A new study led by The Cleveland Clinic shows that giving blood pressure lowering medication to heart disease patients with a “normal” blood pressure dramatically reduces risk of adverse cardiac events and slows disease progression.
In the CAMELOT trial, researchers enrolled patients with coronary heart disease and an average blood pressure of 129/78, which is considered completely “normal” by current standards. Patients were given one of two types of blood pressure lowering drugs or a placebo (a sugar pill).
After two years of treatment with the anti-hypertensive drug amlodipine, a drug in a class known as calcium channel blockers, patients experienced a 31-percent reduction in major adverse cardiovascular events, including heart attack, stroke, death, hospitalization for chest pain and need for angioplasty or bypass surgery.
These unexpected results raise a provocative question: How low a blood pressure is low enough for patients with coronary heart disease?
“The reduction in risk for the amlodpine group was surprisingly large,” said CAMELOT principal investigator Steven Nissen, M.D., a Cleveland Clinic cardiologist. “The patients in this trial were treated with the best existing therapies – 84 percent received cholesterol-lowering drugs and 95 percent received aspirin. Their blood pressures were already well below current treatment guidelines. Yet adding amlodipine to state-of-the-art medications further reduced cardiovascular events in this patient population.
“The CAMELOT study demonstrates the critical importance of lowering blood pressure in patients with heart disease and suggests that current guidelines do not go far enough in recommendations for blood pressure targets in patients with coronary disease,” Dr. Nissen said.
The CAMELOT trial enrolled 1,991 patients at 100 study centers in the United States, Canada and Europe. Patients were divided into three groups: One-third received amlodipine, a calcium channel blocker, (brand name Norvasc); one-third received enalapril, an angiotensin-converting enzyme (ACE) inhibitor, (brand name Vasotec); and one-third received a placebo.
In both the amlodipine and enalapril groups, blood pressure was reduced about 5/3 mm Hg to approximately 124/76. The 31-percent reduction in major adverse cardiovascular events in the amlodipine group was highly statistically significant. Although the group receiving enalapril experienced a 15-percent reduction in adverse events, the difference was not statistically significant.