Risk of ischaemic and non-ischaemic heart failure in patients with systemic sclerosis: a population-based study

To investigate the risk of incident ischaemic and non-ischaemic heart failure (HF) in a population-based cohort of all patients with SSc in Sweden compared with the general population.

We identified patients with incident SSc 2004-19 using nationwide Swedish registers and age- and sex-matched comparators from the general population (1:10). We started follow-up from the date of SSc diagnosis, the same date was assigned to the respective comparators. Our primary outcome was incident HF [International Statistical Classification of Diseases and Related Health Problems (ICD)-10: I50] as main diagnosis stratified into ischaemic and non-ischaemic HF depending on whether a visit listing ischaemic heart disease (ICD-10: I20-I25) was recorded before HF diagnosis or not. We used flexible parametric models to estimate hazard ratios (HRs) over time since SSc diagnosis.

The study cohort comprised 1598 patients with SSc and 16 616 comparators. During follow-up, 101 (6%) patients with SSc developed HF compared with 378 (2%) of the comparators. Ischaemic HF represented 35% and non-ischaemic HF represented 65% of all HF cases in both groups. The relative risk of HF overall, ischaemic HF and non-ischaemic HF was highest soon after SSc diagnosis. HR at the end of the first year of follow-up was 5.7 (95% CI 4.2-7.9) for HF overall, 6.7 (95% CI 3.5-13.0) for ischaemic HF and 5.8 (95% CI 4.0-8.3) for non-ischaemic HF.

SSc is associated with both ischaemic and non-ischaemic HF, emphasizing the role of other mechanisms than ischaemia, such as myocyte dysfunction, myocardial fibrosis and microvascular impairment, in the development of HF in SSc.