Introduction: Myocardial injury is associated with adverse outcomes in the Acute Respiratory Distress Syndrome (ARDS), however the prognostic connotation of changes in cardiac troponin (cTn) levels in ARDS patients is not known.
Hypothesis: Patients with rising cTn levels over the first three days of mechanical ventilation for ARDS will have higher risk of adverse outcomes
Methods: We performed a nested multi-center cohort study of 916 ARDS patients enrolled in two previously completed ARDS Network trials: the ALVEOLI trial of higher versus lower positive end-expiratory pressure and the Fluid and Catheter Treatment Trial of permissive versus restrictive fluid management. We obtained plasma samples via the NIH BIOLINCC repository and measured cTn using the ARCHITECT STAT highly sensitive assay (Abbott Laboratories) at trial day 0 and 3. We constructed Cox proportional hazard models to determine the association between 60-day mortality and quintiles of percentage change in hsTnI (ΔhsTnI). We used linear regression to assess the association between ΔhsTnI and ventilator-free days.
Results: Quintile ranges for ΔhsTnI were 1.<-82%, 2. -82% - -68%, 3. -68% - -41%, 4. -41% - +31%, and 5. > +31% change from day 0 to day 3. In univariate analysis, quintile of ΔhsTnI was associated with mortality (Figure). After adjustment for day 0 troponin, trial assignment, age, sex, and degree of critical illness assessed by SOFA score, heart rate, and vasopressor use, rise in troponin more than 31% (highest quintile) was associated with 2.4 fold increased risk for mortality (95% CI 1.4-4.0, p=0.001) as well as fewer ventilator-free days.
Conclusion: Progressive myocardial injury in ARDS patients is associated with increased risk of death, independent of severity of critical illness. Investigation of the mechanisms underlying this relationship is warranted to guide possible strategies to mitigate myocardial injury in ARDS.