Significance of Late Gadolinium Enhancement in Cardiovascular Magnetic Resonance Imaging (CMR)

Cardiovascular magnetic resonance imaging (CMR) permits optimal differentiation between normal and diseased myocardium with the use of gadoliniumbased contrast agents and special magnetic resonance pulse sequences. Imaging is performed 10-20 min after contrast agent application to produce so-called late gadolinium enhancement (LGE) images which depict diseased myocardium with excellent reproducibility. Areas showing LGE correspond to zones of myocyte necrosis or myocardial fibrosis as shown by comparison with histopathology. Typical patterns of hyperenhancement exist in ischemic heart disease but also in dilated cardiomyopathy, hypertrophic cardiomyopathy and other inflammatory or infiltrative myocardial disease and are described in this article. LGE-CMR is helpful to distinguish advanced ischemic heart disease from nonischemic dilated cardiomyopathy. In ischemic heart disease LGE can also predict the functional recovery after revascularization procedures by directly showing the remaining viable myocardium. LGE may also become useful to predict malignant arrhythmias in patients with ischemic heart disease or nonischemic cardiomyopathy. This may lead in future to an increased role of LGE-CMR as a prognostic tool.     

Asymptomatic myocardial ischemic disease in antiphospholipid syndrome: A controlled cardiac magnetic resonance imaging study

Objective

Antiphospholipid syndrome (APS) may cause coronary thrombosis. This study was undertaken to determine the prevalence of silent myocardial disease in patients with APS, using late gadolinium enhancement (LGE) of cardiac magnetic resonance imaging (CMRI).

Methods

Twenty‐seven consecutive patients with APS and 81 control subjects without known cardiovascular disease underwent CMRI. The prevalence of occult myocardial ischemic disease, as revealed by LGE, was compared between patients with APS and controls, and factors associated with myocardial disease were identified in patients with APS.

Results

Myocardial ischemic disease, as characterized by LGE on CMRI, was present in 8 (29.6%) of 27 patients with APS, and imaging with LGE showed a typical pattern of myocardial infarction (MI) in 3 patients (11.1%). The myocardial scarring revealed on CMRI was not detected by electrocardiography or echocardiography. Although both patients with APS and control subjects shared a low risk of cardiovascular events, as calculated with the Framingham risk equation (mean ± SD 5.1 ± 8.2% and 6.5 ± 7.6%, respectively, for the absolute risk within the next 10 years; P = 0.932), the prevalence of myocardial ischemia was more than 7 times higher in patients with APS (P = 0.0006 versus controls). No association was found between myocardial disease in patients with APS and classic coronary risk factors. The presence of myocardial scarring tended to be more closely associated with specific features of APS, such as duration of the disease, presence of livedo, and positivity for anti–β₂‐glycoprotein I antibodies.

Conclusion

The finding of a significant and unexpectedly high prevalence of occult myocardial scarring in patients with APS indicates the usefulness of CMRI with LGE for the identification of silent myocardial disease in such patients.

     

Myocardial Injury and Fibrosis From Acute Carbon Monoxide Poisoning: A Prospective Observational Study

ObjectivesThis study sought to evaluate the prevalence and patterns of late gadolinium enhancement (LGE) after carbon monoxide (CO) poisoning using cardiac magnetic resonance (CMR) imaging (CMRI) and transthoracic echocardiography (TTE).BackgroundIn acute CO poisoning, cardiac injury can predict mortality. However, it remains unclear why increased mortality and cardiovascular events occur despite normalization of CO-induced elevated troponin I (TnI) and cardiac dysfunction.MethodsPatients with acute CO poisoning with elevated TnI were evaluated. CMRI was performed within 7 days of CO exposure and after 4 to 5 months. Patients were divided into LGE (n = 72; 69.2%) and no-LGE (n = 32; 30.8%) groups.ResultsIn the LGE group, 39.4%, 4.8%, and 25.0% of patients exhibited midwall, subendocardial, and right ventricular insertion point injury, respectively. Diffuse injury was observed in 22.1% of patients, and 67.6% of the 37 patients who underwent follow-up CMRI showed no interval change. On TTE, baseline left ventricular ejection fraction and global longitudinal strain were significantly deteriorated in the LGE group; serial TTE within 7 days indicated that only left ventricular global longitudinal strain remained significantly deteriorated. Three cases of mortality occurred in the LGE group during the 1-year follow-up.ConclusionsThe LGE prevalence in patients with acute CO poisoning with elevated TnI levels, with no underlying cardiovascular diseases and eligible for CMRI, was 69.2%; this proportion primarily comprised patients with a midwall injury. Of the 37 patients who underwent follow-up CMRI, most chronic phase images showed no interval change. Myocardial fibrosis detected on CMR images was related to acute myocardial dysfunction and subacute deterioration of myocardial strain on TTE. (Cardiac Magnetic Resonance Image in Acute Carbon Monoxide Poisoning; NCT04419298)     

The role of cardiovascular magnetic resonance imaging in the diagnosis and prognosis of patients with heart failure

Cardiovascular magnetic resonance (CMR) imaging is a tomographic technique, which allows three-dimensional slice orientation without limitations from acoustic windows inherent to echocardiography. Further advantages of CMR are its high temporal and spatial resolution, its excellent soft tissue resolution and its high blood-to-tissue contrast. Cardiovascular magnetic resonance is currently the only imaging technique, which provides a comprehensive study of both structure and function of the heart as well as myocardial perfusion and viability. Moreover, post-processing of CMR images does not require any geometric assumptions as in echocardiography to determine ventricular dimensions. This is particularly important when evaluating ventricles of patients with chronic heart failure with severely altered morphology that may have regional variations in wall thickness and contractility at least in ischemic cardiomyopathy. The highly reproducible results of CMR imaging have turned this technique into a reference standard for the non-invasive assessment of ventricular dimensions, mass and function. In cases with indeterminate results of clinical, electrocardiographic and particularly echocardiographic findings CMR should be used early in the process of diagnosis of patients with heart failure. Not only can altered structure and degree of ventricular and valvular dysfunctions be accurately assessed but also regional perfusion deficits and/or myocardial scars are easily detected. For therapeutic and prognostic reasons a simple differentiation between ischemic and non-ischemic cardiomyopathy should be achieved as the first diagnostic step. In addition, the type and localization of the late gadolinium enhancement (LGE) phenomenon may aid in non-invasively differentiating the etiology of non-ischemic cardiomyopathy. CMR may also improve the assessment and extent of interventricular and intraventricular dyssynchrony in patients to be selected for cardiac resynchronization therapy (CRT). Lastly, the LGE phenomenon may provide independent prognostic information in patients with a CRT system implanted, as well as in patients with ischemic and non-ischemic cardiomyopathy. Thus, CMR imaging should be implemented early in the diagnostic process of patients with heart failure to significantly improve the speed and accuracy of diagnostic procedures, to control the effect of therapeutic measures, and to select patients with a limited prognosis by assessing the degree of ventricular dysfunction and the extent of myocardial scarring.     

Long-term prognostic value of 201Tl single-photon emission computed tomographic myocardial perfusion imaging after coronary stenting

BACKGROUND: The prognostic value of (201)Tl myocardial imaging has been demonstrated in several studies concerning patients with a known significant coronary artery disease. However, the evolution of a coronary stenosis after stenting is difficult to predict. This study was designed to assess the prognostic value of (201)Tl single-photon emission computed tomography (thallium SPECT) perfusion imaging in patients after intracoronary stenting. METHODS: One hundred fifty-two patients were studied. They were followed up during 40 +/- 13 (mean +/- SD) months after thallium SPECT. Stent-related events were studied after thallium stress testing and included cardiovascular death, myocardial infarction, and revascularization. Stress thallium imaging was performed 5 +/- 2 months after stenting, and ischemia was considered to be present if at least 2 contiguous segments were showing reversible defects. RESULTS: Only 3 (3%) among the 105 nonischemic patients had major cardiac events during the follow-up versus 13 (28%) of the 47 ischemic patients (P < .001) after thallium SPECT. The relative risk of major cardiac events for patients with significant ischemia was 10.5 compared with nonischemic patients (P < .001). Fourteen (30%) of the ischemic patients and 8 (8%) among the nonischemic patients underwent iterative revascularization (P < .001). Therefore, only 11 (10%) of the nonischemic patients had major cardiac events or revascularization compared with 24 (51%) of the ischemic patients (P < .001). CONCLUSIONS: Absence of ischemia on thallium SPECT imaging at 5 months after coronary stenting indicates a low risk for cardiovascular events or interventional procedure. These results may have important clinical implications in patient treatment.     

Prospective validation of a quantitative method for differentiating ischemic versus nonischemic cardiomyopathy by technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography

BACKGROUND: Myocardial perfusion single-photon emission computed tomography (SPECT) permits assessment of stress perfusion and resting left ventricular (LV) function. Quantitative analysis of perfusion patterns among patients with LV dysfunction offers an opportunity for developing criteria to differentiate ischemic from nonischemic cardiomyopathy. HYPOTHESIS: Quantitative assessment of SPECT may allow differentiation between ischemic and nonischemic cardiomyopathy. METHODS: We evaluated 144 patients with LV ejection fraction < or =40%, divided into 63 patients with nonischemic and 81 with ischemic cardiomyopathy. Mean relative myocardial counts were obtained for regions drawn over defect and normal zones on rest and stress polar perfusion maps. RESULTS: Multivariate logistic regression analysis of significant univariate SPECT predictors of ischemic cardiomyopathy revealed that the stress defect severity ratio (SDSR) was the best predictor of ischemic cardiomyopathy (p < 0.0001). By receiver operator characteristic (ROC) curve analysis, an SDSR of < or =45% optimized prediction of ischemic cardiomyopathy (sensitivity 81%, specificity 96%). An SDSR of < or =45% occurred in 65 of 81 (80%) patients with ischemic cardiomyopathy, but in only 3 of the 63 (4%) patients with nonischemic cardiomyopathy (p < 0.0001). Applying the < or =45% SDSR threshold to a prospective group of 89 patients yielded a somewhat lower sensitivity (60%), but retained high specificity (91%) for identifying ischemic cardiomyopathy (p = NS vs. retrospective group). CONCLUSIONS: Presence of a severe and extensive stress perfusion defect is a hallmark of ischemic cardiomyopathy. By contrast, a mild stress perfusion defect (SDSR of >45%) is commonly present among patients with ischemic and nonischemic cardiomyopathy. An SDSR of < or =45% is a reproducible specific marker for identifying the presence of ischemic cardiomyopathy.     

Feature-Tracking Global Longitudinal Strain Predicts Death in a Multicenter Population of Patients With Ischemic and Nonischemic Dilated Cardiomyopathy Incremental to Ejection Fraction and Late Gadolinium Enhancement

Objectives

The aim of this study was to evaluate the prognostic value of cardiac magnetic resonance (CMR) feature-tracking–derived global longitudinal strain (GLS) in a large multicenter population of patients with ischemic and nonischemic dilated cardiomyopathy.

The Hypertrophic Cardiomyopathy Phenotype Viewed Through the Prism of Multimodality Imaging: Clinical and Etiologic Implications

Noninvasive contemporary imaging with echocardiography and cardiovascular magnetic resonance (CMR) provide comprehensive characterization of the hypertrophic cardiomyopathy (HCM) heart including precise definition of left ventricle (LV) wall thickness and reliable identification of morphologic abnormalities of the mitral valve, LV chamber, and myocardial tissue characterization with late gadolinium enhancement (LGE) (fibrosis). Imaging also contributes to identification of patients at risk for sudden death including novel high-risk features such as LV apical aneurysm and extensive LGE. Exercise (stress) echocardiography should be considered to demonstrate physiologic provocation of LV outflow gradients and to distinguish from patients with nonobstructive HCM. Multimodality imaging identifies patients who are optimal candidates for invasive septal reduction therapy and directs preoperative planning for extended myectomy and to optimize alcohol septal ablation. Contemporary imaging interwoven with current management strategies have resulted in a low HCM-related mortality rate.     

Differentiation of ischemic from nonischemic cardiomyopathy with positron emission tomography

This study was undertaken to determine whether positron emission tomography (PET) performed after the intravenous injection of 11C-palmitate permits differentiation of patients with ischemic from those with nonischemic dilated cardiomyopathy. PET was performed after intravenous injection of 11C-palmitate in 10 patients with ischemic and in 10 with nonischemic dilated cardiomyopathy. Regions of homogeneously severely depressed accumulation of 11C-palmitate, representing 15% or more of the expected myocardial cross-sectional area, were observed in 8 of 10 patients with ischemic but in none of 10 patients with nonischemic cardiomyopathy. Patients with nonischemic cardiomyopathy had marked spatial heterogeneity of the accumulation of palmitate throughout the left ventricular myocardium, whereas most tomographic sections from patients with ischemic cardiomyopathy accumulated 11C-palmitate more homogeneously in regions exclusive of discrete defects indicative of remote infarction. Thus, a larger number of discrete noncontiguous regions (17 +/- 5 compared with 12 +/- 4, p less than 0.001) and greater reduction of average 11C-palmitate content (59 +/- 6 compared with 64 +/- 10% maximal myocardial radioactivity, p less than 0.05) were seen in the tomographic reconstructions from patients with nonischemic than in those from patients with ischemic cardiomyopathy. These findings support the hypothesis that multiple myocardial infarctions underlie the process seen as dilated cardiomyopathy in patients with coronary artery disease. Our findings indicate that PET permits differentiation of patients with ischemic from those with nonischemic cardiomyopathy.     

Prognostic value of pulsed tissue Doppler imaging for the assessment of left ventricular systolic function in patients with nonischemic dilated cardiomyopathy

There is still some debate regarding the prognostic significance of left ventricular longitudinal systolic dysfunction as assessed by tissue Doppler (TD) imaging in patients with chronic heart failure (HF), since previous studies have included patients with postischemic wall motion abnormalities. Thus, this study was designed to ascertain whether TD-derived longitudinal systolic dysfunction may influence the outcome of patients with nonischemic chronic HF. In 200 consecutive patients with chronic HF secondary to dilated cardiomyopathy and no history of ischemic heart disease, peak systolic mitral annular velocity (S(m) ) was measured by pulsed TD at the septal and lateral annular sites. The end points were cardiac death or hospitalization for worsening HF. Mean follow-up duration was 30 months. In a time independent analysis, averaged S(m) calculated as the average of septal and lateral S(m) , resulted to be a significant predictor of outcome in the study population (area under receiver-operator characteristic curve: cardiovascular death, 0.69, P < 0.0001; cardiovascular events, 0.64, P = 0.0005). In a time-dependent analysis, average S(m) was associated with both cardiovascular death (hazard ratio 0.832, P = 0.0019) and cardiovascular events (hazard ratio 0.904, P = 0.039), independently of other clinical risk factors and echocardiographic parameters of systolic function. Septal S(m) but not lateral S(m) was independently associated with the outcome measures. In conclusion, the assessment of systolic mitral annular velocity by pulsed TD is a useful indicator for prognostic stratification of patients with nonischemic dilated cardiomyopathy and chronic HF.     

Course of Cardiac Magnetic Resonance Imaging Findings in Acute Myocarditis after COVID-19 mRNA Vaccination

Myocarditis is being increasingly reported as a rare complication of coronavirus disease 2019 (COVID-19) mRNA vaccines. We herein report a case of myocarditis following COVID-19 mRNA vaccination in a man. Cardiac magnetic resonance imaging (CMRI) revealed an area of high signal intensity on short T1 inversion recovery (STIR) and late gadolinium enhancement (LGE), which are characteristic of myocarditis. Follow-up CMRI performed six months later revealed improvement in the myocardial edema and LGE findings. CMRI is a useful non-invasive imaging modality for making an initial diagnosis as well as for follow-up in cases of myocarditis after COVID-19 mRNA vaccination.     

Complexity of scar and ventricular arrhythmias in dilated cardiomyopathy of any etiology: Long‐term data from the SCARFEAR (Cardiovascular Magnetic Resonance Predictors of Appropriate Implantable Cardioverter‐Defibrillator Therapy Delivery) Registry

Background

Late gadolinium enhancement (LGE) assessed with cardiovascular magnetic resonance (CMR) correlates with ventricular arrhythmias and survival in patients with structural heart disease. Whether some LGE characteristics may specifically improve prediction of arrhythmic outcomes is unknown.

Hypothesis

We sought to evaluate scar characteristics assessed with CMR to predict implantable cardioverter‐defibrillator (ICD) interventions in dilated cardiomyopathy of different etiology.

Methods

96 consecutive patients evaluated with CMR received an ICD. Biventricular volumes, ejection fraction, and myocardial LGE were evaluated. LGE was defined as “complex” (Cx‐LGE) in presence of ≥1 of the following: ischemic pattern, involving ≥2 different coronary territories; epicardial pattern; global endocardial pattern; and presence of ≥2 different patterns. The primary endpoint was occurrence of any appropriate ICD intervention. A composite secondary endpoint of cardiovascular death, cardiac transplantation, or ventricular assist device implantation was also considered.

Results

During a median follow‐up of 75 months, 30 and 25 patients reached the primary and secondary endpoints, respectively. Cx‐LGE was correlated with a worse primary endpoint survival (log‐rank P < 0.001). Cx‐LGE and right ventricular end‐diastolic volume were independently associated with the primary endpoint (HR: 3.22, 95% CI: 1.56–6.65, P = 0.002; and HR: 1.06, 95% CI: 1.00–1.12, P = 0.045, respectively), but not with the secondary endpoint.

Conclusions

Cx‐LGE identified at CMR imaging seems promising as an independent and specific prognostic factor of ventricular arrhythmias requiring ICD therapy in dilated cardiomyopathy of different etiologies.     

The Prognostic Value of Late Gadolinium-Enhanced Cardiac Magnetic Resonance Imaging in Nonischemic Dilated Cardiomyopathy: A Review and Meta-Analysis

Objectives

This review and meta-analysis reviews the prognostic value of cardiac magnetic resonance (CMR) in nonischemic dilated cardiomyopathy (DCM).

Prevalence,Patterns, and Clinical Predictors of Left Ventricular Late Gadolinium Enhancement in Patients Undergoing Cardiac Magnetic Resonance Prior to Pulmonary Vein Antral Isolation for Atrial Fibrillation: A Cross-Sectional Observational Study

Cardiac magnetic resonance (CMR) imaging is increasingly used to evaluate patients with atrial fibrillation (AF) before pulmonary vein antral isolation (PVAI). The purpose of this study was to assess the incidence and pattern of left ventricular (LV) late gadolinium enhancement (LGE) in patients undergoing CMR before PVAI and compare the clinical and demographic differences of patients with and without LV LGE.Clinical and demographic data on 62 patients (mean age 61 ± 7.9, 69% male) undergoing CMR before PVAI for AF were collected. Two observers, masked to clinical histories, independently recorded the prevalence, extent (number of myocardial segments), and pattern (subendocardial, midmyocardial, or subepicardial) of LV LGE in each patient. Clinical and demographic predictors of LV LGE were determined using logistic regression.Twenty-three patients (37%) demonstrated LV LGE affecting a mean of 3.0 ± 2.1 myocardial segments. There was no difference in LV ejection fraction between patients with and without LGE, and most (65%) patients with LGE had normal wall motion. Only age (P = 0.04) and a history of congestive heart failure (P = .03) were statistically significant independent predictors of LGE. The most common LGE pattern was midmyocardial, seen in 17 of 23 (74%) patients. Only 4 of 23 (17%) patients had LGE in an “expected” pattern based on clinical history. Of the remaining 19 patients, 4 had known congestive heart failure, 5 nonischemic cardiomyopathy, 4 known coronary artery disease, and 2 prior aortic valve replacement. Six of 23 (26%) patients had no known coronary artery, valvular, or myocardial disease.There is a high prevalence of unexpected LV scar in patients undergoing CMR before PVAI for AF, with most patients demonstrating a nonischemic pattern of LV LGE and no wall motion abnormalities (ie, subclinical disease). The high prevalence of unexpected LGE in these patients may argue for CMR as the modality of choice for imaging integration before PVAI, especially given the demonstrated prognostic value of LGE in this and other patient populations.     

Distinguishing ischemic cardiomyopathy from nonischemic dilated cardiomyopathy with coronary echocardiography.

Transthoracic echocardiographic examination of the proximal left coronary system was performed in 59 patients who had dilated cardiomyopathy to determine if this technique could distinguish between ischemic and nonischemic dilated cardiomyopathy. With use of annular array transducers (3.5 or 5 MHz) and digital image processing, echocardiographic visualization of the coronary arteries was successful in 55 (93%) of 59 patients. As assessed by coronary angiography, 32 subjects had ischemic cardiomyopathy and 27 had nonischemic cardiomyopathy. Twenty-seven (84%) of the 32 patients who had coronary artery disease and 24 (89%) of the 27 patients with nonischemic cardiomyopathy were correctly identified. The accuracy of coronary echocardiography was 86% in the entire study group and 93% when patients with inadequate studies were excluded. All subjects who had ischemic cardiomyopathy had evidence of disease by coronary echocardiography or segmental wall motion abnormalities. Multivariate analysis permitted correct classification of 93% of all subjects based on the results of the coronary echocardiogram, evaluation of segmental wall motion and a history of prior myocardial infarction. The correct diagnosis was made in 86% when the results of coronary echocardiography were excluded from analysis using all other echocardiographic and clinical variables. Transthoracic coronary echocardiography can be performed with a high degree of success in patients with dilated ventricles and the technique can reliably distinguish between ischemic and nonischemic dilated cardiomyopathy.     

The Role of Cardiac MR in New-Onset Heart Failure

In patients with heart failure, cardiovascular magnetic resonance imaging (CMR) allows a multifaceted approach to cardiac evaluation by enabling an assessment of morphology, function, perfusion, viability, tissue characterization, and blood flow during a single comprehensive examination. Given its accuracy and reproducibility, many believe CMR is the reference standard for the noninvasive assessment of ventricular volumes, mass, and function, and offers an ideal means for the serial assessment of disease progression or treatment response in individual patients. Delayed-enhancement (DE)-CMR provides a direct assessment of myopathic processes. This permits a fundamentally different approach than that traditionally taken to ascertaining the etiology of cardiomyopathy, which is vital in patients with nonischemic cardiomyopathy and incidental coronary artery disease and patients with mixed, ischemic and nonischemic cardiomyopathy. Precise tissue characterization with DE-CMR also improves the diagnosis of left ventricular thrombus, for which it is the emerging clinical reference standard. There is a growing body of literature on the utility of CMR for patient risk stratification, and its potential role in important management decisions such as for cardiac resynchronization therapy and defibrillator placement.     

Baseline cardiac magnetic resonance imaging versus baseline endomyocardial biopsy for the prediction of left ventricular reverse remodeling and prognosis in response to therapy in patients with idiopathic dilated cardiomyopathy

Endomyocardial biopsy (EMB) and late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging performed at baseline are both used to evaluate the extent of myocardial fibrosis. However, no study has directly compared the effectiveness of these diagnostic tools in the prediction of left ventricular reverse remodeling (LVRR) and prognosis in response to therapy in patients with idiopathic dilated cardiomyopathy (IDCM). Seventy-five patients with newly diagnosed IDCM who were undergoing optimal therapy were assessed at baseline using LGE-CMR imaging and EMB; the former measured LGE area and the latter measured collagen volume fraction (CVF) as possible predictive indices of LVRR and cardiac event-free survival. Among all the baseline primary candidate factors with P < 0.2 as per univariate analysis, multivariate analysis indicated that only LGE area was an independent predictor of subsequent LVRR (β = 0.44; 95 % confidence interval (CI) 0.87–2.53; P < 0.001), as indicated by decreasing left ventricular end-systolic volume index over the 1-year follow-up. Kaplan–Meier curves indicated significantly lower cardiac event-free survival rates in patients with LGE at baseline than in patients without (P < 0.01). By contrast, there was no significant difference in prognosis between patients with CVF values above (severe fibrosis) and below (mild fibrosis) the median of 4.9 %. Cox proportional hazard analysis showed that LGE area was an independent predictor of subsequent cardiac events (hazard ratio 1.06; 95 % CI 1.02–1.10; P ≤ 0.01). The degree of myocardial fibrosis estimated by baseline LGE-CMR imaging, but not that estimated by baseline EMB, can predict LVRR and cardiac event-free survival in response to therapy in patients with newly diagnosed IDCM.     

Cardiac allograft vasculopathy

Cardiac allograft vasculopathy (CAV) is an accelerated form of coronary artery disease affecting both intramyocardial and epicardial coronary arteries and is observed in patients during long-term survival after cardiac transplantation. We report a case of CAV complicated with silent transmural myocardial infarction and massive left ventricular thrombus formation associated with silent pericarditis and with ischemic and non-ischemic scar tissue, as detected by cardiac magnetic resonance imaging (CMRI). The authors suggest CMRI as an additional technique along with echocardiography during follow-up of heart transplant recipients. CMRI may contribute to the early identification of areas of myocardial wall abnormalities suggestive of CAV, thus guiding diagnosis and prompt percutaneous treatment.     

Prognostic impact of diabetes mellitus in patients with heart failure according to the etiology of left ventricular systolic dysfunction

OBJECTIVES: We sought to determine the relative impact of diabetes mellitus on prognosis in ischemic compared with nonischemic cardiomyopathy. BACKGROUND: Ischemic myocardium is characterized by increased reliance on aerobic and anaerobic glycolysis. Because glucose utilization by cardiomyocytes is an insulin-mediated process, we hypothesized that diabetes would have a more adverse impact on mortality and progression of heart failure in ischemic compared with nonischemic cardiomyopathy. METHODS: We performed a retrospective analysis of the Studies Of Left Ventricular Dysfunction (SOLVD) Prevention and Treatment trials. RESULTS: In adjusted analyses, diabetes mellitus was strongly associated with an increased risk for all-cause mortality in patients with ischemic cardiomyopathy, (relative risk [RR] 1.37, 95% confidence interval [CI] 1.21 to 1.55; p < 0.0001), but not in those with nonischemic cardiomyopathy (RR 0.98, 95% CI 0.76 to 1.32; p = 0.98). The increased mortality in patients with ischemic cardiomyopathy compared with nonischemic cardiomyopathy was limited to those with ischemic cardiomyopathy and diabetes mellitus (RR 1.37, 95% CI 1.21 to 1.56; p < 0.0001). When patients with ischemic cardiomyopathy and diabetes mellitus were excluded, there was no significant difference in mortality risk between the ischemic and nonischemic cardiomyopathy groups after adjusted analysis (RR 0.99, 95% CI 0.86 to 1.15; p = 0.99). Previous surgical revascularization identified patients within the cohort with ischemic cardiomyopathy and diabetes mellitus, with improved prognosis. CONCLUSIONS: The differential impact of diabetes on mortality and heart failure progression according to the etiology of heart failure suggests that diabetes and ischemic heart disease interact to accelerate the progression of myocardial dysfunction. Evaluation of the potential for revascularization may be particularly important in patients with ischemic cardiomyopathy and diabetes mellitus.     

Left Atrial Function Using Cardiovascular Magnetic Resonance Imaging Independently Predicts Life-Threatening Arrhythmias in Patients Referred to Receive a Primary Prevention Implantable Cardioverter Defibrillator

BackgroundIn this study we aimed to investigate left atrial (LA) function, measured from routine cine cardiovascular magnetic resonance imaging, to determine its value for the prediction of sudden cardiac death (SCD) or appropriate implantable cardioverter defibrillator (ICD) shock in patients who received primary prevention ICD implantation.MethodsWe studied 203 patients with ischemic or idiopathic nonischemic dilated cardiomyopathy who underwent cardiovascular magnetic resonance imaging before primary prevention ICD implantation. LA volumes were measured at end-diastole and end-systole from 4- and 2-chamber cine images, and LA emptying function (LAEF) calculated. Patients were followed for the primary composite end point of SCD or appropriate ICD shock.ResultsMean age was 61 ± 12 years with a mean left ventricular ejection fraction of 24 ± 7%. The mean LAEF was 27 ± 15% (range, 0.9%-73%). At a median follow-up of 1639 days, 35 patients (17%) experienced the primary composite outcome. LAEF was strongly associated with the primary outcome (P = 0.001); patients with an LAEF ≤ 30% experienced a cumulative event rate of 26.1% vs 5.7% (hazard ratio, 5.5; P < 0.001) in patients above this cutoff. This finding was maintained in multivariable analysis (hazard ratio, 4.7; P = 0.002) and was consistently shown in the ischemic and nonischemic dilated cardiomyopathy subgroups.ConclusionsLAEF is a simple, powerful, and independent predictor of SCD in patients being referred for primary prevention ICD implantation.