Cholesterol lowering drugs known as statins have become a mainstay in the fight against coronary artery disease (CAD) and are routinely prescribed for people at risk for cardiovascular disease because of hypercholesterolemia. Emory research presented here today at the American Heart Association's Scientific Sessions indicates statins can help heart failure patients in additional ways -- whether or not their condition was caused by CAD.
Heart failure (HF) occurs when the heart loses some of its ability to pump blood through the body. Usually the heart has been weakened over time by an underlying problem, such as clogged arteries from CAD, high blood pressure, a defect in its muscular walls or valves, or some other medical condition. Symptoms of heart failure include shortness of breath, fatigue, difficulty sleeping due to breathing problems, a swollen and/or tender abdomen, loss of appetite, increased urination at night and swelling of the feet and legs.
According to the AHA, approximately five million Americans have heart failure and 550,000 new cases are diagnosed each year. "Despite advances in pharmacological and device-related therapy, morbidity and mortality from heart HF remains high," notes cardiologist Srikanth Sola, MD, Chief Fellow, Emory Division of Cardiology. "We know that in addition to cholesterol lowering, statins have significant effects on cellular and molecular mechanisms in vascular tissue -- so we wanted to see if the use of statins in patients with HF would improve clinical outcomes and reduce markers of inflammation."
The team of researchers, which included Emory Heart Center cardiologist Bobby V. Khan, MD (senior author of the paper) and scientists from Mount Sinai School of Medicine and Louisiana State University Health Sciences Center, followed 446 heart failure patients from the three university medical centers. The research subjects were classified according to treatment with a statin, which was prescribed at the discretion of their treating physician.
"Over a two year period, we looked at changes in lipid levels, serum markers of inflammation, and all causes of illness and deaths," says Dr. Sola.
"After adjusting for co-morbidities, statin therapy in patients with HF was associated with a decreased mortality rate from all causes when compared with those not on statin therapy -- 22 percent vs. 38 percent. In addition, hospitalizations for HF as well as hospitalizations for non-fatal myocardial infarction (MI) were also reduced in patients treated with statins. There was no significant difference in survival or hospitalizations for heart failure patients whose condition was caused by CAD versus other etiologies of HF."
The research team also found that statin therapy was associated with a decrease in several markers of inflammation, including C-reactive protein, interleukin-and tumor necrosis factor-alpha receptor II. In addition, the patients taking statins had a significant increase in erythrocyte superoxide dismutase activity, a marker of anti-oxidant activity.
"The anti-inflammatory activity of statins could explain why they are beneficial to HF patients. Inflammation is associated with worsened autonomic tone, neurohormonal activation, endothelial function, and progression of atherosclerosis, all of which play an adverse role in the progression of left ventricular dysfunction in patients with heart failure," Dr. Sola says.
The improvement in levels of several serum inflammatory and oxidative markers with statin therapy suggests in part mechanisms by which statins may exert their benefits. "More research needs to be done, but the results of our prospective, observational study suggest that patients with heart failure benefit from treatment with statins -- regardless of whether or not it was caused by coronary artery disease," says Dr. Sola.