To determine the utility of serial cardiac magnetic resonance (CMR) imaging for guidance of therapy management in patients treated with anakinra due to recurrent pericarditis (RP), compared with c-reactive protein (CRP) assay alone.

Recurrent pericarditis (RP) is a specific pathology of the pericardium included within the pericardial syndromes by the guidelines of the European Society of Cardiology (ESC). The latter defines RP as pericarditis occurring after a symptom-free interval of 4-6 weeks from a documented first episode of acute pericarditis; the recurrences rate may range from 15 to 30%, with a significant increment of 50% in patients treated with corticosteroids or not treated with colchicine. The diagnosis of recurrences follows the same criteria utilized for acute pericarditis, and a viral etiology can often be demonstrated.

The pathogenesis of RP is still debated, but they are self-sustained by an autoinflammatory/ autoimmune amplified response following an exogenous or endogenous trigger. In this context, the cytokine interleukin 1 (IL-1) has been implicated as a key mediator of RP. Anakinra, an IL-1 antagonist, is of particular interest because it limits the self-sustained pathway of RP and may reduce the recurrences. The current 2015 ESC guidelines for the diagnosis and management of pericardial diseases recommend anakinra in cases of proven infection-negative, corticosteroid-dependent RP not responsive to colchicine, but it remains debated the duration of the therapy and when to start its tapering. In this context, cardiac magnetic resonance (CMR) imaging has recently emerged as an interesting imaging biomarker capable of detecting pericardial inflammation, proving pericardial edema and late gadolinium enhancement (LGE), and distinguishing three defined pericardial inflammation phases: acute (edema and LGE), subacute (only LGE) and burned-out (no edema nor LGE).

To overcome the 2015 ESC guidelines limitations, the investigators sought to determine the utility of serial CMR imaging for guidance of therapy management in patients treated with anakinra due to RP, compared with the c-reactive protein (CRP) assay alone, as currently recommended.

Inclusion Criteria:

• Adult patients treated with anakinra 100 mg/die if ≥ 18 years old, and
• Pediatric patients treated with anakinra 2 mg/kg/die if < 18 years old
• Pediatric and adult patients treated with anakinra due to corticosteroid-dependent or not responsive to colchicine or non-steroidal anti-inflammatory drugs (NSAIDs) recurrent pericarditis

Exclusion Criteria:

• Ongoing infection (proved within serology)
• Refuse to participate in the trial