The Role of Somatostatinergic System in Inflammation Regulation in the Early Post-Infarction Period

The aim of the study was to evaluate the dynamics of endogenous somatostatin (SST) and its association with the intensity of 99mTc-Tektrotyd uptake and the cytokine profile in patients with primary anterior ST-segment elevation myocardial infarction during the early post-infarction period. Materials and Methods. The study included 22 patients admitted within the first 24 h from disease onset with a diagnosis of primary anterior ST-segment elevation myocardial infarction. The median age was 60.0 (53.0–65.5) years. All patients underwent percutaneous coronary intervention, echocardiography, and measurement of serum SST, high-sensitivity C-reactive protein, and interleukins (IL-1β, IL-6, IL-10) on days 1 and 5. On days 5–6, SPECT/CT with 99mTc-Tektrotyd was performed, with calculation of the maximum standardized uptake value of 99mTc-Tektrotyd (SUVmax) in the myocardium. Results. Myocardial 99mTc-Tektrotyd uptake was found in 18 patients (SUVmax — 2.8 [1.8–3.1] g/ml). The SST level on day 1 was 20.2 [11.2–40.8] pg/ml, and on day 5 — 23.2 [15.8–42.4] pg/ml (p=0.874); the dynamics were multidirectional. A negative correlation was found between SST concentration on day 1 and IL-1β level on day 1 (ρ=−0.645; p=0.001) and day 5 (ρ=−0.655; p=0.0001), as well as with left ventricular end-diastolic volume (ρ=−0.453; p=0.036) and the wall motion score index of the left ventricle (ρ=−0.484; p=0.023) on day 5. There was no correlation between SST level and SUVmax (ρ=−0.078; p=0.728). Regression analysis confirmed a significant effect of SST on IL-1β concentration (R2=0.526; p=0.0001 for day 1; R2=0.476; p=0.001 for day 5). Conclusion. In the early post-infarction period, endogenous SST demonstrates a negative relationship with the level of the proinflammatory cytokine IL-1β and left ventricular remodeling parameters, which emphasizes its important anti-inflammatory role. The absence of a direct association between SST concentration and SUVmax of 99mTc-Tektrotyd indicates the complex nature of peptide-receptor interaction and requires further investigation. The obtained data substantiate the potential of studying the somatostatinergic system as a promising therapeutic target in acute myocardial infarction.