Most ruptures and clotting events are too small to produce symptoms, though they still produce heart muscle damage, a slow progressive process resulting in ischemic heart disease, the most common basis for congestive heart failure.
When this inflammation is combined with other stresses, such as high blood pressure (increased mechanical stretching and contraction of the arteries with each heart beat), it can cause the thin covering over the plaque to split, spilling the contents of the vulnerable plaque into the bloodstream.