J Ravichandran, MD, SY Woon, MD, YS Quek, MD, YC Lim, MD, EM Noor, K Suresh, R Vigneswaran, MD, VC Vasile, MD, AS Shah, MD MPH PhD, NL Mills, MD PhD, J Sickan, MD, A Beshiri, MD, AS Jaffe, MD

• •Our findings confirm those from previous studies using less sensitive troponin assays that, in the absence of complications such as hypertension, high-sensitivity cardiac troponin I values are low throughout all trimesters.
• •Two in a hundred pregnant women had troponin concentrations over the 99th centile sex specific threshold
• •High-sensitivity cardiac troponin concentrations were associated with a diagnosis of gestational hypertension or pre-eclampsia

Objective

To examine the association of circulating concentrations of high-sensitivity cardiac troponin I (hs-Tn) in the various trimesters of pregnancy in patients with and without hypertension.

Method

Prospective cross-sectional study of pregnant and post-natal women aged between 18-35 years of age with no coexisting disease. Serum samples were analysed for hs-TnI.

Results

A total of 880 women (mean age 29.1 years [SD 5.1]) were recruited with 129 (14%), 207 (24%) and 416 (47%) patients in the first, second and third trimester. Ninety (10%) participants were recruited in the postnatal period. During pregnancy 28 (3%) patients were classified as having pregnancy induced hypertension and 10 (1%) as pre-eclampsia. High-sensitivity cardiac troponin I was measurable in 546 (62%) participants with a median of 1 ng/L (range 0 to 783 ng/L). Troponin concentrations were greater than 99^th percentile in 19 (2%) individuals. Patients with pregnancy induced hypertension and pre-eclampsia had higher concentrations of hs-TnI (median 11 ng/L [IQR 6 to 22 ng/L] vs 12ng/L [IQR 3 to 98 ng/L] vs 1 ng/L [IQR 0 to 1 ng/L]). In logistic regression modelling hs-TnI concentration remained an independent predictor of pregnancy induced hypertension or pre-eclampsia in both unadjusted and adjusted models (OR 9.3 [95%CI 5.8 to 16.3] and 11.5 [95%CI 6.3 to 24.1] per doubling of hs-TnI concentrations).

Conclusion

Cardiac troponin measured using a high-sensitivity assay is quantifiable in the majority of young pregnant women with 2% of individuals having concentration above the 99^th centile sex specific threshold. Patients with pregnancy induced hypertension or pre-eclampsia had higher cardiac troponin concentrations. Cardiac troponin was a strong independent predictor of pregnancy induced hypertension or pre-eclampsia in pregnant and postnatal women.