Prognostic Importance of Myocardial Injury in Critically Ill Dogs with Systemic Inflammation

BACKGROUND: In noncardiac critical disease in humans, myocardial injury as detected by cardiac troponin I and T (cTnI and cTnT) has been linked to high intensive care unit (ICU) death independent of prognostic composite scoring. HYPOTHESIS: Presence of myocardial injury predicts short-term death in critically ill dogs with systemic inflammation and provides additional prognostic information when combined with established canine prognostic composite scores. ANIMALS: Forty-two dogs admitted to the ICU with evidence of systemic inflammation and no primary cardiac disease. METHODS: Prospective cohort study. Blood samples were obtained at ICU admission for the measurement of cTnI and cTnT, C-reactive protein, and several cytokines. The acute patient physiologic and laboratory evaluation (APPLE) score and the survival prediction index were calculated within the first 24 hours of admission. Receiver operating characteristic (ROC) curves were used to examine the prognostic capacity of each biomarker and severity score. Multiple logistic regression analysis was performed to evaluate whether cardiac markers significantly contributed to severity scores. RESULTS: Twenty-eight day case fatality rate was 26% (11/42 dogs). cTnI concentrations were (median range) 0.416 0.004-141.5 ng/mL and cTnT concentrations were 13.5 <13-3,744 ng/L. cTnI, cTnT, and the APPLE score were all significant prognosticators with areas under the ROC curves 95% CI of 0.801 0.649; 0.907, 0.790 0.637; 0.900, and 0.776 0.621; 0.889, respectively. cTnI significantly contributed to the APPLE score in providing additional prognostic specificity (P = .025). CONCLUSIONS AND CLINICAL IMPORTANCE: Markers of myocardial injury predict short-term death in dogs with systemic inflammation and cTnI significantly contributes to the APPLE score.