Study leads to new approach for treatment of aortic valve stenosis

Montreal Heart InstituteJul 19 2013

A study conducted by the team of Dr. Jean-Claude Tardif, Director of the Research Centre at the Montreal Heart Institute (MHI), has led to the discovery of a new approach to treat aortic valve stenosis through the administration of a compound that prevents valve deterioration and can even reverse the progression of the disease. A condition that is characterized by a narrowing of the aortic valve and that affects approximately 150,000 Canadians , aortic valve stenosis is the most common type of heart valve disease in Western countries. The results of this study were published in the British Journal of Pharmacology on July 15, 2013.

This study conducted in mice suffering from aortic valve stenosis showed successful outcomes with infusions of a compound that mimics HDL (high-density lipoprotein), which is often referred to as "good cholesterol." This treatment could help open narrowed aortic valves, avoid the major complications of aortic valve stenosis (including the need for heart surgery), and prevent heart failure and sudden death.

A less invasive option

"These results are extremely encouraging, as they allow us to hope that this type of treatment will work for people who suffer from aortic valve stenosis. If so, it will represent a brand-new treatment option that may even prevent open-heart surgery to replace valves damaged by stenosis," said Dr. Jean-Claude Tardif. "This treatment may be an alternative to a procedure that is complex, risky and very invasive for patients." Valve replacement surgery is currently the primary treatment option for this condition, with 13,000 surgeries conducted on average each year in Canada .

A growing incidence

Especially common in people over the age of 65, aortic valve stenosis can also affect people who are overweight, eat a high-fat diet, are diabetic or have a congenital abnormality. "In light of the aging of the population and alarming data on excess weight, diabetes, lifestyle and the diet of the population in general, this disease represents a major public health problem," stressed Dr. Tardif.

More details about the MHI study

In this study, mice were put on a cholesterol-enriched diet until aortic valve stenosis was detected using echocardiography (a medical imaging ultrasound system used in humans). The animals were then divided into two groups: a control group that received saline infusions and a treatment group that received infusions of a compound that mimics good cholesterol (an apoA-I mimetic peptide) for two weeks.

These results were particularly impressive as, after only 28 days of treatment, the aortic valve opened more fully in the treatment group compared to the control group. The aortic wall in the treatment group had also reduced in thickness compared to the control group.

Furthermore, microscopic analysis also revealed that the extent of the scar lesions (or accumulated collagen) in the valves was significantly smaller in the treated subjects than in the control subjects.