Susumu Fujino

Quantitative Rest Technetium-99m Tetrofosmin Imaging in Predicting Functional Recovery After Revascularization: Comparison With Rest–Redistribution Thallium-201

OBJECTIVES This study was undertaken to 1) compare the regional myocardial tracer distributions between rest technetium (Tc)-99m tetrofosmin and rest-redistribution thallium (Tl)-201 images in patients with coronary artery disease and left ventricular dysfunction; and 2) assess the comparative values of these agents for predicting functional recovery after revascularization. BACKGROUND Tc-99m tetrofosmin is a new myocardial perfusion imaging agent, but its role for detecting viable myocardium is still unclear. METHODS Thirty-six patients with coronary artery disease and left ventricular dysfunction underwent rest Tc-99m tetrofosmin, rest-redistribution Tl-201 and gated blood pool scintigraphy. In 21 patients with successful revascularization confirmed by follow-up angiography, gated blood pool scintigraphy was repeated after revascularization. Optimal threshold cutoffs to separate reversible from irreversible dysfunction were determined by receive operating characteristic analysis. RESULTS Regional Tc-99m tetrofosimin activity highly correlated with redistribution Tl-201 activity (r = 0.93). The diagnostic performance for predicting functional recovery, as measured by the area under the receiver operating characteristic curves, measured 0.66 +/- 0.07 (mean +/- SD) for Tc-99m tetrofosmin and 0.67 +/- 0.07 for Tl-201 (p = 0.60, 96.7% power to detect difference in area of 0.10). The optimal threshold cutoffs for viability were considered to be 50% of peak activity for Tc-99m tetrofosmin and 55% of peak activity for Tl-201. The positive and negative predictive values for reversible dysfunction were, respectively, 69% and 82% for Tc-99m tetrofosmin and 69% (p = 0.99 vs. Tc-99m tetrofosmin) and 71% (p = 0.66 vs. Tc-99m tetrofosmin) by Tl-201. CONCLUSIONS The diagnostic performance of quantitative rest Tc-99m tetrofosmin imaging in predicting functional recovery after revascularization is comparable to that of rest-redistribution Tl-201.

Comparison of defect size between thallium-201 and technetium-99m tetrofosmin myocardial single-photon emission computed tomography in patients with single-vessel coronary artery disease

Defect size on exercise-rest technetium (Tc)-99m tetrofosmin myocardial perfusion imaging was compared with that on exercise-reinjection thallium-201 imaging with 20 patients with 1-vessel coronary artery disease. In each patient, exercise-reinjection thallium-201 single-photon emission computed tomography (SPECT) and exercise-rest Tc-99m tetrofosmin SPECT imaging were performed. For visual analysis of the obtained SPECT images, the left ventricular myocardium was divided into 20 segments based on 3 short-axis slices from the apical, middle, and basal ventricular levels. For quantitative analysis, a square region of interest was placed on the center of each segment which was used for visual analysis, and relative regional activity to the normal reference region was calculated for each segment. By visual interpretation of the images, exercise Tc-99m tetrofosmin imaging showed a smaller defect size than exercise thallium-201 imaging (6.9 +/- 3.9 vs 8.8 +/- 3.0 segments, p <0.01). In contrast, rest Tc-99m tetrofosmin imaging showed a defect size similar to that on reinjection thallium-201 imaging (5.9 +/- 3.6 vs 5.6 +/- 3.9 segments, p = NS). Similarly, the mean defect sizes during exercise determined by quantitative analysis were smaller on Tc-99m tetrofosmin SPECT than those on thallium-201 SPECT at all tested threshold cutoff points ranging from 50% to 70%, whereas there were no significant differences in defect sizes between rest Tc-99m tetrofosmin and reinjection thallium-201 imaging. These data indicate that exercise Tc-99m tetrofosmin SPECT defect size determined either by visual analysis or by quantitative analysis may be smaller than on exercise thallium-201 SPECT.

Free-Floating Thrombus in Right Heart and Massive Pulmonary Embolism Migrating Into Pulmonary Artery

A 71-year-old man with chronic obstructive pulmonary disease (severe pulmonary emphysema with home oxygen therapy) was referred to our hospital because of 1-day history of dyspnea at rest. His physical examination was remarkable for tachycardia (110 bpm) and tachypnea (32 breaths/min). The ECG demonstrated sinus tachycardia, S waves in leads I and aVL, transition zone to V5, and T-wave inversion in leads III and aVF. A transthoracic echocardiogram (TTE) performed on admission showed that the right atrium and right ventricle were apparently enlarged. The left ventricle had …

Primary Percutaneous Coronary Intervention by a Stentless Technique for Acute Myocardial Infarction with Idiopathic Thrombocytopenic Purpura: A Case Report and Review of the Literature.

A 78-year-old man who had been diagnosed with idiopathic thrombocytopenic purpura (ITP) was admitted to our hospital with chest pain, cold sweating and nausea. An electrocardiogram and echocardiogram revealed an ST elevated acute lateral myocardial infarction. He underwent an immediate cardiac catheterization. An occluded left circumflex artery was detected by coronary angiography. Reperfusion was performed successfully by non-slip element balloon angioplasty alone, without stenting, to avoid prolonged dual anti-platelet therapy. In this report we discussed the management strategies of acute myocardial infarction in a patient with concomitant ITP.

Emergent thoracic aortic angioplasty and stenting for middle aortic syndrome in non-specific aortitis

A 61-year-old Japanese male was admitted to hospital due to severe congestive heart failure and pre-renal failure with middle aortic syndrome. The patient was successfully treated with emergent aortic angioplasty and kissing stents implantation whilst in a hemodynamically unstable state. Our experience confirms that stenosis of the descending aorta when treated with catheter intervention may be palliative, however, it was a very effective method for life threatening clinical conditions in the short and mid-term and may be an alternative to surgery.