High-sensitivity cardiac troponin assays have identified differences in the normal reference range for cardiac troponin between men and women. Current diagnostic thresholds may lead to under diagnosis of myocardial infarction in women and contribute to sex inequalities in treatments and outcomes.

Consecutive patients with suspected acute coronary syndrome ( n=1126, 46% women ) were prospectively identified over a three-month period in a United Kingdom regional cardiac Center. The diagnosis of myocardial infarction was adjudicated by two independent cardiologists using a high-sensitivity troponin I assay with sex-specific diagnostic thresholds ( men 34 ng/L and women 16 ng/L ) and compared to current practice where a contemporary sensitive assay ( 50 ng/L; single cutoff ) was used to guide patient care.

Use of a high-sensitivity cardiac troponin assay markedly increased the diagnosis of myocardial infarction in women ( from 13% to 23%; P less than 0.001 ) but had a minimal effect in men ( from 23 to 24%, P=0. 021 ).

Diagnostic accuracy was greater with the high-sensitivity assay compared to the contemporary assay in women ( area under the curve [ AUC ] 0.91 versus 0.70 ) with smaller improvements in men ( 0.93 versus 0.86 ).

Women with an adjudicated diagnosis of myocardial infarction were less likely to be referred to a cardiologist ( 52% versus 87% ), or to undergo coronary angiography ( 28% versus 67% ) or revascularisation ( 18% versus 58% ) compared to men ( P less than 0.001 for all ).

In comparison to men, women with suspected acute coronary syndrome are more likely to be misdiagnosed and under treated for myocardial infarction.
Whilst having little effect in men, a high-sensitivity troponin assay doubles the diagnosis of myocardial infarction in women. ( Xagena )

Source: European Society of Cardiology ( ESC ) Congress, 2013

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