New paradigms in preventive cardiology: unconventional coronary risk factors.

The 1996 Bethesda Conference acknowledged the following conditions as possible new cardiac risk factors: left ventricular hypertrophy, homocysteine, lipoprotein(a), hypertriglyceridemia, oxidative stress, and fibrinogen. Left ventricular hypertrophy is an independent risk factor for vascular disease, the improvement or progression of which influences subsequent cardiovascular complications. Clinical trials are currently underway to assess potential benefit from lowering homocysteine levels. The role of lipoprotein(a) excess in vascular disease is controversial; its atherogenic potential seems to be neutralized by effective lowering of LDL-cholesterol. Increasing evidence supports the independent role of hypertriglyceridemia in cardiovascular disease and possible clinical benefit from lowering triglyceride levels. Among antioxidant micronutrients, supplementation with vitamin E has been shown to be beneficial in some but not all primary and secondary prevention studies, but data to support use of other antioxidants are much weaker. Preliminary evidence suggests that the reduction of fibrinogen levels in patients with high baseline levels and coronary disease may be beneficial.Despite the potential relation between new risk factors and cardiovascular disease, routine clinical application of these conditions as cardiovascular risk factors would be premature. We first need evidence that these conditions extend prognostic ability beyond conventional risk factors and that modification of these conditions can decrease the risk of cardiovascular events.