Effects of initial and long-term lipid-lowering therapy on vascular wall characteristics.

Several studies have demonstrated the beneficial effects of 3 hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors on vascular properties, but little is known about treatment intensification. We compared patients in whom statins were started (INITIAL, n=30) for hypercholesterolaemia (>6.5 mmol l(-1)) with a matched patient group of long-time statin users, with similar baseline characteristics for lipids, intima-media thickness (IMT), and pulse wave velocity, in whom treatment with statins was intensified (LONG-TERM, n=54). At baseline and after 1 year, lipid profile, IMT of the carotid and femoral arteries, aortic distensibility using pulse-wave velocity and various properties of the peripheral vascular bed using a recently developed bio-impedance method were measured. After 1 year the relative changes in lipid profile were significantly better in the INITIAL compared with the LONG-TERM-group. The relative changes in IMT of the mean internal carotid and common femoral arteries significantly differed between the INITIAL and LONG-TERM-group (-8 and +11%, -11 and +22%, respectively). After 1 year, in both groups, most other vascular wall characteristics were unaltered compared with baseline. In conclusion, the beneficial structural alterations of the vascular wall were greater after starting than after intensifying already existing lipid-lowering treatment. This suggests that other effects of HMG-CoA reductase inhibitors than lipid-lowering alone must be involved in vascular changes.