PO:12:184 | Atrioventricular conduction in chronic inflammatory arthritis: enhanced assessment by new electrocardiographic parameters

Riccardo Accioli¹, Viola Salvini¹, Anna Cantore¹, Fabio Salvadori¹, Enrico Selvi², Virgina Berlengiero², Maurizio Acampa³, Alessandra Cartocci¹, Kateryna Miedviedieva¹, Decoroso Verrengia¹, Sciaila Bernardini¹, Michele Voglino¹, Giovanni Donati¹, Silvia Petri¹, Severino Gallo¹, Stefania Bisogno¹, Pier Leopoldo Capecchi¹, Pietro Enea Lazzerini¹ | ¹Division of Internal Medicine, Electroimmunology Unit, University Hospital of Siena, Italy; ²Division of Rheumatology, University Hospital of Siena, Italy; ³Stroke Unit, University Hospital of Siena, Italy

Background. and aim of the study. It is increasingly accepted and supported by recent population studies that patients with spondylarthritis (SpA) have an increased risk of severe atrioventricular (AV)-block/pacemaker implantation, possibly due to structural and immunological similarities between enthesis and aortic root (“cardiac enthesis”). However, available studies analyzing AV-conduction in SpA, and more generally in chronic inflammatory arthritis (CIA), found in many cases no differences to healthy controls, suggesting that traditional electrocardiographic (ECG) parameters are not suitable for early detection of high-risk patients. Since PR-interval is deeply influenced by heart rate (HR) and atrial depolarization, the aim of this study was to perform an enhanced AV-conduction assessment in CIA patients by adding HR-correction and PR-segment measurements to standard ECG parameters.

Methods. In a cross-sectional study, 97 consecutive patients [60% females, median 52 years] with CIA [60 SpA, 37 rheumatoid arthritis] underwent 12-lead ECG to measure PR-interval, PR-segment and HR. The Rautaharju-Soliman formula was applied to calculate HR-corrected PR-interval (PRc-interval) and PR-segment (PRc-segment). A group of 54 healthy subjects comparable for sex and age [61% females, median 51 years] was used as control.

Results. In patients with CIA, PR-segment and even more PRc-segment were significantly longer when compared to controls (PR-segment: 50.0 [40.0-70.0] vs. 45.5 [36.7-58.0] ms; p=0.033; PRc-segment 52.6 [42.1-69.6] vs. 45.0 [34.0-55.8] ms; p<0.001). Stratification analyses revealed that such differences were observed in SpA patients only (PR-segment: 53.0 [40.0-70.0] vs. 45.5 [36.7-58.0] ms; p=0.012; PRc-segment: 54.3 [41.0-63.4] vs. 45.0 [34.0-55.8] ms, p<0.001), specifically in those with enthesitic involvement (PR-segment: 57.0 [47.0-67.7] vs. 45.5 [36.7-58.0] ms, p<0.001; PRc-segment: 60.8 [46.0-76.5] vs. 45.0 [34.0-55.8] ms, p<0.001) (Figure). Moreover, in this latter subset of patients, the prevalence of PR/PRc-segment prolongation (>90 ms) was significantly higher than in controls (11% vs. 0%, p=0.021). Conversely, no difference in PR/PRc-intervals was observed throughout the groups.

Conclusions. Enhanced ECG assessment reveals delayed AV conduction as a specific feature of patients with enthesitic SpA, supporting the hypothesis that in these subjects musculoskeletal and cardiac involvement are strictly interconnected. Our findings underscore the potential of incorporating PR/PRc-segments into routine ECG evaluation as simple and sensitive tools for the early detection of SpA patients at higher risk for severe AV-block, in whom a tighter control of disease activity may be requested and administration of drugs negatively affecting AV-conduction contraindicated.