News Release

Diuretics And Beta-Blockers Are Best Drugs To Combat High Blood Pressure, Study Finds

Peer-Reviewed Publication

Washington University School of Medicine

St. Louis, March 19, 1998 -- Physicians use a small arsenal of newer drugs -- including calcium channel blockers, ACE inhibitors and alpha-blockers -- to lower high blood pressure. But the results of a study published in the March issue of Hypertension show that two older, less expensive types of drugs,

diuretics and beta-blockers, may lower blood pressure even better. This study, coordinated by a hypertension specialist at Washington University School of Medicine in St. Louis, analyzed data from 6,100 veterans treated at six Hypertension Screening and Treatment Program (HSTP) clinics of the U. S. Department of Veterans Affairs.

"The regimens of diuretic or diuretic plus beta-blocker gave the lowest average pressures and calcium channel blockers the highest," says H. Mitchell Perry Jr., M.D., professor emeritus of medicine at the School of Medicine and Physician Coordinator for Hypertension for the U.S. Department of Veterans Affairs. "There is a big difference in regimen efficacy, and it is statistically significant even after we correct for age, race and geographic region."

The study involved veterans receiving outpatient care at HSTP clinics in St. Louis, Mo., Indianapolis, Ind., Iowa City, Iowa, Memphis, Tenn., Jackson, Miss.and San Juan, Puerto Rico. These physician-supervised clinics, staffed by nurses and physician assistants intensively trained in hypertension, were established in 1974 by the Veterans Administration, as it was then called.

The physician-coordinators and staff members were allowed to choose which antihypertensive regimen to follow. They also could decide how aggressively to pursue the HSTP-recommended diastolic blood pressure goal.

The 46-month hypertension study, which ran from May 1989 to February 1993, did not follow a traditional randomized model. Instead, it relied on "real-world" data collected from clinicians who were primarily interested in treating patients and trying to find the medical regimen that would most effectively bring down blood pressure with a minimum of adverse effects.

"Unlike the more rigid, double-blind, placebo-controlled studies, this one simply says that we have a group of hypertensive patients and we're going to let the individuals who provide the care decide which drug to use and how enthusiastically to push it," Perry says.

The patients were a diverse group: their average age was 60.7 years, 53 percent lived in the five southeastern "Stroke Belt" states, 36 percent were black and 14 percent Hispanic, 23 percent smoked and 10 percent had diabetes mellitus. Of the 6,025 men and 75 women, 46 percent had damage to retina, heart, peripheral blood vessels, kidney or central nervous system -- all organs that are affected by high blood pressure.

Each time a patient visited an HSTP clinic, the staff recorded items of clinical importance, especially blood pressure and medication data. Some patients were taking no antihypertensive drug, while others were taking one or more drugs from the list of common agents: diuretics, beta-blockers, ACE inhibitors, calcium channel blockers or sympatholytic agents that were not beta-blockers. Some 54 percent took a diuretic, most commonly hydrochlorothiazide, and 33 percent took a calcium channel blocker, most often verapamil.

Researchers from the VA Coordinating Center in Perry Point, Md., divided these regimens into 12 categories and analyzed them. The results were decisive: the regimens of diuretic or diuretic plus beta-blocker produced the lowest average pressures (140.1/81.9 mm. Hg) and calcium antagonists the highest (149.0/86.5 mm. Hg).

All of the medications brought some patients down to the HSTP goal. But the pattern of lower treated pressure with the older agents and higher treated pressure with the newer ones was reflected in the percentages of patients whose blood pressure was controlled.

A second part of this study will retrospectively examine the morbidity and mortality associated with the various antihypertensive agents. A much larger traditional blinded and randomized trial, the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), is also scheduled for completion in 2001. This study, funded by the National Heart, Lung, and Blood Institute and the Department of Veterans Affairs, will prospectively examine morbidity and mortality associated with three of the "new" antihypertensive agents, comparing them to diuretics which are considered the gold standard.

"This ALLHAT study should answer the bottomline question: Are any of the currently used antihypertensive agents more effective than others in preventing death or heart attacks or strokes? We think these catastrophic events are closely associated with decrease in blood pressure, but we want to be sure," says Perry.

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Perry HM, Bingham S, Horney A, Rutan G, Sambhi M, Carmody S, Collins J. Antihypertensive efficacy of treatment regimens used in Veterans Administration hypertension clinics. Hypertension, 31, March 1998.



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