Abstract P591: A Significant Dose-Response in Elevated Troponin Levels for Case-Fatality Among Patients With Acute Ischemic Stroke

Abstract

Introduction: About 21% of acute ischemic stroke (AIS) patients present to medical attention with an elevated cardiac troponin (cTn). Previously, we described that elevated cTn is associated with an increased case-fatality at 1 year. However, it is not clear if there is a dose-dependent relationship between cTn and case-fatality, or if this effect is related to causes of death. Methods: Within a catchment area of 1.3 million we screened local hospital admissions using ICD-9/10 codes 430-436/I60-I68, G45-46 in 2014/2015, and ascertained all physician-confirmed AIS cases by retrospective chart review. Positive cTn was defined by the standard 99th percentile. To account for by hospital variance in cTn results in machine brands and normal ranges, cTn values were log-transformed and centered. Case fatality at 1 year and cause of death was obtained from the National Death Index database. Logistic regression evaluated the impact of cTn on case fatality, and included demographic and clinical risk factors in the model. The percentage with all-cause and cardiac/non-cardiac case-fatality was computed by quartiles of centered cTn levels and compared using the chi-square test. Results: In 2014/2015, there were 2989 AIS cases ascertained, which were 53% female, 30% black, with a mean age of 70 (SD 14). 441 patients with hypertropinemia were included in the analysis. See Table for case fatality at 1 year by quartile of centered cTn levels. There was no association between cTN and non-cardiac case-fatality. After adjustment for demographic and clinical characteristics, every 0.5 point increase in the centered cTn level increased the cardiac case-fatality by OR 1.19 (1.09, 1.31), p<0.01. Discussion: We found that the impact of hypertropinemia on case fatality after AIS appears to be a dose-dependent association: as cTn increases, so does the cardiac case-fatality. This suggests that the degree of cTn elevation is likely an important prognostic marker for cardiac death in AIS patients.