The relationship between mortality and preexisting cardiac disease in 5,971 trauma patients.

BACKGROUND: We observed significant morbidity and mortality in patients with preexisting cardiac disease who suffer severe traumatic injuries. We wondered about the types of injury seen and about the cardiac risks factors that predispose to worse outcomes in these patients. Our hypothesis is that significant cardiac comorbidity is associated with adverse trauma outcomes.
METHODS: We reviewed 10,144 trauma admissions to the University of Kentucky during a 5-year period (2002-2007) in patients 21 years or older. The types and extent of injuries were characterized, and risk factors for poor outcome were assessed. Propensity analysis assessed variable interaction and adjusted for important multivariate cardiovascular risk factors.
RESULTS: Of the 10,144 adult trauma patients, there was adequate cardiovascular history before emergency treatment in 5,971 patients (58.9%). Of the 700 trauma deaths, 236 (33.7%) had adequate medical history to allow accurate assessment of cardiovascular disease. Significant multivariate predictors of trauma-related death included older age (odds ratio [OR] = 0.938), injury severity score (OR = 0.893 per unit score), major burn (OR = 5.907), assault with a weapon (OR = 3.205), systolic blood pressure divided by Glasgow coma score (OR = 0.958 per score unit), and female (OR = 1.629). In the cohort of 236 deaths with adequate medical history, severe head and chest injuries caused death in 187 patients (79.2%). Significant propensity-adjusted cardiovascular risks of trauma death included preinjury warfarin use (OR = 2.309, p = 0.001), congestive heart failure (CHF) (OR = 2.060, p = 0.011), and preinjury beta-blocker use (OR = 2.62, p = 0.001). The highest mortality rates occurred in patients with combinations of these cardiovascular risk factors. For example, patients on warfarin with CHF had a 26.3% mortality rate, whereas patients on warfarin and beta-blocker had a 27.3% mortality rate.
CONCLUSIONS: Preinjury cardiac risk factors, especially preinjury warfarin, beta-blocker use, and CHF, are independent multivariate predictors of mortality in patients suffering significant trauma. Although head and chest injuries are the most frequent causes of death, patients with more than one preinjury cardiac risk factor have 5 to 10 times the mortality risk compared with those without cardiac risks.