"Our results prove beyond the shadow of a doubt that there are benefits for heart muscle from effective, sustained control of hypertension. This is yet one more reason for doctors to be very persistent in helping patients reduce their blood pressure to normal levels," says author Richard B. Devereux, M.D., professor of medicine at Weill Medical College of Cornell University and director of the echocardiography laboratory at New York Presbyterian Hospital.
One in four adults has high blood pressure, according to the American Heart Association.
Researchers undertook the study to evaluate whether heart function could improve, and whether that improvement would go beyond what one might expect by just lowering blood pressure.
Devereux compares the heart's performance during chronic high blood pressure to changes in the arm muscles from weightlifting: "The heart walls thicken, just as the biceps thicken from lifting weights, resulting in an increased demand for blood supply and energy," he says.
The study included 647 hypertensive patients who had enrolled in the Losartan Intervention for Endpoint (LIFE) Echocardiography Sub Study. Patients underwent an echocardiogram (ultrasound of the heart) at the start of the study, then yearly for the next two years. Researchers measured the mass of the left ventricle and its contractility. Contractility is a measure of how much the left ventricle cavity reduces and how much the muscular wall thickens during contractions.
Blood pressures were taken at the end of the echocardiogram, while patients were on the examining table. This allowed researchers to relate the heart's function to the blood pressure at the time of examination. Patients were randomly selected to receive antihypertensive medications losartan or atenolol to achieve target blood pressures of 140/90 millimeters of mercury (mm Hg).
Blood pressure was reduced from an average 174/95 mm Hg at the start of the study to 147/82 mm Hg at three years. Normal blood pressure is less than 130 mm Hg systolic pressure (top number) and less than 85 mm Hg diastolic pressure (bottom number). Left ventricular mass was reduced from an average of 234 grams (g) to 194g. Ventricular contractility improved from 97 percent to 105 percent of the predicted value.
The study's lead author is Kristian Wachtell, M.D., Ph.D. Co-authors are Vittorio Palmieri, M.D.; Michael H. Olsen, M.D., Ph.D.; Eva Gerdts, M.D., Ph.D.; Vasilios Papademetriou, M.D.; Markku S. Nieminen, M.D.; Gunnar Smith, M.D.; Björn Dahlöf, M.D., Ph.D.; and Gerard P. Aurigemma, M.D.
CONTACT: For journal copies only,
please call: (214) 706-1396
For other information, call:
Carole Bullock: (214) 706-1279
Maggie Francis: (214) 706-1397