Kai M Eggers1, Tomas Jernberg2, Bertil Lindahl3. 1. Department of Medical Sciences, Uppsala University, Sweden. Electronic address: kai.eggers@ucr.uu.se. 2. Department of Medicine, Section of Cardiology, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden. 3. Department of Medical Sciences, Uppsala University, Sweden; Uppsala Clinical Research Center, Uppsala University, Sweden.
Abstract
OBJECTIVE: Cardiac troponin levels differ between the sexes, with higher values commonly seen in men. The use of sex-specific troponin thresholds is, thus, subject of an ongoing debate. We assessed whether sex-specific cardiac troponin T (cTnT) 99(th) percentiles would improve risk prediction in patients admitted to Swedish coronary care units due to suspected acute coronary syndrome. METHODS: In this retrospective register-based study (48,250 patients), we investigated the prediction of all-cause mortality and the composite of cardiovascular death or nonfatal myocardial infarction within 1 year using the single 99(th) cTnT percentile (>14 ng/L) or sex-specific cTnT 99(th) percentiles (>16/9 ng/L). RESULTS: A total of 1078 men (3.0%) with cTnT 15-16 ng/L and 1854 women (8.4%) with cTnT 10-14 ng/L would have been reclassified regarding their cTnT status by the means of sex-specific 99(th) percentiles. The prevalence of cardiovascular risk factors and crude event rates increased across higher cTnT strata in both men and women. Multivariable-adjusted Cox models, however, did not demonstrate better risk prediction by sex-specific 99(th) percentiles. Assessing cTnT as a continuous variable demonstrated an increase in multivariable-adjusted risk starting at levels around 10-12 ng/L in both men and women. CONCLUSIONS: We found no evidence supporting the use of sex-specific cTnT 99(th) percentiles in men and women admitted because of suspected acute coronary syndrome. This likely depends on sex-specific differences in disease mechanisms associated with small cTnT elevations. From a pragmatic perspective, a single cTnT cutoff slightly below 14 ng/L seems to be preferable as a threshold for medical decision-making.
OBJECTIVE: Cardiac troponin levels differ between the sexes, with higher values commonly seen in men. The use of sex-specific troponin thresholds is, thus, subject of an ongoing debate. We assessed whether sex-specific cardiac troponin T (cTnT) 99(th) percentiles would improve risk prediction in patients admitted to Swedish coronary care units due to suspected acute coronary syndrome. METHODS: In this retrospective register-based study (48,250 patients), we investigated the prediction of all-cause mortality and the composite of cardiovascular death or nonfatal myocardial infarction within 1 year using the single 99(th) cTnT percentile (>14 ng/L) or sex-specific cTnT 99(th) percentiles (>16/9 ng/L). RESULTS: A total of 1078 men (3.0%) with cTnT 15-16 ng/L and 1854 women (8.4%) with cTnT 10-14 ng/L would have been reclassified regarding their cTnT status by the means of sex-specific 99(th) percentiles. The prevalence of cardiovascular risk factors and crude event rates increased across higher cTnT strata in both men and women. Multivariable-adjusted Cox models, however, did not demonstrate better risk prediction by sex-specific 99(th) percentiles. Assessing cTnT as a continuous variable demonstrated an increase in multivariable-adjusted risk starting at levels around 10-12 ng/L in both men and women. CONCLUSIONS: We found no evidence supporting the use of sex-specific cTnT 99(th) percentiles in men and women admitted because of suspected acute coronary syndrome. This likely depends on sex-specific differences in disease mechanisms associated with small cTnT elevations. From a pragmatic perspective, a single cTnT cutoff slightly below 14 ng/L seems to be preferable as a threshold for medical decision-making.