Background: Troponin elevation above the upper limit of normal (ULN) is diagnostic of myocardial infarction, but interpretation of "gray-zone" troponin elevations (1 to 1.5x ULN) remains uncertain. Using the CRUSADE database, we explored relationships between sex and treatment and outcomes among patients with troponin 1 to 1.5x ULN.
Methods and results: We compared treatment and outcomes among women and men using logistic generalized estimating equation method. Overall, 5049 of 85 671 (5.9%) non-ST-segment elevation acute coronary syndromes patients (2156 women, 2893 men) had troponin 1 to 1.5x ULN within 24 hours of presentation. Compared with troponin >1.5x ULN, "gray-zone" patients less often received all guidelines-indicated acute (mean composite score, 63% versus 72%) and discharge therapies (mean composite score, 73% versus 78%), but received them more frequently than patients with troponin <1x ULN (mean composite scores, 58% acute and 67% discharge). Among "gray-zone" patients, acute and discharge therapy use was similar between women and men, except acute aspirin (adjusted odds ratio, 0.80 [95% CI, 0.65 to 0.98]) and discharge angiotensin-converting enzyme inhibitors (adjusted odds ratio, 0.77 [95% CI, 0.67 to 0.88]). "Gray-zone" patients had lower mortality (2.3%) than the >1.5x ULN (4.5%) group but higher than the <1x ULN group (1.1%). Outcomes were similar among "gray-zone" women and men (adjusted odds ratios: death, 0.88 [95% CI, 0.58 to 1.35]; death/myocardial infarction, 0.77 [95% CI, 0.55 to 1.06]; transfusion, 1.04 [95% CI, 0.85 to 1.27]).
Conclusions: Patients with non-ST-segment elevation acute coronary syndromes and low-level troponin elevations had lower overall risk and received less aggressive guidelines-based treatment than those with greater troponin elevations, but treatment patterns were largely similar by sex across troponin elevation groups.