Abstract 16758: Eligibility for Lipid Lowering Therapy, Coronary Artery Calcification, and CHD Events - National Implications for the Appropriate Use of Preventive Pharmacotherapy: Multi-Ethnic Study of Atherosclerosis (MESA)

Abstract

Background: In last 2 decades, the threshold of individuals meeting eligibility criteria (EC) for life long lipid lowering medication (LLM) has progressively decreased. As per CDC, 1 in 4 people 45 and older are using statins. We sought to determine whether coronary artery calcium (CAC) testing may identify subgroups among those meeting/not meeting EC for LLM who are expected to derive the most, and the least, benefit from the prescribed pharmacotherapy.

Methods: MESA is a longitudinal, population-based study of 6,814 men and women aged 45-84 without clinical cardiovascular disease at enrollment. A total of 1100 (16%) participants on LLM at baseline were excluded from analysis. We also excluded 88 individuals (1.3%) with absent LDL levels, as well as 1 participant with no information on CHD event.

Results: The final study population consisted of 5,603 individuals (62±10 years, 47% males) followed for a median 5.8 years. Based on the NCEP guidelines, 1,368 (24%) met EC for LLM. Of those, 468 (34%) with CAC=0 had 2.7 CHD events/1000 person-years. There were 469 (34%) with CAC>100 and they had 28.9 CHD events/1000 person-years, with 2/3 (64%) of events occurring in this group. The number needed to screen(NNS) to identify 1 individual with CAC=0 was 3 among those meeting EC for LLM. On the other hand 17% of individuals not meeting EC for LLM had CAC>100 with CHD rate of 17.2/1000 person-years; 62% of all events occurred in this group and NNS to identify these high risk individuals was 6.

Conclusion: Within MESA, 1/3 of patients meeting EC for LLM had CAC=0 & these individuals experienced a very low event rate. Conversely those with high CAC and not meeting EC for LLM had very high event rates. Our study findings suggest that CAC testing helps in identification of heterogeneity of risk among those considered eligible and not eligible for LLM according to the current guidelines.