Antiphospholipid Antibodies as Potential Prognostic Indicators of Recurrent Myocardial Infarction

Inflammation and autoimmunity are pivotal contributors to myocardial infarction (MI) risk, with emerging evidence linking autoimmune disorders to MI pathogenesis. To further elucidate this relationship, we conducted a prospective cohort study investigating the prognostic impact of antiphospholipid antibodies (aPLs), antinuclear antibodies (ANA), and anti-extractable nuclear antigen antibodies (anti-ENA) on recurrent MI.

In this single-center study, 458 patients with acute MI (AMI) were enrolled and prospectively followed for 3 years. Autoantibody profiles, including aPLs (anti-cardiolipin antibodies [ACA], anti-β2-glycoprotein I [anti-β2GPI], lupus anticoagulant [LA]), ANA, and anti-ENA, were assessed and compared between recurrent AMI and non-recurrent AMI groups. The primary endpoints were all-cause mortality and recurrent AMI at 3-, 12-, and 36-months post-enrollment.

Compared to non-recurrent AMI patients, those with recurrent AMI exhibited significantly higher positivity rates for ACA IgG (p = 0.034), ACA IgM (p = 0.039), anti-β2GPI IgG (p = 0.025), anti-β2GPI IgM (p = 0.035), and PLs + ANA/anti-ENA (p = 0.001). Multivariate analysis identified aPLs + ANA/anti-ENA (HR: 2.84, 95% CI: 1.45 - 6.12, p = 0.033), hypertension (HR: 2.83, 95% CI: 1.23 - 5.65, p = 0.027), and hyperlipidemia (HR: 2.67, 95% CI: 1.34 - 5.37, p = 0.039) as independent risk factors of AMI recurrence. The cumulative recurrence rates at 3, 12, and 36 months were 0.7%, 2.6%, and 6.8%, respectively, while the cumulative mortality rates were 6.5%, 12.0%, and 15.9%.

Concurrent positivity for aPLs and ANA/anti-ENA serves as an independent risk factor for recurrent AMI and is associated with increased mortality in AMI patients. These findings underscore the prognostic significance of autoimmune dysregulation in AMI outcomes.