Oliver Strohm

Prognostic Value and Determinants of a Hypointense Infarct Core in T2-Weighted Cardiac Magnetic Resonance in Acute Reperfused ST-Elevation Myocardial Infarction

Background—A hypointense core of infarcted myocardium in T2-weighted cardiovascular MRI (CMR) has been used as a noninvasive marker for intramyocardial hemorrhage. However, the clinical significance of such findings not yet been established. The aim of this study was to evaluate determinants and prognostic impact of a hypointense infarct core in T2-weighted CMR images, studied in patients after acute, reperfused ST-elevation–myocardial infarction. Methods and Results—We analyzed 346 patients with ST-elevation–myocardial infarction undergoing primary angioplasty <12 hours after symptoms onset. T2-weighted, contrast-enhanced CMR was used for assessment of the area at risk, myocardial salvage, infarct size, hypointense core in T2-weighted images, and late microvascular obstruction. Patients were categorized into 2 groups defined by the presence or absence of a hypointense core. The primary end point of the study was occurrence of major adverse cardiovascular events defined as death, reinfarction, and congestive heart failure within 6 months after infarction. A hypointense core was present in 122 (35%) patients and was associated with larger infarcts, greater amount of microvascular obstruction, less myocardial salvage, and impaired left ventricular function (P<0.001, respectively). The presence of a hypointense core was a strong univariable predictor of major adverse cardiovascular events (hazard ratio, 2.59; confidence interval, 1.27 to 5.27) and was significantly associated with an increased major adverse cardiovascular events rate (16.4% versus 7.0%, P=0.006) 6 months after infarction. Conclusions—A hypointense infarct core within the area at risk of reperfused infarcted myocardium in T2-weighted CMR is closely related to infarct size, microvascular obstruction, and impaired left ventricular function, with subsequent adverse clinical outcome.

Comparison of long and short axis quantification of left ventricular volume parameters by cardiovascular magnetic resonance, with ex-vivo validation

BackgroundThe purpose of the study was to compare the accuracy and evaluation time of quantifying left ventricular (LV), left atrial (LA) volume and LV mass using short axis (SAX) and long axis (LAX) methods when using cardiovascular magnetic resonance (CMR).Materials and methodsWe studied 12 explanted canine hearts and 46 patients referred for CMR (29 male, age 47 ± 18 years) in a clinical 1.5 T CMR system, using standard cine sequences. In standard short axis stacks of various slice thickness values in dogs and 8 mm slice thickness (gap 2 mm) in patients, we measured LV volumes using reference slices in a perpendicular, long axis orientation using certified software. Volumes and mass were also measured in six radial long axis (LAX) views.LV parameters were also assessed for intra- and inter-observer variability. In 24 patients, we also analyzed reproducibility and evaluation time of two very experienced (> 10 years of CMR reading) readers for SAX and LAX.ResultsIn the explanted dog hearts, there was excellent agreement between ex vivo data and LV mass and volume data as measured by all methods for both, LAX (r2 = 0.98) and SAX (r2 = 0.88 to 0.98). LA volumes, however, were underestimated by 13% using the LAX views. In patients, there was a good correlation between all three assessed methods (r2 ≥ 0.95 for all). In experienced clinical readers, left-ventricular volumes and ejection fraction as measured in LAX views showed a better inter-observer reproducibility and a 27% shorter evaluation time.ConclusionWhen compared to an ex vivo standard, both, short axis and long axis techniques are highly accurate for the quantification of left ventricular volumes and mass. In clinical settings, however, the long axis approach may be more reproducible and more time-efficient. Therefore, the rotational long axis approach is a viable alternative for the clinical assessment of cardiac volumes, function and mass.

Impact of the revision of arrhythmogenic right ventricular cardiomyopathy/dysplasia task force criteria on its prevalence by CMR criteria.

OBJECTIVES The purpose of our study was to assess the impact of revised versus original criteria on the prevalence of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) criteria in cardiac magnetic resonance (CMR) studies. BACKGROUND Recently, the ARVC/D task force criteria have been revised, aiming for a better diagnostic sensitivity. The implications of this revision on clinical decision making are unknown. METHODS We retrospectively evaluated the CMR scans of 294 patients referred for ARVC/D between 2005 and 2010, and determined the presence or absence of major and minor CMR criteria using the original and the revised task force criteria. Previously, major and minor abnormalities were identified by the presence of right ventricle dilation (global or segmental), right ventricle microaneurysm, or regional hypokinesis. The revised criteria require the combination of severe regional wall motion abnormalities (akinesis or dyskinesis or dyssynchrony) with global right ventricle dilation or dysfunction (quantitative assessment). RESULTS Applying the original criteria, 69 patients (23.5%) had major original criteria, versus 19 patients (6.5%) with the revised criteria. Forty-three patients (62.3%) with major original criteria did not meet any of the revised criteria. Using the original criteria, 172 patients (58.5%) had at least 1 minor criterion versus 12 patients (4%) with the revised task force criteria; 167 patients (97%) with minor original criteria did not meet any of the revised criteria. In the subgroup of 134 patients with complete diagnostic work-up of ARVC, 10 patients met the diagnosis of proven ARVC/D without counting imaging criteria. Only 4 of 10 met major criteria according to the revised CMR criteria; none met minor criteria. However, 112 of 124 patients without ARVC/D were correctly classified as negative by major and minor criteria (specificity 94% and 96%, respectively). CONCLUSIONS In our experience, the revision of the ARVC/D task force imaging criteria significantly reduced the overall prevalence of major and minor criteria. The revision, although maintaining a high specificity, may not have improved the sensitivity for identifying patients with ARVC/D. Larger studies including follow-up are required.

Homozygous Founder Mutation in Desmocollin-2 (DSC2) Causes Arrhythmogenic Cardiomyopathy in the Hutterite Population

Background—Dominant mutations in cellular junction proteins are the major cause of arrhythmogenic cardiomyopathy, whereas recessive mutations in those proteins cause cardiocutaneous syndromes such as Naxos and Carvajal syndrome. The Hutterites are distinct genetic isolates who settled in North America in 1874. Descended from <100 founders, they trace their origins to 16th-century Europe. Methods and Results—We clinically and genetically evaluated 2 large families of the Alberta Hutterite population with a history of sudden death and found several individuals with severe forms of biventricular cardiomyopathy characterized by mainly left-sided localized aneurysms, regions of wall thinning with segmental akinesis, in addition to typical electric and histological features known for arrhythmogenic right ventricular cardiomyopathy. We identified a homozygous truncation mutation, c.1660C>T (p.Q554X) in desmocollin-2 (DSC2), in affected individuals and determined a carrier frequency of this mutation of 9.4% (1 in 10.6) among 1535 Schmiedeleut Hutterites, suggesting a common founder in that subgroup. Immunohistochemistry of endomyocardial biopsy samples revealed altered expression of the truncated DSC2 protein at the intercalated discs but only minor changes in immunoreactivity of other desmosomal proteins. Recombinant expressed mutant DSC2 protein in cells confirmed a stable, partially processed truncated protein with cytoplasmic and membrane localization. Conclusions—A homozygous truncation mutation in DSC2 leads to a cardiac-restricted phenotype of an early onset biventricular arrhythmogenic cardiomyopathy. The truncated protein remains partially stable and localized at the intercalated discs. These data suggest that the processed DSC2 protein plays a role in maintaining desmosome integrity and function.

Evaluation of left atrial contraction contribution to left ventricular filling using cardiovascular magnetic resonance

To describe a new method to quantify the left atrial contraction contribution (ACC) to left ventricular (LV) filling using cardiovascular magnetic resonance (CMR).

Patent ductus arteriosus demonstrated in an adult patient using cardiovascular magnetic resonance imaging.

A 52-year-old pilot presented for cardiovascular magnetic resonance imaging evaluation of a suspected patent ductus arteriosus (PDA) seen on an echocardiogram that was obtained for renewal of his license. Figure 1 is a maximum-intensity projection image of a contrast-enhanced magnetic resonance angiogram demonstrating the aorta and left pulmonary artery connected by a PDA measuring 2 cm in length and 4 mm in diameter. Figure 2 shows an in-plane phase contrast image demonstrating the retrograde flow jet from the aorta, through the PDA into the pulmonary artery. The calculated flow through the PDA was 3 mL/beat with a systemic to pulmonary blood flow ratio of 1.06. The accompanying video (available at www.pulsus.com) demonstrates the continuous jet of retrograde flow from the PDA into the pulmonary artery. The remainder of the study was normal, and the patient was referred for consideration of percutaneous closure of the PDA. Figure 1) Maximum-intensity projection image of a contrast-enhanced magnetic resonance angiogram demonstrating the aorta (Ao) and left pulmonary artery (LPA) connected by a patent ductus arteriosus (PDA) measuring 2 cm in length and 4 mm in diameter Figure 2) In-plane phase contrast image demonstrating the retrograde flow jet from the aorta (arrowheads), through the patent ductus arteriosus into the pulmonary artery. AAo Ascending aorta; DAo Descending aorta; LPA Left pulmonary artery (arrow); MPA Main pulmonary ...

Evaluation of papillary myocardial infarction: incremental value of a short time inversion vs standard late enhancement imaging

The short TI LGE sequence detected a significant higher number of papillary muscle infarction compared to standard LGE sequence (19/54 versus 15/54 respectively). Moreover, in these images papillary muscle infarction was appeared with more sharpness (84.2% vs 53.3%) The contrast-to-noise ratio was higher between infarcted myocardium and blood (77.9±60 vs 19.3±16, p<0.001) and between papillary muscle infarction and blood (69.4±51 vs 39.4±26 respectively, p=0.0157). Conclusions In patients with myocardial infarction, LGE CMR imaging using short inversion times more sensitively detects papillary muscle infarction when compared with standard LGE imaging. Therefore, the additional use of short TI sequences may be useful for verifying or excluding papillary muscle involvement in patients with myocardial infarction.

Evidence of an increased incidence of myocardial inflammation associated with reduced ventricular function in clinically suspected idiopathic dilated cardiomyopathy - a cardiovascular magnetic resonance study

Background Dilated cardiomyopathy (DCM) occurring due to an unknown etiology or genetic predisposition is termed as idiopathic dilated cardiomyopathy (iDCM), although iDCM may also result from viral exposure. However, the incidence of myocardial inflammation and its relation to left ventricular (LV) function in iDCM remains unknown. Cardiovascular magnetic resonance (CMR) imaging allows for the visualization of myocardial inflammation using early Gadolinium enhancement (EGE). We applied EGE imaging in the setting of clinically suspected iDCM to determine both the incidence and relation of myocardial inflammation to LV function.

Prognostic value and determinants of a hypointense core in T2-weighted cardiac magnetic resonance in acute reperfused ST-elevation myocardial infarction

A hypointense core of infarcted myocardium in T2-weighted CMR has been used as a noninvasive marker for intramyocardial hemorrhage and was related with adverse remodelling in recently published clinical trials. However, the clinical significance of such findings is not yet established.

CMR indications, safety and image quality: single-centre experience in more than 5000 patients

Results The mean age of the patients was 50 +/17; range 9 to 100 years old. The most common clinical indications were myocarditis/cardiomyopathies (2004; 38.8%), coronary artery disease/ischemic heart disease (749; 14.5%), arrhythmogenic right-ventricular dysplasia and/or other right ventricular disease (560; 10.8%), and pulmonary vein anatomy (212; 4.1%). The indications for the remaining cases included: cardiac mass, pericardial disease, thrombus, congenital cases, and valvular disease. Gadolinium-based contrast agent was given to 97% of patients as part of their CMR protocol. Of the 10.1% (494/5165) patients that underwent stress CMR, adenosine was administered in 94.3% of cases and dobutamine was administered in 5.7% of cases. 1/466 patients (0.21%) suffered ventricular tachycardia during adenosine stress and transient, asymptomatic AV block was occasionally observed. Moderate to severe complications after contrast agent administration occurred in 8/5001 (0.16%) contrast-enhanced studies, characterized by nausea and vomiting in six (0.11%) patients and by symptoms of acute systemic allergic reaction in 2 (0.04%) patients. Image quality was good in 82.8%, moderate in 16.3%, and non-diagnostic in 1.0% of cases.