Elevated Lp(a) associated with higher CAC score in individuals with family history of ASCVD
Elevated Lipoprotein(a) levels are associated with coronary artery calcium scores in asymptomatic individuals with a family history of premature atherosclerotic cardiovascular disease
The association between Lp(a) levels and coronary artery calcium (CAC) score has been demonstrated predominantly in individuals at high risk for atherosclerotic cardiovascular disease (ASCVD) as determined by multiple CV risk factors [1,2], whether the association in individuals with low ASCVD risk is questionable [3-5].
In this study, the association between elevated Lp(a) levels (≥50 mg/dL) and CAC score was assessed in a population of asymptomatic individuals with a family history of premature ASCVD. ASCVD was defined as a history of a myocardial infarction, stable angina, ischemic stroke or peripheral artery disease. Premature ASCVD was defined as ASCVD before the age of 51 in males and 56 in females.
Individuals who visited the outpatient clinic for families with premature ASCVD between July 2009 and April 2016 were included consisting of individuals with premature ASCVD and their first-degree family members. CAC score was assessed by coronary CT scan only in Individuals without a family history of ASCVD. Based on the absolute Agatston CAC score participants were divided in two groups: < 100 (no or minimal risk for ASCVD) and ≥ 100 (mild to severe risk for ASCVD).
1369 patients were included, of which 432 had premature ASCVD and 937 were healthy family members without ASCVD.
- 24% of individuals with elevated Lp(a) levels had an absolute CAC score ≥100 compared to 15% of individuals with normal Lp(a) levels (OR 1.79, 95%CI:1.13-2.83, after adjustment for CV risk factors OR 2.33, 95%CI:1.36-4.00).
- In the group of elevated Lp(a) levels, 40% had a gender and age-corrected CAC score ≥80th percentile compared to 28% in the normal Lp(a) group (OR 1.69, 95%CI:1.14-2.50, after adjustment for CV risk factors: OR 1.85, 95% CI:1.21-2.82).
- Patients with premature ASCVD had a higher prevalence of CV events (39%) when Lp(a) was elevated compared to patients with normal Lp(a) levels (30%) (OR 1.49, 95%CI: 1.11-2.01, after adjustment for CV risk factors: OR 1.78, 95%CI: 1.25-2.54).
- In patients with premature ASCVD, elevated Lp(a) was associated with multivessel disease (≥2 affected coronaries with substantial plaques) (OR 1.88, 95%CI: 1.08-3.28), also after adjustment for CV risk factors (OR: 1.89, 95%CI:1.04-3.45).
In asymptomatic individuals with a family history of ASCVD, elevated Lp(a) levels were associated with higher CAC score, both absolute and, age and gender-corrected CAC score percentiles, independent of CV risk factors. These data support the current EAS recommendation to measure Lp(a) in individuals with family history of premature ASCVD to identify subclinical atherosclerosis in healthy family members. For primary prevention, statin therapy could be started in these individuals with elevated Lp(a).