Prevalence of biotin supplement usage in outpatients and plasma biotin concentrations in patients presenting to the emergency department.

BACKGROUND: Several cases of biotin interference with laboratory testing have been reported in the literature. However, there are no publications discussing the extent of biotin use or plasma concentrations observed among the patient population. The objective of this study was to determine the prevalence of biotin consumption using two distinct methods: surveying the outpatient population using a questionnaire and quantifying biotin in plasma samples collected from patients presenting to the Emergency Department (ED). METHODS: Survey questionnaires (n = 4000) were distributed to Mayo Clinic outpatients over one week (July 10-14, 2017). Biotin was quantified in residual waste plasma samples collected for physician-ordered electrolyte panels from patients presenting to the ED (March 6-12, 2017 and March 26-April 4, 2017, n = 1442 unique patient samples). RESULTS: 1944 patients (972 female, 963 male, 9 no answer) with a median (interquartile range) age of 62 (49-72) years returned completed questionnaires (48.6%). From the completed surveys, 7.7% (95% CI, 6.6-8.9%) indicated biotin use. Quantitation of biotin in plasma samples from ED patients (n = 1442) revealed that 7.4% (95% CI, 6.2-8.9%) had concentrations at or above the lowest known threshold (10 ng/mL) for biotin interference in Roche Diagnostics immunoassay tests. CONCLUSIONS: According to our survey results, reported use of biotin was common. The range of biotin concentrations in ED patient samples highlights the magnitude of the biotin interference problem and identifies a population at risk for potential harm. These findings should guide laboratorians and clinicians in developing effective strategies to mitigate safety risks and in assessing biotin usage trends within their own patient populations.

Lipid Biomarkers for Risk Assessment in Acute Coronary Syndromes.

PURPOSE OF REVIEW: The objective of this review was to summarize evidence gathered for the prognostic value of routine and novel blood lipids and lipoproteins measured in patients with acute coronary syndromes (ACS). RECENT FINDINGS: Data supports clear association with risk and actionable value for non-high-density lipoprotein (Non-HDL) cholesterol and plasma ceramides in a setting of ACS. The prognostic value and clinical actionability of apolipoprotein B (apoB) and lipoprotein(a) [Lp(a)] in ACS have not been thoroughly tested, while the data for omega-3 fatty acids and oxidized low-density lipoprotein (Ox-LDL) are either untested or more varied. Measuring basic lipids, which should include Non-HDL cholesterol, at the time of presentation for ACS is guideline mandated. Plasma ceramides also provide useful information to guide both treatment decisions and follow-up. Additional studies targeting ACS patients are necessary for apoB, Lp(a), omega-3 fatty acids, and Ox-LDL.

Cardiac safety analysis of doxorubicin and cyclophosphamide followed by paclitaxel with or without trastuzumab in the North Central Cancer Treatment Group N9831 adjuvant breast cancer trial.

PURPOSE: To assess cardiac safety and potential cardiac risk factors associated with trastuzumab in the NCCTG N9831 Intergroup adjuvant breast cancer trial. PATIENTS AND METHODS: Patients with HER2-positive operable breast cancer were randomly assigned to doxorubicin plus cyclophosphamide (AC) followed by either weekly paclitaxel (arm A); paclitaxel then trastuzumab (arm B); or paclitaxel plus trastuzumab then trastuzumab alone (arm C). Left ventricular ejection fraction (LVEF) was evaluated at registration and 3, 6, 9, and 18 to 21 months. RESULTS: Of 2,992 patients completing AC, 5.0% had LVEF decreases disallowing trastuzumab (decrease below normal: 2.4%, decrease > 15%: 2.6%). There were 1,944 patients with satisfactory or no LVEF evaluation who proceeded to post-AC therapy. Cardiac events (congestive heart failure [CHF] or cardiac death [CD]): arm A, n = 3 (2 CHF, 1 CD); arm B, n = 19 (18 CHF, 1 CD); arm C, n = 19 (all CHF); 3-year cumulative incidence: 0.3%, 2.8%, and 3.3%, respectively. Cardiac function improved in most CHF cases following trastuzumab discontinuation and cardiac medication. Factors associated with increased risk of a cardiac event in arms B and C: older age (P < .003), prior/current antihypertensive agents (P = .005), and lower registration LVEF (P = .033). Incidence of asymptomatic LVEF decreases requiring holding trastuzumab was 8% to 10%; LVEF recovered and trastuzumab was restarted in approximately 50%. CONCLUSION: The cumulative incidence of post-AC cardiac events at 3 years was higher in the trastuzumab-containing arms versus the control arm, but by less than 4%. Older age, lower registration LVEF, and antihypertensive medications are associated with increased risk of cardiac dysfunction in patients receiving trastuzumab following AC.