title: Prognostic Importance of Sex-Specific Cardiac Troponin T 99(th) Percentiles in Suspected Acute Coronary Syndrome.
abstract: 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.
  
  
  
  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).
  
  
  
  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.
  
  
  
  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.
authors.affiliation: Department of Medical Sciences, Uppsala University, Sweden. Electronic address: kai.eggers@ucr.uu.se.
authors.forename: Kai M
authors.initials: KM
authors.lastname: Eggers
authors.affiliation: Department of Medicine, Section of Cardiology, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Jernberg
authors.affiliation: Department of Medical Sciences, Uppsala University, Sweden; Uppsala Clinical Research Center, Uppsala University, Sweden.
authors.forename: Bertil
authors.initials: B
authors.lastname: Lindahl
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood* / Q000401:mortality; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T
keywords: Acute coronary syndrome; Cardiac troponin; Cutoff; Risk prediction; Sex