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Three Part Question

In [a patient with chest pain suggestive of acute pericarditis] do [the cardiac troponins] differentiate between [myocardial infarction and myopericardial inflammation]?

Search Strategy

Medline 1950-2014
("Troponin"[Mesh]) AND "Pericarditis"[Mesh]

Search Outcome

41 citations were identified of which five were relevant to the three part question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Brown et al 2012 USA	212 patients presenting to paediatric emergency department with chest pain, with no previous cardiac history, between January 2003 and June 2010. All patients underwent TnI testing.	Prospective, observational cohort study	TnI levels	Raised in 37 patients, of which 18 (48%) were given a primary cardiac diagnosis at discharge and myocarditis/pericarditis were the next most common diagnoses with raised TnI (27%). Acute MI remains uncommon among the paediatric population and MRI is the best investigation for diagnosis of myopericarditis.	Varying reference ranges for troponin assays. Limited data on paediatric reference ranges for troponins. Variations in practice in Emergency Departments for acquiring troponin levels.
Brown et al 2012 USA	212 patients presenting to paediatric emergency department with chest pain, with no previous cardiac history, between January 2003 and June 2010. All patients underwent TnI testing.	Prospective, observational cohort study	TnI levels	Raised in 37 patients, of which 18 (48%) were given a primary cardiac diagnosis at discharge and myocarditis/pericarditis were the next most common diagnoses with raised TnI (27%). Acute MI remains uncommon among the paediatric population and MRI is the best investigation for diagnosis of myopericarditis.	Varying reference ranges for troponin assays. Limited data on paediatric reference ranges for troponins. Variations in practice in Emergency Departments for acquiring troponin levels.
Cohen et al 2008 France	55 patients retrospectively selected with idiopathic myopericarditis. Clinical presentations, ECG recordings, biologic results, echocardiography results and TnI levels were included in the analysis. Mean follow up 33 months.	Retrospective cohort study	TnI levels	Raised TnI in 27 patients (78%), which was associated with younger patients, recent infection and length of stay. Similar complication rates were shown for positive and negative TnI	Variations ins reference ranges. Potential selection bias and small cohort. Follow up period was not standardized.
Cohen et al 2008 France	55 patients retrospectively selected with idiopathic myopericarditis. Clinical presentations, ECG recordings, biologic results, echocardiography results and TnI levels were included in the analysis. Mean follow up 33 months.	Retrospective cohort study	TnI levels	Raised TnI in 27 patients (78%), which was associated with younger patients, recent infection and length of stay. Similar complication rates were shown for positive and negative TnI	Variations in reference ranges. Potential selection bias and small cohort. Follow up period was not standardized.
Brandt et al 2001 Germany	14 consecutive cases of myopericarditis were selected (mean age 39 years) with a 24 month follow period between January 1998 and December 1999. Only patients presenting within 24 hours of symptom onset were included. Diagnosis of acute pericarditis was defined by at least two of typical chest pain, pericardial rub or characteristic ECG changes.	Retrospective cohort study	TnI levels	TnI was detectable in 10 of 14 patients, which was of an equivalent level to that found in acute coronary syndrome. 2 out of 14 patients had pericardial effusions. Maximum length of time with raised troponin was 6 days after symptom onset.	Potential selection bias with inclusion of only hospital patients and a small cohort. No follow up data.
Brandt et al 2001 Germany	14 consecutive cases of myopericarditis were selected (mean age 39 years) with a 24 month follow period between January 1998 and December 1999. Only patients presenting within 24 hours of symptom onset were included. Diagnosis of acute pericarditis was defined by at least two of typical chest pain, pericardial rub or characteristic ECG changes.	Retrospective cohort study	TnI levels	TnI was detectable in 10 of 14 patients, which was of an equivalent level to that found in acute coronary syndrome. 2 out of 14 patients had pericardial effusions. Maximum length of time with raised troponin was 6 days after symptom onset.	Potential selection bias with inclusion of only hospital patients and a small cohort. No follow up data.
Bonnefoy et al 2000 France	69 patients were selected based on clinical presentation of idiopathic pericarditis from the emergency department (mean age 48 years and 58 were male) between January 1996 and December 1997, who all had TnI measured on admission. Pericarditis was defined as pleuritic chest pain with one or more of pericardial rub, consistent ST segment changes or pericardial effusion.	Retrospective monocentric study	TnI levels	TnI was detected in 34 patients (49%) on admission. TnI was >1.5 ng/ml (level defined for significant myocyte injury) in 15 patients (22%).	Small study size with possible selection bias for more severe cases, as only admissions were included. 12 patients did not undergo troponin testing. The follow-up period was not standardized.
			Detection of ST-elevation on ECG	ST-elevation was present in 23 (67%) of the 34 patients with detectable TnI. ST-elevation was present in 14/15 patients with TnI >1.5 ng/ml and in 31 (57%) of the the 54 patients with TnI <1.5 ng/ml. ST-elevation to detect important injury (as defined by significant TnI levels) had a sensitivity of 93% and specifity of 43%.
Bonnefoy et al 2003 France	69 patients were selected based on clinical presentation of idiopathic pericarditis from the emergency department (mean age 48 years and 58 were male) between January 1996 and December 1997, who all had TnI measured on admission. Pericarditis was defined as pleuritic chest pain with one or more of pericardial rub, consistent ST segment changes or pericardial effusion.	Retrospective monocentric study	TnI levels	TnI was detected in 34 patients (49%) on admission. TnI was >1.5 ng/ml (level defined for significant myocyte injury) in 15 patients (22%).	Small study size with possible selection bias for more severe cases, as only admissions were included. 12 patients did not undergo troponin testing. The follow-up period was not standardized.
			Detection of ST-elevation on ECG	ST-elevation was present in 23 (67%) of the 34 patients with detectable TnI. ST-elevation was present in 14/15 patients with TnI >1.5 ng/ml and in 31 (57%) of the the 54 patients with TnI <1.5 ng/ml. ST-elevation to detect important injury (as defined by significant TnI levels) had a sensitivity of 93% and specifity of 43%.
Imazio et al 2003 Italy	118 consecutive patients admitted to the Emergency Department of Cardiology Department within 24 hours of symptom onset. Diagnosis was based on completion of at least two criteria: typicl chest pain, pericardial rub and widespread ST-segment elevation.	Prospective monocentric cohort	TnI levels	A TnI rise was detected in 38 patients (32.2%), which was mores associated with younger age, male gender, ST-segment elevation and pericardial effusion at presentation. Nine cases (7.6%) had TnI levels raised above the threshold for acute myocardial infarction. These cases had creatinine kinase-MB levels, TnI release pattern and ventricular dysfunction similar to acute myocardial infarction without evidence of coronary artery disease. In a mean follow up of 24 months, TnI levels provided no prognostic value.	Potential selection bias with only hospital admissions and those presenting with 24 hours included.
Imazio et al 2003 Italy	118 consecutive patients admitted to the Emergency Department of Cardiology Department within 24 hours of symptom onset. Diagnosis was based on completion of at least two criteria: typicl chest pain, pericardial rub and widespread ST-segment elevation.	Prospective monocentric cohort	TnI levels	A TnI rise was detected in 38 patients (32.2%), which was associated with younger age, male gender, ST-segment elevation and pericardial effusion at presentation. Nine cases (7.6%) had TnI levels raised above the threshold for acute myocardial infarction. These cases had creatinine kinase-MB levels, TnI release pattern and ventricular dysfunction similar to acute myocardial infarction without evidence of coronary artery disease. In a mean follow up of 24 months, TnI levels provided no prognostic value.	Potential selection bias with only hospital admissions and those presenting with 24 hours included.

Comment(s)

It is well established that cardiac troponins are released following injury to the myocardium and has become part of the diagnostic criteria for non-ST elevation myocardial infarctions. In a variety of non-ACS conditions cardiac troponins are raised, including myopericarditis. The pathophysiology underlying of myopericarditis is poorly understood, but serum cardiac troponin levels approximately correlate with the extent of myocardial inflammation although there is no adverse correlation to higher troponin levels in myopericarditis (Giannitsis and Katus, 2013). These studies suggest that raised troponin levels occur relatively frequently in myopericarditis (32.2-78%) although these studies are subject to potential selection bias. In addition, different assays and reference ranges were used between studies. Raised troponin levels alone are poor at distinguishing between ACS and myopericarditis, as cardiac troponins can be raised to levels consistent with ACS by myopericarditis. Brandt et al, Bonnefoy et al and Imazio et al identified factors correlating to higher levels of troponin in myopericarditis (e.g. pericardial effusion or ventricular dysfunction). As such, the clinical picture can guide the interpretation of troponin levels in cases where myopericarditis is suspected. The studies above have very relatively few patients with varied population groups. The lack of data on paediatric troponin levels makes the data difficult to interpret. Before it is possible to differentiate between myocardial infarction and myopericarditis using troponins more reliable reference ranges are required, especially in paediatrics, and research into the influence of additional clinical factors onto troponin levels are required.

Clinical Bottom Line

Troponin levels are frequently raised in myopericarditis. Troponin levels alone are not useful in differentiating myocardial infarctions from myopericarditis as yet. Several clinical features contribute to higher TnI levels in myopericarditis. These need to be fully evaluated before troponins can be reliably used in differentiating myocardial infarctions from myopericarditis.

References

1. Brown et al Use of troponin as a screen for chest pain the pediatric emergency department Pediatric Cardiology 2012
2. Brown et al Use of troponin as a screen for chest pain the pediatric emergency department Pediatric Cardiology 2012
3. Cohen et al Acute pericarditis in the modern era: a diagnostic challenge Annales de cardiologie et d’angeiologie 2008
4. Cohen et al Acute pericarditis in the modern era: a diagnostic challenge Annales de cardiologie et d’angeiologie 2008
5. Brandt et al Circulating cardiac troponin I in acute pericarditis American Journal of Cardiology 2001
6. Brandt et al Circulating cardiac troponin I in acute pericarditis American Journal of Cardiology 2001
7. Bonnefoy et al Serum cardiac troponin I and ST-segment elevation in patients with acute pericarditis European Heart Journal 2003
8. Bonnefoy et al Serum cardiac troponin I and ST-segment elevation in patients with acute pericarditis European Heart Journal 2003
9. Imazio et al Cardiac troponin I in acute pericarditis American Journal of Cardiology 2003
10. Imazio et al Cardiac troponin I in acute pericarditis American Journal of Cardiology 2003