Effects of immune system status on long-term results of cardiac resynchronization therapy

Aim. Cardiac resynchronization therapy (CRT) is an effective therapy for patients with reduced systolic function and enlarged QRS. Recently, some Authors have demonstrated that the presence of positive antinuclear antibodies (ANAs) may play a role in the development of heart failure in a population of patients implanted with PM. Methods. We investigated the effect of positive ANAs in 90 patients (mean age 71±8 years) implanted with a CRT device in our Centre between May 2010 and June 2013. To assess for immunologic contribution to CRT outcome, patients were divided into positive and negative ANAs (ANA +, ANA-), considering as positive patients with an ANAs dilution > 1:80. The primary endpoint was constituted by a combined endpoint of death or first hospitalization for heart failure; secondary endpoints were constituted by: 1) incidence of first hospitalization for heart failure; and 2) total cause mortality. Results. After a mean follow-up of 1200 days, primary endpoint occurred in 11 patients (30%) of ANA+ group and in 8 patients (15.1%) of ANA-group. The significant difference is due to difference in heart failure events (27% vs. 11.3%, P<0.05), whilst difference in total mortality did not reach statistical significance (10.8% vs. 3.8%). Conclusion. Immune status seems to play a role in patients with congestive heart failure. If this immunological alteration is a determinant or a consequence of heart failure remains unclear.