Left atrium strain in rheumatoid arthritis patients - a sub-study of the prospective Porto-RA cohort

Rheumatoid arthritis (RA) increases heart failure (HF) risk. Left atrial strain (LAs) may allow early detection of cardiac disease but has been seldom studied in RA. This study evaluated associations between LAs, clinical, laboratory, and echocardiographic parameters, and outcomes in RA patients without known cardiac disease.

In this prospective observational study, RA patients underwent LAs analysis and were stratified into two groups by the median left atrium reservoir strain (LARs). The primary endpoint was a composite of myocardial infarction, stroke, atrial fibrillation, HF hospitalization, or cardiovascular death; secondary endpoints were its individual components and all-cause mortality. Median follow-up was 6.2 years.

Of 364 patients enrolled, 260 underwent LAs analysis and comprised the final cohort (median LARs 37.4%). LARs ≤ median (n = 131, 50.4%) was associated with older age, shorter 6-min walk distance, higher troponin-T and NT-proBNP, higher E/e', and lower left-ventricular global longitudinal strain. Primary endpoint incidence was numerically higher in patients with LARs ≤ median, but did not differ significantly between groups (15.5 vs 10.3 events/1000 patient-years; HR 0.64 [0.26-1.57]; p = 0.33). A trend toward higher all-cause mortality was observed in the lower LARs group (12.5 vs 3.75 events/1000 patient-years; HR 0.29 [0.078-1.04]; p = 0.06), with no significant differences in other secondary endpoints.

In RA patients, LARs ≤ 37.4% was associated with shorter walked distances, more pronounced cardiac structural, functional and biomarker alterations. While not significantly associated with adverse cardiovascular outcomes, the findings underscore the need for larger prospective studies to further explore this potential relationship.