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Updated: Aug 12, 2026
In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
Published on: February 16, 2016
Changes in cardiac adrenergic nervous system after transmyocardial laser revascularisation assessed by I-123-MIBG
Anna Teresińska1, Marian Sliwiński, Stefania Konieczna
1Nuclear Medicine Laboratory, National Institute of Cardiology, Warsaw, Poland.
Background:
Metaiodobenzylguanidine (MIBG), a noradrenaline analogue which may be labelled with I-123, has been used in the assessment of pre-synaptic activity of the cardiac adrenergic nervous system (Syst(adren)) in several diseases. The effects of transmyocardial laser revascularisation (TMLR) on Syst(adren) have not yet been established.
Aim:
To examine whether TMLR-induced changes in Syst(adren) may be one of the mechanisms responsible for clinical improvement in patients undergoing this method of revascularisation.
Methods:
The study group consisted of 19 patients (mean age 63+/-9 years) who underwent TMLR, by using high-power CO(2) laser; as a single method of cardiac revascularisation. Syst(adren) was assessed before TMLR (STUDY-0), soon after the procedure (mean 13+/-5 days, STUDY-I), and in 12 patients six months after TMLR (STUDY-II). In total, 50 studies using I-123-MIBG SPECT were performed. The regional distribution of tracer was assessed qualitatively, using a 17-segment model of the left ventricle.
Results:
In 16% of examinations the assessment of the I-123-MIBG uptake was not possible due to the poor quality of images. Thus, 41 SPECT studies (16 - STUDY-0, 16 - STUDY-I, and 9 - STUDY-II) were analysed and compared. In STUDY-0, an impaired uptake of I-123-MIBG was found in 193 of 272 analysed segments. In STUDY-I, the I-123-MIBG uptake increased in 5% of defects (CI(0,95)=3-9%) and deteriorated in 55% (CI(0,95)=48-62%). When STUDY-II was compared with baseline, the uptake was increased in 25% of defects (CI(0,95)=17-34%) and decreased in further 25% of defects. When STUDY-II was compared with STUDY-I, the uptake increased in 67% (CI(0,95)=58-75%) of defects and did not deteriorate in any. The global MIBG uptake in STUDY-I decreased in 15 patients (94%, CI(0,95)=70-100%) when compared with baseline, and increased in all 9 patients with long-term follow-up data available, when STUDY-II to STUDY-I was compared.
Conclusions:
TMLR significantly deteriorates Syst(adren) activity which, however, improves 6 months after the procedure to the values similar to those assessed pre-operatively. TMLR-induced impairment of Syst(adren) may contribute to the clinical improvement observed shortly (<6 months) after the procedure.
