) and extracellular volume imaging. Post-race non-contrast cardiac magnetic resonance included cine and T1/T2 mapping. Non-ischaemic myocardial fibrosis was present in 10 triathletes (LGE+) whereas 20 had no fibrosis (LGE–). At baseline, LGE + triathletes had higher peak exercise systolic blood pressure with 222 ± 21 mmHg compared to LGE– triathletes (192 ± 30 mmHg, P < 0.01). Post-race troponin T and creatine kinase MB were similarly increased in both groups, but there was no change in T2 and T1 from baseline to post-race with 54 ± 3 ms versus 53 ± 3 ms (P = 0.797) and 989 ± 21 ms versus 989 ± 28 ms (P = 0.926), respectively. However, post-race left atrial ejection fraction was significantly lower in LGE + triathletes compared to LGE– triathletes (53 ± 6% vs. 59 ± 6%, P < 0.05). Furthermore, baseline atrial peak filling rates were lower in LGE – triathletes (121 ± 30 ml/s/m2) compared to LGE + triathletes (161 ± 34 ml/s/m2, P < 0.01). Post-race atrial peak filling rates increased in LGE– triathletes to 163 ± 46 ml/s/m2, P < 0.001), but not in LGE + triathletes (169 ± 50ml/s/m2, P = 0.747).ConclusionDespite post-race troponin T release, we did not find detectable myocardial oedema by cardiac magnetic resonance. However, the unfavourable blood pressure response during exercise testing seemed to be associated with post-race cardiac dysfunction, which could explain the occurrence of myocardial fibrosis in triathletes.

Progression of myocardial fibrosis in hypertrophic cardiomyopathy: mechanisms and clinical implications.

AimsMyocardial fibrosis as detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) is a powerful prognostic marker in hypertrophic cardiomyopathy (HCM) and may be progressive. The precise mechanisms underlying fibrosis progression are unclear. We sought to assess the extent of LGE progression in HCM and explore potential causal mechanisms and clinical implications.Methods and resultsSeventy-two HCM patients had two CMR (CMR1-CMR2) at an interval of 5.7 ± 2.8 years with annual clinical follow-up for 6.3 ± 3.6 years from CMR1. A combined endpoint of heart failure progression, cardiac hospitalization, and new onset ventricular tachycardia was assessed. Cine and LGE imaging were performed to assess left ventricular (LV) mass, function, and fibrosis on serial CMR. Stress perfusion imaging and cardiac energetics were undertaken in 38 patients on baseline CMR (CMR1). LGE mass increased from median 4.98 g [interquartile range (IQR) 0.97–13.48 g] to 6.30 g (IQR 1.38–17.51 g) from CMR1 to CMR2. Substantial LGE progression (ΔLGE ≥ 4.75 g) occurred in 26% of patients. LGE increment was significantly higher in those with impaired myocardial perfusion reserve (<MPRI 1.40) and energetics (phosphocreatine/adenosine triphosphate <1.44) on baseline CMR (P ≤ 0.01 for both). Substantial LGE progression was associated with LV thinning, increased cavity size and reduced systolic function, and conferred a five-fold increased risk of subsequent clinical events (hazard ratio 5.04, 95% confidence interval 1.85–13.79; P = 0.002).ConclusionMyocardial fibrosis is progressive in some HCM patients. Impaired energetics and perfusion abnormalities are possible mechanistic drivers of the fibrotic process. Fibrosis progression is associated with adverse cardiac remodelling and predicts an increased risk of subsequent clinical events in HCM.

Clinical Presentation and Outcome in a Contemporary Cohort of Patients With Acute Myocarditis: Multicenter Lombardy Registry.

There is controversy about the outcome of patients with acute myocarditis (AM), and data are lacking on how patients admitted with suspected AM are managed. We report characteristics, in-hospital management, and long-term outcome of patients with AM based on a retrospective multicenter registry from 19 Italian hospitals. A total of 684 patients with suspected AM and recent onset of symptoms (<30 days) were screened between May 2001 and February 2017. Patients >70 years of age and those >50 years of age without coronary angiography were excluded. The final study population comprised 443 patients (median age, 34 years; 19.4% female) with AM diagnosed by either endomyocardial biopsy or increased troponin plus edema and late gadolinium enhancement at cardiac magnetic resonance. At presentation, 118 patients (26.6%) had left ventricular ejection fraction <50%, sustained ventricular arrhythmias, or a low cardiac output syndrome, whereas 325 (73.4%) had no such complications. Endomyocardial biopsy was performed in 56 of 443 (12.6%), and a baseline cardiac magnetic resonance was performed in 415 of 443 (93.7%). Cardiac mortality plus heart transplantation rates at 1 and 5 years were 3.0% and 4.1%. Cardiac mortality plus heart transplantation rates were 11.3% and 14.7% in patients with complicated presentation and 0% in uncomplicated cases (log-rank P<0.0001). Major AM-related cardiac events after the acute phase (postdischarge death and heart transplantation, sustained ventricular arrhythmias treated with electric shock or ablation, symptomatic heart failure needing device implantation) occurred in 2.8% at the 5-year follow-up, with a higher incidence in patients with complicated forms (10.8% versus 0% in uncomplicated AM; log-rank P<0.0001). β-Adrenoceptor blockers were the most frequently used medications both in complicated (61.9%) and in uncomplicated forms (53.8%; P=0.18). After a median time of 196 days, 200 patients had follow-up cardiac magnetic resonance, and 8 of 55 (14.5%) with complications at presentation had left ventricular ejection fraction <50% compared with 1 of 145 (0.7%) of those with uncomplicated presentation. In this contemporary study, overall serious adverse events after AM were lower than previously reported. However, patients with left ventricular ejection fraction <50%, ventricular arrhythmias, or low cardiac output syndrome at presentation were at higher risk compared with uncomplicated cases that had a benign prognosis and low risk of subsequent left ventricular systolic dysfunction.

Reduction in mortality from implantable cardioverter-defibrillators in non-ischaemic cardiomyopathy patients is dependent on the presence of left ventricular scar.

In patients with non-ischaemic cardiomyopathy (NICM), the mortality benefit of a primary prevention implantable cardioverter-defibrillator (ICD) has been challenged. Left ventricular (LV) scar identified by cardiac magnetic resonance (CMR) imaging is associated with a high risk of malignant arrhythmia in NICM. We aimed to determine the impact of LV scar on the mortality benefit from a primary prevention ICD in NICM. We recruited 452 consecutive heart failure patients [New York Heart Association (NYHA) Class II/III] with NICM and LV ejection fraction ≤35% from a state-wide CMR service. All patients fulfilled European Society of Cardiology guidelines for primary prevention ICD implantation; however, the decision to implant was at the treating physician's discretion. Baseline clinical and CMR data were recorded prospectively and heart failure mortality risk (MAGGIC score) was calculated. The primary study outcome measurement was all-cause mortality based on presence or absence of ICD, stratified by LV scar. Median follow-up was 37.9 months and there was no difference in MAGGIC score between those who did and did not receive a primary prevention ICD (19.30 ± 5.46 vs. 18.90 ± 5.67, P = 0.50). In patients without LV scar, ICD implantation was not associated with improved mortality [hazard ratio (HR) = 1.22, 95% confidence interval (CI): 0.53-2.78, P = 0.64]. In patients with LV scar, ICD implantation was independently associated with reduced mortality (HR = 0.45, 95% CI: 0.26-0.77, P = 0.003). In patients with NICM, primary prevention ICD implantation is only associated with reduced mortality in patients with LV scar. This may enable more effective selection of NICM patients for ICD implantation compared with current guidelines.

Heart Failure in Constrictive Pericarditis Improves Rapidly with Medical Therapy in Patients with Higher Inflammatory Burden

Introduction Diastolic heart failure is the primary pathophysiologic manifestation of constrictive pericarditis. Pericardiectomy is the choice of treatment for patients who fail medical therapy. Constrictive pericarditis may be chronic or transient inflammatory or a combination of both. Medical therapy with anti-inflammatory drugs improves the pericardial inflammation in patients with increased delayed hyper-enhancement (DHE) on cardiac magnetic resonance (CMR) imaging. The evolution of constrictive physiology, heart failure manifestations and outcomes with such treatment need more study. Hypothesis We hypothesize that in inflammatory constrictive pericarditis, anti-inflammatory therapy may reduce the need for pericardiectomy by reducing inflammation and improving heart failure symptoms. We also hypothesize that patients with severe inflammation have the best response to medical therapy. Methods Consecutive patients diagnosed with constrictive pericarditis and pericardial inflammation as evidenced by their CMR and elevated inflammatory markers were included. Patients were treated as per standard of care with anti-inflammatory therapy and diuretics, and followed on an outpatient basis. CMR imaging was obtained at approximately 6 month intervals. Patients received pericardiectomy if they had persistent constrictive physiology and signs and symptoms of heart failure despite optimal therapy. Baseline characteristics, laboratory values, echocardiographic and CMR data were collected. Pericardial delayed hyper-enhancement was quantified by measuring the volume of DHE using an intensity cutoff of >6 SD above normal septal myocardium. Results A total of 44 patients with 123 CMRs were included. Pericardiectomy was performed in 19 patients. Mean age was 57.9 ± 14.5 years and 9 (28%) patients were female. Mean left ventricular ejection fraction was 59 ± 6.5 %. There were no significant baseline differences between patients who underwent pericardiectomy and those who did not. On mixed model logistic regression analysis, the odds of having constrictive physiology was reduced by 49% (95% CI: 14%–70%, P=0.011) per year of optimal medical therapy. Patients with DHE above median had a 69% lower risk of needing pericardiectomy (HR: 0.31, 95%CI: 0.10–0.95, P=0.039) (Figure. 1). Conclusions With optimal anti-inflammatory therapy, constrictive physiology resolves significantly over time. The risk of requiring pericardiectomy is lower in patients with higher pericardial delayed hyper-enhancement at baseline.

Proximal pulmonary vascular stiffness as a prognostic factor in children with pulmonary arterial hypertension.

Main pulmonary artery (MPA) stiffness and abnormal flow haemodynamics in pulmonary arterial hypertension (PAH) are strongly associated with elevated right ventricular (RV) afterload and associated with disease severity and poor clinical outcomes in adults with PAH. However, the long-term effects of MPA stiffness on RV function in children with PAH remain poorly understood. This study is the first comprehensive evaluation of MPA stiffness in children with PAH, delineating the mechanistic relationship between flow haemodynamics and MPA stiffness as well as the prognostic ability of these measures regarding clinical outcomes. Fifty-six children diagnosed with PAH underwent baseline cardiac magnetic resonance (CMR) acquisition and were compared with 23 control subjects. MPA stiffness and wall shear stress (WSS) were evaluated using phase contrast CMR and were evaluated for prognostic potential along with standard RV volumetric and functional indices. Pulse wave velocity (PWV) was significantly increased (2.8 m/s vs. 1.4 m/s, P < 0.0001) and relative area change (RAC) was decreased (25% vs. 37%, P < 0.0001) in the PAH group, correlating with metrics of RV performance. Decreased WSS was associated with a decrease in RAC over time (r = 0.679, P < 0.001). For each unit increase in PWV, there was approximately a 3.2-fold increase in having a moderate clinical event. MPA stiffness assessed by non-invasive CMR was increased in children with PAH and correlated with RV performance, suggesting that MPA stiffness is a major contribution to RV dysfunction. PWV is predictive of moderate clinical outcomes, and may be a useful prognostic marker of disease activity in children with PAH.

A NOVEL CLINICAL RISK MODEL FOR THE PREDICTION OF PROGRESSION OF ISCHEMIC MITRAL REGURGITATION IN PATIENTS WITH ADVANCED ISCHEMIC CARDIOMYOPATHY: A MULTIMODALITY STUDY

Ischemic mitral regurgitation (IMR) is associated with poor outcomes. Predicting progression of IMR may aid in risk stratification and management. Consecutive ischemic cardiomyopathy (ICM) patients with baseline cardiac magnetic resonance (CMR) and echocardiography and echocardiographic follow up

"Malignant" Left Ventricular Hypertrophy Identifies Subjects at High Risk for Progression to Asymptomatic Left Ventricular Dysfunction, Heart Failure, and Death: MESA (Multi-Ethnic Study of Atherosclerosis).

BackgroundAs heart failure (HF)‐associated morbidity and mortality continue to escalate, enhanced focus on prevention is increasingly important. “Malignant” left ventricular (LV) hypertrophy (LVH): LVH combined with an elevated cardiac biomarker reflecting either injury (high‐sensitivity cardiac troponin T), or strain (amino‐terminal pro‐B‐type natriuretic peptide) has predicted accelerated progression to HF. We sought to determine whether malignant LVH identified community‐dwelling adults initially free of cardiovascular disease at high risk of asymptomatic decline in LV ejection fraction or a clinical cardiovascular event.Methods and ResultsA total of 4985 of 6814 individuals without prevalent cardiovascular disease underwent baseline cardiac magnetic resonance for LVH in combination with measurement of plasma high‐sensitivity cardiac troponin T and amino‐terminal pro‐B‐type natriuretic peptide as part of MESA (Multi‐Ethnic Study of Atherosclerosis) and were subsequently divided into 4 groups: (1) No LVH, no elevated biomarkers (n=2206; 44.3%); (2) No LVH, ≥1 elevated biomarkers (n=2275; 45.7%); (3) LVH, no elevated biomarkers (n=153; 3.0%); and (4) LVH, ≥1 elevated biomarkers (malignant LVH; n=351; 7.0%). Cardiac magnetic resonance was repeated 10 years later (n=2831) for assessment of LV ejection fraction <50%. Median follow‐up was 12.2 years. Malignant LVH was associated with 7.0‐, 3.5‐, and 2.6‐fold adjusted increases in incidence of HF, cardiovascular death, and asymptomatic LV dysfunction, respectively, versus group 1. New‐onset HF was predominately HF with reduced ejection fraction (9.5‐fold increase).ConclusionsMalignant LVH is predictive of progression to asymptomatic LV dysfunction, HF (particularly HF with reduced ejection fraction), and cardiovascular death. Consequently, malignant LVH represents a high‐risk phenotype among individuals without known cardiovascular disease, which should be targeted for increased surveillance and more‐aggressive therapies.

Persistence of Late Gadolinium Enhancement in Post-Acute Myocarditis Imaging

Background: Diagnosis of acute myocarditis (AM) is based on combining ECG and seromarkers, but endomyocardial biopsy (EMB) remains the gold standard. Cardiac Magnetic Resonance (CMR) has been established as a reference standard for the non-invasive diagnosis. CMR is useful for follow-up since it is able to non-invasively delineate the presence and extent of myocardial edema and myocardial left ventricle (LV) lesions, represented by late gadolinium enhancement (LGE). The follow-up depends on the individual scenario. The aim of this study is to correlate CMR findings with cardiac enzymes and inflammatory markers in patients with AM and to evaluate the utility of CMR follow-up, even after the resolution of the symptomatology.Methods: Between 2008 to 2016 thirty-three consecutive patients with clinical and laboratory suspicion of AM referred for CMR within seven days from the beginning of the symptoms. The final analysis included 24 patients with AM CMR-confirmed. The follow-up was performed between 3 and 24 months from the diagnosis. CMR was performed using a standard protocol. Presence of edema and extent of myocardial LGE were examined. The comparison between the proportion of patients affected by edema at onset and that of patients affected at the various follow-up was conducted through the test of Mc Nemar. The effect of the predictors on the outcome was evaluated with a nonparametric two-sample Wald test.Results: All patients showed edema and LGE at baseline CMR. The LV lateral wall resulted the most affected by edema (in particular the 12th segment), inferior and lateral wall of LV were the most involved by LGE. There was a highly significant effect (P<0.001) of the Troponin peak on the number of areas involved by LGE. At CMR follow-up, edema has resolved in all patients, LGE persisted in 23/24 patients.Conclusions: There is a correlation between the levels of troponin and myocardial LGE extension in baseline CMR but not between clinical conditions of the patients and post-myocarditis imaging. The presence and the extent of LGE in CMR follow-up are not predictive of outcome in patients without severe hemodynamic compromise, but it can be considered rather an early sign of poor prognosis.

Abstract 21264: Age and Gender Related Left Atrial Remodeling With Magnetic Resonance Imaging: Multi Ethnic Study of Atherosclerosis

Introduction: Left atrial (LA) structure and function are associated with future cardiovascular (CV) events and risk factors. Studying the longitudinal change of LA structure and function with age may provide important insights into the natural history of LA remodeling. Hypothesis: The aim of this study is to evaluate associations between age and gender with longitudinal changes in LA remodeling in a large multi-ethnic cohort free of clinical CV disease at baseline. Methods: Cardiac magnetic resonance (CMR) was used to identify longitudinal changes in LA structure and function in 2882 MESA participants who underwent baseline (year 2000-2002) and 10-year follow-up CMR imaging. Multimodality tissue tracking (MTT, Toshiba) software was used to calculate LA structure (LA maximum, minimum and pre-atrial contraction volumes indexed to body surface area - LA Vmax, Vmin and VpreA) and function (LA total, passive and active emptying fraction, LATEF, LAPEF, and LAAEF). Data were analyzed with multivariable mixed-effects regression models in which the outcome was CMR LA measurements, and the covariates included follow-up time and CV risk factors (hypertension, diabetes, smoking, race/ethnicity, body mass index, and lipid levels). Results: Participants were aged 45-84 years at baseline, and 53% were women. At baseline, men had lower LATEF than women (58.4 vs 63.4%, p&lt;0.05), while they had similar LA Vmax (30.3 vs 29.9 ml/m2, p=NS) and larger Vmin (13.1 vs 11.5 ml/m2, p=NS). Median time between baseline and follow-up CMR imaging was 9.4 years. Over this period, LA Vmax and Vmin increased in both men (by 4.8 and 5.2 ml/m2 respectively, p&lt;0.05) and women (by 4.9 and 4.6 ml/m2 respectively, p&lt;0.05); while LATEF decreased in both (-7.3 % in women, and -6.1% in men, p&lt;0.05). Conclusions: In a population free of CV disease, at baseline women had higher LA function than men, as well as lower LA volumes. Aging was associated with increased LA volume and decreased LA function in both men and women.

Late gadolinium enhancement as a predictor of functional recovery, need for defibrillator implantation and prognosis in non-ischemic dilated cardiomyopathy.

Aim of the study was to investigate whether late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR) predict reverse remodeling (RR) in non-ischemic dilated cardiomyopathy (NIDCM). Seventy-one NIDCM patients (age 57±14years, 43 males, median left ventricular ejection fraction [LVEF] 35%, [interquartile range 27-41%]) with two CMR scans within 5years were included. RR was defined as ≥10% reduction in left ventricular (LV) end-diastolic volume and ≥10% LVEF increase. The end-point was a composite of all-cause death, cardiovascular hospitalization or appropriate defibrillator discharge. LGE was assessed both visually and as percentage of LV mass (LGE%). LGE was present in 42 patients (59%). During the interval between the 2 CMR scans (median 28 [15-44]months), 22 patients (31%) displayed RR. LGE absence predicted RR irrespectively of baseline LV volumes and LVEF. Over a median 42[15-73]-month follow-up, the endpoint occurred in 36 patients (51%). LGE absence was associated with better prognosis (P=0.043), with best quantitative LGE cut-point <7% at ROC analysis (P=0.017), but RR was the strongest prognostic predictor. Among 35 patients with baseline LVEF <35%, 25 (69%) crossed the 35% LVEF threshold. Both LGE absence and quantitative LGE <7% were associated with crossing of the 35% LVEF threshold for defibrillator implantation; patients with either LGE or quantitative LGE≥7% had a worse prognosis. In NIDCM, the absence of LGE at baseline CMR is associated with RR. When baseline LVEF is <35%, LGE absence is associated with more frequent crossing of the 35% LVEF threshold for defibrillator implantation.

USE OF CARDIAC MAGNETIC RESONANCE TO IDENTIFY MITRAL VALVE FIBROTIC CHANGES AFTER MYOCARDIAL INFARCTION: VALIDATION IN A LARGE ANIMAL MODEL

Mitral valve (MV) fibrosis and thickening have been described after myocardial infarction (MI), potentially contributing to ischemic mitral regurgitation. There is currently no imaging tool available to explore those changes. MV late gadolinium enhancement (LGE) has been observed retrospectively in post-MI patients with cardiac magnetic resonance (CMR), potentially reflecting MV fibrotic changes. However, MV LGE has never been validated with histopathology. Baseline CMR was performed in 16 sheep. Mid-systolic MV LGE was assessed by CMR (200 milliseconds after QRS to avoid rapid leaflet motion during the acquisition). Metoprolol was given as needed when heart rate was over 100 beats per minute. Inferior MI was induced by surgical coronary ligation in 13 sheep; the survivors (n=9) had repeated CMR 3 months after MI, followed by sacrifice. Three normal animals were used as controls. MV LGE signal was correlated with MV thickness (microscopy) and collagen content (Masson Trichrome). Post-MI sheep had mild decrease in left ventricle ejection fraction (51±4 vs 61±9% at baseline, p=0.02). Among post-MI animals, 3/9 (33%) developed significant (greater than mild) mitral regurgitation. MV LGE was present in 2/16 (13%) sheep at baseline vs 6/9 (66%) after MI (p=0.02). MV LGE was present in all (3/3) post-MI sheep with mitral regurgitation at follow-up, vs 3/6 (50%) of post-MI sheep without regurgitation. By microscopy, post-MI sheep had thicker MV leaflets (p < 0.01), with more collagen positive areas (normalized for leaflet length) vs controls (364±91 vs 195±49 μm2/μm, p=0.01). MV showing LGE were significantly thicker (1057±240 μm vs 656 ±197 μm for those without LGE, p=0.003). In this animal model, MI was associated with thicker mitral valves with increased collagen. Presence of MV LGE was associated with increased MV thickness and all animals with post-MI mitral regurgitation had positive LGE. Development of non-invasive tools to identify MV fibrotic changes can enable the exploration of MV fibrosis in clinical studies.

Effect of Ischemia Duration and Protective Interventions on the Temporal Dynamics of Tissue Composition After Myocardial Infarction.

The impact of cardioprotective strategies and ischemia duration on postischemia/reperfusion (I/R) myocardial tissue composition (edema, myocardium at risk, infarct size, salvage, intramyocardial hemorrhage, and microvascular obstruction) is not well understood. To study the effect of ischemia duration and protective interventions on the temporal dynamics of myocardial tissue composition in a translational animal model of I/R by the use of state-of-the-art imaging technology. Four 5-pig groups underwent different I/R protocols: 40-minute I/R (prolonged ischemia, controls), 20-minute I/R (short-duration ischemia), prolonged ischemia preceded by preconditioning, or prolonged ischemia followed by postconditioning. Serial cardiac magnetic resonance (CMR)-based tissue characterization was done in all pigs at baseline and at 120 minutes, day 1, day 4, and day 7 after I/R. Reference myocardium at risk was assessed by multidetector computed tomography during the index coronary occlusion. After the final CMR, hearts were excised and processed for water content quantification and histology. Five additional healthy pigs were euthanized after baseline CMR as reference. Edema formation followed a bimodal pattern in all 40-minute I/R pigs, regardless of cardioprotective strategy and the degree of intramyocardial hemorrhage or microvascular obstruction. The hyperacute edematous wave was ameliorated only in pigs showing cardioprotection (ie, those undergoing short-duration ischemia or preconditioning). In all groups, CMR-measured edema was barely detectable at 24 hours postreperfusion. The deferred healing-related edematous wave was blunted or absent in pigs undergoing preconditioning or short-duration ischemia, respectively. CMR-measured infarct size declined progressively after reperfusion in all groups. CMR-measured myocardial salvage, and the extent of intramyocardial hemorrhage and microvascular obstruction varied dramatically according to CMR timing, ischemia duration, and cardioprotective strategy. Cardioprotective therapies, duration of index ischemia, and the interplay between these greatly influence temporal dynamics and extent of tissue composition changes after I/R. Consequently, imaging techniques and protocols for assessing edema, myocardium at risk, infarct size, salvage, intramyocardial hemorrhage, and microvascular obstruction should be standardized accordingly.

Ambient Coarse Particulate Matter and the Right Ventricle: The Multi-Ethnic Study of Atherosclerosis.

Background:Coarse particulate matter () is primarily mechanically generated and includes crustal material, brake and tire wear, and biological particles. is associated with pulmonary disease, which can lead to right ventricular (RV) dysfunction. Although RV characteristics have been associated with combustion-related pollutants, relationships with remain unknown.Objectives:To quantify cross-sectional associations between RV dysfunction and mass and components among older adults and susceptible populations.Methods:We used baseline cardiac magnetic resonance images from 1,490 participants (45–84 y old) from the Multi-Ethnic Study of Atherosclerosis and assigned 5-y residential concentrations of mass, copper, zinc, phosphorus, silicon, and endotoxin, using land-use regression models. We quantified associations with RV mass, end-diastolic volume, and ejection fraction after control for risk factors and copollutants using linear regression. We further examined personal susceptibility.Results:We found positive associations of RV mass and, to a lesser extent, end diastolic volume with mass among susceptible populations including smokers and persons with emphysema. After adjustment for copollutants, an interquartile range increase in mass () was associated with (95% CI: 0.0, 1.0), (95% CI: 0.1, 1.7), and (95% CI: 0.4, 2.5) larger RV mass among former smokers, current smokers, and persons with emphysema, respectively. No associations were found with healthy individuals or with ejection fraction.Conclusions:Alterations to RV structure may represent a mechanism by which long-term exposure increases risks for adverse respiratory and cardiovascular outcomes, especially among certain susceptible populations. https://doi.org/10.1289/EHP658

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.

The effects of pulmonary vasodilating agents on right ventricular parameters in severe group 3 pulmonary hypertension: a pilot study.

Pulmonary arterial hypertension (PAH)-approved vasodilators improve right ventricular (RV) function in patients with PAH. However, whether PAH-approved drugs ameliorate RV morphology and function in lung disease-associated pulmonary hypertension (lung-PH) remains unclear. We aimed to prospectively evaluate the changes in RV volume and ejection fraction (RVEF) in 14 consecutive severe lung-PH patients treated with PAH-approved vasodilators. Severe lung-PH was defined as a mean pulmonary arterial pressure (MPAP) of ≥35 mmHg or an MPAP of ≥25 mmHg with a cardiac index (L/min/m2) of <2. Right heart catheterization and cardiac magnetic resonance (CMR) imaging were performed at baseline and at 3 months after starting sildenafil with or without other PAH-approved drugs. Follow-up was conducted at 3 months in 11 participants; compared with baseline values, MPAP and pulmonary vascular resistance (PVR) decreased by 18% and 37%, respectively. Baseline CMR imaging revealed an elevated RV end-diastolic volume index (RVEDVI; mL/m2) of 117.5 ± 35.9 and a below-average RVEF of 25.2% ± 7.2%; after 3 months, RVEDVI decreased by 23.7% (P = 0.0061) and RVEF increased by 32.9% (P = 0.0165). Among the 11 patients, 3 were thought to be a stable and homogenous subset in terms of background lung disease and medical management administered. These 3 patients exhibited similar ameliorations in PVR and RVEF, compared with the other 8 patients. PAH-approved drug treatment may improve RV dilatation and systolic function among patients with severe lung-PH. This study was approved by University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) on September 1, 2013 (UMIN000011541).

Abstract 13848: Anatomic and Hemodynamic Changes in Single Ventricle Patients 3-9 Months After Fontan to the Teenage Years: Insights From Cardiac Magnetic Resonance and Computational Fluid Dyanmics

Introduction: Little is known of baseline cardiac magnetic resonance (CMR) data in single ventricle (SV) pts immediately after Fontan. In addition, total cavopulmonary connection (TCPC) changes from this point to the teen years may shed some light regarding how to optimize clinical outcome. Hypothesis: Anatomic, hemodynamic and computational fluid dynamic (CFD) parameters are significantly altered as pts age. Methods: SV pts 3-9 months after Fontan and teens were studied with CMR. Anatomy, flows and CFD modeling were performed. Significance = P&lt;0.05. Results: 22 were 3-9 months after Fontan (age 3±1.1 yrs, 0.6±0.3 yrs after Fontan) &amp; 25 were teens (age 16±1.8 yrs, 14.1±2.2 yrs after Fontan). Although a higher indexed powerloss (iPL) in teens almost reached significance, Reynold’s number &amp; particle resident time (time a red blood cell remains in the TCPC) were greater in teens than younger pts (table). Superior vena cava (SVC) pulsatility index (PI) was greater in younger pts while inferior vena cava (IVC) PI was greater in teens, owing to the primary caval return changing from SVC to IVC as pts age (table). Both cardiac index &amp; caval return decreased in teens while hepatic flow distribution (HFD) became more evenly distributed in teens (table). The % TCPC stenosis at its narrowest point was greater in teens (42.8 %) than younger pts (20.9%), P=0.009. In teens, iPL (R=0.39) and % TCPC stenosis (R=0.62) correlated with time from Fontan (P&lt;0.39 for both). Conclusion: In teens, iPL correlated with time from Fontan. Significant increase in particle resident time &amp; Reynold’s number occur as SV pts age, with increased narrowing of the TCPC while HFD became more even. SVC PI is higher in younger pts while IVC PI is higher in teens. Cardiac index &amp; caval return both decrease as pts age. These data serve as baseline information in the immediate post-operative state and may be used to aid in designing improved Fontan reconstruction to optimize clinical outcome.