INFLUENCE OF COMORBIDITY ON THE OUTCOME OF PATIENTS TREATED FOR OUT-OF-HOSPITAL VENTRICULAR-FIBRILLATION

Background A number of factors have previously been shown to be predic tive of survival from out-of-hospital ventricular fibrillation. These include witnessed collapse, prompt initiation of cardiopulmonary resus citation, early application of defibrillation, and younger age. Arrest s occurring away from home are also associated with improved survival. Additionally, hospital mortality after successful resuscitation has b een related to a history of congestive heart failure as well as to som e of the factors noted above. An association of prearrest comorbidity with outcome has not been systematically evaluated. Methods and Result s We define here a comorbidity index, which is constructed from histor ies of chronic conditions as well as a number of recent symptoms in 28 2 victims of our-of-hospital VF. This indicator of comorbidity is stro ngly associated with outcome (P=.004). However, when analyzing a compr ehensive set of predictors of survival after out-of-hospital ventricul ar fibrillation, including the index of comorbidity, we could identify overall only about one fourth of the variation that one might hope to account for. Conclusions Comorbidity appears to be an important (but usually overlooked) predictor of survival from out-of-hospital ventric ular fibrillation. However, most of the statistical variability in pre dicting survival remains unexplained when we consider comorbidity in c onjunction with previously identified predictors of survival.