Prognosis for Pericarditis With and Without Myocardial Involvement

Amy Leigh Miller, M.D., Ph.D.; Joseph Loscalzo, M.D., Ph.D.


AccessMedicine from McGraw-Hill 

Acute inflammatory myopericardial syndromes span a range from pure pericarditis to pure myocarditis, with the terms myopericarditis and perimyocarditis used to reflect the dominant component of syndromes with both pericardial and myocardial involvement. The relationship between the degree of myocardial and pericardial involvement on patient prognosis is not well characterized in the literature. In a prospective, multicenter trial, Imazio and colleagues (2013) enrolled patients presenting with acute inflammatory pericardial syndromes for longitudinal follow-up. Patients were diagnosed with acute pericarditis (two or more the following: pericarditic chest pain, diffuse ST-segment elevations or PR depressions, new/worsening pericardial effusion, pericardial friction rub), myopericarditis [acute pericarditis with elevated cardiac biomarkers, but without new impairment in left ventricular (LV) systolic function], or perimyocarditis (acute pericarditis, elevated cardiac biomarkers, and newly depressed LV systolic function); patients with myocarditis without evidence of pericardial involvement were excluded from the study. Echocardiogram was performed at the time of enrollment; cardiac magnetic resonance (CMR) imaging was performed within 2 weeks of enrollment in patients suspected of having myocardial involvement on the basis of atypical electrocardiographic changes, arrhythmias, elevated cardiac biomarkers, or reduced systolic function on echocardiogram. Patients were treated with a nonsteroidal anti-inflammatory drug (NSAID); dose was reduced in patients with myocardial involvement. Colchicine was used at the discretion of the treating provider. Corticosteroids were used in patients intolerant to NSAIDs. Longitudinal follow-up with clinical evaluation, routine labs, and an electrocardiogram was performed at 1, 6, and 12 months post-presentation.

A total of 486 patients were enrolled (initial diagnosis of acute pericarditis in 346 patients, 114 with myopericarditis, and 26 with perimyocarditis). Of the 346 patients diagnosed with acute pericarditis, 115 underwent CMR given findings suggestive of possible myocardial involvement; radiographic evidence of myocarditis was present in 104 of these patients. Etiology was similar across groups (idiopathic in ~85% of patients). Male sex and younger age were associated with a higher incidence of myocardial involvement, which was associated with a greater incidence of arrhythmias and clinical heart failure. Pericardial friction rub and pericardial effusion were associated with a lower incidence of myocardial involvement. Biomarkers were elevated in 140 patients, without a significant difference between patients with myopericarditis and those with perimyocarditis. Over a median follow-up of 36 months, there were no deaths or cases of heart failure. There was one case of constrictive pericarditis occurring in a patient who had presented with myopericarditis. Residual impairment of LV systolic function persisted in 8% of patients with myopericarditis and 15% of cases of perimyocarditis. Symptomatic recurrences occurred in 31.78% of patients with pericarditis and 10.5–11.5% of patients with myocardial involvement. In 95% of relapsed cases, involvement was restricted to the pericardium at the time of recurrence. Level of troponin elevation at initial presentation was not associated with the risk of complications in follow-up.

This study suggests that pericarditis is associated with a good prognostic outcome, irrespective of the degree of myocardial involvement, over an intermediate-term (3-year) follow-up. The longer-term implications of myocardial involvement will require further exploration.