People with high blood pressure are at increased risk for heart attacks, strokes, and kidney disease. These complications can be reduced by lowering blood pressure. Now there's encouraging evidence that lowering blood pressure can slow down and even reverse the development of atherosclerosis.

High blood pressure and its complications are often the result of atherosclerotic plaques that accumulate in the arterial walls. The CAMELOT study compared the effects of two different blood pressure medications and a placebo on cardiovascular complications.

As part of this study, 274 participants underwent a procedure to measure the extent of atherosclerosis in one of their coronary arteries at the beginning of the study and two years later.

The plaque grew in size in people whose blood pressure was in the hypertensive range (140/90 mm Hg or greater). Plaque size did not change in those whose blood pressure was in the "pre-hypertensive" range (systolic pressure 120 to 139 mm Hg or diastolic pressure 80 to 89 mm Hg).

However, the volume of plaque was smaller at the end of the study in those whose blood pressure was "normal" (systolic pressure less than 120 mm Hg and diastolic pressure less than 80 mm Hg).

The study authors concluded that people with coronary artery disease should achieve and maintain blood pressures substantially lower than the often-recommended target of less than 140/90 mm Hg. Many groups, including the American Heart Association, recommend blood pressure below 140/90 as the target for most people, though lower targets are recommended for those with diabetes or kidney disease. These results add to the evidence supporting a change in the designation of "normal" blood pressure to less than 120/80 mm Hg.

Other studies have shown that aggressively lowering cholesterol levels with high doses of statin drugs also reduces the volume of atherosclerosis. Taken together, the results of these two studies provide strong evidence to counter the long-held, pessimistic belief that atherosclerosis inevitably grows worse over time.

Patients and doctors alike should be encouraged by these findings to redouble their efforts to reduce blood pressure and improve the other controllable risk factors for atherosclerosis and coronary artery disease.