Evaluation of sex-specific 0-h high-sensitivity cardiac troponin T thresholds for the risk stratification of non-ST-segment elevation myocardial infarction

OBJECTIVES: We aimed to evaluate sex-specific 0-h high-sensitivity cardiac troponin T (hs-cTnT) thresholds for risk stratification in patients with suspected non-ST-segment elevation myocardial infarction (NSTEMI). METHODS: This retrospective study investigated a derivation cohort of 6,691 (44.4 % female and aged 65 (57-72) years) and a validation cohort of 6,589 (48.4 % female and aged 63 (50-71) years) patients with suspected NSTEMI who visited the emergency department. Uniform and sex-specific thresholds were derived and validated, and their performances were compared. RESULTS: In the derivation cohort, 11.3 % of males and 5.4 % of females were diagnosed with adjudicated NSTEMI. As male-specific thresholds, 0-h hs-cTnT <10 ng/L ruled out 30.1 % of patients with an NPV of 99.6 % [95 % CI (99.0-99.9 %)], and 0-h hs-cTnT ≥65 ng/L ruled in 12.3 % of patients with a PPV of 70.5 % [95 % CI (66.0-74.6 %)]. As female-specific thresholds, 0-h hs-cTnT <9 ng/L ruled out 39.2 % of patients with an NPV of 99.9 % [95 % CI (99.4-100.0 %)], and 0-h hs-cTnT ≥45 ng/L ruled in 6.7 % of patients with a PPV of 71.7 % [95 % CI (64.8-77.8 %)]. The validation cohort showed similar results. Sex-specific and uniform thresholds did not significantly affect rule-in performance, whereas sex-specific thresholds increased female sensitivity by 1 % (99.7 vs. 98.7 %). Patient follow-up did not change when sex-specific thresholds were applied. CONCLUSIONS: Sex-specific 0-h hs-cTnT thresholds could slightly improve the safety in ruling out NSTEMI in females, but their role in terms of efficiency, rule-in performance and prognosis was similar to that of uniform thresholds.