MR-IMPACT II: Magnetic Resonance Imaging for Myocardial Perfusion Assessment in Coronary artery disease Trial: perfusion-cardiac magnetic resonance vs. single-photon emission computed tomography for the detection of coronary artery disease: a comparative multicentre, multivendor trial.

AIMS: Perfusion-cardiac magnetic resonance (CMR) has emerged as a potential alternative to single-photon emission computed tomography (SPECT) to assess myocardial ischaemia non-invasively. The goal was to compare the diagnostic performance of perfusion-CMR and SPECT for the detection of coronary artery disease (CAD) using conventional X-ray coronary angiography (CXA) as the reference standard. METHODS AND RESULTS: In this multivendor trial, 533 patients, eligible for CXA or SPECT, were enrolled in 33 centres (USA and Europe) with 515 patients receiving MR contrast medium. Single-photon emission computed tomography and CXA were performed within 4 weeks before or after CMR in all patients. The prevalence of CAD in the sample was 49%. Drop-out rates for CMR and SPECT were 5.6 and 3.7%, respectively (P = 0.21). The primary endpoint was non-inferiority of CMR vs. SPECT for both sensitivity and specificity for the detection of CAD. Readers were blinded vs. clinical data, CXA, and imaging results. As a secondary endpoint, the safety profile of the CMR examination was evaluated. For CMR and SPECT, the sensitivity scores were 0.67 and 0.59, respectively, with the lower confidence level for the difference of +0.02, indicating superiority of CMR over SPECT. The specificity scores for CMR and SPECT were 0.61 and 0.72, respectively (lower confidence level for the difference: -0.17), indicating inferiority of CMR vs. SPECT. No severe adverse events occurred in the 515 patients. CONCLUSION: In this large multicentre, multivendor study, the sensitivity of perfusion-CMR to detect CAD was superior to SPECT, while its specificity was inferior to SPECT. Cardiac magnetic resonance is a safe alternative to SPECT to detect perfusion deficits in CAD.

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

PURPOSE: To describe a new method to quantify the left atrial contraction contribution (ACC) to left ventricular (LV) filling using cardiovascular magnetic resonance (CMR). MATERIALS AND METHODS: We assessed 120 normal subjects (50% female) using steady-state free precession CMR volumetry. Volumes measurements were performed using short axis and rotational long axis views. The percentage of ACC was calculated by dividing the LV filling volume resulting from left atrial (LA) contraction by the LV stroke volume (LVSV). RESULTS: The described method was well reproducible. The ACC in normal subjects was 15 ± 5% for ages <40 years, 28 ± 8% for ages 40 to 55 years, and 38 ± 5% for ages >55 years. When adjusted for age, ie, dividing the ACC percentage by age, a value between 0.4 and 0.7 was found to represent the normal range of ACC at any age. CONCLUSION: The study presents a new and accurate CMR volumetric method to quantify ACC to LV filling. ACC ranges from 10%-40%, depending on age.

Superior diagnostic performance of perfusion-cardiovascular magnetic resonance versus SPECT to detect coronary artery disease: The secondary endpoints of the multicenter multivendor MR-IMPACT II (Magnetic Resonance Imaging for Myocardial Perfusion Assessment in Coronary Artery Disease Trial).

BACKGROUND: Perfusion-cardiovascular magnetic resonance (CMR) is generally accepted as an alternative to SPECT to assess myocardial ischemia non-invasively. However its performance vs gated-SPECT and in sub-populations is not fully established. The goal was to compare in a multicenter setting the diagnostic performance of perfusion-CMR and gated-SPECT for the detection of CAD in various populations using conventional x-ray coronary angiography (CXA) as the standard of reference. METHODS: In 33 centers (in US and Europe) 533 patients, eligible for CXA or SPECT, were enrolled in this multivendor trial. SPECT and CXA were performed within 4 weeks before or after CMR in all patients. Prevalence of CAD in the sample was 49% and 515 patients received MR contrast medium. Drop-out rates for CMR and SPECT were 5.6% and 3.7%, respectively (ns). The study was powered for the primary endpoint of non-inferiority of CMR vs SPECT for both, sensitivity and specificity for the detection of CAD (using a single-threshold reading), the results for the primary endpoint were reported elsewhere. In this article secondary endpoints are presented, i.e. the diagnostic performance of CMR versus SPECT in subpopulations such as multi-vessel disease (MVD), in men, in women, and in patients without prior myocardial infarction (MI). For diagnostic performance assessment the area under the receiver-operator-characteristics-curve (AUC) was calculated. Readers were blinded versus clinical data, CXA, and imaging results. RESULTS: The diagnostic performance (= area under ROC = AUC) of CMR was superior to SPECT (p = 0.0004, n = 425) and to gated-SPECT (p = 0.018, n = 253). CMR performed better than SPECT in MVD (p = 0.003 vs all SPECT, p = 0.04 vs gated-SPECT), in men (p = 0.004, n = 313) and in women (p = 0.03, n = 112) as well as in the non-infarct patients (p = 0.005, n = 186 in 1-3 vessel disease and p = 0.015, n = 140 in MVD). CONCLUSION: In this large multicenter, multivendor study the diagnostic performance of perfusion-CMR to detect CAD was superior to perfusion SPECT in the entire population and in sub-groups. Perfusion-CMR can be recommended as an alternative for SPECT imaging. TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT00977093.

A new approach towards improved visualization of myocardial edema using T2-weighted imaging: a cardiovascular magnetic resonance (CMR) study.

PURPOSE: To compare T2-weighted cardiovascular magnetic resonance (CMR) imaging with AASPIR (asymmetric adiabatic spectral inversion recovery) and STIR (short T1 inversion recovery) for myocardial signal intensity, image quality, and fat suppression. MATERIALS AND METHODS: Forty consecutive patients (47 ± 16 years old) referred by cardiologists for CMR-based myocardial tissue characterization were scanned with both STIR and AASPIR T2-weighted imaging approaches. Signal intensity of left ventricular myocardium was normalized to a region of interest generating a signal-to-noise ratio (SNR). In six patients with regional edema on STIR the contrast-to-noise ratio (CNR) was assessed. Two independent observers used a scoring system to evaluate image quality and artifact suppression. Six healthy volunteers (three males, 32 ± 7 years) were recruited to compare fat suppression between AASPIR and STIR. RESULTS: SNR of AASPIR was greater than STIR for basal (128 ± 44 vs. 83 ± 40, P < 0.001), mid- (144 ± 65 vs. 96 ± 39, P < 0.01), and apical (145 ± 59 vs. 105 ± 35, P < 0.05) myocardium. Improved image quality and greater suppression of artifacts was demonstrated with AASPIR. In patients with regional edema, CNR increased by 49% with AASPIR, while SNR of pericardial fat did not differ (44 ± 39 vs. 33 ± 30, P > 0.05). CONCLUSION: Our findings support the implementation of an AASPIR-based approach for T2-weighted imaging due to improved pericardial fat suppression, image quality, and artifact suppression with greater CNR and SNR.

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

BACKGROUND: The 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 METHODS: We 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. RESULTS: In 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. CONCLUSION: When 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.

Clinical characteristics and cardiovascular magnetic resonance findings in stress (takotsubo) cardiomyopathy.

CONTEXT: Stress cardiomyopathy (SC) is a transient form of acute heart failure triggered by stressful events and associated with a distinctive left ventricular (LV) contraction pattern. Various aspects of its clinical profile have been described in small single-center populations, but larger, multicenter data sets have been lacking so far. Furthermore, it remains difficult to quickly establish diagnosis on admission. OBJECTIVES: To comprehensively define the clinical spectrum and evolution of SC in a large population, including tissue characterization data from cardiovascular magnetic resonance (CMR) imaging; and to establish a set of CMR criteria suitable for diagnostic decision making in patients acutely presenting with suspected SC. DESIGN, SETTING, AND PATIENTS: Prospective study conducted at 7 tertiary care centers in Europe and North America between January 2005 and October 2010 among 256 patients with SC assessed at the time of presentation as well as 1 to 6 months after the acute event. MAIN OUTCOME MEASURES: Complete recovery of LV dysfunction. RESULTS: Eighty-one percent of patients (n = 207) were postmenopausal women, 8% (n = 20) were younger women (aged ≤50 years), and 11% (n = 29) were men. A stressful trigger could be identified in 182 patients (71%). Cardiovascular magnetic resonance imaging data (available for 239 patients [93%]) revealed 4 distinct patterns of regional ventricular ballooning: apical (n = 197 [82%]), biventricular (n = 81 [34%]), midventricular (n = 40 [17%]), and basal (n = 2 [1%]). Left ventricular ejection fraction was reduced (48% [SD, 11%]; 95% confidence interval [CI], 47%-50%) in all patients. Stress cardiomyopathy was accurately identified by CMR using specific criteria: a typical pattern of LV dysfunction, myocardial edema, absence of significant necrosis/fibrosis, and markers for myocardial inflammation. Follow-up CMR imaging showed complete normalization of LV ejection fraction (66% [SD, 7%]; 95% CI, 64%-68%) and inflammatory markers in the absence of significant fibrosis in all patients. CONCLUSIONS: The clinical profile of SC is considerably broader than reported previously. Cardiovascular magnetic resonance imaging at the time of initial clinical presentation may provide relevant functional and tissue information that might aid in the establishment of the diagnosis of SC.

Cardiac magnetic resonance in outpatients in Germany--indications, complications and protocol suggestions from a high-volume center.

BACKGROUND: Cardiac magnetic resonance (CMR) has developed into a routine examination in many centers in cardiology. However, there is little knowledge about its applicability in outpatients as a diagnostic tool for cardiovascular diseases. We report about the experiences in a high-volume cardiac imaging center and in a "mobile setting" in Germany and provide routinely used examination protocols. METHODS: 8976 patients referred for CMR from cardiologists, internal medicine practices and from general practitioners and 2200 patients examined in a "mobile" system by outpatient cardiologists were included in the study. Indications were as follows: 7672 (69%) examinations for myocardial ischemia and viability, 1313 (12%) for cardiac and pericardial inflammatory disease and cardiac mass, 976 (9%) for detection and quantification of heart valve disease and 466 (4%) for congenital heart disease. 697 (6%) were referred for other indication. Two independent readers performed image analysis of the 8976 patients in our center. RESULTS: Image quality was rated "excellent" in 90.6%, "good" in 8%, "fair" in 1.2% and "poor" in 0.2%. 0.0002% of all examinations were not assessable due to low image quality. Minor complications (temporarily, asymptomatic AV-blockade; mild chest pain and/or dyspnea; nausea) could be observed in 12% and resolved within few minutes. One patient experienced a grand mal seizure due to hyperventilation. 0.9% examinations had to be terminated untimely due to claustrophobia. CONCLUSION: CMR in outpatients is a widely used imaging modality in cardiology in Germany. A large variety of clinical questions may be answered by CMR with excellent image quality and without major complication. With user-adapted protocols, a rapid diagnosis is achieved even in outpatients in a "mobile" setting. Hence, CMR will increase its applicability as a routine imaging tool.

Detection of papillary muscle infarction by late gadolinium enhancement: incremental value of short-inversion time vs. standard imaging.

AIMS: Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can detect myocardial scar in patients with myocardial infarction. The detection of papillary muscle infarction (PMI) may be difficult due to the bright blood signal. The aim of our study was to evaluate the incremental value of LGE CMR imaging using an inversion recovery (IR)-GRE with a short-inversion time (TI) over standard LGE imaging in identifying PMI. METHODS AND RESULTS: Fifty-six patients with myocardial infarction were studied using a standard IR-GRE LGE sequence with an adjusted TI to null the signal intensity of normal myocardium and with a 3D IR-GRE with a short TI (<180 ms). Signal-to-noise and contrast-to-noise ratios (CNR) and the frequency of PMI were determined. Image quality and infarction sharpness were evaluated. The short-TI LGE sequence detected a higher number of PMI compared with standard LGE sequence (19/54 vs. 15/54) with an increased sharpness of PMI (84.2 vs. 53.3%). The CNR was higher between infarcted myocardium and blood (77.9 ± 60 vs. 19.3 ± 16, P < 0.001) and between PMI and blood (69.4 ± 51 vs. 39.4 ± 26, respectively, P = 0.0157). CONCLUSIONS: Our data indicate that in patients with myocardial infarction, LGE CMR imaging using a short TI may be more sensitive than standard LGE imaging for the detection of PMI.

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.

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.

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.

Advanced tissue characterization in non-ischemic cardiomyopathies using contrast-enhanced cardiac magnetic resonance imaging.

Cardio-vascular magnetic resonance imaging (CMR) can be used to obtain integrated information on both cardiac function and on advanced tissue characteristics. Using contrast-enhanced techniques, highly diagnostic information on tissue viability, inflammatory changes, and on storage diseases can be obtained within a 45-minute examination. The combination of functional information (using steady-state free precession sequences cine techniques), assessment of myocardial edema (using T2-based techniques), of reversible injury (for example in inflammatory diseases; using T1-based techniques), and irreversible injury (for example in infarction and regional fibrosis, using late gadolinium enhancement techniques) allows disease-specific and prognostic information to be obtained in patients with non-ischemic cardiomyopathy. Contrast-enhanced CMR allows the accurate diagnosis of non-ischemic cardiomyopathies, identification of primary and secondary cardiomyopathies, and can be used to guide therapy, thus avoiding the need for invasive measures such as endomyocardial biopsy in many cases.

Combined assessment of myocardial perfusion and late gadolinium enhancement in patients after percutaneous coronary intervention or bypass grafts: a multicenter study of an integrated cardiovascular magnetic resonance protocol.

OBJECTIVES: We sought to assess the accuracy of an integrated cardiac magnetic resonance (CMR) protocol for the diagnosis of relevant coronary artery or bypass graft stenosis in patients with suspected coronary artery disease (CAD) or with previously performed percutaneous coronary intervention (PCI) or coronary bypass graft surgery (CABG). BACKGROUND: CMR is suitable for diagnosing inducible myocardial ischemia in patients with suspected CAD and has been proven to be a helpful diagnostic tool for decision of further treatment. However, little is known about its diagnostic accuracy in patients with known CAD who previously were treated by PCI or CABG. METHODS: A total of 477 patients with suspected CAD, 236 with previous PCI, and 110 after CABG referred for coronary X-ray angiography (CXA) underwent an integrated CMR examination before CXA. Myocardial ischemia was assessed using first-pass perfusion after vasodilator stress with adenosine (140 microg/kg/min for 3 min) using gadolinium-based contrast agents (0.1 mmol/kg). Late gadolinium enhancement (LGE) was assessed 10 min after a second contrast bolus. RESULTS: CXA demonstrated a relevant coronary vessel stenosis (> or =70% luminal reduction) in 313 (38%) patients using quantitative coronary analysis. The combination of CMR perfusion and LGE assessment for detecting a relevant coronary stenosis in patients with suspected CAD yielded sensitivity and specificity of 0.94 and 0.87, in PCI patients 0.91 and 0.90, and in CABG patients 0.79 and 0.77, respectively. CONCLUSIONS: A combined CMR protocol for the assessment of myocardial perfusion and LGE is feasible for the detection of relevant coronary vessel stenosis even in patients who previously were treated by PCI or CAG in a routine clinical setting. However, diagnostic accuracy is reduced in patients with CABG. This could be due to different flow and perfusion kinetic. Further studies are needed to optimize the clinical protocols especially in post-surgical patients.

Abnormalities in T2-weighted cardiovascular magnetic resonance images of hypertrophic cardiomyopathy: regional distribution and relation to late gadolinium enhancement and severity of hypertrophy.

PURPOSE: To explore if focal T2 abnormalities accompany late gadolinium enhancement (LGE) lesions in hypertrophic cardiomyopathy (HCM). MATERIALS AND METHODS: All studies were performed under the guidelines of the local ethics committee, which approved the study, and a written informed consent was obtained from each subject. We studied 27 patients (24 males, 51 +/- 18 years) with HCM and evidence for myocardial injury as defined by LGE. The following sequences were performed: steady-state free precession (SSFP) (ventricular volumes, mass, and function), T2-weighted triple inversion-recovery spin-echo and inversion-recovery gradient-echo 10 minutes after intravenous (IV) gadolinium-DTPA (late enhancement). RESULTS: Focal high T2 signal intensity (SI) frequently matching areas of LGE was observed in nine patients (33%). The presence of these abnormalities correlated with more severe left ventricular hypertrophy (1.5 +/- 0.6 vs. 1.0 +/- 0.4 g/cm; P < 0.05). CONCLUSION: In this observational study, we identified focal T2 abnormalities in a subgroup of HCM patients. T2 abnormalities are associated with severe left ventricular hypertrophy. This may provide new insights into the mechanisms of focal irreversible injury in HCM and help in managing these patients.

Detection of cardiac small vessel disease by adenosine-stress magnetic resonance.

BACKGROUND: Patients testing positive for myocardial ischemia but without significant coronary artery (CA) stenosis in coronary angiography (CXA) are characterized as having "small vessel disease" (SVD). The aim of our study was to identify these patients by stress perfusion cardiac magnetic resonance (CMR). METHODS: 317 patients with suspected myocardial ischemia and clinical indication for CXA were scanned < 72 h before CXA in a whole-body 1.5T scanner. After 3 min of adenosine infusion (140 microg/kg/min), a myocardial first-pass perfusion sequence in 4-5 contiguous short-axis orientations using a Gadolinium-based contrast agent (0.1 mmol/kg) was performed. Images were analyzed qualitatively by two independent and blinded investigators. RESULTS: Perfusion deficits were detected in 93% of our patients. In 78% of patients with relevant perfusion delay, perfusion deficits extended to > 1/3 of the wall thickness in > or = 2 myocardial segments, persisted for > 5 heartbeats and were regarded as relevant coronary macroangiopathy. All of these patients had significant CA stenosis (60% had luminal narrowing > 70% and 18% had 50-70%). 22% of the patients had perfusion deficits affecting < or = 1/3 of wall thickness with persistence for < or = 5 heartbeats and were regarded as having SVD. None of these patients had a CA stenosis of > 50% or received CA revascularization. These patients more frequently had hypertension (p<0.0001), diabetes (p<0.05) and circumferential perfusion deficits (p<0.0001) than other patients. CONCLUSION: Stress perfusion CMR allows non-invasive differentiation between patients with significant CA stenosis and patients with SVD caused by hypertension and/or diabetes based on the temporal and spatial extent of perfusion deficits. Patients with SVD more often have diffuse perfusion deficits with shorter persistence than patients with significant CA disease.

Prediction of necessity for coronary artery revascularization by adenosine contrast-enhanced magnetic resonance imaging.

BACKGROUND: Assessing myocardial first-pass wash-in during pharmacological induced stress allows detection of perfusion deficits and indicates stenotic coronary arteries (CA). The aim of our study was to demonstrate clinical relevance of contrast-enhanced stress magnetic resonance imaging (CMR) by predicting necessity of CA intervention. METHODS: 738 patients with scheduled coronary angiography (CXA) were scanned in a 1.5 Tesla CMR scanner. After 3 min of adenosine infusion (140 microg/kg/min), first-pass kinetic of contrast agent was evaluated. Myocardial necrosis was visualized with "myocardial late enhancement (MLE)". Perfusion deficits were described as either "ischemia in viable myocardium", or "no relevant ischemia in viable myocardium" or as "ischemia in chronic myocardial infarction (CMI)" based on spatial and temporal extent of ischemia and of MLE. CXA was performed in all patients within 48 h after CMR and revascularization, if applicable, was performed. Angiograms were read by two independent and blinded investigators and matched with CMR findings. RESULTS: 539 patients (73%) showed "ischemia in viable myocardium" and revascularization was performed in 513 patients (95%). In 111 patients with "no relevant ischemia in viable myocardium", revascularization was performed in only 5 patients (5%). In 88 patients classified as "ischemia in CMI", revascularization was performed in 14 patients (16%). Positive predictive value of CMR for CA intervention was 0.95, negative predictive value was 0.89, sensitivity was 0.96, and specificity was 0.87. CONCLUSION: CMR allows clinical useful prediction of relevant CA disease with need for revascularization prior to CXA and may be used as non-invasive test for myocardial ischemia and viability to guide further therapy.

Safety of adenosine stress magnetic resonance imaging using a mobile cardiac magnetic resonance system.

BACKGROUND: Contrast-enhanced magnetic resonance imaging (ceMRI) allows for the detection of ischemic heart disease. Aim of this prospective study was to show feasibility, practicability and safety of adenosine stress ceMRI in routine outpatients with a mobile scanner. METHODS: Consecutive patients were scanned in six different cardiac outpatient centers with a 1.5 T mobile ceMRI scanner. First-pass wash-in patterns of gadolinium chelate were evaluated after three minutes of adenosine infusion. After a second bolus of gadolinium chelate myocardial late enhancement (MLE) images of the left ventricle were acquired to visualize myocardial necrosis. RESULTS: Five hundred seventy-four patients were enrolled to the study. No major complications during examination and adenosine infusion were observed. One hundred seventy-three minor complications as temporary atrio-ventriculare blockade, mild chest pain or dyspnea and nausea were noticed. None of the complications led to further special treatment CONCLUSION: This ceMRI protocol is suitable for application in outpatient settings. CeMRI stress testing using a mobile scanner in an outpatient setting is feasible and safe.

[Applications in cardiovascular MRI and CT--clinical indications and training]. / Aktueller Stand der kardiovaskulären MRT und CT. Indikationen und Weiterbildung.

The recent technical advances in magnetic resonance imaging (MRI) and multislice computed tomography (MSCT) have led to a routine use of both methods in clinical cardiology. MRI is established for the diagnosis of complex congenital heart disease, aortic and pericardial disease as well as cardiac tumours. New indications include the diagnosis of myocardial infarction and inflammatory heart disease as well as myocardial perfusion measurements. CT is used for the diagnosis of coronary calcification for risk stratification. Moreover, stenoses of the coronary arteries and bypass grafts can be depicted using contrast enhanced multi-slice CT in selected patients. Training of cardiologists in the field of MRI has been defined by the Deutsche Arztetag in 2003 and demands 24 months of full-time training. At least 12 months must be spent in a department of radiology. Alternatively, the approach of the Landesärztekammer Baden-Württemberg is presented.