Is the term "Reversal Treatment" appropriate?

" In view of the modest changes in anatomic severity of coronary artery stenoses after lipid lowering, the commonly used term "regression" or "reversal" might be questioned. Atherosclerosis in the coronary arterial wall consists of a complex mix of cholesterol deposition, cellular proliferation, inflammation, calcification, functional abnormalities of vasomotion, and platelet interactions. With vigorous cholesterol lowering, lipid content and inflammatory cells in the wall decrease and functional abnormalities improve but cellular and fibrotic elements remain with calcification.

Endothelially mediated vasomotor function is adversely affected within hours after a fatty meal associated with the postprandial surge in VLDL, chylomicron remnants, and triglycerides. Abrupt lowering of cholesterol by LDL apheresis improves endothelial function immediately. As shown by PET imaging, both resting perfusion defects and stress perfusion defects are improved within 6 weeks to 3 months after a successful regimen of cholesterol lowering. Exercise capacity, perfusion defects, and coronary flow reserve are improved, with decreased angina, within weeks to months after cholesterol lowering, consistent with improved endothelial mediated vasomotor function.

The arterial lumen becomes somewhat larger due in part to functional vasodilation, to diminution of lipids and inflammation, and in part due to structural remodeling of the artery, which, although improved, remains scarred and smaller than normal. However, with diminution of lipids and inflammation, plaque stabilization occurs, with a decrease in unstable coronary syndromes and coronary events. These pathologic correlates of coronary events, or lack of events, parallel the clinical observation that progression of stenosis severity on arteriograms is associated with subsequent coronary events, whereas stabilization or partial regression by arteriography is associated with low risk of coronary events.

Thus, the term reversal or regression as used clinically incorporates the spectrum of beneficial changes in plaque composition and pathology, compensatory arterial structural changes, arteriographic severity, vasomotor function, flow capacity, symptoms, and prognosis. Certainly, regression back to normal in all of these processes does not occur. However, the term regression or reversal appropriately characterizes the cumulative benefits seen clinically, i.e., a symptom-free individual at low risk of coronary events with continuing lifelong risk factor modification."

K. Lance Gould, MD
Weatherhead PET Imaging Center for Preventing or Reversing Atherosclerosis
University of Texas Medical School
Houston, Texas
www.uth.tmc.edu/pet