Extent of cardiac sympathetic neuronal damage is determined by the area of ischemia in patients with acute coronary syndromes.
BACKGROUND
Prior studies have demonstrated that acute ischemic injury causes sympathetic neuronal damage exceeding the area of necrosis. The aim of this study was to test the hypothesis that sympathetic neuronal damage measured by (123)I-metaiodobenzylguanidine (MIBG) imaging would be determined by the area of ischemia as reflected by area at risk in patients undergoing reperfusion therapy for acute coronary syndromes.


RESULTS
In 12 patients, the myocardium at risk was assessed by (99m)Tc-sestamibi SPECT before reperfusion, and infarct size was measured by follow-up (99m)Tc-sestamibi SPECT 1 week later. All patients also underwent (123)I-MIBG SPECT within a mean of 11 days after onset. The SPECT image analysis was based on a semiquantitative polar map approach. Defect size on the (123)I-MIBG or (99m)Tc-sestamibi SPECT was measured for the left ventricle (LV) with the use of a threshold of -2.5 SD from the mean value of a normal database and was expressed as %LV. The (123)I-MIBG defect size (47+/-18%LV) was larger than the infarct size (27+/-23%LV, P<0. 001) but was similar to the risk area (49+/-18%LV, P=NS). Furthermore, the (123)I-MIBG defect size was closely correlated with the risk area (r=0.905, P<0.001).


CONCLUSIONS
Sympathetic neuronal damage measured by (123)I-MIBG SPECT is larger than infarct size and is closely related to risk area, suggesting high sensitivity of neuronal structures to ischemia compared with myocardial cells.
Matsunari
I
I
Nuklearmedizinische Klinik und Poliklinik, 1. Medizinische Klinik, Technische Universität München, Klinikum rechts der Isar, Munich, Germany.
Schricke
U
U
Bengel
F M
FM
Haase
H U
HU
Barthel
P
P
Schmidt
G
G
Nekolla
S G
SG
Schoemig
A
A
Schwaiger
M
M
D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D006321:Heart / Q000294:innervation; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000473:pathology*; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000473:pathology*; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000473:pathology; D018570:Risk Assessment; D013564:Sympathetic Nervous System / Q000098:blood supply* / Q000473:pathology*; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
D007457:Iodine Radioisotopes; D017256:Technetium Tc 99m Sestamibi; D003402:Creatine Kinase