Monitoring Antihypertensive Medication Adherence by Liquid Chromatography-Tandem Mass Spectrometry: Method Establishment and Clinical Application.

ABSTRACT: Proper medication compliance is critical for the integrity of clinical practice, directly related to the success of clinical trials to evaluate both pharmacological-based and device-based therapies. Here, we established a liquid chromatography-tandem mass spectrometry method to accurately detect 55 chemical entities in the human urine sample, which accounting for the most commonly used 172 antihypertensive drugs in China. The established method had good accuracy and intraday and interday precision for all analyses in both bench tests and validated in 21 hospitalized patients. We used this method to monitor and ensure drug compliance and exclude the inferring impacts of medication compliance as a key confounder for our pivotal trial of a catheter-based, renal mapping and selective renal denervation to treat hypertension. It is found that in the urine samples from 92 consecutive subjects, 85 subjects (92.4%) were consistent with their prescriptions after 28 days run-in periods, 90 (97.8%) and 85 (95.5%) patients completely complied with their medications during the 3-month and 6-month follow-up period, respectively. Thus, using the liquid chromatography-tandem mass spectrometry method with specificity, accuracy, and precision, we ensured drug compliance of patients, excluded the key confounder of drug interferences, and ensured the quality of our device-based clinical trial for treatment of hypertension.

Selective vs. Global Renal Denervation: a Case for Less Is More.

PURPOSE OF REVIEW: Review the renal nerve anatomy and physiology basics and explore the concept of global vs. selective renal denervation (RDN) to uncover some of the fundamental limitations of non-targeted renal nerve ablation and the potential superiority of selective RDN. RECENT FINDINGS: Recent trials testing the efficacy of RDN showed mixed results. Initial investigations targeted global RDN as a therapeutic goal. The repeat observation of heterogeneous response to RDN including non-responders with lack of a BP reduction, or even more unsettling, BP elevations after RDN has raised concern for the detrimental effects of unselective global RDN. Subsequent studies have suggested the presence of a heterogeneous fiber population and the potential utility of renal nerve stimulation to identify sympatho-stimulatory fibers or "hot spots." The recognition that RDN can produce heterogeneous afferent sympathetic effects both change therapeutic goals and revitalize the potential of therapeutic RDN to provide significant clinical benefits. Renal nerve stimulation has emerged as potential tool to identify sympatho-stimulatory fibers, avoid sympatho-inhibitory fibers, and thus guide selective RDN.