The histology of viable and hibernating myocardium in relation to imaging characteristics (original) (raw)
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Circulation, 1998
Background —Both radionuclide perfusion tracers and contractile response to dobutamine have been used to identify hibernating myocardium. The aim was to compare 201 Tl (thallium) single photon emission CT (SPECT), 99m Tc-tetrofosmin (tetrofosmin) SPECT, and dobutamine cine MRI for identifying regions of reversible myocardial dysfunction. Methods and Results —Thirty patients with 3-vessel coronary artery disease and impaired left ventricular function (mean LVEF, 24.0%; SD, 8.3%) scheduled for coronary bypass grafting were recruited. All underwent rest/dobutamine stress (5 to 10 μg · kg −1 · min −1 ) cine MRI, stress/rest tetrofosmin SPECT, and stress/redistribution and separate-day rest/redistribution thallium SPECT before surgery. Stress/redistribution thallium SPECT and resting MRI were repeated after surgery. In a 9-segment model, SPECT images were scored visually for tracer uptake, which was also measured from a polar plot of myocardial counts. MRI was scored visually for endocar...
Identification of hibernating myocardium with myocardial contrast echocardiography
International Journal of Cardiology, 2008
Very little is known about the accuracy of intravenous myocardial contrast echocadiography (MCE) in the detection of myocardial hibernation. There are also currently no data on the comparison of MCE to late gadolinium-enhanced magnetic resonance (LGE-MR) in this clinical setting. The aim of this pilot study was to predict recovery of regional function in patients with ischemic LV dysfunction undergoing bypass surgery and to compare the accuracy of MCE with LGE-MR in this clinical setting. The sensitivity of preserved myocardial perfusion during MCE for segmental function recovery (hibernating myocardium) of akinetic segments was 78% and was similar to LGE-MR (87%, p-NS). Specificity of MCE was higher than for LGE-CMR (72%, and 52%, respectively; p b 0.01). This pilot study has showed good diagnostic accuracy of MCE for prediction of function recovery after bypass surgery, which is comparable to "gold standard" in assessing myocardial viability -LGE-MR.
Imaging techniques for the assessment of myocardial hibernation
European heart …, 2004
This report of an ESC Study Group reviews current knowledge on myocardial hibernation and relevant imaging techniques, and provides an algorithm for investigation and management when a patient presents with ischaemic left ventricular dysfunction. It covers the definitions of myocardial viability, stunning and hibernation, it reviews the morphological findings in hibernation and it describes relevant clinical settings. The imaging and other techniques that are reviewed are electrocardiography, positron-emitting and single photon-emitting scintigraphic imaging, echocardiography, radionuclide angiocardiography, magnetic resonance imaging, X-ray transmission tomography, invasive X-ray angiocardiography and electromechanical mapping. The evidence for the techniques to predict improvement of regional and global function after revascularisation is summarised and patient symptoms and clinical outcome are also considered. Each technique is classified in its ability to assess myocardial viability, function and perfusion and also for their roles in the assessment of the patient with ischaemic left ventricular dysfunction who is asymptomatic or who has angina or heart failure. A simplified clinical algorithm describes the initial assessment of left ventricular function, then viability and then perfusion reserve allowing regions of myocardium to be characterised as transmural scar, intramural scar, hibernation or ischaemia.
Circulation, 2003
Background— There are currently no data on the accuracy of intravenous myocardial contrast echocardiography (MCE) in detecting myocardial hibernation in man and its comparative accuracy to dobutamine echocardiography (DE) or thallium 201 (Tl 201 ) scintigraphy. Methods and Results— Twenty patients with coronary artery disease and ventricular dysfunction underwent MCE 1 to 5 days before bypass surgery and repeat echocardiography at 3 to 4 months. Patients also underwent DE (n=18) and rest-redistribution Tl 201 tomography (n=16) before revascularization. MCE was performed using continuous Optison infusion (12 to 16 cc/h) with intermittent pulse inversion harmonics and incremental triggering (1:1 to 1:8). Myocardial contrast intensity (MCI) replenishment curves were constructed to derive quantitative MCE indices of blood velocity and flow. Recovery of function occurred in 38% of dysfunctional segments. MCE parameters of perfusion in hibernating myocardium were similar to segments with ...
Circulation, 2003
Background-There are currently no data on the accuracy of intravenous myocardial contrast echocardiography (MCE) in detecting myocardial hibernation in man and its comparative accuracy to dobutamine echocardiography (DE) or thallium 201 (Tl 201 ) scintigraphy. Methods and Results-Twenty patients with coronary artery disease and ventricular dysfunction underwent MCE 1 to 5 days before bypass surgery and repeat echocardiography at 3 to 4 months. Patients also underwent DE (nϭ18) and restredistribution Tl 201 tomography (nϭ16) before revascularization. MCE was performed using continuous Optison infusion (12 to 16 cc/h) with intermittent pulse inversion harmonics and incremental triggering (1:1 to 1:8). Myocardial contrast intensity (MCI) replenishment curves were constructed to derive quantitative MCE indices of blood velocity and flow. Recovery of function occurred in 38% of dysfunctional segments. MCE parameters of perfusion in hibernating myocardium were similar to segments with normal function and higher than dysfunctional myocardium without recovery of function (PϽ0.001). The best MCE parameter for predicting functional recovery was Peak MCIϫ, an index of myocardial blood flow (area under the curve, 0.83). MCE parameters were higher in segments with contractile reserve and Tl 201 uptake Ն60% (PϽ0.05) and identified viable segments without contractile reserve by DE. The sensitivity of Peak MCIϫ Ͼ1.5 dB/s for recovery of function was 90% and was similar to Tl 201 scintigraphy (92%) and any contractile reserve (80%); specificity was higher than for Tl 201 and DE (63%, 45%, and 54%, respectively; PϽ0.05).
Evaluation of Hibernating Myocardium in Patients with Ischemic Heart Disease
American Journal of Medicine, 1998
Patients with ischemic heart disease and significant left ventricular dysfunction are often difficult to manage medically. Revascularization procedures may improve left ventricular function and prognosis in this population if hypocontractile yet viable myocardium (hibernating myocardium) is demonstrated. Nuclear cardiology studies (single photon and positron methods), two-dimensional echocardiography, and magnetic resonance imaging studies have been utilized to identify hibernating myocardium. If thallium-201 studies are performed, the use of reinjection of thallium and repeat imaging improves the sensitivity of these studies for the detection of viable myocardium. Dobutamine echocardiographic studies may have a higher specificity and positive predictive value for the subsequent improvement of regional systolic left ventricular function after revascularization than the nuclear techniques. However, thallium studies have an excellent negative predictive value. Positron emission tomography (PET) allows the simultaneous assessment of perfusion and metabolic activity; however, these studies are expen-sive and not widely available. Functional evaluation with PET is in its infancy. Functional cardiac magnetic resonance imaging (MRI), although not widely available yet, provides the most accurate evaluation of regional ventricular function. MRI spectroscopy may be utilized to assess myocardial viability. As acquisition times improve and ''real-time'' imaging becomes a reality, MRI and MRI spectroscopy will likely become very accurate tools for assessing functional reserve and metabolic activity. The selection of the most appropriate method for assessment of myocardial viability will include consideration of a patient's characteristics, the presence of coronary arterial tree amenable to revascularization techniques, the techniques available to the clinician to assess viability, and local revascularization experience in this population. The result of an individual patient's evaluation is relevant to the consideration of coronary revascularization, or if this is not possible, cardiac transplantation. Am J Med. 1998;104:69 -77. ᭧1998 by Excerpta Medica, Inc.
Hibernating myocardium: clinical and functional response to revascularisation
European Journal of Cardio-Thoracic Surgery, 1997
We assessed the effects of coronary bypass grafting on left ventricular (LV) function, exercise capacity and symptom profile in patients with LV impairment and evaluated the role of identifying myocardial hibernation in a prospective non-randomised study. Methods: Of 120 patients screened, 47 patients with LV ejection fraction B35% and three vessel coronary artery disease were studied. All underwent stress/redistribution and separate day rest/redistribution Tl-201 imaging together with cine MRI at enrolment, and cine MRI at follow-up. Group 1, 30 patients undergoing bypass surgery, underwent symptom limited treadmill exercise testing with peak VO 2 measurement, and symptom profile evaluation less than 3 months before, and 3-6 months after operation. Revascularisation was assessed by post-operative Tl-201 imaging and repeat coronary angiography. Group 2, 17 patients treated on medical therapy alone underwent symptom profile assessment at enrolment and follow-up for those who survived. Segmental hibernation was defined as the equivalent of greater than 50% of maximal Tl-201 uptake where wall motion was severely impaired on resting imaging. Patients were considered to be hibernating where two of nine LV segments fulfilled these criteria. Results: In group 1, five patients died (17%), peri-or post-operatively, two defaulted and 23 attended follow-up studies. In group 2, three patients died prior to follow-up (18%). In the surgical group there was an increase in mean LVEF from 24.0 98% to 29.7 911% (P B0.05) while in the medical group there was a fall from 25.7 9 10% to 20.6 98% (P B0.05). In group 1, the mean NYHA dyspnoea grade improved from 2.7 to 1.4 while in the medical group it was unchanged, 2.6 to 2.5. In patients with myocardial hibernation identified pre-operatively, 18/19 (95%) improved LVEF after CABG compared with 2/4 (50%) of patients without hibernation. 17/19 (86%) patients with hibernation improved NYHA dyspnoea class compared with 2/4 (50%) of patients without. 60/93 (65%) of hibernating segments improved function after revascularisation while 47/53 (89%) hibernating segments showed no improvement on medical therapy alone. Conclusion: In patients with severe LV impairment with myocardial hibernation, coronary artery bypass grafting improves both global and regional systolic LV function, and symptom profile. Medical treatment of patients with LV impairment and myocardial hibernation does not improve LV contractile function or symptoms. Both surgical and medical therapy carry a high mortality rate. © 1997 Elsevier Science B.V.
European Heart Journal, 2013
A very large body of evidence-predominantly retrospective-suggests that revascularization is superior to optimal medical therapy in patients with a significant amount of 'hibernating' myocardium. Contemporary cardiological practice has embraced this standard of practice, as many centres worldwide place great emphasis upon the results of viability testing by non-invasive imaging techniques in determining the need for coronary revascularization. This practice has been challenged by the recent results of the Surgical Treatment for Ischaemic Heart Failure (STICH) trial, which suggested both lack of mortality benefit from revascularization and also from viability testing. In this review article, we have summarized the pathophysiology of hibernating myocardium, briefly discussed each of the non-invasive imaging modalities used in contemporary practice for detecting myocardial hibernation before critically appraising the prospective studies in this field, most importantly the main STICH trial and viability sub-study. STICH was clearly a complex trial but has not ended the question over the benefit of revascularization in ischaemic heart failure. Finally, we have suggested a possible methodology for an 'ideal trial' designed to evaluate the role of revascularization in such patients and also explored how viability testing should be used in clinical practice in the post-STICH era.