MMP9 Levels Associated with Risk of Atherosclerotic Plaque Rupture
A great deal of effort goes into preparing for atherosclerotic plaques to rupture, and then coping with the consequences of the resulting stroke or heart attack, and all too little effort into reversal of plaque formation. Researchers here examine plaque rupture in structural detail in a group of patients with sufficiently detailed prior imaging data to determine what happened at the site of rupture. This is less interesting than the associated data showing that raised levels of MMP-9 appear to be predictive of risk of plaque rupture. Whether this means that inhibiting MMP-9 can reduce that risk is an interesting question, but still a poor path forward in comparison to greater work in means to prevent and reverse plaque formation.
In atherosclerosis, fat is accumulated in the artery walls creating atherosclerotic plaques. Plaques that rupture can cause a stroke or myocardial infarction, and a deeper understanding of the mechanisms underlying plaque rupture is needed to prevent serious complications. Researchers now show that atherosclerotic plaques in the carotid arteries often rupture at the beginning of the plaque, at a location closest to the heart. "In our study, we were able to pinpoint exactly where plaques rupture. This is an important step, allowing for a better understanding of why they rupture."
The research is based on studies of atherosclerotic plaques in the carotid arteries from a total of 188 individuals. The researchers used electron microscope and RNA sequencing techniques to get a detailed picture of the location where most plaques rupture. High blood pressure and type 2 diabetes are factors that increase the risk of atherosclerosis and therefore these patient groups were also included in the study.
RNA sequencing showed a strong association between the enzyme MMP-9 and the area where plaques rupture. High levels of MMP-9 could also be associated with an increased risk of future cardiovascular disease in individuals with atherosclerosis. The researchers hope to be able to use MMP-9 as a marker to predict which patients are at risk of having a myocardial infarction or a stroke. They are also investigating if it is possible to develop new treatments that reduce the risk of plaque rupture based on inhibition or blockade of MMP-9.