ABSTRACT
OBJECTIVE: To investigate whether plasma big endothelin-1 (ET-1) predicts ventricular arrythmias (VAs) and end-stage events in primary prevention implantable cardioverter-defibrillator (ICD) indication patigents. METHODS: In total, 207 patients fulfilling the inclusion criteria from Fuwai Hospital between January 2013 and December 2015 were retrospectively analyzed. The cohort was divided into three groups according to baseline plasma big ET-1 tertiles: tertile 1 (< 0.38 pmol/L, n = 68), tertile 2 (0.38-0.7 pmol/L, n = 69), and tertile 3 (> 0.7 pmol/L, n = 70). The primary endpoints were VAs. The secondary endpoints were end-stage events comprising all-cause mortality and heart transplantation. RESULTS: During a mean follow-up period of 25.6 ± 13.9 months, 38 (18.4%) VAs and 78 (37.7%) end-stage events occurred. Big ET-1 was positively correlated with NYHA class (r = 0.165, P = 0.018), serum creatinine concentration (Scr; r = 0.147, P = 0.034), high-sensitivity C-reactive protein (hs-CRP; r = 0.217, P = 0.002), Lg NT-pro BNP (r = 0.463, P < 0.001), left ventricular end diastolic diameter (LVEDD; r = 0.234, P = 0.039) and negatively correlated with left ventricular ejection fraction (LVEF; r = -0.181, P = 0.032). Kaplan-Meier analysis showed that elevated big ET-1 was associated with increased risk of VAs and end-stage events (P < 0.05). In multivariate Cox regression models, big ET-1 was an independent risk factor for VAs (hazard ratio (HR) = 3.477, 95% confidence interval (CI): 1.352-8.940, P = 0.010, tertile 2 vs. tertile 1; HR = 4.112, 95% CI: 1.604-10.540, P = 0.003, tertile 3 vs. tertile 1) and end-stage events (HR = 2.804, 95% CI: 1.354-5.806, P = 0.005, tertile 2 vs. tertile 1; HR = 4.652, 95% CI: 2.288-9.459, P < 0.001, tertile 3 vs. tertile 1). CONCLUSIONS: In primary prevention ICD indication patients, plasma big ET-1 levels can predict VAs and end-stage events and may facilitate ICD-implantation risk stratification.
ABSTRACT
The chemical shift of fluoxetine hydrochloride appears at delta 14.15 in 19F NMR analysis. The delta moved upfield slightly from 14.158 to 14.145 when the concentration of solution became diluted from 2.00 to 0.05 mmol x L(-1). Spiking test was suggested to confirm the existence of the compound for qualitative analysis. 19F NMR detection sensitivity test illustrated that a concentration of 17 mg in 1 L water could be detected while the sample was scanned 500 times with optimum parameters. In quantitative analysis, standard curve of concentration versus fluorine signal intensity was proposed to determine the amount of fluoxetine. Long capillary tube containing trifluoroacetic acid was used as internal standard for the integration measurements and straight line was obtained with good fitting. Direct additions of trifluoroethanol to fluoxetine solutions gave a poorer standard curve.
