Aims: Negative emotions have an adverse effect on cardiac prognosis. We investigated whether social inhibition (inhibited self-expression in social interaction) modulates the effect of negative emotions on clinical outcome following percutaneous coronary intervention (PCI).
Methods and results: Eight hundred and seventy-five consecutive patients from the RESEARCH registry (Erasmus Medical Centre, Rotterdam) completed depression, anxiety, negativity (negative emotions in general), and social inhibition scales 6 months following PCI. The endpoint was major adverse cardiac event (MACE-death, myocardial infarction, coronary artery bypass graft (CABG), or PCI) at 9 months following assessment. There were 100 MACE; patients who were high in both negativity and inhibition were at increased risk of MACE (38/254=15%) when compared with high negativity/low inhibition patients (13/136=10%; P=0.018). Depression (P=0.23) or anxiety (P=0.63) did not explain away this moderating effect of inhibition. High negativity/high inhibition (HR=1.92, 95%CI 1.22-3.01, P=0.005) and previous CABG (HR=1.90, 95%CI 1.04-3.47, P=0.038) were independent predictors of MACE. Patients with high negativity but low inhibition were not at increased risk (P=0.76). High negativity/high inhibition also independently predicted death/MI (n=20) as a more specific endpoint (HR=5.85, P=0.001).
Conclusion: The interaction effect of social inhibition and negative emotions, rather than negative emotions per se, predicted poor clinical outcome following PCI. Social inhibition should not be overlooked as a modulating factor.