The Framingham heart trial revealed some of the most important risk factors for heart disease.

New and more novel risk factors include homocysteine levels and C-reactive protein. Homocysteine is an amino acid degradation product. Studies indicate that excessive homocysteine may produce an inflammatory reaction in the artery. This inflammation weakens the artery, thereby inviting cholesterol deposits. Vitamins such as folic acid and B-12 may help to reduce homocysteine levels. High levels of the circulating blood protein C-reactive protein also seem to increase inflammatory reactions in the artery wall. In the absence of more conventional factors, such as high cholesterol, physicians can screen for increased cardiac risk by looking for these factors. While the role of excessive iron has been discussed, to date, no conclusive data have emerged. Finally, vitamins C and E have been promoted as antioxidants that protect the arteries. However, the recent HOPE trial has cast some doubt on the efficacy of vitamins C and E for reducing coronary artery risk. Additional studies are currently underway, and there is promising data about L-arginine and coenzyme Q10, but no proof that they reduce heart attack or stroke risk.