Differential associations seen between Lp(a) levels and stroke, depending on AF-status
Associations of Lipoprotein(a) Levels With Incident Atrial Fibrillation and Ischemic Stroke: The ARIC (Atherosclerosis Risk in Communities) StudyLiterature - Aronis KN, Zhao D, Hoogeveer RC et al., - J Am Heart Assoc. 2017;6:e007372. Originally published December 15, 2017
- In participants free of AF at baseline, the overall AF incidence rate was 8.8 events per 1000 person-years (PY). Blacks showed a lower rate than whites (6.1 vs. 9.5 per 1000 PY) and women a lower rate than men (7.3 vs. 10.8 per 1000 PY).
- No association was observed between Lp(a) levels and AF incidence. In a fully adjusted model, the HR for AF for Lp(a) ≥50 mg/dL compared with <10 mg/dL was 0.98 (95%CI: 0.82-1.17).
- No effect modification of the relation between Lp(a) and AF risk was seen by race or sex.
- The incidence of stroke was four times higher in participants with AF compared to those without (10.8 vs. 2.9 events per 1000 PY).
- In those without a history of AF, those with Lp(a) ≥50 mg/dL had 42% higher risk of stroke compared with those with <10 mg/dL (HR: 1.42, 95%CI: 1.07-1.90), even after adjustment for various CVD risk factors, other lipid markers and the CHA2DS2-VASc score. Lower levels of Lp(a) did not show a significantly higher risk of stroke in these participants.
- No statistically significant relative increase in ischemic stroke risk was observed with high Lp(a) in participants with a history of prevalent AF (HR: 1.06, 95%CI: 0.70-1.61).
- Race or sex did not modify the effect of Lp(a) on stroke risk.
In this large community-based cohort, no association was observed between elevated Lp(a) levels and AF risk, in black nor whites, and in men nor women. Participants in the highest Lp(a) category (≥50 mg/dL) without AF did show a 40% higher risk of ischemic stroke, as compared with the lowest Lp(a) category (<10 mg/dL). This elevated risk is, however about 10-fold lower than the risk of stroke conveyed by AF itself.