At age 51 or 52 after years of negative results on all testing, I was fortunately cathed 3 to 4 years ago at Stanford and diagnosed with moderate endothelial dysfunction via actylcholine challenges with no visible occlusion and elevated LP(a). I take an array of meds (Coreg, Nitro, Nitro-Quick, Pravastatin, Niacin, Fish Oil and Vit D and small dose Xanax. Lipids are good overall, but HDL could be higher and 1000 Slo-Niacin has not pushed down LP(a).