April 12, 2013 — A research study of more than 600 black patients with uncontrolled hypertension found that less than half were prescribed a diuretic drug with proven benefit that costs just pennies a day, report researchers at Weill Cornell Medical College and the Visiting Nurse Service of New York's (VNSNY) Center for Home Care Policy and Research. The researchers say these new findings should be taken as a serious wake-up call for physicians who treat black patients with hypertension.
Their study, reported in the American Journal of Hypertension, found that the patients in the study who used the common diuretic drugs had, on average, lower blood pressure (both systolic and diastolic) than the patients who did not receive them.
"We were surprised to find that this beneficial and low-cost drug was not being prescribed for more patients who would benefit from it," says the study's lead investigator, Linda Gerber, a professor of public health and director of the Biostatistics and Research Methodology Core at Weill Cornell Medical College.
Many previous studies have shown that diuretics are particularly helpful in black patients with hypertension and should be used as first or second-line treatment — findings that have been written into treatment guidelines. Also, several recent clinical trials have reported that newer classes of agents are not superior to the older diuretic agents, especially in blacks. Newer drugs for hypertension include angiotensin-converting enzyme inhibitors (ACEs), angiotensin-receptor blockers (ARBs) and calcium-channel blockers (CCBs).
"Yet, we find that physicians are not using the drugs as they should in a population that is especially hard hit by high blood pressure, and who suffer greater prevalence, severity, organ damage and mortality from the disease compared to other groups," says Gerber, who is also a professor of epidemiology in medicine at Weill Cornell.
While Gerber did not speculate on why this phenomenon is occurring since doctors were not interviewed as part of this research, study co-author, Samuel Mann, a professor of clinical medicine at Weill Cornell and a hypertension specialist at the Hypertension Center of NewYork-Presbyterian Hospital/Weill Cornell Medical Center, has some theories.
"Guidelines are not rules and they are not enforceable, and some physicians may worry about potential side effects of diuretics — which, although not uncommon, are not a major problem. And in patients with uncontrolled hypertension, the benefit of treating with a diuretic far outweighs the risk of side effects that are generally very manageable," says Mann. "Also, newer drugs are promoted much more aggressively than diuretics. However, many studies show that diuretics work very well, particularly in black patients, so between their effectiveness and low cost, their use should be a no-brainer."
The Weill Cornell research team worked in close collaboration with researchers from the VNSNY Center for Home Care Policy and Research, who received funding support from the National Heart, Lung and Blood Institute (NHLBI) to seek ways to improve hypertension management and outcomes. 658 black patients receiving home care were enrolled in the study; all had uncontrolled hypertension defined as 140/90 or above (130/80 or above if they were diabetic). Although the patients were receiving post-acute care from a single health organization, their prescribing providers came from a wide variety of medical settings.
"Communicating effectively with patients' physicians and persuading them to review the medications of patients with uncontrolled hypertension is an ongoing challenge for home care nurses," says study co-author Penny Feldman, director of the VNSNY Center for Home Care Policy and Research and senior vice president for Research and Evaluation at VNSNY. "Our study shows that close monitoring of patient medications can help identify inconsistencies and divergence from current approved medical guidelines and make inroads to help improve the health and quality of life of black patients with hypertension."
Study investigators found that 5.5 percent of participants were not prescribed any antihypertensive drugs, and that only 46 percent were prescribed a diuretic. They also discovered that participants who were not taking a diuretic had systolic and diastolic blood pressures that were, on average, five and four millimeters higher, respectively, than those who were taking a diuretic.
"A majority of patients surveyed were taking multiple drugs for hypertension, as many as three or four, and many of those still were not taking a diuretic," says Gerber. "The absence of diuretic use in the regimen of more than half of the patients in this study is contrary to guidelines and may be harmful to patients, both medically in terms of uncontrolled hypertension, and economically, in terms of medication cost and compliance."
Gerber adds that a strength of the study is that "it focuses on members of an undertreated and understudied population whose high blood pressure has proven particularly damaging, and for whom guidelines strongly recommend a diuretic as a mainstay of treatment."
Other contributing study co-authors include Margaret V. McDonald and Sridevi Sridharan, from the VNSNY Center for Home Care Policy and Research, and Ya-Lin Chiu of the Department of Public Health at Weill Cornell Medical College.
The research study was supported by grant ROI HL078585 awarded to VNSNY by NHLBI.
For more information: weill.cornell.edu