Triglicerydes/high-density lipoprotein ratio as a risk factor of post-Covid-19 sinus tachycardia: A retrospective study.

Inappropriate sinus tachycardia (IST) is one of the manifestations of the post-COVID-19 syndrome (PCS), which pathogenesis remains largely unknown. This study aimed to identify potential risk factors for IST in individuals with PCS. The 1349 patients with PCS were included into the study. Clinical examination, 24H Holter ECG, 24H ambulatory blood pressure monitoring and biochemical tests were performed 12-16 weeks after the COVID-19 in all participants. IST was found in 69 (3.5%) individuals. In the clinical assessment IST patients were characterized by a higher age (p < 0.001) and lower prevalence of the diagnosed hypertension (p = 0.012), compared to remaining patients. Biochemical testing showed higher serum triglycerides (1.66 vs. 1.31 pmol/L, p = 0.007) and higher prevalence of a low high-density lipoprotein (HDL) cholesterol (24.6% vs. 15.2%, p = 0.035) in the IST group. Subsequently, the triglicerydes (TG)/HDL ratio, an indicator of insulin resistance, was significantly higher in the IST individuals (3.2 vs. 2.4, p = 0.005). 24H monitoring revealed a significantly higher minimum diastolic, maximum systolic and mean arterial blood pressure values in the IST group (p < 0.001 for all), suggesting a high prevalence of undiagnosed hypertension. A multivariate analysis confirmed the predictive value TG/HDL ratio >3 (OR 2.67, p < 0.001) as predictors of IST development. A receiver operating characteristic curve analysis of the relationship between the TG/HDL ratio and the IST risk showed that the predictive cut-off point for this parameter was 2.46 (area under the ROC curve = 0.600, p = 0.004). Based on these findings, one can conclude that insulin resistance seems to be a risk factor of IST, a common component of PCS.