Falling cholesterol trend at acute coronary syndrome presentation is strongly related to statin use for secondary prevention

Background Lifestyle changes are believed responsible for temporal trends of reduced population total cholesterol (TC), but it is uncertain whether this applies to patients with known coronary heart disease (CHD) often prescribed lipid lowering therapy (LLT). We studied temporal TC trends at presentation with acute coronary syndrome (ACS) to determine the contribution of LLT given for secondary prevention. Methods TC and LLT were obtained in 5592 patients in annual surveys of ACS admissions in Australia between 1999 and 2013, and annual mean trends analysed by linear and segmented regression. Results TC declined from 5.13±1.1 to 4.53±1.2mmol/L (p<0.001) and LLT (96% statin) use at presentation increased from 37.4% to 47.5% (p=0.005). TC decline was greater in those on LLT vs. those not on therapy, with LLT contributing to 57% of the TC decline. The decline in TC and increase in LLT use was non-linear and much steeper in those with, than without CHD history, and LLT contributed substantially more to the TC decline (79%, p<0.001 vs. 27%, p=0.06 respectively). The rapid decline in TC and increase in LLT, plateauing after 2005 in those with CHD history differed markedly from trends in recent population studies, while TC trend for those without CHD history was slower, linear and consistent with population trends. Conclusions Declining TC level at presentation for ACS was strongly associated with increasing LLT use in those with a history of CHD, indicating that increasing uptake of LLT for secondary prevention has impacted TC changes in the new millennium.