Association between big endothelin-1 and CHADS2/CHA2DS2-VASc scores in non-valvular atrial fibrillation

Background Endothelial function,as measured by big endothelin-1(ET-1),has been demonstrated to be useful in predicting adverse long-term events in patients with cardiovascular disease.Nevertheless,there are little data about the association between big ET-1 and thromboembolism risk in atrial fibrillation(AF).We aimed to investigate the relationship between big ET-1 and CHADS2/CHA2DS2-VASc scores used for evaluating thromboembolic risk in patients with non-valvular AF.Methods The study population consisted of 238 consecutive AF patients(67.6%with paroxysmal AF and 32.4%with persistent AF).The patients were divided into two groups(high-or low-intermediate risk group)based on CHADS2 and CHA2 DS2-VASc scores(score≥2 or<2,respectively).Clinical,laboratory,and echocardiographic parameters were evaluated,and the CHADS2/CHA2DS2-VASc scores were compared between groups.The association between big ET-1 levels and CHADS2/CHA2DS2-VASc score was assessed.Multivariate logistic regression analysis was performed to identify independent predictors of CHADS2/CHA2DS2-VASc scores.Results The high CHADS2/CHA2DS2-VASc score group had older age,higher big ET-1 levels,and enlarged left atrial diameter than the low CHADS2/CHA2DS2-VASc score group(P<0.05).Multiple logistic regression analysis revealed that big ET-1 level was an independent determinant of high CHADS2/CHA2DS2-VASc scores[odds ratio(OR)=2.545 and OR=3.816;both P<0.05].Conclusions Our study indicates that in non-valvular AF,big ET-1 was significantly correlated with CHADS2/CHA2DS2-VASc scores and an independent predictor of high CHADS2/CHA2DS2-VASc scores.Big ET-1 may serve as a useful marker for risk stratification in this setting.

Correlations between low thyroid function and incidence of atrial fibrillation in hypertrophic obstructive cardiomyopathy

Background::Atrial fibrillation (AF) is the most common arrhythmia in patients with hypertrophic obstructive cardiomyopathy (HOCM). Data regarding the correlations of thyroid dysfunction and the incidence of AF in HOCM are quite limited. This study aimed to reveal the correlations between different thyroid status and the corresponding incidence of AF in a large HOCM cohort.Methods::A total of 806 HOCM patients with complete information on thyroid function tests and comprehensive cardiac evaluations were recruited. The participants were divided into the AF group (n = 159) and non-AF group (n = 647) according to established medical history and results of Holter monitoring. The thyroid status of the study population and the corresponding incidence of AF were assessed and analyzed.Results::Hypothyroidism accounted for the greatest proportion of thyroid dysfunction in HOCM patients. The incidence of AF significantly increased in individuals with both overt ( P = 0.022) and subclinical ( P = 0.007) hypothyroidism. Compared with participants in the non-AF group, those with positive AF episodes presented with lower free triiodothyronine (FT3) (2.86 ± 0.52 pg/mL vs. 3.01 ± 0.42 pg/mL, P = 0.001), higher free thyroxine (FT4) (1.24 ± 0.25 ng/dL vs. 1.15 ± 0.16 ng/dL, P < 0.001), and remarkably increased levels of thyrotropin (TSH) (12.6% vs. 5.3%, P = 0.001). Multivariable analyses demonstrated that the concentrations of FT3 (odds ratio [OR] = 0.470, 95% confidence interval [CI]: 0.272-0.813, P = 0.007) and FT4 (OR = 17.992, 95% CI: 5.750-56.296, P < 0.001), as well as TSH levels above normal ranges (OR = 2.276, 95% CI: 1.113-4.652, P = 0.024) were independently associated with the occurrence of AF in the large HOCM cohort. Conclusions::This study indicated a strong link between low thyroid function and the presence of AF in HOCM. Hypothyroidism (both overt and subclinical states) seems to be valuable for assessing the incidence of AF in patients with HOCM.