Cardiac Troponin I in Non-ST-Elevation ACS-- Importance of Gender
Cardiac Troponin I in Non-ST-Elevation ACS-- Importance of Gender
Background Measurement of high-sensitivity cardiac troponin levels is increasingly used in non–ST-elevation acute coronary syndrome (NSTE-ACS). However, studies investigating the distribution and prognostic implications of high-sensitivity troponin levels in men and women separately are currently lacking.
Methods Cardiac troponin I (cTnI) levels were determined using a high-sensitivity assay (Abbott Laboratories, Abbott Park, IL) in 1,677 male and 1,073 female NSTE-ACS patients participating in the GUSTO IV study. The prognostic associations of cTnI to outcome (30-day composite end point of recurrent myocardial infarction and 1-year mortality) were assessed in multivariable models, using cTnI both as a continuous variable and dichotomized at different sets of single and gender-specific 99th percentiles.
Results Median cTnI levels were 947 and 175 ng/L in men and women, respectively (P < .001). The adjusted odds ratios for cTnI (ln) were similar in men and women. The adjusted odds ratios for cTnI above the tested 99th percentiles levels in contrast were twice as high in women compared with men. This was a consequence of differences in the cTnI distribution and risk gradients across cTnI levels, in particular due to lower event rates in women without cTnI elevation. Gender-specific cutoffs did not improve risk prediction.
Conclusions Despite overall lower levels, cTnI above the tested 99th percentiles exhibited stronger prognostic information in women with NSTE-ACS compared with men. This likely reflects differences in the pathophysiology and the clinical presentation in NSTE-ACS. Our data, thus, emphasize that women with symptoms of unstable coronary artery disease encompass a broader risk panorama than men.
Circulating cardiac troponin levels are essential for diagnostic assessment and risk prediction in patients with symptoms of unstable coronary artery disease. To discriminate normal from elevated concentrations, the 99th percentile of levels determined in healthy reference populations should be used. With the implementation of high-sensitivity assays, it has become clear that cardiac troponin levels and their 99th percentiles differ between the genders with higher concentrations commonly found in men. However, only few studies have assessed differences in the release pattern and prognostic implications of cardiac troponin levels in men and women with unstable coronary artery disease, and none have done so using high-sensitivity assays.
The aim of the present study was to further investigate this issue in a large sample of mainly conservatively managed patients with non–ST-elevation acute coronary syndrome (NSTE-ACS) in whom cardiac troponin I (cTnI) levels had been measured using a novel high-sensitivity assay.
Abstract and Introduction
Abstract
Background Measurement of high-sensitivity cardiac troponin levels is increasingly used in non–ST-elevation acute coronary syndrome (NSTE-ACS). However, studies investigating the distribution and prognostic implications of high-sensitivity troponin levels in men and women separately are currently lacking.
Methods Cardiac troponin I (cTnI) levels were determined using a high-sensitivity assay (Abbott Laboratories, Abbott Park, IL) in 1,677 male and 1,073 female NSTE-ACS patients participating in the GUSTO IV study. The prognostic associations of cTnI to outcome (30-day composite end point of recurrent myocardial infarction and 1-year mortality) were assessed in multivariable models, using cTnI both as a continuous variable and dichotomized at different sets of single and gender-specific 99th percentiles.
Results Median cTnI levels were 947 and 175 ng/L in men and women, respectively (P < .001). The adjusted odds ratios for cTnI (ln) were similar in men and women. The adjusted odds ratios for cTnI above the tested 99th percentiles levels in contrast were twice as high in women compared with men. This was a consequence of differences in the cTnI distribution and risk gradients across cTnI levels, in particular due to lower event rates in women without cTnI elevation. Gender-specific cutoffs did not improve risk prediction.
Conclusions Despite overall lower levels, cTnI above the tested 99th percentiles exhibited stronger prognostic information in women with NSTE-ACS compared with men. This likely reflects differences in the pathophysiology and the clinical presentation in NSTE-ACS. Our data, thus, emphasize that women with symptoms of unstable coronary artery disease encompass a broader risk panorama than men.
Introduction
Circulating cardiac troponin levels are essential for diagnostic assessment and risk prediction in patients with symptoms of unstable coronary artery disease. To discriminate normal from elevated concentrations, the 99th percentile of levels determined in healthy reference populations should be used. With the implementation of high-sensitivity assays, it has become clear that cardiac troponin levels and their 99th percentiles differ between the genders with higher concentrations commonly found in men. However, only few studies have assessed differences in the release pattern and prognostic implications of cardiac troponin levels in men and women with unstable coronary artery disease, and none have done so using high-sensitivity assays.
The aim of the present study was to further investigate this issue in a large sample of mainly conservatively managed patients with non–ST-elevation acute coronary syndrome (NSTE-ACS) in whom cardiac troponin I (cTnI) levels had been measured using a novel high-sensitivity assay.