Non‐adherence to heart failure medications predicts clinical outcomes: Assessment in a single spot urine sample by liquid chromatography – tandem mass spectrometry (results of a prospective multicentre study)

Abstract Aims None of the existing studies on adherence have directly measured levels of all medications (or their metabolites) in patients with heart failure (HF). Methods and results We used liquid chromatography–tandem mass spectrometry to measure the presence of prescribed drugs (diuretics, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and mineralocorticoid receptor antagonists) in the urine of patients reviewed 4–6 weeks after hospitalization with HF. Patients were unaware that adherence was being assessed. Of the 341 patients studied, 281 (82.4%) were adherent, i.e. had all prescribed drugs of interest detectable in their urine. Conversely, 60 patients (17.6%) were partially or completely non-adherent. Notably, 24 of the 60 were non-adherent to only diuretic therapy and only seven out of all 341 patients studied (2.1%) were completely non-adherent to all prescribed HF drugs. There were no major differences in baseline characteristics between adherent and non-adherent patients. Conclusion Non-adherence, assessed using a single spot urine measurement of drug levels, was confirmed in one of five patients evaluated 4–6 weeks after hospitalization with HF.

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Determination of Urinary Creatinine in Washington State Residents via Liquid Chromatography/Tandem Mass Spectrometry

International Journal of Analytical Chemistry ◽

10.1155/2014/247316 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

Caroline E. West ◽

Blaine N. Rhodes

Keyword(s):

Mass Spectrometry ◽

Liquid Chromatography ◽

Tandem Mass Spectrometry ◽

Washington State ◽

Urine Samples ◽

Tandem Mass ◽

Urinary Creatinine ◽

Spot Urine ◽

Chromatography Tandem Mass Spectrometry ◽

Liquid Chromatography Tandem Mass

A viable, quick, and reliable method for determining urinary creatinine by liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed and used to evaluate spot urine samples collected for the Washington Environmental Biomonitoring Survey (WEBS): part of the Washington State Department of Health, Public Health Laboratories (PHL). 50 µL of urine was mixed with a 1 : 1 acetonitrile/water solution containing deuterated creatinine as the internal standard and then analyzed by LC/MS/MS. Utilizing electrospray ionization (ESI) in positive mode, the transition ions for creatinine and creatinine-d3were determined to be 114.0 to 44.1 (quantifier), 114.0 to 86.1 (qualifier), and 117.0 to 47.1 (creatinine-d3). The retention time for creatinine was 0.85 minutes. The linear calibration range was 20–4000 mg/L, with a limit of detection at 1.77 mg/L and a limit of quantitation at 5.91 mg/L. LC/MS/MS and the colorimetric Jaffé reaction were associated significantly (Pearsonr=0.9898andR2=0.9797,ρ≤0.0001). The LC/MS/MS method developed at the PHL to determine creatinine in the spot urine samples had shorter retention times, and was more sensitive, reliable, reproducible, and safer than other LC/MS/MS or commercial methods such as the Jaffé reaction or modified versions thereof.

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