SAN FRANCISCO — Approximately 16% of 264,697 patients in a community-based practice network had treatment-resistant hypertension in 2007.
The true prevalence may be 8%-11% after adjustment for pseudoresistance, which previous studies suggest accounts for 30%-50% of suspected treatment-resistant hypertension, Dr. Brent M. Egan said at the annual meeting of the American Society of Hypertension.
At the same time, many of these patients are undertreated. Only two or fewer antihypertensive medications were prescribed for 60% of 49,043 patients who had diabetes or chronic kidney disease plus uncontrolled hypertension and for 78% of 66,337 patients who had uncontrolled hypertension without the other two cardiovascular risk factors, said Dr. Egan, professor of medicine and director of the Hypertension Initiative at the Medical University of South Carolina, Charleston.
The findings have significant implications as the U.S. population becomes older and more obese with more complex medical histories and more kidney disease. “The numbers are becoming substantial. In our practice network, well over 40,000 patients are likely to have true treatment-resistant hypertension,” he said.
Resistant hypertension is defined as blood pressure above goal while on a regimen of three or more antihypertensive medications, or controlled blood pressure while on four or more antihypertensives. Pseudoresistance can result from patients not taking prescribed medications, inaccurate blood pressure measurement, white-coat hypertension, or inadequate therapy.
Blood pressure goals for hypertensive patients without diabetes or chronic kidney disease were less than 140/90 mm Hg. Blood pressure goals for hypertensive patients with diabetes or chronic kidney disease were less than 130/80 mm Hg.
Blood pressure was uncontrolled in 36% of patients without diabetes or kidney disease and in 60% of patients with those diseases. African Americans were more likely than were whites to have uncontrolled hypertension.
Among patients with uncontrolled blood pressure, those with diabetes or kidney disease were prescribed more antihypertensive drugs and had lower mean pressures at the last patient visit (143/80 mm Hg) compared with patients without diabetes or kidney disease (mean pressures 157/93 mm Hg).
Physicians were more aggressive in treating hypertension in patients with diabetes or kidney disease, prescribing three or more antihypertensives in 35% of patients who achieved goal and 39% of those who did not. Among patients without diabetes or kidney disease, 17% who achieved goal and 22% who did not reach goal received three or more drugs.
Dr. Egan has received funding from, or been an adviser, speaker, or consultant for Novartis, AstraZeneca Pharmaceuticals, Pfizer Inc., and GlaxoSmithKline, some of which make antihypertensive medications.
'In our practice network, well over 40,000 patients' are likely to have resistant hypertension.
Source DR. EGAN