Prevalence of Troponin Elevation in Pericarditis
Troponin elevation occurs in approximately 32-49% of patients with acute pericarditis, with the frequency varying based on assay sensitivity and whether myocardial involvement (myopericarditis) is present. 1
Documented Prevalence Rates
The prevalence of troponin elevation in pericarditis varies across studies but consistently demonstrates that myocardial involvement is common:
- 49% of patients had detectable cardiac troponin I in a prospective study of 69 consecutive patients with idiopathic acute pericarditis 1
- 22% exceeded the myocardial infarction threshold (>1.5 ng/mL) in the same cohort, representing clinically significant myopericarditis 1
- In a large U.S. urban hospital study, troponin I was measured in 70% of pericarditis patients, with elevated levels documented in a substantial proportion 2
- Approximately 15% of acute pericarditis cases have significant myocardial involvement as assessed by biological markers, representing the myopericarditis subset 3
Clinical Correlates of Troponin Elevation
When troponin is elevated in pericarditis, specific clinical patterns emerge:
- ST-segment elevation is strongly associated with troponin positivity: 93% of patients with troponin I >1.5 ng/mL had ST-segment elevation versus only 57% without elevation 1
- Younger patients are more likely to have troponin elevation (mean age 37 years vs 52 years for those without elevation) 1
- Recent infection is associated with higher troponin levels: 66% of patients with troponin I >1.5 ng/mL had recent infection versus 31% without 1
- Infectious etiologies predominate in myopericarditis (86% of cases) compared to idiopathic pericarditis 3
Important Prognostic Implications
Contrary to acute coronary syndromes, elevated troponin in pericarditis does not predict worse short-term outcomes and may actually indicate a more favorable prognosis:
- Elevated troponin I was associated with lower recurrence rates (4% vs 17%) and reduced composite adverse outcomes (13% vs 36%) in a large cohort study 2
- Troponin elevation in myopericarditis does not carry adverse prognosis when left ventricular function is preserved, unlike in acute coronary syndromes 4
- Despite markedly elevated cardiac enzymes (median troponin I 21.4 ng/mL, range 5.0-134.4 ng/mL), clinical evolution appears benign without myocardial dysfunction in pediatric myopericarditis 4
- Three-year follow-up showed no difference in global complications between myopericarditis and pericarditis, though one study noted higher cardiac mortality in myopericarditis 3
Critical Diagnostic Considerations
The absence of troponin elevation does not exclude pericarditis, as the diagnosis requires only 2 of 4 criteria (pericarditic chest pain, friction rub, characteristic ECG changes, or pericardial effusion) according to European Society of Cardiology guidelines 5:
- Troponin elevation defines myopericarditis (pericarditis plus myocardial involvement) but is not required for pericarditis diagnosis 5
- Repeat troponin measurements at 3-6 hour intervals may capture delayed rises in patients with initially normal values 5
- Inflammatory markers (CRP, ESR) may be more consistently elevated than troponin and support the diagnosis even without troponin elevation 5
Common Pitfalls to Avoid
- Do not assume acute coronary syndrome based solely on elevated troponin in the setting of pericarditic chest pain and diffuse ST-elevation - coronary angiography in troponin-positive pericarditis patients consistently shows normal coronary arteries 1, 4
- Do not interpret elevated troponin as indicating poor prognosis in pericarditis as you would in acute coronary syndromes - the prognostic implications are fundamentally different 2, 4
- Do not dismiss pericarditis diagnosis due to normal troponin - approximately 50% of cases have no detectable troponin elevation 1
- Recognize that ST-segment elevation has only 43% specificity for detecting myocardial injury in pericarditis, despite 93% sensitivity 1