Yuko Kawai

Significance of reduced uptake of iodinated fatty acid analogue for the evaluation of patients with acute chest pain

OBJECTIVES To assess whether 15-(p-[iodine-123] iodophenyl)-3-(R,S) methylpentadecanoic acid (BMIPP) imaging can identify previous ischemic areas, BMIPP SPECT was performed in patients with acute chest pain to compare its findings with those of technetium-99m-tetrofosmin (tetrofosmin) SPECT and coronary angiography. BACKGROUND Basic studies indicate that BMIPP can identify previous ischemia as reduced tracer uptake. METHODS This study prospectively enrolled 111 consecutive patients with acute chest pain without myocardial infarction. Tetrofosmin SPECT was performed at rest within 24 h after the last episode of chest pain. Coronary angiography and BMIPP SPECT were also performed on the following day. RESULTS Sixty-four of the 87 patients with coronary stenosis or spasm showed BMIPP abnormalities corresponding to the areas of coronary abnormalities (sensitivity 74%), whereas only 33 of them showed perfusion abnormalities (sensitivity 38%) (p < 0.001). Of 24 patients [corrected] without coronary stenosis or spasm, 22 showed normal BMIPP SPECT (specificity = 92%) [corrected] and 23 showed normal tetrofosmin SPECT (sensitivity = 96%) [corrected]. Coronary stenosis was more often seen in the group with abnormal tetrofosmin/abnormal BMIPP (82%) and with normal tetrofosmin/abnormal BMIPP (69%) than in the group with normal tetrofosmin/normal BMIPP (36%) (p < 0.05). Coronary spasm was observed more often in the group with abnormal tetrofosmin/abnormal BMIPP (83%) and with normal tetrofosmin/abnormal BMIPP (90%) than in the group with normal tetrofosmin/normal BMIPP (27%) (p < 0.05). The extent and severity scores of tetrofosmin and BMIPP in the patients with organic stenosis were significantly higher than those of patients with no organic stenosis or spasm (p < 0.0001). CONCLUSIONS These data indicate that BMIPP SPECT may specifically identify previous ischemic lesions due to coronary stenosis or spasm in patients with acute chest pain.

Use of 123I-BMIPP single-photon emission tomography to estimate areas at risk following successful revascularization in patients with acute myocardial infarction

Abstract. Previous studies have indicated that iodine-123 labelled β-methyliodophenyl pentadecanoic acid (BMIPP), an iodinated fatty acid analogue, can identify persistent alteration of fatty acid metabolism after restoration of blood flow. To assess whether fatty acid imaging can delineate areas at risk following successful revascularization in patients with acute myocardial infarction (AMI), BMIPP findings at 1 week post AMI were compared with perfusion imaging before and after revascularization therapy. Sixty-five patients with AMI underwent technetium-99m tetrofosmin single-photon emission tomography (SPET) before m (TF0) and 1 week (TF1) after successful revascularization therapy. BMIPP SPET was also performed under a fasting state at 1 week (BM1) post AMI. The extent scores were calculated from the defect scores in 20 segments. The BM1 score (7.7±3.9) was similar to the TF0 score (8.8±4.2) (r=0.86, P<0.0001), but significantly higher than the TF1 score (5.8±3.9) (P<0.0001). A significant correlation was observed between the BM1 score and TF0 score (r=0.86, P<0.0001). Among a total of 1300 segments, the BM1 score was identical to the TF0 score in 1156 (88.9%). These data indicate that the ability of BMIPP imaging at 1 week post AMI to identify areas at risk is similar to that of tetrofosmin perfusion imaging in the acute phase. This may be due to the impairment of fatty acid uptake and metabolism reflecting prior severe ischaemic insult which persists at least 1 week after recovery of perfusion in the acute phase of AMI.

Investigation of gastric and duodenal mucosal defects caused by low-dose aspirin in patients with ischemic heart disease.

Background Low-dose aspirin is used for secondary prevention of ischemic heart disease and ischemic cerebrovascular disease. Currently, the frequency of gastrointestinal disorder among usersof low-dose aspirin is unknown. Aims To investigate through endoscopic examination the frequency of gastroduodenal disorder associated with buffered and enteric-coated aspirin (ECA). Methods Screening upper endoscopic examinations were prospectively performed on 236 patients with ischemic heart disease. Endoscopic findings including ulcers and flat erosions were assessed as mucosal defects. Results Mucosal defects were found in 92 of 190 (48.4%) users of low-dose aspirin and 6 of 46 (13.0%) nonusers. There were significantly more mucosal defects among users of low-dose aspirin than among those using no aspirin (P<0.0001). Mucosal defects were found in 54 of 98 (60.7%) users of buffered aspirin (BA), whereas 38 of 101 (37.6%) users of ECA had mucosal defects. Users of ECA had significantly fewer erosions than did those of BA (P=0.0015). The frequency of ulcer is similar between BA users and ECA users. Conclusions As endoscopy frequently reveals gastroduodenal disorder among low-dose aspirin users, both administration of BA and of enteric-coated aspirin warrant concern for gastroduodenal ulcer.

Endoscopic survey of low-dose-aspirin-induced gastroduodenal mucosal injuries in patients with ischemic heart disease.

Background and Aim:  Low‐dose aspirin is effective for the prevention of cardiovascular and cerebrovascular events, but the frequency of gastrointestinal injuries among users of low‐dose aspirin in Japan is currently unknown. In the present study endoscopic examination was performed to investigate the frequency of gastroduodenal injuries associated with low‐dose aspirin in patients with ischemic heart disease (IHD).

Future aspects of BMIPP.

Iodinated fatty acid compounds have an important role in early detection of myocardial abnormalities and provide insights into pathological states in the heart. Among them, 15-(p-iodophenyl)-3R,S-methyl pentadecanoic acid (BMIPP) has been most widely used providing excellent images of the left ventricular myocardium due to high myocardial uptake and long retention. The previous chapters have focused on the basic characters and clinical applications of this compound. However, the precise mechanisms of myocardial kinetics should be further investigated under various conditions. Most of the studies showed reduced BMIPP uptake relative to perfusion in a variety of myocardial disorders, whereas an increase in BMIPP uptake relative to perfusion is often reported. The potential mechanisms of such conflicting results are discussed, but basic studies should be performed to clarify such results in detail. There are a number of clinical values of this compound. Since alteration of fatty acid is observed in the repetitive ischemia, BMIPP can be used for detecting severe ischemic episodes. The concept of ‘ischemic memory’ imaging can be applied for patients with unstable or vasospastic angina at rest and for those with acute myocardial infarction with successful revascularization to identify the risk area. The discordant decrease in BMIPP uptake relative to perfusion is often seen in ischemic but viable myocardium, and therefore, the combined imaging of BMIPP and perfusion can be used for assessment of tissue viability. Furthermore, abnormal BMIPP uptake is most often observed in hypertrophic cardiomyopathy, and thus, this compound can be used for an early detection and differential diagnosis of the cardiomyopathy. Although BMIPP imaging seems to be quite promising in many fields, the number of patient data remain limited. In this respect, a multicenter study with a vast majority of patients is warranted to confirm these important values of BMIPP. In addition, this attractive tracer should be available all over the world to confirm its clinical value in the near future.