Time-related trends in variability of cIMT changes in statin trials

This brief article provides complementary data supporting the results reported in "Changing Characteristics of Statin-related cIMT Trials from 1988 to 2006" [1]. That article described time-related trends in baseline factors and study characteristics that may have influenced the variability of carotid intima media thickness (cIMT) endpoints (mean of mean and maximum common carotid artery [CCA]/cIMT) in published statin trials. In this brief report, additional details for the studies included in the analysis, and further supporting data, including mean of the maximum CCA/cIMT changes and subgroup data (mean and maximum CCA/cIMT) are provided. For the analysis, study-level data was extracted from 17 statin cIMT trials conducted during 1988-2006, selected on the basis of having at least one statin monotherapy arm in the absence of mixed therapy, and baseline- and study-end values for mean mean and mean maximum CCA/cIMT endpoints. The baseline mean CCA/cIMT, maximum mean CCA/cIMT and LDL-C levels, and annualized cIMT changes were estimated for the overall studies, those conducted before/after 2000, and in risk-based subgroups. Interestingly, all 8 studies conducted before 2000 were significant for cIMT change in which patients did not receive prior LLT; whereas after 2000, the results were more variable and in 4 of 6 trials that did not show a significant cIMT change, patients had received prior treatment. Baseline mean maximum cIMT and LDL-C levels, and annualized changes in studies conducted before 2000 were higher than those conducted after 2000, similar to the results reported in the original article for the mean mean cIMT endpoint. These findings were consistent across study populations of patients with CHD risk versus those without, and in studies with greater LDL-C reductions and with thickened baseline cIMT at study entry for both mean and maximum cIMT changes. Taken together, these results are consistent with trends in recent years toward greater use of lipid-lowering therapy and control of LDL-C that may have impacted the variability in the results of cIMT studies.