Some recommended therapies may be underused in resistant hypertension

Physicians may be underprescribing certain guideline-recommended therapies for resistant hypertension, according to a new study.

Researchers performed a retrospective cohort study using data from a medical claims database to analyze antihypertensive use in patients with resistant hypertension. Included patients had a diagnosis of hypertension according to ICD-9-CM criteria and had concurrently filled prescriptions for at least four antihypertensive agents during the study period (May 1, 2008 to June 30, 2009). Of the four agents, at least two had to be recommended as a first-line agent by the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC 7). Patients who had a diagnosis of heart failure were excluded. Recommended first-line agents included angiotensin-converting enzyme (ACE) inhibitors, angiotensin-receptor blockers (ARBs), beta-blockers, calcium-channel blockers, and diuretics. Chlorthalidone and aldosterone antagonists were considered evidence-based and recommended antihypertensive therapy, while therapy with an ACE inhibitor plus an ARB or with a combination of drugs from the same class was considered minimally efficacious. The study results were published early online Oct. 30 by Hypertension.

A total of 140,126 patients, 54.5% men, met the inclusion criteria. The mean age was 63.8 years. The most commonly prescribed drug classes were ACE inhibitors and/or ARBs (96.2%), diuretics (93.2%), calcium-channel blockers (83.6%) and beta-blockers (80%). Chlorthalidone and aldosterone antagonists were prescribed in 3.0% and 5.9% of patients, respectively, while 15.6% of patients were receiving both an ACE inhibitor and an ARB.

The authors noted that their study did not classify patients according to blood pressure measurements and that only a relatively short time had passed between publication of guidelines on resistant hypertension therapies and the beginning of the study, among other limitations. However, they concluded that while guideline-recommended first-line agents were frequently prescribed for resistant hypertension, other evidence-based therapies, such as chlorthalidone and aldosterone antagonists, were not used to full advantage. Also, they found that a significant proportion of patients was prescribed ineffective therapies, such an ACE inhibitor plus an ARB. They called for more research and better clinician education on optimal treatment for resistant hypertension.

An accompanying editorial labeled the problem one of “resistant prescribing” and called the gap between recommendations and clinical practice “unacceptably wide.” He predicted that the population of patients with resistant hypertension will only continue to grow and said that clinicians need to understand their approach to current management in order to improve it. “Before attributing [resistant hypertension] to host factors beyond our control, we need to first ensure that we have not contributed to its presence by failing to use effective combinations and evidence-based therapies,” he wrote.