Ever wonder what happens to your heart after you have a heart attack, assuming you survive? Your heart starts fixing itself, or remodeling, a sign of permanent cardiac injury. Your heart will never be the same. Heart remodeling implies the heart attack caused detrimental changes in the size, function, or shape of the heart because the heart attack killed part of the pump and thus the pump has to be rebuilt (remodeled). The more remodeling, the more damage the heart attack inflicted.
You can estimate how severe the injury is by a remodeling blood test called MMP-9. After a heart attack, doctors measure this and similar tests to see when you can leave the hospital. The higher your MMP-9 is the worse the damage, the longer your stay in the CCU, and the higher your chance of death.
Many things influence remodeling, including the severity of the heart attack, where it was in the heart, and the inflammation it caused afterwards. Some medications lower MMP-9, especially angiotensin-converting enzyme (ACE) inhibitors. That’s one of the reasons that just one of the many ACE inhibitors used in the world (Coversyl or perindopril) had sales last year exceeding a billion dollars.
Until late in 2011, no one had ever thought of measuring MMP-9 and comparing the results to vitamin D levels in patients who had just had heart attacks. However, Dr. Hossein Khalili and colleagues at the University of Medical Sciences in Iran recently changed that.
Khalili H, Talasaz AH, Salarifar M. Serum vitamin D concentration status and its correlation with early biomarkers of remodeling following acute myocardial infarction. Clin Res Cardiol. 2011 Dec 11. [Epub ahead of print]
First, they found what you would expect: the lower your vitamin D levels, the greater your risk of dying. Although the numbers were small (139 participants), the significance (P<0.001) of death if you had the lowest vitamin D level was not.
They also found that the higher your vitamin D levels, the lower your MMP-9. What does it mean? The higher your vitamin D levels the less damage in the first place? The higher your vitamin D level the less the inflammation during the repair of the heart? Alternatively, is it a marker for something else?
I don’t know, but I do know that if I have a heart attack my vitamin D levels will be a lot higher than the people in Iran having heart attacks. Their average vitamin D levels, of all 139 patients in the study, were 10.8 ng/ml. We know from numerous other studies that low vitamin D levels are probably a risk factor for heart attack, and we know it from exactly the type of study Dr. Khalili preformed.