Distribution of plasma cardiac troponin I values in healthy subjects: pathophysiological considerations (original) (raw)
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Clinical Chemistry, 2013
BACKGROUND We aimed to investigate the effects of sex, prevalent cardiovascular disease (CVD), and aging on the 99th percentile of cardiac troponin I (cTnI). METHODS cTnI was measured using a high-sensitivity assay (Abbott Diagnostics) in 814 community-dwelling individuals at both 70 and 75 years of age. We determined the cTnI 99th percentiles separately using nonparametric methods in the total sample, in men and women, and in individuals with and without CVD. RESULTS The cTnI 99th percentile at baseline was 55.2 ng/L for the total cohort. Higher 99th percentiles were noted in men (69.3 ng/L) and individuals with CVD (74.5 ng/L). The cTnI 99th percentile in individuals free from CVD at baseline (n = 498) increased by 51% from 38.4 to 58.0 ng/L during the 5-year observation period. Relative increases ranging from 44% to 83% were noted across all subgroups. Male sex [odds ratio, 5.3 (95% CI, 1.5–18.3)], log-transformed N-terminal pro-B-type natriuretic peptide [odds ratio, 1.9 (95% CI...
Clinical Chemistry and Laboratory Medicine (CCLM)
In accordance with all the most recent international guidelines, the variation of circulating levels of cardiac troponins I and T, measured with high-sensitivity methods (hs-cTnI and hs-cTnT), should be used for the detection of acute myocardial injury. Recent experimental and clinical evidences have demonstrated that the evaluation of hs-cTnI and hs-cTnT variations is particularly relevant: a) for the differential diagnosis of Acute Coronary Syndromes (ACS) in patients admitted to the Emergency Department (ED); b) for the evaluation of cardiovascular risk in patients undergoing major cardiac or non-cardiac surgery, and in asymptomatic subjects of the general population aged >55 years and with co-morbidities; c) for the evaluation of cardiotoxicity caused by administration of some chemotherapy drugs in patients with malignant tumors. The aim of this document is to discuss the fundamental statistical and biological considerations on the intraindividual variability of hs-cTnI and h...
Changes in cardiac troponin level in Myocardial infracted patients and its relation with age
Myocardial infarction (MI) is one of the most common diseases in all over the world. It is commonly diagnosed by measurements of cardiac enzymes named as cardiac troponin I (cTnI) and cardiac troponin T (cTnT). Raised cardiac troponin levels are considered as the cornerstone in the susceptibility and sensitivity of myocardial infarction. A study was conducted for the evaluation of serum Troponin I (cTnI) levels in different age groups of both gender. There was significant (p<0.05) difference between male and females cTnI, values indicating high mortality rate in males (60.09%) as compared to females (48.57%). However, there was no significant difference (p>0.05) between age groups and cTnl values which shows that susceptibility of MI is not associated with age and some other factors may also responsible for high troponin levels included as high blood pressure, obesity and living style.
The American Journal of Emergency Medicine, 1999
This study evaluated the role of serum cardiac troponin I as a biochemical marker for the diagnosis of acute coronary syndromes in the presence of noncardiac diseases. Diagnostic characteristics were examined in 102 consecutive patients who were found to have serum cardiac troponin I levels higher than the upper reference limit of 0.6 ng/mL. Of 102 patients with cardiac troponin I levels of >0.6 ng/mL, 35 did not have the final diagnoses of acute coronary syndromes (myocardial infarction or unstable angina) but had various other final diagnoses, including nonischemic dilated cardiomyopathy, muscular disorders, central nervous systern disorders, HIV disease, chronic renal failure, sepsis, lung diseases, and endocrine disorders. The mean value of serum cardiac troponin I in the patients with diseases other than acute coronary syndromes was significantly lesser than in those with acute coronary syndromes (2.0 -+ 1.9 [SD] v 24.7 -28.2 ng/mL; P < .0001). There were significantly fewer histories of chest pain and prior myocardial infarction in patients with diseases other than acute coronary syndromes than in those with acute coronary syndromes (history of chest pain, 3 v 48 patients [P < .001]; history of prior myocardial infarction, 0 v 30 patients [P < .001]). In conclusion, elevated serum levels of cardiac troponin I, especially in the lower ranges, should be interpreted with caution, particularly in patients suffering from acute illnesses who lack other diagnostic features suggestive of acute coronary ischemic events. (Am J Emerg Med 1999;17:225-229.
Clinical Performance of Two Highly Sensitive Cardiac Troponin I Assays
2008
BACKGROUND: Theaimofthisstudywastocomparethe clinical performance of 2 sensitive cTnI assays with 10% CV imprecision below the 99th percentile upper reference limit. METHODS: We measured cardiac troponin and N- terminal pro-brain natriuretic peptide (NT-proBNP) concentrations in a random sample of the Global Use of Strategies To Open Occluded Coronary Arteries (GUSTO) IV cohort (n 1251). Outcome data of 1-year mortality and the
European journal of preventive cardiology, 2014
Low prevalence of detectable cardiac troponin in healthy people and low-risk patients previously curtailed its use. With a new high-sensitive cardiac troponin assay (hs-cTnT), concentrations below conventional detection may have prognostic value, notably in combination with N-terminal pro-B-type natriuretic peptide (NT-pro-BNP). Biomarker concentrations were determined from serum obtained at enrolment in the CLARICOR trial involving 4197 patients with stable coronary artery disease (CAD) followed for 2.6 years. Serum hs-cTnT was detectable (above 3 ng/l) in 78% and above the conventional 99th percentile (13.5 ng/l) in 23%. Across all levels of hs-cTnT there was a graded increase in the risk of cardiovascular death after adjustment for known prognostic indicators: hazard ratio (HR) per unit increase in the natural logarithm of the hs-cTnT level, 1.49; 95% confidence interval (CI), 1.23-1.81; similarly for all-cause mortality (HR 1.48, 95% CI 1.29-1.70) and myocardial infarction (HR 1...
Clinical Chemistry, 2013
BACKGROUND A rise or fall of cardiac troponin is a prerequisite for the diagnosis of acute myocardial infarction. Defining significant changes requires knowledge of both biological and analytical variation. The short-term biological variation of cardiac troponin in healthy individuals is 3%–48%. However, healthy individuals may not be representative for patients in whom cardiac troponin measurement is often of clinical importance. Therefore, we studied the individual variation of cardiac troponin in patients with symptoms of stable coronary artery disease. METHODS Twenty-four patients scheduled for elective coronary angiography were included. Blood samples were drawn once at enrollment and serially at six 4-h intervals on the day before coronary angiography. Cardiac troponin was measured with hs-cTn assays from Abbott Laboratories (premarket cTnI assay) and Roche Diagnostics (Elecsys® cTnT assay with two different lots). RESULTS The short-term individual variation in cardiac troponi...
Long-Term Health Outcomes Associated with Detectable Troponin I Concentrations
Clinical Chemistry, 2006
Background: Recent data suggest that older men with detectable cardiac troponin I (cTnI) concentrations that remain below the 99th percentile concentration cutoff are at increased risk for subsequent cardiovascular events. We designed this study to extend this observation by examining risk prediction in both men and women presenting to an emergency department with chest discomfort. Methods: We obtained data for all-cause mortality and hospital discharges associated with either acute myocardial infarction (AMI) or congestive heart failure (CHF) for up to 8 years after the initial presentation in 448 patients who originally presented in 1996 with acute coronary syndrome (ACS). We performed retrospective analysis for cTnI (AccuTnI™; Beckman Coulter) in frozen plasma samples based on the patients' reported time from onset of symptoms. Peak cTnI concentration was used for risk assessment. Results: Patients with cTnI concentrations >0.02 g/L (i.e., limit of detection), including those whose peak values remained below the 99th percentile (0.04 g/L), were at greater risk for death and AMI/CHF readmissions at 2, 5, and 8 years of follow-up compared with those with peak cTnI <0.02 g/L. All results were statistically significant (P <0.05) except for death within 2 years among patients with normal but detectable cTnI (0.02 to 0.03 g/L), relative to the group with values <0.02 g/L. Kaplan-Meier analyses indicated that both men and women with cTnI >0.02 g/L had worse outcomes (P <0.001). Conclusion: Both men and women who present with possible ACS with detectable cTnI concentrations that remain below the 99th percentile are at a greater risk for future adverse events.