Benefits of lipid-lowering therapy in men with elevated apolipoprotein B are not confined to those with very high low density lipoprotein cholesterol

Abstract

Objectives: Do the benefits of intensive lipid-lowering therapy extend to patients with only borderline or moderately elevated levels of low density lipoprotein (LDL) cholesterol?

Background: The merits of the present LDL cholesterol treatment goal of < or = 100 mg/dl need to be clarified for patients without high levels of LDL cholesterol, particularly for those patients previously classified as having only borderline high (130 to 159 mg/dl) or desirable (101 to 130 mg/dl) levels.

Methods: Disease change and clinical events were examined in LDL cholesterol subgroups in the Familial Atherosclerosis Treatment Study (FATS) trial, a randomized, blinded, quantitative arteriographic comparison of one conventional and two intensive lipid-lowering strategies in men with coronary artery disease, a positive family history and apolipoprotein B > or = 125 mg/dl. The primary end point, disease change per patient, was measured as the mean change in severity of stenosis (delta %SProx) among nine standard proximal segments.

Results: Of the 120 patients completing the 30-month protocol, 60 had a baseline LDL cholesterol < 90th percentile (mean LDL cholesterol 152 mg/dl) and 60 > 90th percentile (mean LDL cholesterol 221 mg/dl). Thirty-one patients had levels < 160 mg/dl (mean LDL cholesterol 134 mg/dl) and 89 > 160 mg/dl (mean LDL cholesterol 205 mg/dl). Patients with LDL cholesterol < 90th percentile benefited angiographically from therapy (delta %SProx = -1.5% diameter stenosis [regression] during intensive therapy vs. +2.3% diameter stenosis [progression] during conventional therapy, p < 0.01), as did patients with LDL cholesterol < 160 mg/dl (delta %SProx = -4.2% vs. +3.3% diameter stenosis, p = 0.0001). By comparison, angiographic benefit was less pronounced among those entering with very high LDL cholesterol (delta %SProx = -0.2% vs. +1.9% diameter stenosis, p = 0.07) or with LDL cholesterol > or = 160 mg/dl (delta %SProx = +0.2% vs. +1.6% diameter stenosis, p = 0.13). Intensive therapy resulted in a statistically significant reduction in clinical events only in the subgroup with baseline LDL cholesterol < 90th percentile (2 of 42 vs. 8 of 29 patients initially enrolled, p = 0.01) and a trend toward fewer events in patients with LDL cholesterol < 160 mg/dl (2 of 20 vs. 6 of 15 patients, p = 0.05). No such difference was seen in the higher LDL cholesterol subgroups.

Conclusions: Treatment benefit in the FATS trial was not confined to patients with very high levels of LDL cholesterol and was in fact particularly evident in those patients with levels < 160 mg/dl. Such patients should be considered more likely, not less, to benefit from intensive lipid-lowering therapy.