Clinical features and anti-heart autoantibody (AHA) titre in idiopathic recurrent acute pericarditis
| High titre (≥1/80) AHA (n=7) | Low titre (<1/80) or negative AHA (n=33) | p Value | |
| Age at onset (years) | 44±21 | 36±14 | NS |
| Male/female | 4/3 | 21/12 | NS |
| Symptoms (years) | 12±15 | 4±3 | 0.006 |
| Follow-up (years) | 14±16 | 7±6 | 0.06 |
| Recurrences | 12±16 | 5±3 | 0.02 |
| Recurrences/year | 2±1 | 2±1 | NS |
| Hospital admissions | 3±2 | 3±2 | NS |
| End-diastolic septal thickness (mm) | 10±1 | 9±1 | NS |
| End-diastolic posterior wall thickness (mm) | 10±2 | 8±1 | 0.02 |
| Left ventricular ejection fraction (%) | 61±4 | 62±4 | NS |
| Immunosuppressant agents and/or pericardiectomy(%) | 5 (71) | 15 (45) | NS |
| Drug combination at last follow-up (%) | 4 (57) | 8 (24) | 0.08 |