Can MMP-1 levels in blood predict the course of coronary artery disease?

This study investigated whether MMP-1 levels in blood helps determine the risk of death among patients with coronary artery disease. 

Coronary artery disease is when blood vessels that supply the heart muscle with blood and oxygen (coronary arteries) become narrow.

Cholesterol and fat can build up in the walls of the artery and form plaques, which narrow the space through which blood flows. Immune cells gather in the artery wall, causing the wall to thicken further.

Sudden changes in blood flow or blood pressure (such as during physical exertion or emotional stress) can cause the plaques to burst. This leads to the formation of a blood clot which can block the artery. When a coronary artery becomes completely blocked, a heart attack occurs and can cause death to part of the heart muscle.

Matrix metalloproteinases (MMPs) are proteins in the body that are thought to make plaques more vulnerable to rupturing. MMPs are released by immune cells and a certain type of MMP, called MMP-1, has also been shown to trigger blood clot formation. 

This study investigated whether high levels of MMP-1 in patients with coronary artery disease helps predict the risk of death.

A total of 364 male patients with coronary artery disease who were referred for surgery to unblock a coronary artery were included in this study. MMP-1 levels were measured in each patient.

Patients were then followed-up for 5 years to record the occurrence of all-cause mortality (death due to all causes and not just specifically heart events such as a heart attack). 

The study found that elevated MMP-1 levels measured in the patients’ blood at the beginning of the study increased the risk of death by 49% at 5 years. The investigators compared MMP-1 with a host of different proteins associated with coronary artery disease, and still found that MMP-1 independently increased the risk of mortality. 

The authors concluded that elevated levels of MMP-1 was associated with an increased risk of mortality in patients with coronary artery disease. 

The study only included male patients and therefore caution should be warranted when generalising the results for females. Also the study only recorded the occurrence of all-cause mortality and therefore some deaths that occurred may not have been associated with MMP-1 levels. 

If you or someone you know have coronary artery disease, talk to a doctor about measuring blood MMP-1 levels to measure your risk of future health problems and death, and discuss what treatments and steps you can take to reduce this risk.