Bone and Cartilage Growth to Blame for Heart Valve Disease
Heart valve degeneration
Research to be published in the April 18 issue of the Journal of the American College of Cardiology provides the first explanation of an active rather than passive process that leads to heart valve degeneration, furthering a Northwestern researcher's effort to lead a paradigm shift in the medical community's beliefs about the cause of valve disease.
Heart valve disease is caused not by a 'wear and tear' phenomenon, but by an inflammatory process likely triggered by high cholesterol that stimulates certain cells to reprogram into bone cells in the aortic valve and cartilage cells in the mitral valve, says principal investigator Nalini Rajamannan, MD, newly appointed director of the Center for Heart Valve Disease in the Bluhm Cardiovascular Institute of Northwestern Memorial Hospital and assistant professor of medicine, Northwestern University Feinberg School of Medicine, who examined diseased mitral and aortic valves removed during surgery for the study.
"Common wisdom in the medical community has always been that thickening of the mitral valves was part of the aging process as deposits of calcium, a mineral found in the blood, built up on the valves. Therefore, research has never focused on preventing the problem," says Dr. Rajamannan. "Currently the only option is to surgically repair or replace the damaged valves. Our findings open the door to the idea that medical therapies such as statins may be able to play a role in preventing or slowing the process and curtailing the need for surgery."
Valvular heart disease is on the rise with the aging of the United States population, and is second only to coronary artery disease as a cause for open heart surgery. Heart valve disease leads to 100,000 surgeries in the U.S. each year to repair or replace damaged valves. Mitral valve disease is a leading cause of atrial fibrillation, which is a major culprit in strokes and heart failure. Aortic valve disease can lead to heart failure, arrhythmia, infections in the heart, and sudden death may occur in 15 to 20 percent of people who have symptoms.
Dr. Rajamannan has focused her research for the past seven years on advancing the knowledge of mechanisms of aortic and mitral valve disease using animal models and human studies. "I wanted to know why diseased valves had were hardened with a glassy whitish appearance