Vitamin C supplementation along with proline and lysine makes sense from the standpoint of repairing damage done to coronary arteries, particularly the endothelium. I liked what Matthias Rath put out about this early in his career, but his current approach (correct me if I am wrong) is that micro nutrient deficiencies cause everything, which is GARBAGE.
More fundamental than collagen repair is to stop the inflammation that causes (or is a huge factor in developing) coronary arterial disease in the first place. As such, I have switched to a pure carnivore diet which does not have the inflammation created by refined and starchy carbs (including of course sugar). I feel better than I have in many years and other health problems have disappeared.
IMHO, eliminating these carbs is the most fundamental and important strategy to cut the risk of MI and stroke. The research bears this out (3 times LESS inflammation and other associated problems). This article discusses the fact that Vitamin C supplementation does not affect inflammatory markers (meaning does not lower them):
https://www.ncbi.nlm.nih.gov/pubmed/18427418