The influence of thyroid status on long-term complications after stenting in patients with acute coronary syndrome without ST-segment elevation.

Backround. It is known that both subclinical hypothyroidism (SHT) and subclinical thyrotoxicosis (STT) can influence the outcome of coronary heart disease. The feasibility of routinely determining thyroid status in patients without obvious signs of thyroid dysfunction with acute coronary syndrome without ST-segment elevation (NSTEACS) to assess the effect on the status of implanted stents has not been determined. Objective. To evaluate the effect of subclinical hypothyroidism and subclinical thyrotoxicosis on lumen loss and the degree of endothelialization of drug-eluting stents after stenting for NSTE-ACS. Design and methods. The study included 173 patients who were urgently stented for NSTE-ACS, and who subsequently underwent repeat coronary angiography within a year on a planned or emergency basis with a targeted assessment of the condition of the installed stents. In 40 patients with everolimus-eluting stents, the condition of the coronary arteries was assessed 6.3 + 0.3 months after stenting using optical coherence tomography (OCT). All patients included in the study had their thyroid status assessed. Results. SHT was detected in 8 (21.6 %) patients with loss of lumen in the stent area and in 26 (19.1 %) patients without loss of lumen, p = 0.73. STT was detected in 2 (5.4 %) and 3 (2.2 %) patients, respectively, p = 0.30. A prognostic analysis performed by logistic regression with forced inclusion as predictors of lumen loss identified the parameters Syntax Score I, stent diameter, and the number of affected coronary arteries. No effect of thyroid status on lumen loss was found. In patients with subclinical hypothyroidism, OCT data revealed insufficient endothelialization of everolimus-eluting stents 6 months after stenting for NSTE-ACS. The percentage of uncovered stent struts depended on TSH levels (r = 0.42, p = 0.007). The higher the TSH level, the higher the healing index and the worse the stent endothelialization (r = 0.37, p = 0.016). Conclusion. Thus, routine determination of thyroid status indicators in patients with NSTE-ACS in order to identify subclinical thyroid dysfunction does not provide significant prognostic information regarding the risk of lumen loss of implanted stents. Considering the potential risk of thrombotic complications associated with insufficient endothelialization of everolimus-eluting stents in the presence of subclinical hypothyroidism, it seems advisable to identify it when deciding on de-escalation of antithrombotic therapy. The question remains open about the need to correct the parameters of subclinical thyroid dysfunction in order to modify the prognosis.