Wednesday May 21, 2008
Troponin I Elevation in patients without Acute Coronary Syndromes !


Q; How many patients may have Cardiac Troponin I elevation without Acute Coronary Syndromes ?

A; Upto 35% !!

In a recent paper, just published in Am J Cardiol 1, 883 consecutive hospitalized patients were studied with increased cardiac troponin I levels. The discharge diagnosis was reclassified and troponin increase attributed to ACS or another process. Patients were followed for a median of 30 months.

Results: 311 patients were classified as having a non-ACS–related troponin increase (35.2%). An alternative explanation for troponin increase was found in 99% of these patients. Troponin level had poor accuracy in discriminating patients with and without ACS.

Of the 311 patients without ACS,

• 89 (28%) were diagnosed as having sepsis,
• 49 (16%) had acute left heart failure,
• 41 (13%) were after coronary artery bypass graft,
• 31 (10%) had atrial or ventricular arrhythmia,
• 23 (7%) were after cardiopulmonary resuscitation,
• 21 (7%) had a cerebrovascular event,
• 11 (4%) had myocarditis,
• 11 (4%) had acute bleeding,
• 10 (3%) had chest contusion,
• 6 (2%) had pulmonary embolism.
• 19 patients (6%) had another diagnosis such as diabetic ketoacidosis, carbon monoxide intoxication, pancreatitis, hypoxemia, hypercarbia, lymphoma, and electrocution.

Mean serum troponin level for

• patients without ACS were significantly lower (15.3 +/- 15.9 ng/ml)
• the values of patients with STEMI (32.5 +/- 18.1 ng/ml)
• NSTEMI (20.4 +/- 18.4 ng/ml)
• The highest troponin level in the non-ACS group was found in 10 patients diagnosed as having myocarditis (27.7 +/- 21.5 ng/ml)

Coronary angiography was frequently unhelpful in excluding a non-ACS–related troponin increase because 77% of patients in the non-ACS group had significant flow-limiting coronary artery disease.
But patients with non-ACS–related troponin increase had significantly higher in-hospital and long-term mortalities compared with patients with ACS.


Conclusion:

• Cardiac troponin level is frequently increased in hospitalized patients in the absence of an ACS
• it portends poor short- and long-term outcomes.
• Most of these patients have an alternative explanation for cardiac troponin increase.
• Cardiac diagnostic procedures are frequently unhelpful in excluding a non-ACS–related troponin increase.
  
  

Reference: Click to get abstract

Cardiac Troponin I Elevation in Hospitalized Patients Without Acute Coronary Syndromes - Am J Cardiol 2008;101:1384–1388, 15 May 2008