Thrombophilia, Inflammation and Hyperhomocysteinaemia in Patients With Elevated Lipoprotein(a) Levels and Myocardial Infarction

Background Lipoprotein(a) [Lp(a)] is a pro-atherosclerotic, pro-thrombotic and pro-inflammatory molecule. In patients with elevated Lp(a) and atherosclerotic cardiovascular disease, intensive management of co-existing risk factors is recommended. Co-existing thrombotic-, inflammatory- and hyperhomocysteinaemia-related risk in these very high-risk patients is not known. Methods Plasma Lp(a), high-sensitivity C-reactive protein (hs-CRP), homocysteine and thrombophilia testing were performed at clinic follow-up in consecutive patients with myocardial infarction (MI) and very elevated Lp(a) (defined as ≥1.0g/L at time of MI). Positive beta-2 glycoprotein and anticardiolipin antibody was defined as >10U/mL and >40UmL, respectively. Elevated hs-CRP was defined as >3mg/L, and homocysteine as >12μmol/L (females) or >14μmol/L (males). Data was collected from medical records. Results Overall, 30 patients [age 62.7±12.4 years, 22 (73.3%) male] with prior MI and high Lp(a) were included. Lupus anticoagulant was detected in 5 (16.7%) patients, positive beta-2 glycoprotein in 4 (13.3%), positive anticardiolipin antibody in 1 (3.3%) and heterozygous factor V Leiden gene mutation in 3 (10.0%); 11 (36.7%) had at least one thrombophilia finding. Elevated hs-CRP and homocysteine was detected in 8 (26.7%) and 6 (20.0%) patients, respectively; 2 (6.7%) had both elevated hs-CRP and homocysteine. Positive thrombophilia finding plus elevated hs-CRP and/or homocysteine was observed in at least 1 in 5 patients (n=7 [23.3%]). Conclusions Co-existing thrombotic, inflammatory, or hyperhomocysteinaemia-related risk is not infrequent in patients with very elevated Lp(a) and MI. This may have implications for management (e.g., anti-thrombotic/anti-inflammatory medications) or for testing of close family members for elevated Lp(a) and coagulation disorders, but larger studies are required.