Vascular calcification and plaque rupture

There are two types of vascular calcification,  intimal calcification of atherosclerosis and medial calcification. Both are associated with increased incidence of ischemic heart disease. Plaque rupture is manly restricted to intimal plaques fibrous cap calcification. Calcification of this fibrous cap is associated with increased incidence of ischemic heart disease. Below discussion is about controversy associated with fibrous cap calcification.

Type of Vascular Calcification

Whether intimal calcification stabilizes the plaque or makes it prone for rupture is a matter debate. Calcified and fibrotic lesions are more hypo-cellular, they are stiffer than cellular lesions, and further more biomechanical data suggest calcification reduces the “stresses” in a plaque does not cause rupture.  Plaques with heavily calcified are 5 times stiffer that non-calcified lesions.

But calcium crystal have shown to aggravate inflammation

Above observation are contradictory to each other. If calcium induces inflammation than plaque should get destabilize?

Under mechanical stress produced by balloon angioplasty, calcified plaque is more likely to rupture than non-calcified plaque, and the rupture occurs along the interface between the calcium deposit and soft tissue. So this suggest that plaque rupture may occur at these week points

Conclusion

It has been stated that when entire plaque is calcified it protects against rupture unlike focal calcification

The ratio of surface area to volume in calcium deposits may determine whether they are harmful or protective