Abstract 12255: The Prevalence and Comorbidity of Nonspecific Troponin Elevation Detected by Highly Sensitive Assay in Patients with Acute Chest Pain
Background: Cardiac troponin is considered as a specific marker for the diagnosis of acute myocardial infarction (AMI) and latest generation of sensitive troponin assays have improved sensitivity for AMI. Nonspecific troponin elevation, however, has been shown in some recent studies and may lead to reduced specificity to diagnose AMI. We sought to investigate the prevalence and comorbidity of nonspecific troponin elevation detected by highly sensitive assay in patients with acute chest pain.
Methods and Results: Highly sensitive cardiac troponin I was measured on admission and approximately 6 h postadmission in 368 consecutive patients (76% men, 67±13 years) with acute chest pain. The higher value of the two timings was evaluated. Positive troponin test defined as above the 99th percentile of normal reference (0.04ng/mL) was observed in 320 patients (87%). In patients with positive troponin test, 249 (78%) had significant coronary stenosis on angiography and AMI is the presumed cause. Other 71 (22%) patients may contain nonspecific troponin elevation, but 11 of them could not undergo further examination because of severe general condition or refusal. Among other 60 patients, 42 had potential etiology of troponin elevation other than AMI; i.e. heart failure (28 patients), tachyarrythmia (8 patients), severe renal insufficiency (10 patients), diagnosis of Takotsubo cardiomyopathy (3 patients) or myocarditis (5 patients). Heart failure was the most frequent comorbidity (28 (47%) in 60 patients). Remaining 18 patients did not have any comorbidity mentioned above. We could undergo drug or hyperventilation induced coronary spasm provocation test in 13 of the 18 patients with informed consent, and 11 (85%) had positive results for coronary spastic angina.
Conclusions: Nonspecific elevation is often detected by highly sensitive troponin assay among patients presenting with acute chest pain in clinical practice. Heart Failure is the major comorbidity of nonspecific troponin elevation, and coronary spastic angina may explain unidentified etiology in those patients.
- © 2011 by American Heart Association, Inc.