PO:12:177 | Systemic inflammation and QTc interval prolongation in new-onset polymyalgia rheumatica: the effect of corticosteroid therapy

Anna Colangelo¹, Riccardo Accioli², Viola Salvini², Francesco Tromby¹, Giulia Cruciani¹, Martina Nicchi¹, Biancamaria Pianese¹, Francesca Lalli¹, Anna Cantore², Caterina Antonini¹, Decoroso Verrengia², Andrea Castellucci¹, Giacomo Cafaro¹, Carlo Perricone¹, Roberto Gerli¹, Pietro Enea Lazzerini², Elena Bartoloni¹ | ¹SC Reumatologia. Università di Perugia, Italy; ²Dipartimento di Scienze Mediche, Università di Siena, Italy

Objective. Recent evidence suggests that in systemic inflammatory disorders, particularly rheumatoid arthritis, a prolonged heart rate-corrected QT interval (QTc) is linked to disease activity and a heightened risk of ventricular arrhythmias. This phenomenon appears to be driven by the direct impact of pro-inflammatory cytokines on cardiac electrophysiology. Polymyalgia rheumatica (PMR), due to its acute inflammatory nature and intense cytokine release, offers a unique model for exploring this relationship. Prior studies have reported increased aortic stiffness in newly diagnosed PMR patients, which correlates with systemic inflammation and significantly improves following corticosteroid treatment. Moreover, rare but severe QT-related arrhythmias, such as torsade de pointes, have been described in PMR. To date, no studies have systematically assessed QTc duration and its association with inflammation in this context. This study aimed to investigate QTc interval in patients with newly diagnosed PMR, its correlation with inflammatory and clinical activity markers, and the effect of 4-weeks steroid therapy on these parameters.

Methods. Consecutive patients with new-onset PMR (meeting 2012 ACR/EULAR classification criteria) were prospectively enrolled. At baseline, demographic data, cardiovascular risk factors, and disease activity scores (PMR activity score [PMR-AS], physician and pain visual analogue scales [VAS-ph, VAS-p], upper limb elevation [EUL]) were collected, along with serum electrolytes and inflammatory markers (CRP, ESR). All participants underwent a 12-lead ECG for QTc evaluation at diagnosis. The same assessments were repeated after 4 weeks of oral prednisone (15 mg/day).

Results. A total of 45 patients were included (mean age 74.2±7.1 years, 64% female) (Table 1). At baseline, 22% of patients exhibited a prolonged QTc (>440 ms). After 4 weeks of corticosteroid treatment, this proportion was halved, decreasing to 11% (Figure 1B). Mean QTc duration was significantly reduced (from 429.5±19.4 ms to 419.4±19.0 ms, p<0.001) (Figure 1A), in parallel with significant improvements in inflammatory markers and disease activity scores (Table 2). The QTc reduction showed a significant correlation with decreases in CRP and ESR (Figures 2A–B), as well as with improvements in PMR-AS, VAS-ph, and VAS-p.

Conclusions. Our findings demonstrate for the first time that QTc prolongation occurs in newly diagnosed PMR and tends to rapidly normalize following effective suppression of inflammation. Although transient, such changes may increase the risk of ventricular arrhythmias, reinforcing the need for timely disease control to mitigate cardiovascular complications in PMR.

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