Reduction of QTD--A Novel Marker of Successful Reperfusion in NSTEMI. Pathophysiologic Insights by CMR.

BACKGROUND/OBJECTIVES: Non-ST segment elevation myocardial infarction (MI) poses similar detrimental long-term prognosis as ST-segment elevation MI. No marker on ECG is established to predict successful reperfusion in NSTEMI. QT dispersion is increased by myocardial ischemia and reduced by successful restoration of epicardial blood flow by PCI. Whether QT dispersion reduction translates to smaller infarcts and thus indicates successful reperfusion is unknown. We hypothesized that the relative reduction of QT dispersion (QTD-Rrel ) on a standard ECG in acutely reperfused NSTEMI is related to infarct size and infarct transmurality as assessed by delayed enhancement CMR (DE-CMR). METHODS AND RESULTS: 69 patients with a first acute NSTEMI were included. QTD-Rrel was stratified according to LV function and volumes, infarct transmurality and size as assessed by DE-CMR. Extensive myocardial infarction was defined as above median infarct size. LV function and end-systolic volume were only mildly related to QTD-Rrel . QTD-Rrel was inversely related to infarct size (r=-0.506,p=0.001) and infarct transmurality (r=-0.415, p=0.001). QTD-Rrel was associated with extensive myocardial infarction in univariate analysis (odds ratio (OR) 0.958, CI 0.935-0.982; p=0.001). Compared to clinical and angiographic data QTD-Rrel remained the only independent predictor of non-transmural infarcts (OR 1.110, CI 1.055-1.167; p=0.049). CONCLUSION: In patients with acute Non-ST-Segment Myocardial infarction QTd-Rrel calculated on a surface ECG prior and post PCI for restoration of epicardial blood flow detects small, non-transmural infarcts as assessed by delayed enhancement CMR. Thus, QTd-Rrel can indicate successful reperfusion therapy.

Accuracy and variability of right ventricular volumes and mass assessed by dual-source computed tomography: influence of slice orientation in comparison to magnetic resonance imaging.

OBJECTIVE: To evaluate the accuracy and variability of right ventricular (RV) volumes and mass using dual-source computed tomography (DSCT) and the influence of slice orientation in comparison to cardiac magnetic resonance imaging (CMR). METHODS: In 33 patients undergoing cardiac DSCT and CMR, RV parameters were calculated using the short-axis (DSCT, CMR) and axial orientation (DSCT). Intra- and interobserver variability were assessed by Bland-Altman analysis. RESULTS: Short-axis orientation: RV parameters of the two techniques were not statistically different. Axial orientation: RV volumes and mass were significantly overestimated compared with short-axis parameters whereas EF was similar. The short-axis approach resulted in low variability, although the axial orientation had the least amount of intra- and interobserver variability. CONCLUSION: RV parameters can be more accurately assessed by DSCT compared with CMR using short-axis slice orientation. RV volumes and mass are significantly higher using axial compared with short-axis slices, whereas EF is unaffected. RV parameters derived from both approaches yield high reproducibility.

Rapid MR assessment of left ventricular systolic function after acute myocardial infarction using single breath-hold cine imaging with the temporal parallel acquisition technique (TPAT) and 4D guide-point modelling analysis of left ventricular function.

We compared four-dimensional guide-point modelling left ventricular function analysis (4DVF) results of cine images in four short-axis and two long-axis slices acquired in a single breath-hold, obtained with the temporal parallel acquisition technique (TPAT), with standard left ventricular function (LVF) analysis results determined by the summation of discs method, in patients who had recently suffered myocardial infarction. Despite wall motion abnormalities, 4DVF yields results for left ventricular ejection fractions and end-diastolic and end-systolic volumes that are in excellent agreement with standard LVF analysis results in these patients. A shortened cardiac magnetic resonance (CMR) protocol using single breath-hold cine image acquisition could facilitate the assessment of left ventricular function soon after myocardial infarction in critically ill patients who are unable to comply with the multiple breath-holds required for standard LVF analysis.

Right ventricular involvement in acute left ventricular myocardial infarction: prognostic implications of MRI findings.

OBJECTIVE: The purpose of this study was to investigate the prevalence and prognostic importance of the cardiac MRI finding of right ventricular involvement in patients with acute ST-segment elevation myocardial infarction (MI). SUBJECTS AND METHODS: Fifty patients (41 men, nine women; mean age, 58 +/- 11 years) with first-ST-segment elevation MI underwent 1.5-T cardiac MRI immediately after successful percutaneous coronary intervention. The cardiac MRI protocol included steady-state free precession cine sequences for functional assessment of the left, right, and both ventricles and inversion recovery FLASH delayed enhancement sequences after contrast administration for the quantification of myocardial damage. The prevalence of right ventricular involvement detected with ECG and echocardiography was compared with the prevalence detected with cardiac MRI, which was the reference standard. Patients underwent follow-up for 32 +/- 8 months. RESULTS: Right ventricular involvement was diagnosed with cardiac MRI in 27 patients (54%): 14 of 30 patients (47%) with inferior ST-segment elevation MI and 13 of 20 patients (65%) with anterior ST-segment elevation MI. ECG and echocardiographic findings showed only moderate agreement with cardiac MRI findings in the detection of right ventricular involvement in inferior acute MI (kappa = 0.38). Patients with right ventricular involvement in anterior ST-segment elevation MI had larger infarcts (delayed enhancement, 25.9% +/- 14.5% vs 11.4% +/- 10.1%; p = 0.030), lower left ventricular ejection fraction (34.3% +/- 8.2% vs 45.2% +/- 9.5%; p < 0.015), and lower right ventricular ejection fraction (39.8% +/- 6.6% vs 54.9% +/- 8.8%; p < 0.001) than those without right ventricular involvement. In a multivariate logistic regression model, right ventricular involvement was a strong independent predictor (odds ratio, 15.8; 95% CI, 4-63%) of major cardiac adverse events. CONCLUSION: Right ventricular involvement in ST-segment elevation MI is detected more frequently with cardiac MRI than with ECG and echocardiography and is an independent prognostic indicator.

Current variables, definitions and endpoints of the European cardiovascular magnetic resonance registry.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is increasingly used in daily clinical practice. However, little is known about its clinical utility such as image quality, safety and impact on patient management. In addition, there is limited information about the potential of CMR to acquire prognostic information. METHODS: The European Cardiovascular Magnetic Resonance Registry (EuroCMR Registry) will consist of two parts: 1) Multicenter registry with consecutive enrolment of patients scanned in all participating European CMR centres using web based online case record forms. 2) Prospective clinical follow up of patients with suspected coronary artery disease (CAD) and hypertrophic cardiomyopathy (HCM) every 12 months after enrolment to assess prognostic data. CONCLUSION: The EuroCMR Registry offers an opportunity to provide information about the clinical utility of routine CMR in a large number of cases and a diverse population. Furthermore it has the potential to gather information about the prognostic value of CMR in specific patient populations.

Impact of hyperglycemia at admission in patients with acute ST-segment elevation myocardial infarction as assessed by contrast-enhanced MRI.

BACKGROUND: Blood glucose level at admission in ST-segment elevation myocardial infarction (STEMI) is a predictor of heart failure and mortality. This study was performed to investigate the impact of hyperglycemia at admission in non-diabetic patients on infarct size, microvascular obstruction, and long-term outcome using contrast-enhanced magnetic resonance imaging (CMR) in patients with acute STEMI. METHODS: One hundred and seven consecutive patients (84 males; mean age 59.4 years ± 11.3 years) with a first acute STEMI successfully treated by primary PCI were included. Admission hyperglycemia was defined as blood glucose above 7.8 mmol/l. CMR was performed 3.6 days ± 1.9 days after admission on a 1.5-tesla MR system. The imaging protocol included single-shot steady-state free precession (SSFP) cine sequences for assessing segmental and global left ventricular (LV) function and microvascular obstruction (MVO)/late gadolinium enhancement (LGE) imaging immediately and 10 min after the administration of 0.2 mmol gadodiamide/kg of body weight using an inversion-recovery SSFP (IR-SSFP) sequence. A receiver operating characteristics analysis was used to detect the best cut-off point of microvascular obstruction that predicted myocardial infarction and death during follow-up. RESULTS: Of 107 patients, 37 (35%) had hyperglycemia on admission. Compared to normoglycemic patients, patients with admission hyperglycemia had a lower LV ejection fraction (38.6 ± 13.7% vs. 47.5 ± 12.2%, p < 0.001), greater ESV (88.8 ± 41.8 ml vs. 72.3 ml ± 35.1 ml, p = 0.01), greater infarct size (LGE% 21.1 ± 14.9% vs. 9.8 ± 8.7%, p < 0.001), and greater MVO (MVO% 9.6 ± 9.9% vs. 2.5 ± 4.3%, p < 0.001). Admission hyperglycemia was an independent predictor of the presence and extent of microvascular obstruction. Microvascular obstruction as a percentage of left ventricular mass was the only variable independently related to clinical outcome in a Cox proportional hazard model (Wald 18.78, HR 1.155, p < 0.001). CONCLUSION: Hyperglycemia at admission in STEMI patients who are successfully treated by PCI is independently associated with the presence and extent of microvascular obstruction on contrast-enhanced CMR. Thus, microvascular obstruction as assessed by CMR may be a mechanism that relates admission hyperglycemia in acute STEMI to worse outcome.

Comparison between on-label versus off-label use of drug-eluting coronary stents in clinical practice: results from the German DES.DE-Registry.

BACKGROUND: Observational studies from the USA have demonstrated that off-label use of drug-eluting stents (DES) is common. Data on off-label use in Western Europe are limited. METHODS: We analyzed the data of consecutive patients receiving DES prospectively enrolled in the multicenter German DES.DE registry (Deutsches Drug-Eluting Stent Register) between October 2005 and October 2006. Off-label use was defined in the presence of one of the following criteria: ST-elevation myocardial infarction, in-stent stenosis, chronic total occlusion, lesions in a bypass graft, in bifurcation or left main stem, stent length per lesion ≥32 mm, and vessel diameter <2.5 or >3.5 mm. RESULTS: Overall, 4,295 patients were included in this analysis and divided into two groups: 2,366 (55.1%) received DES for off-label and 1,929 (44.9%) for on-label indications. There were substantial differences in the rates of off-label use at the participating hospitals. Patients with off-label DES more often presented with high-risk features such as acute coronary syndrome, cardiogenic shock, congestive heart failure, and more complex coronary anatomy. Among hospital survivors, the incidence of the composite endpoint of death, myocardial infarction and stroke (MACCE) (9.2 vs. 7.4%, p < 0.05), and target vessel revascularization (TVR) (11.3 vs. 9.1%, p < 0.05) was increased in the off-label group at the 1-year follow-up. However, in the multivariate analysis off-label use was not linked with an elevated risk for MACCE (hazard ratio 0.86, 95% confidence interval 0.62-1.18) and TVR (hazard ratio 1.05, 95% confidence interval 0.78-1.42). CONCLUSIONS: In clinical practice, DES was very frequently used off-label. After adjustment for confounding variables, off-label use was not associated with an increase of adverse events.

Relation of B-type natriuretic peptide (BNP) and infarct size as assessed by contrast-enhanced MRI.

BACKGROUND: Plasma B-type natriuretic peptide (BNP) measured in acute coronary syndromes independently predicts mortality, myocardial infarction and congestive heart failure. OBJECTIVES: To investigate the relationship between the extent of delayed enhancement (DE) and microvascular obstruction (MO) in contrast-enhanced MRI and the plasma level of BNP in patients with acute myocardial infarction. METHODS: The study group consisted of 41 consecutive patients (26 males, mean age 57±11 years) with a first STEMI and complete reperfusion by primary PCI. EDTA-plasma samples were obtained 40±15 h after admission and analyzed for NT-pro-BNP. Cardiac MRI (CMR) was performed 50±29 h after coronary intervention on a 1.5 Tesla scanner. Cine images were acquired in contiguous short-axis views using a segmented steady-state free precession (SSFP) sequence (TR, 3 ms; TE, 1.5 ms; FA, 60°). Additionally, contrast-enhanced imaging was performed using a single shot steady-state free precession (IR-SSFP) sequence with an inversion recovery prepulse (TR, 2.4 ms; TE, 1.1 ms; FA, 50°; TI, 180 to 260 ms). RESULTS: Strong correlations between NT-pro-BNT plasma levels and delayed enhancement extent (r=0.74, p<0.001) as well as MO (r=0.7, p<0.001) were observed. The correlation between LVEF and plasma levels of BNP, however, was only moderate (r=-0.44, p=0.002). In a multiple linear regression model, DE remains the only parameter with an independent linear association with BNP. CONCLUSION: NT-pro-BNP, a surrogate biomarker for prognosis after STEMI, is closely associated with myocardial damage as assessed by contrast-enhanced CMR.

Assessment of left ventricular function and mass in dual-source computed tomography coronary angiography: influence of beta-blockers on left ventricular function: comparison to magnetic resonance imaging.

PURPOSE: To quantify left ventricular (LV) function and mass (LVM) derived from dual-source computed tomography (DSCT) and the influence of beta-blocker administration compared to cardiac magnetic resonance imaging (CMR). METHODS: Thirty-two patients undergoing cardiac DSCT and CMR were included, where of fifteen received metoprolol intravenously before DSCT. LV parameters were calculated by the disc-summation method (DSM) and by a segmented region-growing algorithm (RGA). All data sets were analyzed by two blinded observers. Interobserver agreement was tested by the intraclass correlation coefficient. RESULTS.: 1. Using DSM LV parameters were not statistically different between DSCT and CMR in all patients (DSCT vs. CMR: EF 63+/-8% vs. 64+/-8%, p=0.47; EDV 136+/-36 ml vs. 138+/-35 ml, p=0.66; ESV 52+/-21 ml vs. 52+/-22 ml, p=0.61; SV 83+/-22 ml vs. 87+/-19 ml, p=0.22; CO 5.4+/-0.9l/min vs. 5.7+/-1.2l/min, p=0.09, LVM 132+/-33 g vs. 132+/-33 g, p=0.99). 2. In a subgroup of 15 patients beta-blockade prior to DSCT resulted in a lower ejection fraction (EF), stroke volume (SV), cardiac output (CO) and increase in end systolic volume (ESV) in DSCT (EF 59+/-8% vs. 62+/-9%; SV 73+/-17 ml vs. 81+/-15 ml; CO 5.7+/-1.2l/min vs. 5.0+/-0.8 l/min; ESV 52+/-27 ml vs. 57+/-24 ml, all p<0.05). 3. Analyzing the RGA parameters LV volumes were not significantly different compared to DSM, whereas LVM was higher using RGA (177+/-31 g vs. 132+/-33 g, p<0.05). Interobserver agreement was excellent comparing DSM values with best agreement between RGA calculations. CONCLUSION: Left ventricular volumes and mass can reliably be assessed by DSCT compared to CMR. However, beta-blocker administration leads to statistically significant reduced EF, SV and CO, whereas ESV significantly increases. DSCT RGA reliably analyzes LV function, whereas LVM is overestimated compared to DSM.

Myocardial scar visualized by cardiovascular magnetic resonance imaging predicts major adverse events in patients with hypertrophic cardiomyopathy.

OBJECTIVES: We sought to establish the prognostic value of a comprehensive cardiovascular magnetic resonance (CMR) examination in risk stratification of hypertrophic cardiomyopathy (HCM) patients. BACKGROUND: With annual mortality rates ranging between 1% and 5%, depending on patient selection, a small but significant number of HCM patients are at risk for an adverse event. Therefore, the identification of and prophylactic therapy (i.e., defibrillator placement) in patients with HCM who are at risk of dying are imperative. METHODS: Two-hundred forty-three consecutive patients with HCM were prospectively enrolled. All patients underwent initial CMR, and 220 were available for clinical follow-up. The mean follow-up time was 1,090 days after CMR. End points were all-cause and cardiac mortality. RESULTS: During follow-up 20 of the 220 patients died, and 2 patients survived sudden cardiac death due to adequate implantable cardioverter-defibrillator discharge. Most events (n = 16) occurred for cardiac reasons; the remaining 6 events were related to cancer and accidents. Our data indicate that the presence of scar visualized by CMR yields an odds ratio of 5.47 for all-cause mortality and of 8.01 for cardiac mortality. This might be superior to classic clinical risk factors, because in our dataset the presence of 2 risk factors yields an odds ratio of 3.86 for all-cause and of 2.20 for cardiac mortality, respectively. Multivariable analysis also revealed the presence of late gadolinium enhancement as a good independent predictor of death in HCM patients. CONCLUSIONS: Among our population of largely low or asymptomatic HCM patients, the presence of scar indicated by CMR is a good independent predictor of all-cause and cardiac mortality.

Impact of admission blood glucose on outcomes of nondiabetic patients with acute ST-elevation myocardial infarction (from the German Acute Coronary Syndromes [ACOS] Registry).

High blood glucose in patients with acute coronary syndromes have been associated with adverse short-term outcomes in patients without diabetes. However, the relation of admission glucose to long-term outcomes in these patients was less well established. Accordingly, consecutive patients with ST-elevation myocardial infarction (STEMI) without diabetes enrolled at 155 sites from July 2000 to November 2002 in the ACOS Registry were evaluated. Patients were categorized into tertiles based on admission blood glucose. Clinical end points of interest were 1-year mortality and composite of death, reinfarction, stroke, or rehospitalization (major adverse cardiac clinical events [MACCEs]) in the hospital and after discharge. Of 5,866 patients with STEMI, 36.9% had blood glucose <120 mg/dl; 33.1%, 120 to 150 mg/dl; and 30.0%, >150 mg/dl. Admission blood glucose was significantly related to increased risk of not only in-hospital events (death, glucose >150 vs <120 mg/dl, adjusted odds ratio [OR] 2.86, 95% confidence interval [CI] 2.13 to 3.82, p <0.0001; and MACCE, >150 vs <120 mg/dl, adjusted OR 1.88, 95% CI 1.52 to 2.33; p <0.0001), but this increased risk persisted beyond the acute phase during 1-year follow-up of a mean 380 days (median 387; death, glucose >150 vs <120 mg/dl, adjusted OR 1.46, 95% CI 1.04 to 2.03, p <0.0001; and MACCE, >150 vs <120 mg/dl, adjusted OR 1.31, 95% CI 1.00 to 1.71, p <0.0001). In conclusion, high blood glucose at admission to the hospital independently correlated with short- and midterm mortality in patients with STEMI.

A simple MR algorithm for estimation of myocardial salvage following acute ST segment elevation myocardial infarction.

PURPOSE: To assess myocardial salvage in acute ST segment elevation myocardial infarction (STEMI) by using contrast-enhanced CMR. METHODS: Forty-four consecutive patients (38 male; mean age 59 +/- 10 years) with a first acute STEMI underwent acute percutaneous coronary intervention with successful restoration of TIMI grade 3 flow. CMR was performed 2 +/- 1 days after reperfusion on a standard 1.5 T MR Scanner that included a steady-state free precession cine imaging for LV function and an inversion-recovery fast low angle shot (TR 8 ms, TE 4 ms, FA 25 degrees ) sequences for late gadolinium enhancement (LGE) following the injection of 0.2 mmol/kg BW gadodiamide. The myocardium at risk (MR) was approximated by the volume of myocardium exhibiting LGE and/or impaired wall motion. The myocardial salvage index (MSI) was calculated as the volume of the MR minus the volume of LGE divided by the volume of the MR. Reperfusion therapy was rated successful with an ST elevation resolution (STR) > or =70% and was considered inadequate below 70%. RESULTS: Infarct size (LGE) was 17 +/- 13% of LV mass, the mean STR was 53.4 +/- 28.3%, and the MSI was 10.9 +/- 6.2%. There was a good correlation between the MSI and the STR (r = 0.695, P < 0.0001). Thirty patients had an STR below 70%, and 14 patients had an STR greater than 70%. The MSI was greater in patients with a STE resolution of more than 70% (12 +/- 11 vs. 6 +/- 3%, P < 0.0001). CONCLUSION: A simple MR algorithm based upon the relationship of functional impairment, which includes myocardial stunning, to the extent of LGE (infarct necrosis) is in accordance with STR as a clinical marker of successful reperfusion in acute myocardial infarction.

EuroCMR (European Cardiovascular Magnetic Resonance) registry: results of the German pilot phase.

OBJECTIVES: During its German pilot phase, the EuroCMR (European Cardiovascular Magnetic Resonance) registry sought to evaluate indications, image quality, safety, and impact on patient management of routine CMR. BACKGROUND: CMR has a broad range of applications and is increasingly used in clinical practice. METHODS: This was a multicenter registry with consecutive enrollment of patients in 20 German centers. RESULTS: A total of 11,040 consecutive patients were enrolled. Eighty-eight percent of patients received gadolinium-based contrast agents. Twenty-one percent underwent adenosine perfusion, and 11% high-dose dobutamine-stress CMR. The most important indications were workup of myocarditis/cardiomyopathies (32%), risk stratification in suspected coronary artery disease/ischemia (31%), as well as assessment of viability (15%). Image quality was good in 90.1%, moderate in 8.1%, and inadequate in 1.8% of cases. Severe complications occurred in 0.05%, and were all associated with stress testing. No patient died during or due to CMR. In nearly two-thirds of patients, CMR findings impacted patient management. Importantly, in 16% of cases the final diagnosis based on CMR was different from the diagnosis before CMR, leading to a complete change in management. In more than 86% of cases, CMR was capable of satisfying all imaging needs so that no further imaging was required. CONCLUSIONS: CMR is frequently performed in clinical practice in many participating centers. The most important indications are workup of myocarditis/cardiomyopathies, risk stratification in suspected coronary artery disease/ischemia, and assessment of viability. CMR imaging as used in the centers of the pilot registry is a safe procedure, has diagnostic image quality in 98% of cases, and its results have strong impact on patient management.

Clinical outcomes after sirolimus-eluting, paclitaxel-eluting, and bare metal stents (from the first phase of the prospective multicenter German DES.DE Registry).

The prospective multicenter German Drug-Eluting Stent (DES.DE) registry is an observational study to analyze and evaluate the therapeutic principle of the differential drug-eluting stents (sirolimus- and paclitaxel-eluting stents) and bare metal stents under real world conditions in the context of the German healthcare system. The baseline clinical and angiographic characteristics and follow-up events for 1 year were recorded for all enrolled patients. In addition, a health economics assessment was performed at 3, 6, 9, and 12 months after initial stent placement. The composite of death, myocardial infarction, and stroke, defined as major adverse cardiac and cerebrovascular events, and target vessel revascularization were used as the primary objectives. From October 2005 to October 2006, 6,384 patients were enrolled (sirolimus-eluting stents, n = 2,137; paclitaxel-eluting stents, n = 2,740; bare metal stents, n = 485) at 98 Deutsches Drug-Eluting Stent Register sites. With similar baseline clinical and descriptive morphology of coronary artery disease between both drug-eluting stent groups, no differences were present at 1 year of follow-up in the rates of overall mortality (3.8% vs 4.1%), target vessel revascularization (10.4% vs 10.4%), overall stent thrombosis (3.6% vs 3.8%), and major adverse cardiac and cerebrovascular events (8.1% vs 8.0%). Compared with the bare metal stent group, patients treated with drug-eluting stents had significantly lower rates of myocardial infarction (3.2% vs 6.0%; p <0.01), stroke (1.2% vs 2.7%; p <0.05), and target vessel revascularization (10.4% vs 14.9%; p <0.01) without any difference in the stent thrombosis rate (3.7% vs 4.3%; p = 0.57) or mortality rate (4.0% vs 5.2%; p = 0.21). In conclusion, the data generated from the German Drug-Eluting Stent registry revealed no differences between patients receiving a paclitaxel-eluting stent and sirolimus-eluting stent in a "real-world" setting with regard to the clinical outcomes at 1 year.

Prognostic impact of contrast-enhanced CMR early after acute ST segment elevation myocardial infarction (STEMI) in a regional STEMI network: results of the "Herzinfarktverbund Essen".

BACKGROUND AND PURPOSE: In acute ST segment elevation myocardial infarction (STEMI), rapid restoration of epicardial coronary blood flow and myocardial perfusion limits infarct size and improves survival. Primary percutaneous coronary intervention (PCI) is superior to systemic fibrinolysis when instantly performed by experienced operators. The "Herzinfarktverbund Essen" (HIVE) is an urban STEMI network supporting direct patient transfer for primary PCI to four PCI centers covering a city area of 600,000 inhabitants. Integrated health care is an optional part of the HIVE allowing for reimbursement of medical innovations such as the evaluation of infarct size and the presence and extent of microvascular obstruction by contrast-enhanced cardiac magnetic resonance (CMR). The aim of this study was to assess the prognostic impact of contrast-enhanced CMR in the patient cohort of a regional STEMI network. PATIENTS AND METHODS: Within the 1st year (09/2004 to 08/2005) of the HIVE registry, 489 patients with acute myocardial infarction were treated in the four primary PCI centers. In one of the centers, including 143 patients, early CMR imaging using a standardized MR protocol for infarct quantification was performed whenever possible. Patients with hemodynamic instability, emergency coronary artery bypass grafting, resuscitation or death prior to CMR, claustrophobia, and other general contraindications to MRI had to be excluded, leaving 67 patients (54 male; mean age 61 +/- 12 years) for final evaluation. CMR was performed 4.5 +/- 2.5 days after admission on a 1.5-T MR scanner (Sonata, Siemens Medical Solutions, Erlangen, Germany) including steady-state free precession (SSFP) cine imaging for left ventricular function and single-shot inversion-recovery SSFP imaging for delayed enhancement (DE) and no-reflow (NR) evaluation following injection of 0.2 mmol/kg body weight gadodiamide (Omniscan, GE Healthcare Buchler, Munich, Germany). NR and DE volumes were calculated from single-shot short-axis stacks taken within the 1st minute following gadodiamide infusion by manual planimetry and summation of disks. 1-year follow-up data (telephone interview) for major adverse cardiac events (MACE: cardiac death, myocardial infarction, and rehospitalization for congestive heart failure, angina pectoris, or revascularization) were available for all patients. RESULTS: DE as a measure of infarct size was 9% +/- 7% (range 0-33%) of left ventricular mass (LVM), and mean volume of microvascular obstruction was 2% +/- 3% (range 0-17%). Microvascular obstruction was present in 61% of patients. 16 MACE (one cardiac death, one myocardial infarction, and 14 rehospitalizations for congestive heart failure or unstable angina pectoris with PCI in six cases) occurred within the follow-up period of 430 +/- 63 days. Patients with MACE had larger infarcts (14% +/- 10% vs. 8% +/- 6% DE), lower left ventricular ejection fraction (LVEF 44% +/- 17% vs. 48% +/- 14%) and larger NR (3% +/- 5% vs. 2% +/- 3%). Using a stepwise logistic regression model, only NR > 0.5% of LVM was independently related to outcome (odds ratio = 3.9, confidence interval 1.1-13.9). CONCLUSION: NR as a correlate of microvascular obstruction remains independently related to prognosis in patients with acute myocardial infarction treated by PCI.

Detection and characterization of intracardiac thrombi on MR imaging.

OBJECTIVE: The aim of our study was to compare the diagnostic accuracy achieved using different MR techniques with the diagnostic accuracy achieved using transthoracic and transesophageal echocardiography to detect intracardiac thrombi. MATERIALS AND METHODS: Twenty-four patients with known or suspected intracardiac thrombi were examined using MR imaging and echocardiography. All MR examinations were performed on a 1.5-T MR scanner using dark-blood-prepared half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences, fast imaging steady-state free precession (trueFISP) cine sequences, and inversion recovery gradient-echo fast low-angle-shot (inversion recovery turbo FLASH) sequences after injection of 0.2 mmol/kg of gadolinium diethylene triamine pentaacetic acid. RESULTS: MR imaging and echocardiography revealed 12 thrombi-two in the right atrium, one in the right ventricle, three in the left atrium, and six in the left ventricle. Compared with echocardiography, MR imaging revealed three additional thrombi in the left ventricle; these thrombi were confirmed at surgery. All 15 thrombi appeared as filling defects on early contrast-enhanced inversion recovery turbo FLASH MR images. Only seven thrombi were detected on HASTE images, and 10 thrombi were seen on trueFISP images. Four thrombi showed enhancement 10-20 min after contrast material injection and were characterized as organized clots. CONCLUSION: Contrast-enhanced inversion recovery turbo FLASH sequences were superior to dark-blood-prepared HASTE and trueFISP cine MR images in revealing intracardiac thrombi. Compared with transthoracic echocardiography, MR imaging was more sensitive for the detection of left ventricular thrombi. The characterization of thrombi may be used to predict the risk of embolism, which is higher for subacute clots than for organized thrombi.