Patients with chronic inflammatory diseases (CIDs) are at increased risk of cardiovascular events. However, the prognostic impact of CID after an acute coronary event has been poorly studied.

To examine the effect of history of CID on long-term outcome in patients with ST-segment elevation myocardial infarction (STEMI).

We analysed data from SCALIM, a regional registry that prospectively enrolled patients with STEMI between June 2011 and May 2019. The presence of CID (including inflammatory bowel diseases, rheumatic conditions, inflammatory skin diseases, multiple sclerosis, vasculitis and autoimmune diseases) was identified. The primary outcome was all-cause death. Secondary outcomes were cardiovascular death, myocardial infarction, ischaemic stroke, peripheral vascular events and rehospitalization for cardiovascular conditions.

Data from 1941 patients with STEMI (mean age 64.8±14.1 years, 75.1% men) were analyzed. The prevalence of any CID was 4.6% (n=89). After a mean follow-up of 3.4±2.6 years, the overall death rate was 16.2%, with similar 5-year survival between patients with and without CID (74.2% vs. 81.9%, respectively; P=0.121), with no significant mortality excess (hazard ratio: 1.15, 95% confidence interval: 0.73−1.82; P=0.55). However, among CID patients, 35 (39.3%) were on corticosteroid therapy and showed decreased 5-year survival (52.8% vs. 89.5% without corticosteroids; P=0.001). We found no increased rate of secondary endpoints, except for peripheral vascular events (5-year survival free of peripheral events: 93.3% vs. 98.6% in those without CID; P=0.005).

Approximately 1 in 20 patients with STEMI has CID. We found no effect of CID on long-term survival. However, patients on corticosteroid therapy appeared to have higher rates of death during follow-up. Whether this finding is related to the use of corticosteroids or to the more progressive nature of their condition warrants further investigation.