Absence Of Late Gadolinium Enhancement Research Articles

Response to Letter Regarding Article, “Role of Cardiovascular Magnetic Resonance as a Gatekeeper to Invasive Coronary Angiography in Patients Presenting With Heart Failure of Unknown Etiology”

We thank Dr Hamilton-Craig and colleagues for their insightful remarks regarding our work. We concur with their assertion that “the absence of late gadolinium enhancement does not necessarily obviate the need to image coronary arteries,” because a small proportion (0%–7.1%) of patients will have global hibernation secondary to proximal severe coronary artery disease (CAD) without infarction.1,2 In their own study, revascularization in these patients resulted in improved outcome stemming from augmented ventricular function.2 For precisely this reason, our protocol used magnetic …

Prevalence and Clinical Profile of Myocardial Crypts in Hypertrophic Cardiomyopathy

In hypertrophic cardiomyopathy (HCM), cardiovascular MR can detect morphological abnormalities of the left ventricle (LV) not visualized with echocardiography. Although myocardial crypts (ie, narrow, blood-filled invaginations within the LV wall) have been recognized in HCM, all clinical implications of these structural abnormalities within the broad clinical HCM spectrum are not completely resolved. Therefore, we sought to characterize the prevalence and diagnostic significance of myocardial crypts in HCM patients. Cine and late gadolinium enhancement cardiovascular MR and 2-dimensional echocardiography were obtained in 292 consecutive patients with HCM including 31 genotype-positive/phenotype-negative family members without LV hypertrophy (28 ± 16 years; 51% male) and 261 patients with LV hypertrophy (46 ± 18 years; 60% male). Ninety-eight subjects without cardiovascular disease were controls. Myocardial crypts (1-6/patient) were identified only by cardiovascular MR in 19 of 31 genotype-positive/phenotype-negative patients (61%) compared with only 10 of 261 (4%) patients with HCM with LV hypertrophy (P<0.001) and were absent in control subjects. Twelve-lead electrocardiograms were normal in 10 (53%) of the genotype-positive/phenotype-negative patients with crypts. Crypts were confined to the basal LV, most commonly in the ventricular septum (n=21) or posterior LV free wall (n=4), and associated with normal LV contractility and absence of late gadolinium enhancement in all but one patient. LV myocardial crypts represent a distinctive morphological expression of HCM, occurring with different frequency in HCM patients with or without LV hypertrophy. Crypts are a novel cardiovascular MR imaging marker, which may identify individual HCM family members who should also be considered for diagnostic genetic testing. These data support an expanded role for cardiovascular MR in early evaluation of HCM families.

T2 Mapping of the myocardium, a quantitative tool for assessment of myocarditis

Background To quantify myocardial T2 value in patients with myocarditis and correlate the distribution of abnormal T2 values with the extent of macroscopic late gadolinium enhancement (LGE). Methods 25 patients with myocarditis were retrospectively evaluated for the utility of T2 mapping in diagnosing myocarditis. Patients with elevated troponins, negative coronary angiogram, and atypical LGE were diagnosed as acute myocarditis. Patients with normal troponins and macroscopic LGE at the time of cardiac MRI were diagnosed as remote myocarditis. As per our institutional protocol, T2 mapping sequences were performed in all cases with suspected myocarditis in addition to standard LGE images on 1.5 T scanner (Magnetom Aera and Avanto, Siemens medical solutions). T2 mapping was performed on three short axis images (base, mid chamber, and apex), yielding 16 myocardial segments for analysis (AHA segments). Single 4 chamber view image was obtained in addition. Minimum, peak and mean segmental T2 values were calculated by the first reader. Average segmental T2 values were documented along with documentation of the number of segments with elevated T2 values. The presence or absence of LGE was documented by a second reader blinded to the T2 results. Average segmental T2 values were then correlated with troponin levels at the time of the MRI examination. Results In patients with acute myocarditis, mean T2 values were elevated in segments showing LGE (average T2 value of 70 msec). The T2 values were also elevated in myocardial segments with no macroscopic LGE (avg 60 msec). On an average, there were 6 additional segments that showed elevated T2 values and no macroscopic LGE. In patients with remote myocarditis, the T2 values were normal in areas of LGE.

Insights from magnetic resonance imaging of left ventricular non-compaction in adults of North African descent

BackgroundLeft ventricular non-compaction (LVNC) is a recently recognized rare disorder. Magnetic resonance imaging (MRI) may help to clarify the uncertainties related to this genetic cardiomyopathy. Despite the fact that many articles have been published concerning the use of MRI in the study of LVNC, there is a lack of data describing the disease in the North African population. The aim of our study is to clarify MRI findings of LVNC in North African patients.MethodsIn our retrospective cohort, twelve patients (7 male, mean age 53 ± 8 years) underwent MRI for suspected LVNC. Correlations were investigated between the number of non-compacted segments per patient and left ventricular ejection fraction (LVEF), then between the number of non-compacted segments and left ventricular end diastolic diameter. The presence or absence of late gadolinium enhancement (LGE) was qualitatively determined for each left ventricular myocardial segment.ResultsNon-compaction was more commonly observed at the apex, the anterior and the lateral walls, especially on their apical and mid-cavity segments. 83% of patients had impaired LVEF. There was no correlation between the number of non-compacted segments per patient and LVEF (r = -0.361; p = 0.263), nor between the number of non-compacted segments per patient and left ventricular end diastolic diameter (r = 0.280; p = 0.377). LGE was observed in 22 left ventricular segments. No association was found between the pattern of fibrosis and non-compaction distribution (OR = 2.2, CI [0.91-5.55], p = 0.076).ConclusionThe distribution of LVNC in North African patients does not differ from other populations. Ventricular dysfunction is independent from the number of non-compacted segments. Myocardial fibrosis is not limited to non-compacted areas but can extend to compacted segments.

Abstract 8914: Late Gadolinium Enhancement Predicts Poor Prognosis in Patients with Known or Suspected Heart Failure

Background: Myocardial scar as detected by cardiac magnetic resonance (CMR) has been documented to provide important diagnostic information in patients with heart failure (HF). What is less clear is its' prognostic value in this cohort of patients. Methods: A total of 153 consecutive patients with known or suspected HF referred for CMR imaging from 2005 to 2008 were prospectively followed for clinical events. The primary composite end point (EP) was all-cause mortality or unplanned cardiovascular hospitalization. Secondary composite EP included unplanned HF hospitalization, worsening of NYHA class or cardiac resynchronization therapy implantation. Patients were divided into two groups: late gadolinium enhancement (LGE) + and LGE- depending on the presence and absence of LGE respectively. Post-scan follow-up was assessed by review of case notes, clinic visits and review of the National Survival database. Results: LGE was present in 94 patients (61%). Of these, 53% had infarct, 26% had mid-wall and 8% had patchy distribution of LGE. The LGE+ patients were older, more likely to be male, with larger left ventricular (LV) volumes, increased LV mass and a lower LV ejection fraction. At a mean follow-up of 3.1 ± 1.4 years, 39 (41%) in the LGE+ and 10 (17%) in the LGE- groups experienced the primary EP. Forty-six (49%) in the LGE+ and 12 (20%) in the LGE- groups experienced the secondary EP. Kaplan-Meier analysis revealed that LGE was a significant predictor of the primary (p=0.003) (Fig.1) and secondary (p=0.001) EPs. Cox regression analysis showed that presence of LGE was associated with an increase in composite primary and secondary EPs (HR: 2.73, p=0.005 and HR: 2.77, p=0.002, respectively). Multivariate analysis showed that LGE was the only independent predictor of both EPs. Conclusions: In patients with known or suspected HF, the presence of LGE is an independent prognostic marker of adverse events, with incremental value to standard clinical information.

Imaging of Scar in Patients with Ventricular Arrhythmias of Right Ventricular Origin: Cardiac Magnetic Resonance Versus Electroanatomic Mapping

Assessment of late gadolinium enhancement (LGE) at cardiac magnetic resonance is often used to detect scar in patients with arrhythmias of right ventricular (RV) origin. Recently, electroanatomic mapping (EAM) has been shown to reliably detect scars corresponding to different cardiomyopathic substrates. We compared LGE with EAM for the detection of scar in patients with arrhythmias of RV origin. Thirty-one patients with RV arrhythmias and biopsy-proven structural heart disease (18 ARVC and 13 myocarditis), and 5 with idiopathic RV outflow tract arrhythmias underwent LGE analysis and EAM with scar validation through EAM-guided endomyocardial biopsy. EAM scars were present in 23 (64%) patients (all with structural heart disease), whereas LGE was present only in 12 (33%). In 2 cases, EAM provided a false-positive diagnosis of a small scar in the basal perivalvular area. LGE correctly diagnosed EAM scar in 48% of patients, resulting in high positive (92%) but low negative (50%) predictive values. The distribution of LGE was significantly associated with the distribution of EAM scars (P < 0.001 in the free wall, P = 0.003 in the outflow tract, and P = 0.023 in the posterior/inferior wall). Presence of LGE reflected a higher extension of EAM scars (34.4 ± 16.5% vs 7.9 ± 10.1% of the RV area, P < 0.001). At receiver operating characteristic (ROC) analysis, an extension of scar ≥20% of the RV area was the best cut-off value to detect LGE (sensitivity 83%, specificity 92%). Of note, LGE missed 10 of 11 (91%) patients with EAM scars <20% of RV area. LGE is significantly less sensitive than EAM in identifying RV cardiomyopathic substrates. Absence of LGE does not rule out the presence of small scars, and EAM with biopsy should be considered to increase the diagnostic yield.

Left ventricular function, morphology, and myocardial tissue characterization in Sickle Cell Disease: a multi-modality imaging study

Methods Thirty-one stable, African-American outpatients with SCD (mean age 32±8 yrs) prospectively underwent CMR (Philips 1.5 Tesla) and TTE (Philips iE33). Retrospectivelygated cines of left ventricular (LV) 2-, 3-, and 4-chamber, and short axis cine stack were obtained using SSFP (temporal resolution 25-40ms). Late gadolinium enhancement (LGE) images of the same views were obtained 10-20 minutes after infusion of Gd-DTPA (0.15 mmol/kg) using phase sensitive inversion recovery (TR 4.5 ms, TE 2.2ms, TI 250-300 ms, flip angle 30°, PSIR flip angle 5°). Single short-axis, mid-ventricular myocardial T2* slice and coronal, hepatic T2* slice were acquired with a single breath-hold, at six echo-times (2.3 to 14 msec) using a gradient echo sequence. Tissue T2* signal intensity was measured in LV septum and liver at two separate echo times and T2*= ΔTE/ln (SITE2/ SITE1) where ΔTE represents time difference between the two echo times and ITE1 and ITE2 represent signal intensity at echo time one and two. Myocardial and hepatic T2* were abnormal if <20ms and <18ms, respectively. CMR LV volumes, ejection fraction (EF), and mass were calculated using method of disks and indexed for body surface area. The presence or absence of LGE was determined. Diastolic dysfunction (DD) was identified based on echocardiographic measurements including tissue Doppler (age adjusted E/A ratio) and left atrial volumes.

Myocardial Fibrosis Predicts Appropriate Device Therapy in Patients With Implantable Cardioverter-Defibrillators for Primary Prevention of Sudden Cardiac Death

The purpose of this study was to evaluate the association between regional myocardial fibrosis and ventricular arrhythmias in patients with cardiomyopathy. Patients with heart failure are at risk of sudden cardiac death (SCD). Current guidelines recommend implantable cardioverter-defibrillator (ICD) devices for a subgroup based on impaired left ventricular function. A significant proportion of devices never discharge, hence a more accurate method for targeting those at risk is desirable. We prospectively enrolled 103 patients meeting criteria for ICD implantation for primary prevention of SCD. Cardiac magnetic resonance imaging was performed before device implantation. Regional fibrosis was identified with late gadolinium enhancement (LGE). Median follow-up was 573 days (interquartile range: 379 to 863 days). The LGE identified regional fibrosis in 31 of 61 (51%) patients with nonischemic cardiomyopathy (NICM) and in all 42 patients with ischemic cardiomyopathy (ICM). There was a 29% (9 of 31) discharge rate in the NICM group with LGE compared with a 14% (6 of 42) discharge rate in the ICM group (p = NS). There were no ICD discharges in the NICM group without LGE, which was significantly lower than the rate observed in both the ICM patients (p = 0.04) and the NICM patients with LGE (p < 0.01). Left ventricular ejection fraction was similar in patients with and without device therapy (24 ± 12% vs. 26 ± 8%, p = NS) and those with or without LGE (25 ± 9% vs. 26 ± 9%, p = NS). Patients with advanced cardiomyopathy and myocardial fibrosis demonstrated by LGE on cardiac magnetic resonance imaging have a high likelihood of appropriate ICD therapy. Correspondingly, absence of LGE may indicate a lower risk for malignant ventricular arrhythmias.

Diffuse Late Gadolinium Enhancement by Cardiovascular Magnetic Resonance Predicts Significant Intraventricular Systolic Dyssynchrony in Patients With Non-Ischemic Dilated Cardiomyopathy

Left ventricular dyssynchrony and myocardial fibrosis are common findings in patients with nonischemic dilated cardiomyopathy (NDCM). The aim of this study was to investigate the association between myocardial fibrosis and intraventricular systolic dyssynchrony (DYS-sys) in patients with NDCM. Thirty-nine patients with NDCM and sinus rhythm were enrolled. Intraventricular DYS-sys was evaluated using Doppler tissue imaging, and cardiac fibrosis was assessed with cardiovascular magnetic resonance imaging with a 17-segment cardiac model. Each segment was graded on a 2-point scale (segmental fibrosis score): 0 = absence of late gadolinium enhancement, and 1 = presence of late gadolinium enhancement. A cardiac fibrosis index was calculated as 17/(17 - sum of fibrotic segments). Receiver operating characteristic analysis was performed to determine the utility of the cardiac fibrosis index to predict intraventricular systolic dyssynchrony. Patients with DYS-sys had larger left atrial size (P = .004) and left ventricular end-systolic (P = .028) and end-diastolic (P = .034) volumes and lower tricuspid annular Doppler tissue imaging peak systolic velocities (P = .037) compared with patients without DYS-sys. A cardiac fibrosis index > or = 1.4 predicted significant DYS-sys with 92% sensitivity and 60% specificity (area under the receiver operating characteristic curve, 0.703; 95% confidence interval, 0.512-0.893; P = .035). Patients with cardiac fibrosis indexes > or = 1.4 (group 1) had larger left ventricular end-systolic (P = .044) and end-diastolic (P = .034) volumes than those with cardiac fibrosis indexes < 1.4 (group 2). Nine of 11 patients (82%) in group 1 and 6 of 28 patients (21%) in group 2 had significant DYS-sys (Pearson's chi(2) = 12.169, P < .0001). Logistic regression analysis revealed that cardiac fibrosis index > or = 1.4 (odds ratio, 11.2; 95% confidence interval, 1.72-71.4; P = .012) was an independent predictor of DYS-sys. Patients with NDCM and prominent cardiac fibrosis have significant DYS-sys. The cardiac fibrosis index is a useful tool to predict DYS-sys.

Myocardial Fibrosis Predicts Appropriate Device Therapy in Patients with Implantable Cardioverter Defibrillators for Primary Prevention of Sudden Cardiac Death

Objectives The purpose of this study was to evaluate the association between regional myocardial fibrosis and ventricular arrhythmias in patients with cardiomyopathy. Background Patients with heart failure are at risk of sudden cardiac death (SCD). Current guidelines recommend implantable cardioverter-defibrillator (ICD) devices for a subgroup based on impaired left ventricular function. A significant proportion of devices never discharge, hence a more accurate method for targeting those at risk is desirable. Methods We prospectively enrolled 103 patients meeting criteria for ICD implantation for primary prevention of SCD. Cardiac magnetic resonance imaging was performed before device implantation. Regional fibrosis was identified with late gadolinium enhancement (LGE). Results Median follow-up was 573 days (interquartile range: 379 to 863 days). The LGE identified regional fibrosis in 31 of 61 (51%) patients with nonischemic cardiomyopathy (NICM) and in all 42 patients with ischemic cardiomyopathy (ICM). There was a 29% (9 of 31) discharge rate in the NICM group with LGE compared with a 14% (6 of 42) discharge rate in the ICM group (p = NS). There were no ICD discharges in the NICM group without LGE, which was significantly lower than the rate observed in both the ICM patients (p = 0.04) and the NICM patients with LGE (p Conclusions Patients with advanced cardiomyopathy and myocardial fibrosis demonstrated by LGE on cardiac magnetic resonance imaging have a high likelihood of appropriate ICD therapy. Correspondingly, absence of LGE may indicate a lower risk for malignant ventricular arrhythmias.

Absence of late gadolinium enhancement does not exclude total coronary occlusion

Methods We retrospectively searched our clinical database from January 2004 to June 2009 for all patients with total coronary occlusions in coronary angiography and a CMR scan. We identified 1077 patients with total coronary occlusions and a CMR report. 523 were excluded due to non-contrast CMR study or presence of coronary bypass grafts. The remaining 554 patients formed the study group. In all had of them we obtained a contiguous short axis stack of segmented inversion recovery gradient echo images (TR 11 ms, TE 4 ms, slice thickness 10 mm, inversion time set to null viable myocardium) after 0.2 mmol/ kg bw gadolinium-DTPA. Left ventricular ejection fraction (LVEF) was calculated based on biplanar long axis SSFP cine loops. We used cross validation and logistic regression analysis to compare patients with and without scar. Results Median time between CMR and coronary angiography was 5 days. Median age was 69 years. 85% were male. Body mass index was 28 ± 5 kg/m2. Mean LVEF was 45 ± 14%. 36 patients (7%) had normal wall motion, 138 (25%) had normal LVEF. In 49 of 554 (8.8%) CMR could exclude myocardial scar despite coronary occlusion. All were chronic CAD patients with angiographic evidence of coronary collaterals. There was a trend for higher age and better LVEF in patients without scar. The groups did not differ in sex, BMI or presence of risk factors. Hypertension was prevalent in 31% of the patients. 77% were diabetic, 72% were smokers.

Inflammation in takotsubo cardiomyopathy: insights from cardiovascular magnetic resonance imaging

Takotsubo cardiomyopathy (TTC) is an increasingly recognised acute cardiac syndrome, whose underlying pathophysiological mechanisms remain unknown. Inflammation might play a role as this has been shown in endomyocardial biopsies. The aim of this study was to assess inflammatory parameters in patients with TTC using a comprehensive cardiovascular magnetic resonance imaging (CMR) approach. Thirty-seven patients with the suspected diagnosis of TTC underwent CMR. T2-weighted imaging to calculate the oedema ratio, T1-weighted imaging before and after contrast agent administration to calculate the global relative enhancement (gRE), and late gadolinium enhancement (LGE) imaging were performed. In 11 patients CMR revealed the diagnosis of myocardial infarction (n = 7; 19%) or myocarditis (n = 4; 11%) with typical patterns of LGE. In all other patients (n = 26; 70%), no LGE was detected consistent with the diagnosis of TTC. Of these, in 16 patients (62%) both inflammatory markers (oedema ratio and gRE) were elevated with concomitant pericardial effusion, indicating acute inflammation. Follow-up CMR after 3 months showed complete normalisation of left ventricular function and inflammatory parameters in the absence of LGE and pericardial effusion. This CMR study provides further insights into the pathophysiological mechanisms in TTC, supporting the contribution of an inflammatory process in the acute setting.

Abstract 5920: Usefulness of Late Gadolinium Enhancement as Non-invasive Arrhythmic Risk Marker in Patients with Heart Failure and Systolic Dysfunction

The identification of prognostic markers in patients with heart failure of both ischemic and non ischemic etiology is an increasing need in the era of devices therapy. Risk stratification for sudden cardiac death (SCD) remains problematic with reliance on left ventricular function which predicts total mortality rather than arrhythmic events (AE). Recently cardiac magnetic resonance was employed to predict susceptibility for malignant arrhythmias. This study sought to determine the utility of late gadolinium enhancement (LGE) to predict AE. Three hundred consecutive patients with symptomatic heart failure and systolic dysfunction of both ischemic and non ischemic cause undergoing CMR, were classified into two groups attending to the presence (n 160) or absence of LGE (n 140), and were followed prospectively during 842 days. The primary endpoint was the combined of SCD or Ventricular tachycardia (VT). 23 patients had AE (8 SCD/15 VT) during the follow-up, 19 of them presenting LGE (83%). The presence of LGE was associated to a significantly higher AE rate (11.8.% vs 2.8% p&lt; 0.001)(figure ). Compared to patients without LGE, midwall fibrosis and an ischemic pattern of LGE predicted AE. (3% vs 5% vs 14%, p= 0.001) LGE is a new non-invasive predictor of AE in patients with heart failure and systolic dysfunction. This suggest a potential role for risk stratification and better selection of patients who needs device therapy

Can late gadolinium enhancement by cardiovascular magnetic resonance identify coronary artery disease as the etiology of new onset congestive heart failure?

New left ventricular systolic dysfunction affects 500,000 Americans and coronary artery disease (CAD) is responsible for two-thirds of cases. Identifying CAD has both prognostic and therapeutic implications. We evaluated the ability of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance imaging (CMR) to detect CAD as the etiology of recent onset congestive heart failure (CHF). CMR and LGE were performed in 26 patients with new onset left ventricular systolic dysfunction. All patients received an x-ray angiography for identification of CAD. Patients with an acute coronary syndrome with troponin I > 1.0 ng/ml or a history of CAD were excluded. The presence and distribution of LGE was evaluated. Significant coronary stenoses were present in 5 of 26 patients (19%). LGE in an infarct pattern was found in 2 of the 5 patients with CAD. Of the 21 patients without CAD, 2 had midwall enhancement but none had evidence of LGE in an infarct pattern. When present, LGE in an infarct pattern suggests CAD as the etiology of new onset CHF. However, the absence of LGE does not exclude CAD as the underlying etiology. A small proportion of patients with a nonischemic cause of new onset CHF have LGE limited to the midwall.