The Assessment of Serum Drug Levels to Diagnose Non-Adherence in Stable Chronic Heart Failure Patients

Adherence to heart failure treatment in patients with peripartum cardiomyopathy

AIMS

Peripartum cardiomyopathy (PPCM) is characterized by left ventricular (LV) dysfunction developing towards the end of pregnancy or in the first months postpartum. Although about 60% of women with PPCM (the majority of which are prescribed evidence based heart failure [HF] medications) show LV recovery within 6 to 12 months, others remain with persistently impaired LV function. Poor adherence to medical therapy represents a major cause of avoidable hospitalizations, disability, and death in other cardiovascular conditions. In this study, we aimed to determine drug adherence to HF therapy among women with PPCM and to identify possible associations between drug adherence and LV recovery, functional status and psychological well-being.

METHODS AND RESULTS

In this single-centre, prospective, observational study, we included 36 consecutive women with PPCM. Adherence to HF treatment was assessed by (i) verifying the collection of pharmacy refills and (ii) using liquid chromatography high-resolution mass spectrometry (LC-HRMS). Participants were thereby classified as 'adherent' (i.e. all prescribed HF drugs were detectable by LC-HRMS), 'partially adherent' (i.e. at least one prescribed drug detectable) or 'non-adherent' (i.e. none of the prescribed drugs detectable). Health state index scores were assessed by EQ-5D-5L and HADS-A/D (for anxiety/depression). Patients' median age was 32.4 years (IQR 27.6-36.1). At the adherence visit (which occurred at a median of 16 months [IQR 5-45] after PPCM diagnosis), prescription included beta-blockers (77.8%), angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (75%), mineralocorticoid receptor antagonists (47.2%) and loop diuretics (95.2%). Less than two thirds of patients (63.9%) collected all their pharmacy refills in the 6 months prior to adherence visit. According to LC-HRMS, 23.5% participants were classified as adherent, 53.0% as partially adherent, and 23.5% as non-adherent. Adherence was associated with significantly lower LVEDD at follow-up (47 mm [IQR 46-52), vs. 56 mm [IQR 49-64] with partial adherence, and 62 mm [IQR 55-64] with non-adherence, P = 0.022), and higher LVEF at follow-up (60% [IQR 41-65]), vs. partially adherence (46% [IQR 34-50]) and non-adherence (41.0% [IQR 29-47], P = 014). Adherent patients had a lower overall EQ- 5D score (5.5 [IQR 5-7.5], vs. 6 [IQR 5-7] in partially adherent, and 10 [IQR 8-15] in non-adherent patients, P = 0.032) suggestive of a better self-rated health status.

CONCLUSIONS

Adherence to HF therapy was associated with favourable LV reverse remodelling in PPCM and better self-rated health status. Our study highlights the importance of drug adherence for functional recovery. Drug adherence should be an important component of patient communication and specific interventions in PPCM.

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)

AIMS

Liquid chromatography-mass spectrometry (LC-MS/MS) is an objective new technique to assess non-adherence to medications. We used this method to study the prevalence, predictors and outcomes of non-adherence in patients with heart failure with reduced left ventricular ejection fraction (HFrEF).

METHODS AND RESULTS

This study included 1296 patients with HFrEF from BIOSTAT-CHF, a study that aimed to optimise guideline-recommended therapies. Angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARBs), mineralocorticoid receptor antagonists, β-blockers and loop diuretics were measured in a single spot urine sample at 9 months using LC-MS/MS. The relationship between medication non-adherence and the composite endpoint of all-cause death or heart failure hospitalisation, over a median follow-up of 21 months, was evaluated. Non-adherence to at least one prescribed medication was observed in 45.9% of patients. The strongest predictor of non-adherence was non-adherence to any of the other medication classes (P < 0.0005). Regional differences within Europe were observed. On multivariable analyses, non-adherence to ACEi/ARBs and β-blockers was associated with an increased risk of the composite endpoint [hazard ratio (HR) 1.38, 95% confidence interval (CI) 1.09-1.95, P = 0.008 and HR 1.48, 95% CI 1.12-1.96, P = 0.006, respectively). Non-adherence to β-blockers was also associated with an increased risk of death (HR 2.48, 95% CI 1.67-3.68, P < 0.0005). Patients who were non-adherent to loop diuretics were healthier and had a decreased risk of the composite endpoint (HR 0.69, 95% CI 0.51-0.93, P = 0.014). Non-adherence to mineralocorticoid receptor antagonists was not related to any clinical outcome.

CONCLUSION

Non-adherence to medications, assessed by a single urine test, is common and predicts clinical outcomes in patients with HFrEF.

Adherence to prescribed medications in patients with heart failure: insights from liquid chromatography-tandem mass spectrometry-based urine analysis

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.

Hyphenated mass spectrometry techniques for assessing medication adherence: advantages, challenges, clinical applications and future perspectives

Nonadherence to prescribed pharmacotherapy is an understated public health problem globally and is costing many patients their chance to return to good health and healthcare systems billions. Clinicians need an accurate assessment of adherence to medications to aid the clinical decision-making process in the event of poor patient progress and to maximise the patient health outcomes from the drug therapies prescribed. An overview of indirect and direct methods used to measure medication adherence is presented, highlighting the potential for accurate measuring of drugs in biological samples using hyphenated mass spectrometry (MS) techniques to provide healthcare professionals with a reliable evidence base for clinical decision making. In this review we summarise published applications of hyphenated MS techniques for a diverse range of clinical areas demonstrating the rise in the use of such direct methods for assessing medication adherence. Although liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods using plasma, serum and urine samples are the most popular, in recent years increased attention has been given to liquid chromatography high-resolution mass spectrometry (LC-HRMS) methods and alternative biosample matrices including hair, saliva and blood microsamples. The advantages and challenges of using hyphenated MS techniques to address this healthcare problem are also discussed alongside future perspectives.