Clinical implications of high-sensitivity cardiac troponin measurements in hospitalized medical patients.

Gideon Y Stein,Danny Alon,Shmuel Fuchs,Roman Korenfeld,Monika R Asnani

doi:10.1371/journal.pone.0117162

Abstract

BackgroundThe increased use of high sensitivity cardiac troponins (hs-cTn), have made the diagnosis of non-ST elevation myocardial infarction (MI) challenging, especially in complex medical patients, in whom the clinical presentation of MI is nonspecific and multiple comorbidities as well as non-ischemic acute conditions may account for elevated hs-cTn levels. The aim of this study was to assess the frequency of both elevated hs-cTn levels and dynamic changes in hospitalized patients.Methods and FindingsWe conducted a retrospective study identifying all patients hospitalized in the Internal Medicine Division of Rabin Medical Center, Israel between January 2011 to December 2011, for whom at least one hs-cTn T (hs-cTnT) measurement was obtained. Collected data included patient demographics, acute and chronic diagnosis, hs-cTnT and creatinine levels and date of death. Hs-cTnT levels were obtained in 5,696 admissions and was above the 99th percentile (> = 13 ng/L) in 61.6% of the measurements. A relative change of 50% or higher was observed in 24% of the admissions. Among those with elevated hs-cTnT levels, acute coronary syndromes (ACS) accounted for only 6.1% of acute diagnoses. Maximal hs-cTnT levels above 100 ng/L but not dynamic changes discriminated between ACS and non-ACS conditions (positive and negative predictive values of 12% and 96% respectively). The frequency of elevated hs-cTnT levels was age-dependent and over 75% of patients aged >70 years-old had levels above the 99th percentile. Multivariate analysis identified hs-cTnT levels higher than the 99th percentile, as an independent, strong predictor for 30-day mortality (OR 4.58 [2.8, 7.49], p<0.0001).ConclusionsElevated hs-cTnT levels together with dynamic changes are frequent findings among hospitalized patients and in most cases, are not related to the ACS diagnosis. These findings highlight the diagnostic challenge of ACS in this complex population. Further studies are needed in order to optimize the use of hs-cTnT measurements in hospitalized patients.

Highlights

The 3rd universal definition of myocardial infarction using high-sensitivity troponin is broadly applied to rule out acute myocardial infarction (AMI) with very high negative predictive values of 97–100%.[1,2,3] due to the reciprocal relation between sensitivity and specificity of the assay, the positive predictive values for AMI are lower, ranging in selected patient populations between 50% to 84%.[2,3] While in these studies the prevalence of AMI was 17%, it was estimated that in a typical chest pain unit, where the probability of AMI is 5%, a larger percentage of patients with elevated high sensitivity cardiac troponins (hs-cTn) levels above the 99th percentile not meeting criteria for AMI, will be evident.[4]
Further studies are needed in order to optimize the use of hs-cTn T (hs-cTnT) measurements in hospitalized patients
We found that maximal hs-cTnT levels but not dynamic changes best differentiated between patients with acute coronary syndromes (ACS) and those with other diagnoses (Fig. 7A)

Summary

Introduction

The 3rd universal definition of myocardial infarction using high-sensitivity troponin (hs-cTn) is broadly applied to rule out acute myocardial infarction (AMI) with very high negative predictive values of 97–100%.[1,2,3] due to the reciprocal relation between sensitivity and specificity of the assay, the positive predictive values for AMI are lower, ranging in selected patient populations between 50% to 84%.[2,3] While in these studies the prevalence of AMI was 17%, it was estimated that in a typical chest pain unit, where the probability of AMI is 5%, a larger percentage of patients with elevated hs-cTn levels above the 99th percentile not meeting criteria for AMI, will be evident.[4]. [5] the aims of the current study were twofold: 1) to explore the frequency of elevated hs-cTnT and dynamic changes, obtained according to common daily practice, among hospitalized patients with ACS, cardiac and non-cardiac medical conditions, and 2) to assess the impact of hs-cTnT levels and dynamic changes on early mortality. The increased use of high sensitivity cardiac troponins (hs-cTn), have made the diagnosis of non-ST elevation myocardial infarction (MI) challenging, especially in complex medical patients, in whom the clinical presentation of MI is nonspecific and multiple comorbidities as well as non-ischemic acute conditions may account for elevated hs-cTn levels. The aim of this study was to assess the frequency of both elevated hs-cTn levels and dynamic changes in hospitalized patients

Objectives

Methods

Results

Conclusion