A Mayo Clinic study shows that an hourglass-shaped stent could improve blood flow and reduce severe and recurring chest pain in people with microvascular disease. Of 30 participants in a phase 2 clinical trial, 76% saw an improvement in their daily life. For example, some participants who reported being unable to walk around the block or climb a flight of stairs without chest pain were able to do these usual physical activities at the end of a 120-day period. Clinical measures of blood flow related to the microvasculature of the heart improved significantly during follow-up, according to findings published in Journal of the American College of Cardiology: Cardiovascular Interventions.
Microvascular disease is a condition in which the tiny blood vessels in the heart do not work properly, resulting in reduced blood flow to the heart. The resulting chest pains, or angina, can be debilitating, limiting a person’s ability to exercise, do housework, or even walk to the mailbox. About 40% of patients who receive a diagnostic coronary angiogram for chest pain do not have blocked arteries that can also cause angina. However, up to 66% of these patients have coronary microvascular disease, which is more common in women overall and is found in people with conditions such as diabetes, high blood pressure and obesity.
For decades, there have been few viable treatment options to improve blood flow through the heart’s tiny vessels. At most, doctors have treated angina symptoms with many medications and heart disease prevention methods, such as a healthy diet, weight loss, and regular exercise. Using a stent could target the problem behind the chest pain -? the severe decrease in blood flow affecting the heart muscle.
Unlike the tube-shaped stents used to open blocked arteries, the hourglass-shaped stent narrows in the middle. The different design is believed to increase back pressure, more fully redistributing blood flow through small vessels in the heart that weren’t working at capacity.
Patients with heart-related microvascular dysfunction in this study had little ability to control their chronic angina, which severely limited their daily activities. Beyond the reductions in chest pain and the ability to comfortably handle more physical activity, the majority of patients in the study also showed a link between changes in their coronary flow reserve, a measure of peak blood flow, and changes in their quality of life responses to the survey. This shows the relationship between the physiological measurement and angina symptoms.”
Amir Lerman, MD, a cardiologist at the Mayo Clinic and senior author of the study
Dr. Lerman notes that more studies are needed to better understand how the reduction stent works and its long-term effects on blood flow. The stent did not improve chest pain symptoms in 20%-30% of participants, so future research studies should better determine which patients respond best to this treatment.
