Cesar Higa Nomura

Myocardial tissue characterization in Chagas’ heart disease by cardiovascular magnetic resonance

BackgroundChagas’ heart disease is an important public health problem in South America. Several aspects of the pathogenesis are not fully understood, especially in its subclinical phases. On pathology Chagas’ heart disease is characterized by chronic myocardial inflammation and extensive myocardial fibrosis. The latter has also been demonstrated by late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR). In three clinical phases of this disease, we sought to investigate the presence of LGE, myocardial increase in signal intensity in T2-weighted images (T2W) and in T1-weighted myocardial early gadolinium enhancement (MEGE), previously described CMR surrogates for myocardial fibrosis, myocardial edema and hyperemia, respectively.MethodsFifty-four patients were analyzed. Sixteen patients with the indeterminate phase (IND), seventeen patients with the cardiac phase with no left ventricular systolic dysfunction (CPND), and twenty-one patients with the cardiac phase with left ventricular systolic dysfunction (CPD). All patients underwent 1.5xa0T CMR scan including LGE, T2W and MEGE image sequences to evaluate myocardial abnormalities.ResultsLate gadolinium enhancement was present in 72.2xa0% of all patients, in 12.5xa0% of IND, 94.1xa0% of the CPND and 100xa0% of the CPD patients (pu2009<u20090.0001). Myocardial increase in signal intensity in T2-weighted images (T2W) was present in 77.8xa0% of all patients, in 31.3xa0% of the IND, 94.1xa0% of the CPND and 100xa0% of the CPD patients (pu2009<u20090.0001). T1-weighted myocardial early gadolinium enhancement (MEGE) was present in 73.8xa0% of all patients, in 25.0xa0% of the IND, 92.3xa0% of the CPND and 94.1xa0% of the CPD (pu2009<u20090.0001). A good correlation between LGE and T2W was observed (ru2009=u20090.72, and pu2009<u20090.001).ConclusionsIncrease in T2-weighted (T2W) myocardial signal intensity and T1-weighted myocardial early gadolinium enhancement (MEGE) can be detected by CMR in patients throughout all phases of Chagas’ heart disease, including its subclinical presentation (IND). Moreover, those findings were parallel to myocardial fibrosis (LGE) in extent and location and also correlated with the degree of Chagas’ heart disease clinical severity. These findings contribute to further the knowledge on pathophysiology of Chagas’ heart disease, and might have therapeutic and prognostic usefulness in the future.

Is there a consistent association between coronary heart disease and ischemic stroke caused by intracranial atherosclerosis

Coronary heart disease and ischemic stroke are frequent coexistent conditions that share risk factors and pose major burdens to global health. Even though a clear relation has been established between extracranial internal carotid artery atherosclerosis and symptomatic or asymptomatic coronary heart disease, there is a gap in knowledge about the association between intracranial atherosclerosis and coronary heart disease. Intracranial atherosclerosis is associated with high risks of stroke recurrence and vascular death. More research and clinical trials are needed to answer whether early diagnosis of asymptomatic coronary heart disease and aggressive treatment can decrease the risk of vascular death in patients with ischemic stroke caused by intracranial atherosclerosis.

Accuracy of Myocardial Biomarkers in the Diagnosis of Myocardial Infarction After Revascularization as Assessed by Cardiac Resonance: The Medicine, Angioplasty, Surgery Study V (MASS-V) Trial

BACKGROUNDnThe lack of a correlation between myocardialxa0necrosis biomarkers and electrocardiographic abnormalities after revascularization procedures has resulted in a change in the myocardial infarction (MI) definition.nnnMETHODSnPatients with stable multivessel disease who underwent percutaneous or surgical revascularization were included. Electrocardiograms and concentrations of high-sensitive cardiac troponin I (cTnI) and creatine kinase (CK)-MB were assessed before and after procedures. Cardiac magnetic resonance and late gadolinium enhancement were performed before and after procedures. MI was defined as more than five times the 99th percentile upper reference limit for cTnI and 10 times for CK-MB in percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), respectively, and new late gadolinium enhancement for cardiac magnetic resonance.nnnRESULTSnOf the 202 patients studied, 69 (34.1%) underwent on-pump CABG, 67 (33.2%) off-pump CABG, and 66 (32.7%) PCI. The receiver operating characteristic curve showed the accuracy of cTnI for on-pump CABG, off-pump CABG, and PCI patients was 21.7%, 28.3%, and 52.4% and for CK-MB was 72.5%, 81.2%, and 90.5%, respectively. The specificity of cTnI was 3.6%, 9.4%, and 42.1% and of CK-MB was 73.2%, 86.8%, and 96.4%, respectively. Sensitivity of cTnI was 100%, 100%, and 100% and of CK-MB was 69.2%, 64.3%, and 44.4%, respectively. The best cutoff of cTnI for on-pump CABG, off-pump CABG, and PCI was 6.5 ng/mL, 4.5 ng/mL, and 4.5 ng/mL (162.5, 112.5, and 112.5 times the 99th percentile upper reference limit) and of CK-MB was 37.5 ng/mL, 22.5 ng/mL, and 11.5 ng/mL (8.5, 5.1, and 2.6 times the 99th percentile upper reference limit), respectively.nnnCONCLUSIONSnCompared with cardiac magnetic resonance, CK-MB was more accurate than cTnI for diagnosing MI. These data suggest a higher troponin cutoff for the diagnosis of procedure-related MI.

Hypotheses, rationale, design, and methods for prognostic evaluation of cardiac biomarker elevation after percutaneous and surgical revascularization in the absence of manifest myocardial infarction. A comparative analysis of biomarkers and cardiac magnetic resonance. The MASS-V Trial

BackgroundAlthough the release of cardiac biomarkers after percutaneous (PCI) or surgical revascularization (CABG) is common, its prognostic significance is not known. Questions remain about the mechanisms and degree of correlation between the release, the volume of myocardial tissue loss, and the long-term significance. Delayed-enhancement of cardiac magnetic resonance (CMR) consistently quantifies areas of irreversible myocardial injury. To investigate the quantitative relationship between irreversible injury and cardiac biomarkers, we will evaluate the extent of irreversible injury in patients undergoing PCI and CABG and relate it to postprocedural modifications in cardiac biomarkers and long-term prognosis.Methods/DesignThe study will include 150 patients with multivessel coronary artery disease (CAD) with left ventricle ejection fraction (LVEF) and a formal indication for CABG; 50 patients will undergo CABG with cardiopulmonary bypass (CPB); 50 patients with the same arterial and ventricular condition indicated for myocardial revascularization will undergo CABG without CPB; and another 50 patients with CAD and preserved ventricular function will undergo PCI using stents. All patients will undergo CMR before and after surgery or PCI. We will also evaluate the release of cardiac markers of necrosis immediately before and after each procedure. Primary outcome considered is overall death in a 5-year follow-up. Secondary outcomes are levels of CK-MB isoenzyme and I-Troponin in association with presence of myocardial fibrosis and systolic left ventricle dysfunction assessed by CMR.DiscussionThe MASS-V Trial aims to establish reliable values for parameters of enzyme markers of myocardial necrosis in the absence of manifest myocardial infarction after mechanical interventions. The establishments of these indices have diagnostic value and clinical prognosis and therefore require relevant and different therapeutic measures. In daily practice, the inappropriate use of these necrosis markers has led to misdiagnosis and therefore wrong treatment. The appearance of a more sensitive tool such as CMR provides an unprecedented diagnostic accuracy of myocardial damage when correlated with necrosis enzyme markers. We aim to correlate laboratory data with imaging, thereby establishing more refined data on the presence or absence of irreversible myocardial injury after the procedure, either percutaneous or surgical, and this, with or without the use of cardiopulmonary bypass.

Left ventricular function in response to dipyridamole stress: head-to-head comparison between 82Rubidium PET and 99mTc-sestamibi SPECT ECG-gated myocardial perfusion imaging

PurposeMyocardial perfusion imaging (MPI) with 99mTc-sestamibi (sestamibi) SPECT and rubidium-82 (82Rb) PET both allow for combined assessment of perfusion and left ventricular (LV) function. We sought to compare parameters of LV function obtained with both methods using a single dipyridamole stress dose.Materials and methodsA group of 221 consecutive patients (65.2u2009±u200910.4xa0years, 52.9% male) underwent consecutive sestamibi and 82Rb MPI after a single dipyridamole stress dose. Sestamibi and 82Rb summed rest (SRS), stress (SSS) and difference (SDS) scores, and LV end-diastolic (EDV) and end-systolic (ESV) volumes and left ventricular ejection fraction (LVEF) were compared.ResultsBland-Altman analysis showed that with increasing ESV and EDV the difference between the two perfusion tracers increased both at rest and post-stress. The mean difference in EDV and ESV between the two perfusion tracers at rest could both be independently explained by the 82Rb SDS and the sestamibi SRS. The combined models explained approximately 30% of the variation in these volumes between the two perfusion tracers (R2u2009=u20090.261, pu2009=u20090.005; R2u2009=u20090.296, pu2009<u20090.001, for EDV and ESV respectively). However, the mean difference in LVEF between sestamibi and 82Rb showed no significant trend post-stress (R2u2009=u20090.001, pu2009=u20090.70) and only a modest linear increase with increasing LVEF values at rest (R2u2009=u20090.032, pu2009=u20090.009).ConclusionsDifferences in left ventricular volumes between sestamibi and 82Rb MPI increase with increasing volumes. However, these differences did only marginally affect LVEF between sestamibi and 82Rb. In clinical practice these results should be taken into account when comparing functional derived parameters between sestamibi and 82Rb MPI.

Detection of myocardial inflammation in Chagas' disease by cardiac magnetic resonance

Methods Fifty-four patients with CD were analyzed, 16 patients in the indeterminate form (IND), 17 patients with the cardiac form without systolic dysfunction (CF), and 21 patients with the cardiac form with systolic dysfunction (CFSD). All patients underwent 1.5-T cardiac magnetic resonance (CMR) using three pulse sequences, previously described as useful for the diagnosis of viral myocarditis: the myocardial delayed enhancement (MDE) technique, Triple-IR FSE T2-weighted sequence and the T1 weighted global enhancement acquired before and after contrast injection, to identify fibrosis, edema and hyperemia of the myocardium, respectively. The parameters for all sequences followed precisely the recommendations for acute myocarditis published on JACC White Paper (Friedrich et al. J Am Coll Cardiol. 2009 Apr 28;53(17):1475-87).

Idiopathic interstitial pneumonias: review of the latest American Thoracic Society/European Respiratory Society classification

The diagnosis of idiopathic interstitial pneumonias (IIPs) involves a multidisciplinary scenario in which the radiologist assumes a key role. The latest (2013) update of the IIP classification by the American Thoracic Society/European Respiratory Society proposed some important changes to the original classification of 2002. The novelties include the addition of a new disease (idiopathic pleuroparenchymal fibroelastosis) and the subdivision of the IIPs into four main groups: chronic fibrosing IIPs (idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia); smoking-related IIPs (desquamative interstitial pneumonia and respiratory bronchiolitis-associated interstitial lung disease); acute or subacute IIPs (cryptogenic organizing pneumonia and acute interstitial pneumonia); rare IIPs (lymphoid interstitial pneumonia and idiopathic pleuroparenchymal fibroelastosis); and the so-called “unclassifiable” IIPs. In this study, we review the main clinical, tomographic, and pathological characteristics of each IIP.

Biomarker release after percutaneous coronary intervention in patients without established myocardial infarction as assessed by cardiac magnetic resonance with late gadolinium enhancement: VIEIRA DE MELO et al.

This study aimed to evaluate the amount and pattern of cardiac biomarker release after elective percutaneous coronary intervention (PCI) in patients without evidence of a new myocardial infarction (MI) after the procedure as assessed by cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE).

Myocardial perfusion in patients with suspected coronary artery disease: comparison between 320-MDCT and rubidium-82 PET

ObjectivesDespite advances in non-invasive myocardial perfusion imaging (MPI) evaluation, computed tomography (CT) multiphase MPI protocols have not yet been compared with the highly accurate rubidium-82 positron emission tomography (82RbPET) MPI. Thus, this study aimed to evaluate agreement between 82RbPET and 320-detector row CT (320-CT) MPI using a multiphase protocol in suspected CAD patients.MethodsForty-four patients referred for MPI evaluation were prospectively enrolled and underwent dipyridamole stress 82RbPET and multiphase 320-CT MPI (five consecutive volumetric acquisitions during stress). Statistical analyses were performed using the R software.ResultsThere was high agreement for recognizing summed stress scores ≥ 4 (kappa 0.77, 95% CI 0.55–0.98, p < 0.001) and moderate for detecting SDS ≥ 2 (kappa 0.51, 95% CI 0.23–0.80, p < 0.001). In a per segment analysis, agreement was high for the presence of perfusion defects during stress and rest (kappa 0.75 and 0.82, respectively) and was moderate for impairment severity (kappa 0.58 and 0.65, respectively). The 320-CT protocol was safe, with low radiation burden (9.3 ± 2.4 mSv).ConclusionsThere was a significant agreement between dipyridamole stress 320-CT MPI and 82RbPET MPI in the evaluation of suspected CAD patients of intermediate risk. The multiphase 320-CT MPI protocol was feasible, diagnostic and with relatively low radiation exposure.Key Points• Rubidium-82 PET and 320-MDCT can perform MPI studies for CAD investigation.• There is high agreement between rubidium-82 PET and 320-MDCT for MPI assessment.• Multiphase CT perfusion protocols are feasible and with low radiation.• Multiphase CT perfusion protocols can identify image artefacts.

Myocardial T1 mapping and extracellular volume quantification in patients with left ventricular non-compaction cardiomyopathy.

AimsnFrom pathophysiological mechanisms to risk stratification and management, much debate and discussion persist regarding left ventricular non-compaction cardiomyopathy (LVNC). This study aimed to characterize myocardial T1 mapping and extracellular volume (ECV) fraction by cardiovascular magnetic resonance (CMR), and investigate how these biomarkers relate to left ventricular ejection fraction (LVEF) and ventricular arrhythmias (VA) in LVNC.nnnMethods and resultsnPatients with LVNC (nu2009=u200936) and healthy controls (nu2009=u200918) were enrolled to perform a CMR with T1 mapping. ECV was quantified in LV segments without late gadolinium enhancement (LGE) areas to investigate diffuse myocardial fibrosis. Patients with LVNC had slightly higher native T1 (1024u2009±u200943u2009ms vs. 995u2009±u200922u2009ms, Pu2009=u20090.01) and substantially expanded ECV (28.0u2009±u20094.5% vs. 23.5u2009±u20092.2%, Pu2009<u20090.001) compared to controls. The ECV was independently associated with LVEF (βu2009=u2009-1.3, Pu2009=u20090.001). Among patients without LGE, VAs were associated with higher ECV (27.7% with VA vs. 25.8% without VA, Pu2009=u20090.002).nnnConclusionnIn LVNC, tissue characterization by T1 mapping suggests an extracellular expansion by diffuse fibrosis in myocardium without LGE, which was associated with myocardial dysfunction and VA, but not with the amount of non-compacted myocardium.