WASHINGTON, May 11 - Adults with high blood pressure and additional risk factors for heart disease may benefit more from taking one tablet rather than two, if their current treatment combines the lipid-lowering medication atorvastatin with the blood pressure-lowering medication amlodipine, researchers reported at the American Heart Association's 8th Scientific Forum on Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke.
In an analysis, researchers found that a single-tablet combination of the two medications is less costly than a two-tablet combination and is at least as effective, if not more so, in preventing cardiovascular events. Patients take the single-tablet medication or the two-tablet medication daily.
"This is a novel research approach that examines the economic and clinical implications of high blood pressure and cholesterol in the real world," said Timothy W. Smith, lead author of the study and senior director of Informatics for ValueMedics Research (a unit of IMS Health Inc), a health outcomes research and consulting firm in Falls Church, Va. Researchers used a treatment approach and a population similar to the Anglo-Scandinavian Cardiac Outcomes Trial - Lipid-Lowering Arm (ASCOT-LLA), which demonstrated the benefits of adding atorvastatin to high blood pressure treatment in adults with three or more risk factors for heart disease, including abnormal ratio of total-to-high density lipoprotein (HDL - the "good" cholesterol), previous stroke, male gender, 55 years or older and smoking.
In ASCOT-LLA, researchers examined 10,305 patients with high blood pressure and additional risk factors for heart disease with low-to-moderate cholesterol levels and found the addition of atorvastatin to high blood pressure treatment resulted in a significant reduction in unfavorable outcomes: fatal and non-fatal heart attack, stroke and chest pain. Nearly one in three U.S. adults has high blood pressure. About one-third of them do not know they have it. Uncontrolled high blood pressure can lead to stroke, heart attack, heart failure or kidney failure.
High blood pressure is defined as systolic pressure of 140 mm Hg or higher or diastolic pressure of 90 mm Hg or higher. Systolic pressure is the force of blood in the arteries when the heart contracts to pump blood to the body. Diastolic pressure is the force in the arteries when the heart relaxes between beats. Normal blood pressure is less than 120 mm Hg systolic pressure and less than 80 mm Hg diastolic pressure.
The results of the study showed that when hypothetical cohorts of 100,000 people fully adhered to the one-tablet and two-tablet regimens, each treatment group had 3,520 cardiovascular events over four years, such as fatal and non-fatal heart attack, chest pain and stroke. Medical costs over four years were $7,665 for the two-tablet regimen and $6,471 for the one-tablet regimen.
A further analysis, examining the impact of lower compliance more typical in real-world populations, showed that four-year cardiovascular events increased for the two-tablet regimen to 6,990 versus 6,859 for the one-tablet regimen. Researchers concluded the one-tablet regimen was less costly and at least as effective as the two-tablet regimen. Sensitivity analyses confirmed these results when varying the effectiveness associated with partial adherence from 0 percent to 100 percent of the effectiveness of full adherence.
Researchers in the ValueMedics study used U.S. databases to estimate direct medical costs and adverse treatment outcomes over four years among adults with similar characteristics to those examined in ASCOT-LLA. Amlodipine (brand name Norvasc) is in a class of medications called calcium channel blockers. It lowers blood pressure by relaxing the blood vessels so the heart does not have to pump as hard.
Atorvastatin (brand name Lipitor) is in a class of medications known as statins or HMG-CoA reductase inhibitors. It lowers the level of cholesterol in the blood.
A single tablet combination of amlodipine/atorvastatin is available as Caduet.
Co-authors are Spencer B. Cherry; Joshua S. Benner, Sc.D. and Simon S. Tang, M.P.H.
Funding for this study was provided by Pfizer Inc.
Statements and conclusions of abstract authors that are presented at American Heart Association/American Stroke Association scientific meetings are solely those of the abstract authors and do not necessarily reflect association policy or position. The associations make no representation or warranty as to their accuracy or reliability.
Note: Presentation time is 9:30-11 a.m. EDT, Friday, May 11, 2007.