Myocardial viability in chronic ischemic heart disease: comparison of contrast-enhanced magnetic resonance imaging with (18)F-fluorodeoxyglucose positron emission tomography.
ABSTRACT We sought to compare contrast-enhanced magnetic resonance imaging (ceMRI) with nuclear metabolic imaging for the assessment of myocardial viability in patients with chronic ischemic heart disease and left ventricular (LV) dysfunction.
Contrast-enhanced MRI has been shown to identify scar tissue in ischemically damaged myocardium.
Twenty-six patients with chronic coronary artery disease and LV dysfunction (mean ejection fraction 31 +/- 11%) underwent (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET), technetium-99m tetrofosmin single-photon emission computed tomography (SPECT), and ceMRI. In a 17-segment model, the segmental extent of hyperenhancement (SEH) by ceMRI, defined as the relative amount of contrast-enhanced tissue per myocardial segment, was compared with segmental FDG and tetrofosmin uptake by PET and SPECT.
In severely dysfunctional segments (n = 165), SEH was 9 +/- 14%, 33 +/- 25% (p < 0.05), and 80 +/- 23% (p < 0.05) in segments with normal metabolism/perfusion, metabolism/perfusion mismatch, and matched defects, respectively. Segmental glucose uptake by PET was inversely correlated to SEH (r = -0.86, p < 0.001). By receiver operator characteristic curve analysis, the area under the curve was 0.95 for the differentiation between viable and non-viable segments. At a cutoff value of 37%, SEH optimally differentiated viable from non-viable segments defined by PET. Using this threshold, the sensitivity and specificity of ceMRI to detect non-viable myocardium as defined by PET were 96% and 84%, respectively.
Contrast-enhanced MRI allows assessment of myocardial viability with a high accuracy, compared with FDG-PET, in patients with chronic ischemic heart disease and LV dysfunction.
Article: Effect of thrombolytic therapy on the incidence of early left ventricular infarct expansion in acute anterior myocardial infarction.[show abstract] [hide abstract]
ABSTRACT: To determine the incidence of early left ventricular infarct expansion within five days after first anterior ST-segment elevation myocardial infarction and the effect of early thrombolytic therapy on the incidence of early infarct expansion compared with late thrombolytic therapy. In a prospective study of 101 patients (75males and 26 females), with the first attack of acute anterior myocardial infarction, their ages ranged from 40-80 years (mean age: 61.07±10.78) who had been admitted to the Coronary Care Unit of Hawler Teaching Hospital for the period from July 2007 through to September 2009. Those who received alteplase ≤3 hours of acute myocardial infarction were labelled as group-I (49 patients) and those who received alteplase >3-12 hours were labelled as group-II (52 patients). The incidence of early left ventricular infarct expansion was diagnosed by 2D-echocardiography and was found to be 17.8%. Group I patients had a lower incidence of early left ventricular infarct expansion (8.16%) compared with group-II (26.92%; p=0.014). Patients with early left ventricular infarct expansion had a higher frequency rate of left ventricular systolic dysfunction (94.44%) compared to patients without early left ventricular infarct expansion (8.43%; p<0.001). There was a significant difference in the incidence of in-hospital mortality between the patients who developed early left ventricular infarct expansion (11.1%) compared with patients without early left ventricular infarct expansion (1.2%; p=0.025). Early reperfusion therapy in acute anterior myocardial infarction can decrease the incidence of early left ventricular infarct expansion, preserve left ventricular systolic function and decrease in-hospital mortality.Oman medical journal. 11/2011; 26(6):431-5.
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ABSTRACT: Over the past years, cardiovascular magnetic resonance (CMR) has proven its efficacy in large clinical trials, and consequently, the assessment of function, viability, and ischaemia by CMR is now an integrated part of the diagnostic armamentarium in cardiology. By combining these CMR applications, coronary artery disease (CAD) can be detected in its early stages and this allows for interventions with the goal to reduce complications of CAD such as infarcts and subsequently chronic heart failure (CHF). As the CMR examinations are robust and reproducible and do not expose patients to radiation, they are ideally suited for repetitive studies without harm to the patients. Since CAD is a chronic disease, the option to monitor CAD regularly by CMR over many decades is highly valuable. Cardiovascular magnetic resonance also progressed recently in the setting of acute coronary syndromes. In this situation, CMR allows for important differential diagnoses. Cardiovascular magnetic resonance also delineates precisely the different tissue components in acute myocardial infarction such as necrosis, microvascular obstruction (MVO), haemorrhage, and oedema, i.e. area at risk. With these features, CMR might also become the preferred tool to investigate novel treatment strategies in clinical research. Finally, in CHF patients, the versatility of CMR to assess function, flow, perfusion, and viability and to characterize tissue is helpful to narrow the differential diagnosis and to monitor treatment.European Heart Journal 03/2011; 32(7):799-809. · 10.48 Impact Factor
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ABSTRACT: Cardiac magnetic resonance imaging (MRI) has emerged as a prime player in the clinical and preclinical detection of ischemic heart disease (IHD) as well in the prognosis assessment by offering a comprehensive approach for all spectrums of coronary artery disease (CAD) patients. The aim of this review is to provide the reader a state-of-the art on how the newest cardiac MRI techniques can be used to study IHD patients. In patients with suspected/stable CAD, functional and perfusion imaging both at rest and during vasodilatatory stress (adenosine, dypiridamole)/dobutamine stress can accurately depict ischemic myocardium secondary to significant coronary artery stenosis. In patients with acute MI, MRI is a robust tool for differentiating and sizing the jeopardized and the infarcted myocardium by using a combination of functional, edema, perfusion and Gd contrast imaging. Moreover, important prognostic factors like myocardial salvage, the presence of microvascular obstruction (MVO), post reperfusion myocardial hemorrhage, RV involvement and infarct related complications can be assessed in the same examination. In patients with chronic ischemic cardiomyopathy, the role of the MRI extends from diagnosis by means of Gadolinium contrast scar imaging to therapy and prognosis by functional assessment and viability testing with rest and dobutamine stress imaging. In all the circumstances mentioned, MRI derived information has been proven valuable in every day clinical decision making and prognosis assessment. Thus, MRI is becoming more and more an accepted alternative to other imaging modalities both in the acute and chronic setting.Journal of medicine and life 11/2011; 4(4):330-45.