New understanding of heart disease-causing macrophages
According to a new study by researchers from the University of Toronto and Massachusetts General Hospital, plaque within the walls of the arteries may not grow in quite the same way as previously assumed. Because this buildup of plaque leads to a greater risk for heart disease, this new knowledge may change how heart disease is treated. Since heart disease is the leading cause of death both in the United States and worldwide, this discovery could have a big impact on the future of medicine.
Atherosclerosis, the narrowing of the arteries due to the hardening of plaque around the artery walls, is the leading cause of heart disease. Previously, scientists thought macrophages — white blood cells associated with inflammation that can lead to atherosclerosis — grew mainly because of monocytes, white blood cells that fight pathogens within the bloodstream. According to the new research, though, it may not be as simple as that. Instead, the research indicates that atherosclerosis may be caused by macrophages reproducing within the plaques rather than within the bloodstream.
This research could change the focus of cardiovascular disease treatment. Previously, treatment research was focused on blocking the white blood cells from getting into the plaque. If, however, atherosclerosis is caused by macrophages reproducing once they are within the plaque, treatment and research will need to change to better support the new knowledge.
Because the study was conducted using mice as research subjects, there is still more research needed to fully conclude if the results translate to humans. There was, however, also evidence of macrophage growth within human carotid arteries, the arteries supplying the head and neck with oxygenated blood. Only future research can tell what these new findings will actually mean for the future of treatment of heart disease. The full results of the study can be found in Nature Medicine.