Lp(a) above 73 mg/dL predicts future heart attacks in patients with stable coronary disease, the LIPID trial substudy of 7863 patients (Arterioscler Thromb Vasc Biol 2013)

Objective: Association between lipoprotein(a) (Lp(a)) level and a first-ever coronary (CHD) event is recognized. Less is evident in patients with overt CHD and stable symptoms in whom we investigated associations between Lp(a) and future events.

Approach And Results: Relationships between Lp(a) concentration and CHD and cardiovascular disease outcomes during 6 years' median follow-up were evaluated in the Long-Term Intervention with Pravastatin in Ischaemic Disease (LIPID) study. Lp(a) concentrations were measured in plasma from 7863 patients who had sustained a previous coronary event and been randomized to pravastatin or placebo. Lp(a) levels were categorized by lowest half, third quartile, 75th to 90th percentile, and highest decile. The prognostic value of Lp(a) on outcomes was assessed by fitting a Cox proportional-hazards model after adjustment for other risk factors and baseline cardiovascular disorders. The prognostic value of a change in Lp(a) at year 1 categorized by quartiles was assessed using Cox regression in a landmark model incorporating the above factors and baseline levels. Baseline Lp(a) concentration was associated with total CHD events (P<0.001), total cardiovascular disease events (P=0.002), and coronary events (P=0.03). Greatest risk occurred at >73 mg/dL, upper decile. For events after year 1, an increase in Lp(a) at 1 year was associated with adverse outcomes for total CHD events and total cardiovascular disease events (P=0.002 each).

Conclusions: In the LIPID study, baseline Lp(a) was associated with future cardiovascular disease and CHD events. Increased Lp(a) concentrations after 1 year were also associated with future events, supporting measurement of Lp(a) for risk assessment of patients with known CHD.