High-Sensitivity vs Conventional Troponin in Acute Chest Pain
Objectives High-sensitivity troponin (hs-cTn) is substituting conventional cTn for evaluation of chest pain. Our aim was to assess the impact on patient management and outcome.
Methods A total of 1372 consecutive patients presenting at the emergency department with non-ST-elevation acute chest pain were divided into two periods according to the cTn assay used, conventional (n=699, March 2008 to July 2010) or hs-cTn (n=673, November 2010 to March 2013). Management policies were similar and according to guidelines. The primary endpoint was major adverse cardiac events (MACE) at 6 months (death, myocardial infarction, readmission by unstable angina or postdischarge revascularisation).
Results There were minor differences in baseline characteristics. In the hs-cTn period, more patients elevated cTn (73% vs 37%, p=0.0001) leading to more coronary angiograms (77% vs 55%, p=0.0001) and revascularisations (45% vs 31%, p=0.0001); conversely, fewer patients were initially assigned to exercise testing (14% vs 36%, p=0.0001) and, therefore, discharged early after a negative result (7% vs 22%, p=0.0001). At 6 months, 135 patients suffered MACE, including 54 deaths. After adjusting for a Propensity Score, hs-cTn use was not significantly associated with MACE (HR=0.99; 95% CI 0.70 to 1.41; p=0.98) or mortality (HR=1.02; 95% CI 0.59 to 1.77; p=0.95), though the risk of longer hospitalisation stay increased at the index episode (OR=1.35, 95% CI 1.07 to 1.71, p=0.02).
Conclusions hs-cTn simplified chest pain triage on avoiding a more complex evaluation with non-invasive tests in the chest pain unit, but prompted longer hospitalisations and more invasive procedures without impacting on the 6-month outcomes.
Troponin (cTn) plays a central role in the management of acute chest pain. The conventional cTn assays lack precision for measuring cTn at low concentrations corresponding to the 99th percentile value of a normal reference population; this is the cut-off for the diagnosis of acute myocardial infarction (AMI). In contrast, the high-sensitivity cTn (hs-cTn) assays show precision at the 99th percentile cut-off.
Due to this better accuracy, hs-cTn allows the identification of some high risk patients from within the vast population of acute chest pain who would otherwise go undetected using conventional cTn. In addition, cTn release can be detected as early as 2 h from AMI onset. However, ruling in AMI when hs-cTn is mildly elevated or ruling out unstable angina when hs-cTn is normal remains matters of debate.
Currently, hs-cTn is substituting conventional cTn in many hospitals, but there is scarce information regarding how this change is modifying patient management and outcome. Some data suggest that hs-cTn use might improve patient prognosis, but more information is needed to confirm these findings. In this study, two consecutive series of patients with acute chest pain managed with conventional or hs-cTn assay were compared. The main purpose was to investigate the impact of hs-cTn on postdischarge outcome as well as on the inhospital diagnostic work-up and management.
Abstract and Introduction
Abstract
Objectives High-sensitivity troponin (hs-cTn) is substituting conventional cTn for evaluation of chest pain. Our aim was to assess the impact on patient management and outcome.
Methods A total of 1372 consecutive patients presenting at the emergency department with non-ST-elevation acute chest pain were divided into two periods according to the cTn assay used, conventional (n=699, March 2008 to July 2010) or hs-cTn (n=673, November 2010 to March 2013). Management policies were similar and according to guidelines. The primary endpoint was major adverse cardiac events (MACE) at 6 months (death, myocardial infarction, readmission by unstable angina or postdischarge revascularisation).
Results There were minor differences in baseline characteristics. In the hs-cTn period, more patients elevated cTn (73% vs 37%, p=0.0001) leading to more coronary angiograms (77% vs 55%, p=0.0001) and revascularisations (45% vs 31%, p=0.0001); conversely, fewer patients were initially assigned to exercise testing (14% vs 36%, p=0.0001) and, therefore, discharged early after a negative result (7% vs 22%, p=0.0001). At 6 months, 135 patients suffered MACE, including 54 deaths. After adjusting for a Propensity Score, hs-cTn use was not significantly associated with MACE (HR=0.99; 95% CI 0.70 to 1.41; p=0.98) or mortality (HR=1.02; 95% CI 0.59 to 1.77; p=0.95), though the risk of longer hospitalisation stay increased at the index episode (OR=1.35, 95% CI 1.07 to 1.71, p=0.02).
Conclusions hs-cTn simplified chest pain triage on avoiding a more complex evaluation with non-invasive tests in the chest pain unit, but prompted longer hospitalisations and more invasive procedures without impacting on the 6-month outcomes.
Introduction
Troponin (cTn) plays a central role in the management of acute chest pain. The conventional cTn assays lack precision for measuring cTn at low concentrations corresponding to the 99th percentile value of a normal reference population; this is the cut-off for the diagnosis of acute myocardial infarction (AMI). In contrast, the high-sensitivity cTn (hs-cTn) assays show precision at the 99th percentile cut-off.
Due to this better accuracy, hs-cTn allows the identification of some high risk patients from within the vast population of acute chest pain who would otherwise go undetected using conventional cTn. In addition, cTn release can be detected as early as 2 h from AMI onset. However, ruling in AMI when hs-cTn is mildly elevated or ruling out unstable angina when hs-cTn is normal remains matters of debate.
Currently, hs-cTn is substituting conventional cTn in many hospitals, but there is scarce information regarding how this change is modifying patient management and outcome. Some data suggest that hs-cTn use might improve patient prognosis, but more information is needed to confirm these findings. In this study, two consecutive series of patients with acute chest pain managed with conventional or hs-cTn assay were compared. The main purpose was to investigate the impact of hs-cTn on postdischarge outcome as well as on the inhospital diagnostic work-up and management.
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