Philippe Germain

Increased levels of procoagulant tissue factor-bearing microparticles within the occluded coronary artery of patients with ST-segment elevation myocardial infarction: role of endothelial damage and leukocyte activation.

OBJECTIVE During myocardial infarction, platelet activation and endothelial apoptosis are responsible for the release of procoagulant membrane-derived microparticles (MPs) in the bloodstream. Few data are available on the potential role played by MPs in coronary atherothrombosis. In the present study, we investigated the levels and cellular origins of MPs within the occluded coronary artery of patients with ST-segment elevation myocardial infarction (STEMI) treated by primary angioplasty (PCI). METHODS A total of 12 patients with STEMI treated by primary PCI within 24h of symptom onset were included in this study. MPs procoagulant activity and cellular origin were characterized within the occluded coronary artery before PCI (C(0)), after restoration of the epicardial blood flow (C(1)), and in blood collected from the femoral artery (F). RESULTS Levels of leukocyte-derived CD11a(+) MPs, endothelial-derived CD105(+) MPs, and tissue factor (TF)-bearing MPs were significantly higher within the occluded coronary artery than in peripheral blood samples. Restoration of the epicardial blood flow led to a significant reduction of procoagulant CD11a(+) and CD105(+) MPs by 30% and 42%, respectively (p<0.05). CONCLUSIONS Elevation of procoagulant MPs within the occluded coronary artery of patients with STEMI suggests their pathophysiological role in coronary atherothrombosis.

Myocardial Tagging with MR Imaging: Overview of Normal and Pathologic Findings

Magnetic resonance tagging is used to evaluate the dynamic deformation of lines or grids superimposed on the myocardium during the cardiac cycle. From these data, a specific postprocessing procedure provides two kinds of metrics: (a) three orthogonal components of myocardial motion (longitudinal, circumferential, and radial), and (b) rotation and torsion. Strain expresses the local myocardial deformation and is prone to important physiologic heterogeneities. Peak systolic strain is in the range of -15% to -20% for the longitudinal and circumferential components (fiber shortening) and 30%-40% for the radial component (wall thickening). The helical arrangement of myofibers that run in opposite directions at the epicardium and endocardium explains systolic twist (~15°). This torsion may be enhanced during the early stage of several diseases (eg, hypertrophic cardiomyopathy) or in heart failure with a normal left ventricular ejection fraction. Strain is generally impaired in ischemic heart disease and cardiomyopathy, but the most diagnostically significant finding is the early identification of contractile dysfunction on the basis of longitudinal and circumferential strain reduction in patients with apparently preserved systolic function. Thus, strain impairment appears to be a sensitive and promising marker of subclinical disease, with the potential for improving patient management.

Fetal shoulder measurements with MRI.

Objective We studied the ability of MRI to predict fetal shoulder width (FSW). Materials and Methods In 30 patients referred for MR pelvimetry, measurement of FSW was performed and compared with caliper measurements at term. We report here the feasibility of a method using axial and coronal MR images oriented to the fetal body axes. Results Shoulder width by MRI (mean = 12.76 ± 1.42 cm) correlated significantly with postnatal orthopedic caliper measurements (mean = 12.99 ± 1.37 cm; r = 0.955, SEE = 4.29 mm, p = 0.00001) and with birth weight (r = 0.63, p = 0.0005). Mean paired differences showed a statistically significant 2.3 ± 4.2 mm underestimation of FSW by MRI (p = 0.01). This reasonably quick nonionizing technique seems to have the potential for evaluating shoulder dystocia and deserves further evaluation.

Native T1 Mapping of the Heart – A Pictorial Review

T1 mapping is now a clinically feasible method, providing pixel-wise quantification of the cardiac structures T1 values. Beyond focal lesions, well depicted by late gadolinium enhancement sequences, it has become possible to discriminate diffuse myocardial alterations, previously not assessable by noninvasive means. The strength of this method includes the high reproducibility and immediate clinical applicability, even without the use of contrast media injection (native or pre-contrast T1). The two most important determinants of native T1 augmentation are (1) edema related to tissue water increase (recent infarction or inflammation) and (2) interstitial space increase related to fibrosis (infarction scar, cardiomyopathy) or to amyloidosis. Conversely, lipid (Anderson–Fabry) or iron overload diseases are responsible for T1 reduction. In this pictorial review, the main features provided by native T1 mapping are discussed and illustrated, with a special focus on the awaited clinical purpose of this unique, promising new method.

Myocardial flow reserve parametric map, assessed by first-pass MRI compartmental analysis at the chronic stage of infarction

Regional myocardial flow and flow reserve (MFR) were assessed by compartmental analysis of Gd‐enhanced MRI first‐pass data in 7 patients with atypical chest pain, and in 15 patients with previous transmural myocardial infarction. The FE product (Flow × Extraction coefficient), derived from the modified Kety equation, was measured in regions corresponding to the Tetrofosmine‐SPECT fixed defect and in remote normal regions. The FE product at rest and hyperemic FE product were similar in healed revascularized tissues (70.5 ± 15.6 and 112.5 ± 19.5ml/mn/100g, respectively) and in normal myocardium (76.2 ± 18.3 and 142.2 ± 33.0, respectively). In contrast, the FE index (48.8 ± 15.2 and 60.7 ± 18.0, respectively, P < 0.01 versus the two previous groups) and the MFR (1.27 ± 0.20 vs. 1.91 ± 0.29 in normal regions) were reduced in healed fibrotic tissues when the infarct‐related artery remained occluded. Myocardial flow reserve maps allowed correct identification of regions corresponding to an occluded infarct‐related artery. J. Magn. Reson. Imaging 2001;13:352–360.

Severe ventricular arrhythmias in a patient with cardiac sarcoidosis: insights from MRI and PET imaging and importance of early corticosteroid therapy

A 37-year-old male was referred to our institution for evaluation of exertional angina and non-sustained ventricular tachycardia. Physical examination and laboratory results were normal. The echocardiogram ( Panel E ) revealed left ventricular (LV) hypertrophy (interventricular septum 16 mm, posterior wall 13.8 mm) with normal ejection fraction. Coronary angiography was normal. Further exploration including cardiac magnetic …

Longitudinal 2D strain can help diagnose coronary artery disease in patients with suspected non-ST-elevation acute coronary syndrome but apparent normal global and segmental systolic function

BACKGROUND The clinical work-up of patients presenting with chest pain is a diagnostic challenge. We investigated the diagnostic performance of global (GLS) and territorial (TLS) longitudinal strain to predict coronary artery disease (CAD) in patients presenting with suspected non-ST-segment elevation acute coronary syndrome (NSTE-ACS) but apparent normal global and regional systolic function. METHODS 150 consecutive suspected NSTE-ACS patients were initially screened for inclusion ; 58 patients with normal LVEF (≥55%) and WMSI (=1) were prospectively enrolled. Speckle-tracking echocardiography was performed on admission and all the patients underwent coronary angiography. CAD was defined as the presence of stenosis of >50%. RESULTS CAD was present in 33 patients (57%). LVEF was 60.7±4.6% in group 1 (CAD) and 61.1±5.0% in group 2 (no CAD). Global longitudinal strain (GLS) was altered in group 1 (-16.7±3.4%) as compared to group 2 (-22.4±2.9%, p<0.001). ROC curve analysis showed a high diagnostic value of GLS for the prediction of CAD (AUC=0.92 [0.84-1.00], p=0.0001). TLS was able to discriminate between coronary stenosis in the LAD, LCX or RCA. CONCLUSIONS Longitudinal 2D strain has a good diagnostic value and can efficiently localize the culprit lesion in patients presenting with NSTE-ACS but apparent normal global and regional systolic function.

Left Ventricular Involvement in Arrhythmogenic Right Ventricular Cardiomyopathy – A Cardiac Magnetic Resonance Imaging Study

Background Few studies evaluated left ventricular (LV) involvement in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The aim of this study is to determine the frequency, clinical presentation, and pattern of LV involvement in ARVD/C (LV-ARVD/C). Methods We retrospectively evaluated the cardiac magnetic resonance (CMR) in 202 patients referred between 2008 and 2012 to our institution, and we determined the presence or the absence of CMR criteria in the revised task force criteria 2010 for the diagnosis of ARVD/C. A total of 21 patients were diagnosed with ARVD/C according to the revised task force criteria 2010. All included patients had no previous history of myocarditis, acute coronary syndrome, or any other cardiac disease that could interfere with the interpretations of structural abnormalities. The LV involvement in ARVD/C was defined by the presence of one or more of the following criteria: LV end-diastolic volume (LVEDV; >95 mL/m2), LV ejection fraction (LVEF; <55%), LV late enhancement of gadolinium (LVLE) in a non-ischemic pattern, and LV wall motion abnormalities (WMAs). In the follow-up for the occurrence of cardiac death, ventricular tachycardia (VT) was obtained at a mean of 31 ± 20.6 months. Results A total of 21 patients had ARVD/C. The median age was 48 (33-63) years. In all, 11 patients (52.4%) had LV-ARVD/C. The demographic characteristics of patients with or without LV were similar. There was a higher frequency of left bundle-branch block (LBBB) VT morphology in ARVD/C (P = 0.04). In CMR, regional WMAs of right ventricle (RV) and RV ejection fraction (RVEF; <45%) were strongly correlated with LV-WMAs (r = 0.72, P = 0.02, r = 0.75, P = 0.02, respectively). RV late enhancement of gadolinium (RVLE) was associated with LV-WMs and LVLE (r = 0.7, P = 0.03; r = 0.8, P = 0.006). LVLE was associated with LV-WMAs, LVEF, and LVEDV (r = 0.9, P = 0.001; r = 0.8, P = 0.001; r = 0.8, P = 0.01). Conclusion LV involvement in ARVD/C is common and frequently associated with moderate to severe right ventricular (RV) abnormalities. The impact of LV involvement in ARVD/C on the prognosis needs further investigations.

Quantification of left ventricular dyssynchrony in patients with systolic dysfunction: A comparison of circumferential strain MR‐tagging metrics

To define which circumferential strain MR‐tagging metrics of left intraventricular dyssynchrony better identifies patients with systolic dysfunction against control subjects.

Characterization of an intra-cardiac melanoma metastasis by magnetic resonance T1 and T2 mapping

This case demonstrates how the integration of new cardiac imaging techniques can contribute to the exploration of a cardiac mass, and ultimately help the etiological diagnosis. Recent years have witnessed the advent of the use of new CMR T1 and T2 mapping sequences [1]: access to a true absolute quantification of relaxation times rather than a simple weighting of the image contrast is a material change in MRI. If T1 and T2 mapping sequences have been already extensively described in the setting of cardiomyopathies, only seldom case reports have focused on T1 or T2 mapping in cardiac masses [2]. To our knowledge, this is the first report of an intracardiac melanoma being evaluated by CMR Tx mapping. These sequences allow a significant progress in the approach of tissue characterization, providing complementary information to that of other imaging modalities and thus can be useful for the evaluation of cardiac tumors and masses. A 64 year-old male patient with a history of melanoma was referred to our department for cardiac magnetic resonance (CMR) evaluation of an intra-cardiac mass. The echocardiography showed an ovoid tumoral mass embedded in the right atrial floor, just behind the tricuspid annulus, suspected to be a cardiac location of melanoma metastasis. CMR 1.5T T1 and T2 mapping sequences revealed low native T1 value inside the mass (736 ms) (Fig. 1, panel A) in comparison to myocardium (normal range 1030 ± 34 ms) consistent with a melanin content whose paramagnetic effect is related to the presence of free radicals and non-apparied electrons, and slightly elevated T2 (58 ms, normal range 50 ± 2 ms) (Fig. 1, panel B). After gadolinium injection, post-contrast T1 mapping sequence showed a 59 % T1 drop in the tumor (Fig. 1, panel C) and late-enhancement was clearly identified with PSIR sequence disclosing heterogeneous uptake inside the mass (Fig. 1, panel D). The tumor was surgically removed and histopathology confirmed the diagnosis of melanoma metastasis.