Effect of Older Age on Troponin T in the Emergency Department
Background The effect of age on diagnostic and prognostic performance of high-sensitivity cardiac troponin T (hs-cTnT) has not been addressed adequately, so far.
Methods High-sensitivity cardiac troponin T was measured serially in patients with acute symptoms presenting to our emergency department. We tested the diagnostic and prognostic performance of baseline and serial hs-cTnT concentrations related to age in all consecutive patients with acute coronary syndrome (ACS) (n = 342) or hs-cTnT increases not due to ACS (n = 442).
Results Prevalence of elevated hs-cTnT in the study population was higher among patients ≥75 years compared with younger patients (89.1 % vs 73.3 %, hazard ratio [HR] 1.2, P < .0001). Elevated hs-cTnT was more likely due to ACS in the younger patients (HR 1.4, P = .001) and conversely more frequently due to non-ACS conditions in the elderly patients (HR 1.3, P = .0001). Diagnostic performance of hs-cTnT using the 99th percentile was significantly superior in younger than in elderly patients (P < .0001). For receiver operating characteristic–optimized cutoffs, a trend to significance was found between younger and older patients (area under the curve 0.87 vs 0.79, P = .074), with higher sensitivities (98.2 % vs 72.6%) and negative predictive values (97.3% vs. 78.5%) for patients <75 years. Moreover, receiver operating characteristic–optimized cutoff values for diagnosis of non–ST-segment elevation myocardial infarction were significantly higher in elderly patients (32.9 ng/L) compared with younger patients (12.9 ng/L). The prognostic information of single and serial hs-cTnT measurements was comparably poor in both age groups, showing no better prognostic information to hs-cTnT measurement on presentation.
Conclusions Elevated hs-cTnT is more common in the elderly due to higher prevalence of non-ACS conditions and significantly impairs diagnostic performance in discriminating non–ST-segment elevation myocardial infarction.
Current European Society of Cardiology guidelines for the management of acute coronary syndrome (ACS) without ST-segment elevation promote the use of more sensitive cardiac troponin (cTn) assays as they allow more accurate and earlier diagnosis of acute myocardial infarction (AMI) than previous less sensitive formulations. However, increased analytical sensitivity does not only increase the detection rate of AMI but prompts identification of a higher number of cTn elevations due to acute or chronic cardiovascular pathologies including myocardial damage unrelated to myocardial ischemia. Recently, elevated cTn concentrations were detected in 24.4% of hospitalized patients in a study using more sensitive cTn assays, and most reasons for cTn elevations included non-ACS conditions. Accordingly, patients with elevated cTnT concentrations can also be found in departments other than cardiology. In patients presenting acutely to an emergency department (ED) with typical symptoms or unequivocal electrocardiographic (ECG) changes, cTn elevations are most likely due to ACS conditions. However, in the absence of a typical presentation, other acute conditions such as pulmonary embolism, myocarditis, takotsubo cardiomyopathy, tachycardias, or decompensated valvular disease and numerous coexisting chronic conditions including renal failure, chronic pulmonary hypertension, and hypertensive heart disease must be considered. The prevalence and reasons of elevated cTn in a consecutive elderly population presenting to an ED with acute symptoms not only suggestive of ACS are unknown. Prevalence of cardiovascular disease and renal insufficiency increases with age, and higher cTn concentrations have been observed in an older, presumably healthy population.
Therefore, our observational study sought to determine the effect of older age on the diagnostic and prognostic performance of the new high-sensitivity cardiac troponin T (hs-cTnT) assay (Roche Diagnostics, Rotkreuz, Switzerland) in patients presenting with acute symptoms to an ED. We also evaluated the prevalence of and the reasons for cTn values >99th percentile.
Abstract and Introduction
Abstract
Background The effect of age on diagnostic and prognostic performance of high-sensitivity cardiac troponin T (hs-cTnT) has not been addressed adequately, so far.
Methods High-sensitivity cardiac troponin T was measured serially in patients with acute symptoms presenting to our emergency department. We tested the diagnostic and prognostic performance of baseline and serial hs-cTnT concentrations related to age in all consecutive patients with acute coronary syndrome (ACS) (n = 342) or hs-cTnT increases not due to ACS (n = 442).
Results Prevalence of elevated hs-cTnT in the study population was higher among patients ≥75 years compared with younger patients (89.1 % vs 73.3 %, hazard ratio [HR] 1.2, P < .0001). Elevated hs-cTnT was more likely due to ACS in the younger patients (HR 1.4, P = .001) and conversely more frequently due to non-ACS conditions in the elderly patients (HR 1.3, P = .0001). Diagnostic performance of hs-cTnT using the 99th percentile was significantly superior in younger than in elderly patients (P < .0001). For receiver operating characteristic–optimized cutoffs, a trend to significance was found between younger and older patients (area under the curve 0.87 vs 0.79, P = .074), with higher sensitivities (98.2 % vs 72.6%) and negative predictive values (97.3% vs. 78.5%) for patients <75 years. Moreover, receiver operating characteristic–optimized cutoff values for diagnosis of non–ST-segment elevation myocardial infarction were significantly higher in elderly patients (32.9 ng/L) compared with younger patients (12.9 ng/L). The prognostic information of single and serial hs-cTnT measurements was comparably poor in both age groups, showing no better prognostic information to hs-cTnT measurement on presentation.
Conclusions Elevated hs-cTnT is more common in the elderly due to higher prevalence of non-ACS conditions and significantly impairs diagnostic performance in discriminating non–ST-segment elevation myocardial infarction.
Introduction
Current European Society of Cardiology guidelines for the management of acute coronary syndrome (ACS) without ST-segment elevation promote the use of more sensitive cardiac troponin (cTn) assays as they allow more accurate and earlier diagnosis of acute myocardial infarction (AMI) than previous less sensitive formulations. However, increased analytical sensitivity does not only increase the detection rate of AMI but prompts identification of a higher number of cTn elevations due to acute or chronic cardiovascular pathologies including myocardial damage unrelated to myocardial ischemia. Recently, elevated cTn concentrations were detected in 24.4% of hospitalized patients in a study using more sensitive cTn assays, and most reasons for cTn elevations included non-ACS conditions. Accordingly, patients with elevated cTnT concentrations can also be found in departments other than cardiology. In patients presenting acutely to an emergency department (ED) with typical symptoms or unequivocal electrocardiographic (ECG) changes, cTn elevations are most likely due to ACS conditions. However, in the absence of a typical presentation, other acute conditions such as pulmonary embolism, myocarditis, takotsubo cardiomyopathy, tachycardias, or decompensated valvular disease and numerous coexisting chronic conditions including renal failure, chronic pulmonary hypertension, and hypertensive heart disease must be considered. The prevalence and reasons of elevated cTn in a consecutive elderly population presenting to an ED with acute symptoms not only suggestive of ACS are unknown. Prevalence of cardiovascular disease and renal insufficiency increases with age, and higher cTn concentrations have been observed in an older, presumably healthy population.
Therefore, our observational study sought to determine the effect of older age on the diagnostic and prognostic performance of the new high-sensitivity cardiac troponin T (hs-cTnT) assay (Roche Diagnostics, Rotkreuz, Switzerland) in patients presenting with acute symptoms to an ED. We also evaluated the prevalence of and the reasons for cTn values >99th percentile.