Long-term natural history of transient constrictive pericarditis

Background In recent years, there has been increasing recognition of a potentially-reversible, transient/ subacute form of constrictive pericarditis (CP). To date, studies have been small with lack of long-term longitudinal follow-up. Purpose We aimed to elucidate the causes and natural history of subacute CP. Methods Patients were included if (1) they had a diagnosis of CP, (2) had cardiac magnetic resonance (CMR) within 12 months of symptom onset with evidence of pericardial delayed enhancement/ inflammation (Figure) (3) received anti-inflammatory medications. Results A total of 78 individuals were included, comprising 61 men (78%) with a mean age of 59±14 years. Causes of subacute CP included idiopathic/ viral pericarditis (58%), post-pericardiotomy (29%), autoimmune (6%), radiation therapy (3%) and others (4%). After median follow-up of 4.4 years, 31 (40%) required pericardiectomy. There were no deaths. Patients who underwent pericardiectomy had longer duration of symptoms at presentation [6 (4–9) vs. 3 (2–5) months, P<0.01], were more likely to be on diuretic therapy (87 vs. 45%, P<0.001), had lower ultra-sensitive C-reactive protein [4.4 (2.6–13.1) vs. 11.95 (1.8–61.55) mg/dl, P<0.001] and lower erythrocyte sedimentation rate [5 (2–10) vs. 25 (6–43 mm/hr), P=0.031] compared to those who were managed medically. There were no other significant differences in clinical characteristics or baseline anti-inflammatory therapy. The presence of elevated inflammatory markers (HR: 0.18; 95% CI: 0.06–0.58, P<0.01) was an independent predictor of freedom from pericardiectomy after adjustment for relevant clinical and imaging parameters. Conclusions We present the original observations of the largest cohort of patients with transient CP to date and demonstrate that increased inflammatory markers were independently associated with long-term freedom from pericardiectomy. Our results suggest that a trial of anti-inflammatory therapy in the setting of elevated inflammatory markers may be appropriate prior to referral for surgery given the possible reversibility. Pericardial delayed enhancement Funding Acknowledgement Type of funding source: None