Enver Tahir

Tissue characterization by T1 and T2 mapping cardiovascular magnetic resonance imaging to monitor myocardial inflammation in healing myocarditis

Aims Monitoring disease activity in myocarditis is important for tailored therapeutic strategies. This study evaluated the ability of T1 and T2 mapping cardiovascular magnetic resonance (CMR) to monitor the course of myocardial inflammation in healing myocarditis. Methods and Results Forty-eight patients with strictly defined acute myocarditis underwent CMR at 1.5 T in the acute stage, at 3-months (n = 39), and at 12-months follow-up (FU) (n = 21). Normal values were obtained in a control group of 27 healthy subjects. The CMR protocol included standard (‘Lake-Louise’) sequences as well as T1 (modified Look-Locker inversion recovery sequence, MOLLI) and T2 (gradient- and spin-echo sequence, GraSE) mapping. T1, T2, and extracellular volume (ECV) maps were generated using an OsiriX plug-in. Native myocardial T1, T2, and ECV values were increased in the acute stage, but declined with healing of myocarditis. The performances of global native T1 and T2 to differentiate acute from healed myocarditis stages were significantly better compared with all other global CMR parameters with AUCs of 0.85 (95% CI, 0.76–0.94) and 0.83 (95% CI, 0.73–0.93). Furthermore, regional native T1 and T2 in myocarditis lesions provided AUCs of 0.97 (95% CI, 0.93–1.02) and 0.93 (95% CI, 0.85–1.01), which were significantly superior to any other global or regional CMR parameter. Conclusion Healing of myocarditis can be monitored by native myocardial T1 and T2 measurements without the need for contrast media. Both native myocardial T1 and T2 provide an excellent performance for assessing the stage of myocarditis by CMR.

Acute versus Chronic Myocardial Infarction: Diagnostic Accuracy of Quantitative Native T1 and T2 Mapping versus Assessment of Edema on Standard T2-weighted Cardiovascular MR Images for Differentiation

Purpose To analyze the diagnostic accuracy of native T1 and T2 mapping compared with visual and quantitative assessment of edema on T2-weighted cardiac magnetic resonance (MR) images to differentiate between acute and chronic myocardial infarction. Materials and Methods This study had institutional ethics committee approval. Written informed consent was obtained from 67 consecutive patients (57 years ± 12; 78% men) with a first acute myocardial infarction, who were prospectively enrolled between April 2011 and June 2015. Four serial 1.5-T MR imaging examinations were performed at 8 days ± 5, 7 weeks ± 2, 3 months ± 0.5, and 6 months ± 1.4 after infarction and included T2-weighted, native T1/T2 mapping, and late gadolinium enhancement MR imaging. Complete follow-up data were obtained in 42 patients. Regional native T1/T2 relaxation time, T2-weighted ratio, and extracellular volume were serially measured in infarcted and remote myocardium. Receiver operating characteristic (ROC) analysis was used to determine the diagnostic accuracy of the MR imaging parameters for discriminating between acute and chronic myocardial infarction. Results Native T1 of infarcted myocardium decreased from 1286 msec ± 99 at baseline to 1077 msec ± 50 at 6 months (P < .0001), whereas T2 decreased from 84 msec ± 10 to 58 msec ± 4 (P < .0001). The T2-weighted ratio decreased from 4.1 ± 1.0 to 2.4 ± 0.6 (P < .0001). Of all the MR imaging parameters obtained, native T1 and T2 yielded the best areas under the ROC curve (AUCs) of 0.975 and 0.979, respectively, for differentiating between acute and chronic myocardial infarction. Visual analysis of the presence of edema at standard T2-weighted cardiac MR imaging resulted in an inferior AUC of 0.863 (P < .01). Conclusion Native T1 and T2 of infarcted myocardium are excellent discriminators between acute and chronic myocardial infarction and are superior to all other MR imaging parameters. Online supplemental material is available for this article.

Prediction of the estimated 5-year risk of sudden cardiac death and syncope or non-sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy using late gadolinium enhancement and extracellular volume CMR

AbstractObjectivesTo evaluate the ability of late gadolinium enhancement (LGE) and mapping cardiac magnetic resonance (CMR) including native T1 and global extracellular volume (ECV) to identify hypertrophic cardiomyopathy (HCM) patients at risk for sudden cardiac death (SCD) and to predict syncope or non-sustained ventricular tachycardia (VT).MethodsA 1.5-T CMR was performed in 73 HCM patients and 16 controls. LGE size was quantified using the 3SD, 5SD and full width at half maximum (FWHM) method. T1 and ECV maps were generated by a 3(3)5 modified Look-Locker inversion recovery sequence. Receiver-operating curve analysis evaluated the best parameter to identify patients with increased SCD risk ≥4% and patients with syncope or non-sustained VT.ResultsGlobal ECV was the best predictor of SCD risk with an area under the curve (AUC) of 0.83. LGE size was significantly inferior to global ECV with an AUC of 0.68, 0.70 and 0.70 (all P < 0.05) for 3SD-, 5SD- and FWHM-LGE, respectively. Combined use of the SCD risk score and global ECV significantly improved the diagnostic accuracy to identify HCM patients with syncope or non-sustained VT.ConclusionsCombined use of the SCD risk score and global ECV has the potential to improve HCM patient selection, benefiting most implantable cardioverter defibrillators.Key Points• Global ECV identified the best HCM patients with increased SCD risk. • Global ECV performed equally well compared to a SCD risk score. • Combined use of the SCD risk score and global ECV improved test accuracy. • Combined use potentially improves selection of HCM patients for ICD implantation.

T1 mapping cardiovascular magnetic resonance imaging to detect myocarditis-Impact of slice orientation on the diagnostic performance.

BACKGROUND T1 mapping is a promising diagnostic tool to improve the diagnostic accuracy of cardiovascular magnetic resonance (CMR) in patients with suspected myocarditis. However, there are currently no data on the potential influence of slice orientation on the diagnostic performance of CMR. Thus, we compared the diagnostic performance of global myocardial T1 and extracellular volume (ECV) values to differentiate patients with myocarditis from healthy individuals between different slice orientations. METHODS This study included 48 patients with clinically defined myocarditis and 13 healthy controls who underwent CMR at 1.5T. A modified Look-Locker inversion-recovery (MOLLI) sequence was used for T1 mapping before and 15min after administration of 0.075mmol/kg Gadolinium-BOPTA. T1 mapping was performed on three short and on three long axes slices, respectively. Native T1, post-contrast T1 and extracellular volume (ECV) -BOPTA maps were calculated using a dedicated plug-in written for the OsiriX software and compared between the mean value of three short-axes slices (3SAX), the central short-axis (1SAX), the mean value of three long-axes slices (3LAX), the four-chamber view (4CH), the three-chamber view (3CH) and the two-chamber view (2CH). RESULTS There were significantly lower native T1 values on 3LAX (1081ms (1037-1131ms)) compared to 3SAX (1107ms (1069-1143ms), p=0.0022) in patients with myocarditis, but not in controls (1026ms (1009-1059ms) vs. 1039ms (1023-1055ms), p=0.2719). The areas under the curve (AUC) to discriminate between myocarditis and healthy controls by native myocardial T1 were 0.85 (p<0.0001) on 3SAX, 0.85 (p<0.0001) on 1SAX, 0.76 (p=0.0002) on 3LAX, 0.70 (p=0.0075) on 4CH, 0.72 (p=0.0020) on 3CH and 0.75 (p=0.0003) on 2CH. The AUCs for ECV-BOPTA were 0.83 (p<0.0001) on 3 SAX, 0.82 (p<0.0001) on 1SAX, 0.77 (p=0.0005) on 3LAX, 0.71 (p=0.0079) on 4CH, 0.69 (p=0.0371) on 3CH and 0.75 (p=0.0006) on 2CH. CONCLUSION Native T1 and ECV-BOPTA on short axes slices provide a better diagnostic performance in myocarditis than long axes slices since long axes slices seem to underestimate native myocardial T1 in myocarditis. T1 mapping in suspected myocarditis can be restricted to a single mid-ventricular short-axis slice without a significant loss in diagnostic performance.

Clinico-radiological comparison and short-term prognosis of single acute pancreatitis and recurrent acute pancreatitis including pancreatic volumetry

Purpose The necrosis-fibrosis hypothesis describes a continuum between single attacks of acute pancreatitis (SAP), recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP) with endocrine and exocrine pancreatic insufficiency. For prevention purposes we evaluated clinico-radiological parameters and pancreatic volumetry to compare SAP and RAP and provide prognostic relevance on short-term mortality, need for intervention and the hospitalization duration. Materials and methods We retrospectively investigated 225 consecutive patients (150 males, range 19-97years) with acute pancreatitis (74%SAP, 26%RAP) according to the revised Atlanta classification. All patients received an intravenous contrast-enhanced CT after a median time of 5 (IQR 5–7) days after onset of symptoms. Two experienced observers rated the severity of AP by 3 CT scores (CTSI, mCTSI, EPIC). Moreover, total pancreatic volumes and additional parenchymal necrosis volumes were assessed, when appropriate. Clinical parameters were etiology of AP, lipase on admission, CRP 48 hours after admission (CRP48), and the presence of organ dysfunction, assessed by the modified Marshall score. The modified Marshall score included systolic blood pressure, serum creatinine, and the ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2 ratio) and was assessed on admission and 48 hours after admission to find patients with persistent organ failure. Outcome parameters were total hospitalization duration, short-term mortality and need for intervention. Results Lipase, CRP48, etiology of AP, EPIC, PaO2/FiO2 ratio, and the presence of a pleural effusion differed significantly in both groups (p<0.05). In 109 patients with interstitial edematous AP, the total pancreatic volume was significantly smaller in patients with RAP compared to those with SAP (69±35cm3; (RAP) vs 106±45cm3; (SAP), p<0.001). All outcome parameters including the mortality rates (SAP vs. RAP: 15% vs. 7%) were comparable in both groups (p>0.05). In the necrotizing RAP group, only the necrotic volume correlated significantly with total hospitalization time (r = 0.72, p<0.001), whereas the systolic blood pressure was the only, but weak predictor for short-term mortality (β-coefficient: -0.05, p = 0.03) and the need for intervention (β-coefficient: -0.02, p = 0.048) in the total RAP group. In patients with SAP, the modified Marshall score was the strongest predictor of short-term mortality, followed by the mCTSI on multivariate logistic regression (Marshall score: β-coefficient: 1.79, p<0.001; mCTSI: β-coefficient: 0.40, p<0.001). CTSI was the best predictor for required intervention in necrotizing SAP (β-coefficient: 0.46, p<0.001), followed by the volume of intrapancreatic necrosis (β-coefficient: 0.17, p = 0.03). Conclusion Total pancreatic volume differed significantly between interstitial RAP and SAP and intrapancreatic necrosis volume revealed prognostic value for the total hospitalization duration in necrotizing RAP. Although all outcome parameters were comparable between SAP and RAP, only systolic blood pressure and pancreatic volumetry were prognostic in RAP. In SAP, only the modified Marshall score and mCTSI revealed prognostic value for short-term mortality, whereas CTSI was predictive for the need for intervention.

Peak enhancement ratio of myocardium to aorta for identification of myocardial ischemia using dynamic myocardial computed tomography perfusion imaging

BACKGROUND This study aimed to evaluate the feasibility of peak enhancement (PE) ratio of myocardium to aorta (PER) derived from stress dynamic computed tomography myocardial perfusion imaging (CTP) for the detection of myocardial ischemia assessed by magnetic resonance (MR) imaging. METHODS Forty-four patients who underwent stress dynamic CTP and MR imaging were retrospectively evaluated. From the time-attenuation curve, myocardial PE, PER, and myocardial blood flow (MBF) were calculated on a segment-based analysis. The correlation between myocardial and aortic PE was assessed by Spearmans correlation, and the differences in myocardial PE and PER between normal and ischemic myocardium were assessed by the Mann-Whitney U-test. The diagnostic accuracies of myocardial PE, PER, and MBF for detecting myocardial ischemia were compared by receiver operating characteristic analysis. RESULTS Of 704 segments, 258 segments (37%) were diagnosed as myocardial ischemia with MR imaging. Myocardial and aortic PE were significantly correlated in both normal and ischemic segments (r=0.76 and 0.58; p<0.05, in each). The myocardial PE and PER of ischemic segments were significantly lower than those of normal segments (p<0.05, in each). Sensitivity and specificity were 61% [95% confidence interval (CI), 55-70%] and 83% (95% CI, 73-87%) for myocardial PE, 78% (67-88%) and 82% (95% CI, 70-91%) for PER, and 81% (95% CI, 73-87%) and 85% (95% CI, 79-92%) for MBF. There was a significantly larger area under the curve for PER (0.87; 95% CI, 0.84-0.90) and MBF (0.88; 95%CI, 0.85-0.91), compared to myocardial PE (0.75; 95% CI, 0.70-0.79) (p<0.05, in each). There was no significant difference in area under the curve between PER and MBF. CONCLUSIONS The semi-quantitative parameter of PER showed a high diagnostic accuracy for the detection of myocardial ischemia, comparable to that of MBF.

Asymptomatic Cocaine Abuse ― Myocardial Tissue Characterization Using Cardiac Biomarkers and Cardiovascular Magnetic Resonance Imaging ―

BACKGROUND Use of cocaine is widespread and associated with several cardiovascular diseases. Recent CMR studies indicate frequent myocardial scar/fibrosis in asymptomatic cocaine abusers (CA).Methods and Results:This study used a combination of advanced CMR tissue characterization techniques, including late gadolinium enhancement (LGE) for focal, and extracellular volume (ECV) imaging for diffuse myocardial injury/fibrosis, with circulating biomarkers for a comprehensive characterization of myocardial injury. We included 20 cardiac asymptomatic CA and a control group of 20 healthy volunteers. The comprehensive assessment included physical examination, resting ECG, exercise ECG, cardiac biomarkers, transthoracic echocardiogram and CMR. We did not find significant differences between CA and controls either in functional CMR parameters such as LVEDVi, LVESVi, LVEF, LV mass index, or in global myocardial ECV. Neither CA nor controls had evidence of myocardial edema on T2-weighted CMR, but 8 CA (40%), and none of the controls had focal myocardial scar (P<0.01). Interestingly, CA with focal myocardial scar on LGE had significantly higher high-sensitivity troponin I (hs-TNI) compared with CA without focal scar (median, 1.7 ng/L; IQR, 1.3-2.5 ng/L vs. 0.6 ng/L; 0.4-1.3 ng/L; P<0.01). CONCLUSIONS Focal myocardial injury in terms of subtle LGE in 40% of asymptomatic CA was associated with higher hs-TNI. Comprehensive assessment including advanced ECV imaging indicates a focal rather than diffuse pattern of myocardial involvement in asymptomatic CA.

Comparison of global extracellular volume (ECV) and late gadolinium enhancement (LGE) to predict the estimated 5 year risk of sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM)

University Medical Center Hamburg-Eppendorf, Hamburg, Germany Full list of author information is available at the end of the article Figure 1 Correlation of global ECV (R = 0.68, p < 0.01) and global LGE with the SCD Risk Score (R = 0.39, p = 0.08). Dashed lines define a 95% confidence interval. Continuous line represents the fitting line. Avanesov et al. Journal of Cardiovascular Magnetic Resonance 2016, 18(Suppl 1):P127 http://www.jcmr-online.com/content/18/S1/P127

Reproducibility of native and contrast-enhanced CMR techniques to measure lesion size following acute myocardial infarction

Methods Lesion size was independently quantified by 2 experienced observers in total of 120 consecutive CMRs obtained in 30 patients within the first 6 months after AMI using native and contrast-enhanced sequences. Lesion sizes were quantified using a threshold method (cutoff >2SD of remote normal myocardium) on basal, midventricular and apical short-axis left ventricular slices. Lesion size is given as the mean of both observers. Bland-Altman analysis was performed to determine the agreement between the two observers. Non-parametric Levene’s test was used to compare the variances of the relative differences. Statistical analysis was performed using GraphPad Prism 6.

Effects on blood pressure, cardiac mass and function after renal denervation in patients with resistant hypertension

Background In recent years, catheter-based renal denervation (RDN) has been investigated as a promising strategy in the treatment of resistant hypertension. Due to a reduction of whole body sympathetic activity, additional benefits on cardiac adaptation have been proposed. The purpose of this study was to investigate the effect of RDN on blood pressure (BP) as well as cardiac mass and function via cardiac magnetic resonance imaging (CMRI).