Risk stratification of patients with prior myocardial infarction and advanced left ventricular dysfunction by gated myocardial perfusion SPECT imaging.

Abstract

BACKGROUND:

The Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II) has shown that the prophylactic implantable cardiac defibrillator improves the survival rate of patients with prior myocardial infarction and advanced left ventricular (LV) dysfunction. However, a more accurate noninvasive predictor should be found to identify subgroups at high risk, one that would allow implantable cardiac defibrillator therapy to be directed specifically to the patients who would benefit most.

METHODS AND RESULTS:

To elucidate whether technetium 99m tetrofosmin electrocardiogram-gated single photon emission computed tomography (SPECT) imaging at rest can determine the risk of arrhythmic death, 106 patients who met the MADIT-II criteria (LV ejection fraction <or=0.3, myocardial infarction >1 month earlier, and no sustained ventricular tachyarrhythmia) were recruited from a pool of 4628 consecutive patients who had undergone resting Tc-99m tetrofosmin SPECT imaging. By use of the endpoints of lethal arrhythmic events, which included documentation of sustained ventricular tachycardia, ventricular fibrillation, or diagnosis of sudden cardiac death, we performed follow-up for a mean of 30 months. Lethal arrhythmic events occurred in 14 patients. Patients with lethal arrhythmic events had a lower LV ejection fraction, greater LV end-systolic and end-diastolic volume indices, and a greater perfusion defect volume than the remaining patients. By receiver operating characteristic curve analysis, myocardial defect volume was the strongest predictor for the development of lethal arrhythmic events.

CONCLUSION:

Our results confirm that perfusion defect volume by Tc-99m tetrofosmin scintigraphy is the most pivotal predictor of the future occurrence of lethal arrhythmic events and of sudden cardiac death. Tc-99m tetrofosmin SPECT images may assist in identifying subsets of patients with a greater likelihood of arrhythmic death among patients with LV dysfunction.

• Authors: Itsuro Morishima, Takahito Sone, Hideyuki Tsuboi, Hiroaki Mukawa, Michitaka Uesugi, Shuji Morikawa, Kensuke Takagi, Toru Niwa, Yasuhiro Morita, Ryuichiro Murakami, Yasushi Numaguchi, Toyoaki Murohara, Kenji Okumura
• Journal: Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology (J Nucl Cardiol) 2008 Sep-Oct Vol. 15 Issue 5 Pg. 631-7 ISSN: 1532-6551 [Electronic] United States
• PMID: 18761265 (Publication Type: Clinical Trial, Journal Article, Multicenter Study)

Chemical References

• Organophosphorus Compounds
• Organotechnetium Compounds
• Radiopharmaceuticals
• technetium tc-99m tetrofosmin

Topics

• Adult
• Aged
• Aged, 80 and over
• Arrhythmias, Cardiac (pathology, therapy)
• Defibrillators, Implantable
• Female
• Humans
• Male
• Middle Aged
• Myocardial Infarction (diagnosis, pathology)
• Myocardial Perfusion Imaging (methods)
• Organophosphorus Compounds (pharmacology)
• Organotechnetium Compounds (pharmacology)
• Radiopharmaceuticals (pharmacology)
• Tomography, Emission-Computed, Single-Photon (methods)
• Ventricular Dysfunction, Left (pathology)