Comparison of sestamibi single-photon emission computed tomography with positron emission tomography for estimating left ventricular myocardial viability.
ABSTRACT Technetium-99m methoxyisobutyl isonitrile (technetium-99m sestamibi [MIBI]) is distributed in the myocardium according to blood flow. Reports comparing stress rest sestamibi protocols with reinjection thallium or resting fluorodeoxyglucose (FDG), or both, in patients with coronary artery disease have shown appreciable discordance regarding myocardial viability in these settings. We performed this analysis with regard to regional comparisons within discordant segments and made comparisons in a subset of patients who underwent revascularization. Thirty-seven patients with coronary artery disease had single-photon emission computed tomography MIBI, N-13 ammonia/18FDG positron emission tomography (PET), and radionuclide ventriculography performed at rest. One hundred two segments were viable and 29 were nonviable by both MIBI and FDG. The concordance was 71%. In MIBI nonviable/FDG viable segments, most of the discordance was in the inferior wall. In MIBI nonviable discordant segments, FDG accurately predicted an increase in percent regional ejection fraction (preoperative 36% [+/- 5 SE] to postoperative 48% [+/- 5.5 SE][p < 0.0006]). MIBI underestimates myocardial viability as assessed by PET. Seventy-one percent of myocardial segments were concordant by both quantitative sestamibi single-photon emission computed tomography and FDG PET. Discordance in MIBI nonviable segments was predominantly in the inferior wall. PET can be helpful in detecting myocardial viability in patients suspected of having had MIBI nonviability in the inferior wall.
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ABSTRACT: The management of patients with coronary artery disease, both in the post-infarction setting, and in patients with chronic advanced left ventricular (LV) dysfunction, is complicated by the presence of both reversibly damaged and infarcted myocardium. Although acute revascularization with thrombolytic therapy and percutaneous angioplasty have served to reduce the overall mortality from myocardial infarction, the ability to predict whether or not dysfunctional myocardium will recoverfollowing revascularization presents the clinician with a serious challenge. The success of revascularization, both on improvement of LV function, and short and long-term prognosis, depends on both the existence and extent of viable but dysfunctional myocardium present, as there is little to be gained from revascularizing a territory consisting exclusively of scar. There is a clear demand for procedures that can identify reversible asynergy prospectively and thus deliver the information that is needed for clinical decision-making. The objective of this review is to summarize the diagnostic tools that are currently availablefor the identification of reversible injury (ie., stunned or hibernating myocardium). The relative merits of echocardiography, nuclear medicine imaging, and magnetic resonance imaging are discussed in detail. Within the discussion of each modality, special attention is paid to the more recent innovations that have arisen to enhance the diagnostic and prognostic value of older approaches. Cost, availability, and local expertise will always affect the clinical popularity of a given diagnostic approach. However, the overriding conclusion that emerges from this review is that the future "techniques of choice" will be those that can reliably predict and quantify the extent of potential functional recovery.Journal of Cardiovascular Magnetic Resonance 02/2002; 4(3):381-410. · 3.72 Impact Factor
Article: Acute ethanol exposure fails to elicit preconditioning-like protection in in situ rabbit hearts because of its continued presence during ischemia.Journal of the American College of Cardiology 11/2001; 38(4):1271. · 14.16 Impact Factor
Journal of the American College of Cardiology 11/2001; 38(4):1271-3. · 14.16 Impact Factor