Electronic compliance monitoring in resistant hypertension: the basis for rational therapeutic decisions

Objective Incomplete compliance is one of several possible causes of uncont rolled hypertension. Yet, noncompliance remains largely unrecognized and is falsely interpreted as treatment resistance, because it is difficult to co nfirm or exclude objectively. The goal of this study was to evaluate the po tential benefits of electronic monitoring of drug compliance in the managem ent of patients with resistant hypertension. Methods Forty-one hypertensive patients resistant to a three-drug regimen ( average blood pressure 156/106 +/- 23/11 mmHg, mean +/- SD) were studied pr ospectively. They were informed that for the next 2 months, their presently prescribed drugs would be provided in electronic monitors, without any cha nge in treatment, so as to provide the treating physician with a measure of their compliance, Thereafter, patients were offered the possibility of pro longing the monitoring of compliance for another 2 month period, during whi ch treatment was adapted if necessary. Results Monitoring of compliance alone was associated with a significant im provement of brood pressure at 2 months (145/97 +/- 20/15 mmHg, P < 0.01). During monitoring, blood pressure was normalized (systolic < 140 mmHg or di astolic < 90 mmHg) in one-third of the patients and insufficient compliance was unmasked in another 20%. When analysed according to tertiles of compli ance, patients with the lowest compliance exhibited significantly higher ac hieved diastolic brood pressures (P = 0.04). In 30 patients, compliance was monitored up to 4 months and drug therapy was adapted whenever necessary. In these patients, a further significant decrease in blood pressure was obt ained (from 150/100 +/- 18/15 to 143/94 +/- 22/11 mmHg, P = 0,04/0.02). Conclusions These results suggest that objective monitoring of compliance u sing electronic devices may be a useful step in the management of patients with refractory hypertension, as it enables physicians to take rational dec isions based on reliable and objective data of drug compliance and hence to improve blood pressure control. (C) 2001 Lippincott Williams & Wilkins.