Abstract
BACKGROUND: Adverse cardiac events that follow cardiac surgery are an important source of perioperative morbidity and mortality for women. Troponin I provides a sensitive measure of cardiac injury, but the levels after cardiac surgery may vary between sexes. Our purpose in this study was to evaluate the prognostic value of troponin I levels for predicting cardiovascular complications in postmenopausal women undergoing cardiac surgery.
METHODS: The cohort of this study were women enrolled in a previously reported clinical trial evaluating the neuroprotective potential of 17β-estradiol in elderly women. In that study, 175 postmenopausal women not receiving estrogen replacement therapy and scheduled to undergo coronary artery bypass graft (with or without valve surgery) were prospectively randomized to receive 17β-estradiol or placebo in a double-blind manner beginning the day before surgery and continuing for 5 days postoperatively. Serial 12-lead electrocardiograms were performed and serum troponin I concentrations were measured before surgery, after surgery on arrival in the intensive care unit, and for the first four postoperative days. The primary end-point of the present study was major adverse cardiovascular events (MACE) defined as a Q-wave myocardial infarction, low cardiac output state or death within 30 days of surgery. The diagnosis of Q-wave myocardial infarction was made independently by two physicians blinded to treatment and patient outcomes with the final diagnosis requiring consensus. Low cardiac output state was defined as cardiac index <2.0 L · min–1 · m–2 for >8 h regardless of treatment.
RESULTS: Troponin I levels on postoperative day 1 were predictive of MACE (area under the receiver operator curve = 0.862). A cutoff point for troponin I of >7.6 ng/mL (95% confidence interval, 6.4–10.8) provided the optimal sensitivity and specificity for identifying patients at risk for MACE. The negative predictive value of a Troponin I level for identifying a patient with a composite cardiovascular outcome was high (96%) and the positive predictive value moderate (40%). Postoperative troponin I levels were not different between women receiving perioperative 17β-estradiol treatment compared with placebo and the frequency of MACE was not influenced by 17β-estradiol treatment.
CONCLUSIONS: In postmenopausal women, elevated troponin I levels on postoperative day 1 are predictive of MACE. Monitoring of perioperative troponin I levels might provide a means for stratifying patients at risk for adverse cardiovascular events.
Showing posts with label cardiac troponin. Show all posts
Showing posts with label cardiac troponin. Show all posts
Tuesday
Monday
Value of Cardiac Troponin I Cutoff Concentrations below the 99th Percentile for Clinical Decision-Making
Proteomics and Protein Markers
Value of Cardiac Troponin I Cutoff Concentrations below the 99th Percentile for Clinical Decision-Making
Background: The aim of this study was to evaluate factors influencing the 99th percentile for cardiac Troponin I (cTnI) when this cutoff value is established on a highly sensitive assay, and to compare the value of this cutoff to that of lower cutoffs in the prognostic assessment of patients with coronary artery disease.
Methods: We used the recently refined Access AccuTnI assay (Beckman-Coulter) to assess the distribution of cTnI results in a community population of elderly individuals [PIVUS (Prospective Study of the Vasculature in Uppsala Seniors) study; n = 1005]. The utility of predefined Troponin I cutoffs for risk stratification was then evaluated in 952 patients from the FRISC II (FRagmin and Fast Revascularization during InStability in Coronary artery disease) study at 6 months after these patients had suffered acute coronary syndrome .
Results: Selection of assay results from a subcohort of PIVUS participants without cardiovascular disease resulted in a decrease of the 99th percentile from 0.044 µg/L to 0.028 µg/L. Men had higher rates of cTnI elevation with respect to the tested thresholds. Whereas the 99th percentile cutoff was not found to be a useful prognostic indicator for 5-year mortality, both the 90th percentile (hazard ratio 3.1; 95% CI 1.9–5.1) and the 75th percentile (hazard ratio 2.8; 95% CI 1.7–4.7) provided useful prognostic information. Sex-specific cutoffs did not improve risk prediction.
Conclusions: The 99th percentile of cTnI depends highly on the characteristics of the reference population from which it is determined. This dependence on the reference population may affect the appropriateness of clinical conclusions based on this threshold. However, cTnI cutoffs below the 99th percentile seem to provide better prognostic discrimination in stabilized acute coronary syndrome patients and therefore may be preferable for risk stratification.
Kai M. Eggers1,a, Allan S. Jaffe4, Lars Lind2, Per Venge3 and Bertil Lindahl1
Departments of1 Medical Sciences, Cardiology,2 Medicine, and 3 Clinical Chemistry, Uppsala University Hospital, Sweden, and4 Mayo Medical School, Rochester, MN.
Value of Cardiac Troponin I Cutoff Concentrations below the 99th Percentile for Clinical Decision-Making
Background: The aim of this study was to evaluate factors influencing the 99th percentile for cardiac Troponin I (cTnI) when this cutoff value is established on a highly sensitive assay, and to compare the value of this cutoff to that of lower cutoffs in the prognostic assessment of patients with coronary artery disease.
Methods: We used the recently refined Access AccuTnI assay (Beckman-Coulter) to assess the distribution of cTnI results in a community population of elderly individuals [PIVUS (Prospective Study of the Vasculature in Uppsala Seniors) study; n = 1005]. The utility of predefined Troponin I cutoffs for risk stratification was then evaluated in 952 patients from the FRISC II (FRagmin and Fast Revascularization during InStability in Coronary artery disease) study at 6 months after these patients had suffered acute coronary syndrome .
Results: Selection of assay results from a subcohort of PIVUS participants without cardiovascular disease resulted in a decrease of the 99th percentile from 0.044 µg/L to 0.028 µg/L. Men had higher rates of cTnI elevation with respect to the tested thresholds. Whereas the 99th percentile cutoff was not found to be a useful prognostic indicator for 5-year mortality, both the 90th percentile (hazard ratio 3.1; 95% CI 1.9–5.1) and the 75th percentile (hazard ratio 2.8; 95% CI 1.7–4.7) provided useful prognostic information. Sex-specific cutoffs did not improve risk prediction.
Conclusions: The 99th percentile of cTnI depends highly on the characteristics of the reference population from which it is determined. This dependence on the reference population may affect the appropriateness of clinical conclusions based on this threshold. However, cTnI cutoffs below the 99th percentile seem to provide better prognostic discrimination in stabilized acute coronary syndrome patients and therefore may be preferable for risk stratification.
Kai M. Eggers1,a, Allan S. Jaffe4, Lars Lind2, Per Venge3 and Bertil Lindahl1
Departments of1 Medical Sciences, Cardiology,2 Medicine, and 3 Clinical Chemistry, Uppsala University Hospital, Sweden, and4 Mayo Medical School, Rochester, MN.
Tuesday
Clinical significance of cardiac troponins I and T in acute heart failure
Background
Elevated cardiac troponin (cTn) levels are relatively common in acute heart failure (AHF).
Aims
To evaluate the prevalence and prognostic significance of elevated cTnI and cTnT in AHF.
Methods
FINN-AKVA is a prospective, multicenter study in AHF. In this analysis, 364 non-ACS patients with measurements of cTnI and cTnT taken on admission and 48 h thereafter were analyzed.
Results
Of the 364 AHF patients, 51.1% had cTnI and 29.7% cTnT levels above the cut-off value. Six-month all-cause mortality was 18.7%. Both cTnI (OR 2.0, 95% CI 1.2–3.5, p = 0.01) and cTnT (OR 2.6, 95% CI 1.5–4.4, p = 0.0006) were associated with adverse outcome. The mortality risk was proportional to the magnitude of cTn release. On multivariable analysis, Cystatin C (OR 6.3, 95% CI 3.2–13, p < 0.0001), logNT-proBNP (OR 1.4, 95% CI 1.0–1.8, p = 0.03) and systolic blood pressure on admission (/10 mm Hg increase, OR 0.9, 95% CI 0.8–0.9, p = 0.0004) were independent risk markers, whereas the troponins were not significantly associated with increased mortality.
Conclusions
cTn elevations are frequent in AHF patients without ACS. cTnI is more often elevated than cTnT. Both cTnI and cTnT elevations are associated with increased mortality proportional to the degree elevation but they do not act as independent risk markers.
ARTICLE
Elevated cardiac troponin (cTn) levels are relatively common in acute heart failure (AHF).
Aims
To evaluate the prevalence and prognostic significance of elevated cTnI and cTnT in AHF.
Methods
FINN-AKVA is a prospective, multicenter study in AHF. In this analysis, 364 non-ACS patients with measurements of cTnI and cTnT taken on admission and 48 h thereafter were analyzed.
Results
Of the 364 AHF patients, 51.1% had cTnI and 29.7% cTnT levels above the cut-off value. Six-month all-cause mortality was 18.7%. Both cTnI (OR 2.0, 95% CI 1.2–3.5, p = 0.01) and cTnT (OR 2.6, 95% CI 1.5–4.4, p = 0.0006) were associated with adverse outcome. The mortality risk was proportional to the magnitude of cTn release. On multivariable analysis, Cystatin C (OR 6.3, 95% CI 3.2–13, p < 0.0001), logNT-proBNP (OR 1.4, 95% CI 1.0–1.8, p = 0.03) and systolic blood pressure on admission (/10 mm Hg increase, OR 0.9, 95% CI 0.8–0.9, p = 0.0004) were independent risk markers, whereas the troponins were not significantly associated with increased mortality.
Conclusions
cTn elevations are frequent in AHF patients without ACS. cTnI is more often elevated than cTnT. Both cTnI and cTnT elevations are associated with increased mortality proportional to the degree elevation but they do not act as independent risk markers.
ARTICLE
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