Comparison of outcomes of illicit drug users and nonusers hospitalized with heart failure

The long-term effects of illicit drug use (IDU) on the clinical outcome of patients with heart failure (HF) are not well described. The objective of the present study was to describe the characteristics of patients with HF who used illicit drugs and to determine the effects of IDU on the clinical outcomes such as in-hospital mortality and hospital readmission for HF. A retrospective cohort study was conducted that included all patients admitted with HF from June 2003 to September 2004 and followed up until 2008 at a university hospital serving an at-risk population. The patients were divided into 2 groups: IDU and non-IDU according to self-reported use or positive laboratory results. The outcome measures were in-hospital mortality, HF readmission rate, interval to readmission for HF, and average brain natriuretic peptide and troponin levels throughout the follow-up period. Of 646 reviewed records, 542, representing 357 patients, were included in the present analysis. Of the 357 patients, 53 patients were in the IDU group and 304 were in the non-IDU group. Kaplan-Meier log-rank analysis and Cox proportional hazard analysis showed that IDU was associated with a shorter interval to readmission for HF (hazard ratio 3.8, 95% confidence interval 2.3 to 10.7, p <0.0001) but not with in-hospital mortality (hazard ratio 0.7, 95% confidence interval 0.3 to 1.7, p = 0.4). Multiple linear regression analysis identified IDU as an independent variable for the HF readmission rate (p = 0.0001) but not for average brain natriuretic peptide or average troponin levels. In conclusion, the results of the present study have demonstrated that IDU was associated with a decreased interval to readmission for HF and greater HF readmission rates.