Heart-type fatty acid binding protein and the diagnosis of acute coronary syndrome in the ED.

BACKGROUND: In combination with cardiac troponin, heart-type fatty acid binding protein (h-FABP)-a biomarker of myocardial necrosis-offers the possibility of rapidly eliminating the diagnosis of acute myocardial infarction (AMI). OBJECTIVE: The main objective of this study was to assess the incremental value of h-FABP to cardiac troponin for a rapid elimination of AMI, according to the pretest probability (PTP) of AMI. METHODS: In consecutive patients presenting to emergency departments (ED) with chest pain less than 6 hours suggestive of AMI, h-FABP levels were measured, blinded to the ED physicians, who were asked to quote the PTP of AMI. The discharge diagnosis was adjudicated by 2 independent experts, blind to the h-FABP level. RESULTS: Three hundred seventeen patients (mean age of 57 years) were included in whom 149 had (47%) low, 117 (37%) moderate, and 51 (16%) high PTP. The final diagnosis was AMI in 45 patients (14%), including 16 STEMIs (5%). The negative predictive value for diagnostic elimination of AMI of an h-FABP less than 3 µg/L, combined with a negative cTnI was not higher than that of cardiac troponin I (cTnI) alone (96% [95% confidence interval, 93%-98%] vs 95% [93%-98%]), regardless of the PTP). Even in the low-PTP group, we did not demonstrate a significant improvement in negative predictive value with the addition of h-FABP, compare with that of cTnI alone (100% [97%-100%] vs 99% [96%-100%]). CONCLUSION: In triage of patients with chest pain, use of h-FABP does not provide useful additional information to cTnI for excluding the diagnosis of ST-elevation myocardial infarction and non-ST-elevation myocardial infarction diagnosis, whatever the PTP.

High-sensitivity versus conventional troponin in the emergency department for the diagnosis of acute myocardial infarction.

INTRODUCTION: Recently, newer assays for cardiac troponin (cTn) have been developed which are able to detect changes in concentration of the biomarker at or below the 99th percentile for a normal population. The objective of this study was to compare the diagnostic performance of a new high-sensitivity troponin T (HsTnT) assay to that of conventional cTnI for the diagnosis of acute myocardial infarction (AMI) according to pretest probability (PTP). METHODS: In consecutive patients who presented to our emergency departments with chest pain suggestive of AMI, levels of HsTnT were measured at presentation, blinded to the emergency physicians, who were asked to estimate the empirical PTP of AMI. The discharge diagnosis was adjudicated by two independent experts on the basis of all available data. RESULTS: A total of 317 patients were included, comprising 149 (47%) who were considered to have low PTP, 109 (34%) who were considered to have moderate PTP and 59 (19%) who were considered to have high PTP. AMI was confirmed in 45 patients (14%), 22 (9%) of whom were considered to have low to moderate PTP and 23 (39%) of whom were considered to have high PTP (P < 0.001). In the low to moderate PTP group, HsTnT levels ≥ 0.014 µg/L identified AMI with a higher sensitivity than cTnI (91%, 95% confidence interval (95% CI) 79 to 100, vs. 77% (95% CI 60 to 95); P = 0.001), but the negative predictive value was not different (99% (95% CI 98 to 100) vs. 98% (95% CI 96 to 100)). There was no difference in area under the receiver operating characteristic (ROC) curve between HsTnT and cTnI (0.93 (95% CI 0.90 to 0.98) vs. 0.94 (95% CI 0.88 to 0.97), respectively). CONCLUSIONS: In patients with low to moderate PTP of AMI, HsTnT is slightly more useful than cTnI. Our results confirm that the use of HsTnT has a higher sensitivity than conventional cTnI.

Copeptin for rapid rule out of acute myocardial infarction in emergency department.

BACKGROUND: Copeptin, in combination with conventional troponin (cTn), has been suggested as a means of rapid rule out of the diagnosis of acute myocardial infarction (AMI). This study aims to assess the value of copeptin for rule out of AMI, according to the pre-test probability (PTP). METHODS: In a prospective multicentric study, we enrolled patients presenting into emergency departments with chest pain <6h, copeptin was measured, and PTP was quoted. The discharge diagnosis was adjudicated by 2 independent experts using all available data, including cTnI. RESULTS: 317 patients were included: 148 (46%) had low, 110 (35%) moderate and 59 (19%) high PTP. Final diagnosis was AMI in 45 patients (14%). Median copeptin level was higher in AMI patients compared with that in patients having other diagnoses (23.2 vs. 9.9 pmol/L, p=0.01). A copeptin level ≥10.7 pmol/L in combination with cTnI detected AMI with higher sensitivity than for cTnI alone (98 [87-100] vs. 71 [55-83] %, p=0.001), whatever the PTP. The negative predictive value of the combination copeptin+cTnI was increased, compared to that of cTnI alone (99 [97-100] vs. 95 [92-97] %, p<0.05). CONCLUSIONS: In triage of chest pain patients, the additional use of copeptin with conventional cTnI might allow a rapid and reliable rule out of the diagnosis of AMI regardless of the PTP.