Peri-operative troponin monitoring using a prototype high-sensitivity cardiac troponin I (hs-cTnI) assay: comparisons with hs-cTnT and contemporary cTnI assays.

BACKGROUND

Non-cardiac surgery is associated with major vascular complications and higher incidences of elevated plasma troponin (cTn) concentration. Goal-directed therapy (GDT) is a stroke volume (SV)-guided approach to intravenous (IV) fluid therapy that improves tissue perfusion, oxygenation and reduces post-operative complications. In patients undergoing major gastro-intestinal surgery, we compared high sensitive and contemporary troponin assays and correlated results with patient outcome.

METHODS

Patients (n = 135) were randomized to receive IV fluid, guided by either the central venous pressure (CVP group, n = 45) or SV (± dopexamine inotrope, n = 45 per group). Serum was obtained pre- and post-operatively (0, 8 and 24 h) for troponin analysis by a prototype hs-cTnI assay (Abbott Laboratories), hs-cTnT (Roche Diagnostics) and contemporary cTnI (Beckman Coulter) assays.

RESULTS

All troponin measurements were increased (P ≤ 0.05) post-operatively but there was no difference (P > 0.05) amongst treatments. Post-operative increases were reported more frequently (P ≤ 0.05) and earlier with hs-cTnI. Temporal increases (P ≤ 0.05) were reported in patients with and without complications for hs-cTnI/T assays but only in the complications group for cTnI measurements. Elevations ≥99th centile occurred most often (P ≤ 0.05) for hs-cTnT measurements but with similar frequency for both outcome groups (all assays). Only the hs-cTnI assay showed an increased relative risk of mortality (P ≤ 0.05) for elevations ≥99th centile

CONCLUSIONS

Our study may suggest a possible preference for the hs-cTnI assay in the peri-operative setting; however, our findings should be verified for larger cohort studies where emerging reference range data is incorporated for improving risk prediction with hs-cTn assays.