Abstract 4847: Anti-Endothelial Cell Autoantibodies are Independent Predictive Markers of Death or Transplantation in Myocarditis
Objective: In autoimmune disease autoantibodies may provide non-invasive negative prognostic markers. We aimed at assessing the potential predictive role of serum autoantibodies against various cardiac autoantigens in myocarditis.
Methods. We studied 189 consecutive patients with biopsy-proven myocarditis (118 male, aged 36±18 years, left ventricular ejection fraction 43±15, all with angiographically normal coronary arteries; follow-up 47±40 months). Serum at diagnosis was assessed for anti-heart (AHA), anti-intercalated disk (AIDA) and cardiac endothelial cells (AECA) autoantibodies by indirect immunofluorescence on cryostat sections of normal O blood group human myocardium and skeletal muscle, blindly from clinical diagnosis. Control groups included sera from patients with non-inflammatory cardiac disease (n=160, 80 male, aged 37±17), with ischemic heart failure (n=141, 131 male, age 51±12) and normal blood donors (n=270, 123 male, aged 35±11). Antibody status was related to clinical and diagnostic features at presentation by Cox univariate and multivariate analysis.
Results. The frequency of AHA, AIDA and AECA was higher in myocarditis than in non-inflammatory cardiac disease (54%;16%,12% vs 5%; 4%;1% respectively, p=0.0001), ischemic heart failure (54%;16%,12% vs 1%;2%;1% respectively, p=0.0001) or normal subjects (54%;16%,12% vs 5%;0%;2.5% respectively, p=0.0001). Univariate predictors of death/transplantation were: young age, longer symptom duration, giant cell myocarditis, NYHA II-IV, presentation with left ventricular (LV) dysfunction, clinical signs/symptoms of heart failure, multiple echocardio-graphic and hemodynamic indexes of LV and right ventricular dysfunction and AECA. Independent negative predictors by Cox regression were higher mean right atrial pressure (RR 1.3, p=0.02), lower LV ejection fraction (RR 1.03, p=0.038) and AECA (RR 5.8, p=0.01). AECA was the only independent predictor for death/transplantation after correction for hemodynamic variables (p=0.02, RR 6.5, 95% CI 1.7–25, p=0.007).
Conclusion. The finding of AECA provides an independent non-invasive predictor of death or transplantation in biopsy-proven myocarditis.