Case Report: Pleuro-myopericarditis in a frail older patient in an acute geriatric unit: the evidence gap in guideline-based therapy.

Introduction: Current ESC guidelines recommend NSAIDs and colchicine as first-line therapy for acute pericarditis. However, supporting evidence is largely derived from younger and clinically stable populations, with frail older patients underrepresented, highlighting a gap between guideline recommendations and real-world applicability. Case presentation: We report the case of an 87-year-old frail man with multiple comorbidities who developed pleuro-myopericarditis with moderate-to-severe pericardial effusion. First-line therapy with ibuprofen and colchicine was initiated but discontinued early due to severe gastrointestinal intolerance and worsening renal function. Pericardiocentesis was considered; however, according to current guideline recommendations, it is primarily indicated in the presence of cardiac tamponade or for selected diagnostic purposes. In this case, the absence of hemodynamic compromise and the high procedural risk related to frailty led to conservative management. A corticosteroid-based regimen was therefore initiated, resulting in clinical improvement and gradual reduction of pericardial effusion. Discussion: This case highlights the limitations of guideline-directed therapy in frail elderly patients, in whom comorbidities, renal dysfunction, and polypharmacy frequently limit the tolerability of NSAIDs and colchicine. It underscores the gap between guideline recommendations and real-world clinical applicability, emphasizing the need for individualized therapeutic strategies. Conclusion: Management of acute pericarditis in frail older adults should be individualized, integrating guideline recommendations with geriatric assessment and clinical judgment. Optimal treatment may differ from guideline-based strategies when patient-specific risks outweigh expected benefits. This case underscores the urgent need for evidence specifically addressing this growing and vulnerable population.