Hepatitis C (HCV) and the Risk of QTC Prolongation - An Exploratory Cohort Study Among Opiate Users in Substitution

Abstract

Background: Prolongation of the QT interval is a known adverse event associated with certain pharmacotherapies, stress sensitivity, female gender, and low potassium level. It can potentially lead to fatal outcomes by inducing Torsade de pointes arrhythmia. Patients with opiate dependence are highly vulnerable to this condition due to the side effects of opioids and other accumulated risk factors. Methods: A convenience sample of 99 patients with opiate dependence receiving substitution treatment was recruited in an Inner-city substitution clinic in Germany. All patients were assessed with an ECG before and after taking opiate-agonist medication. Additional sociodemographic information and medical history were also collected. To determine the impact of different variables on QTc interval, a multiple variables linear regression with a stepwise selection was fitted. Findings: A concerning high prevalence of QT prolongation was observed among participants (32·3% before and 17·2% after medication intake). A significant finding in this study was the identification of Hepatitis C infection as an important risk factor in addition to baseline QTc prolongation, female gender, tobacco - dependence and QT-prolonging medications. Interpretation: The accumulation of risk factors for QT prolongation can have serious adverse consequences in patients with substance use disorder receiving opiate-agonist medications. Addressing these factors for example treatment of HCV infection needs to be considered as part of an integrated treatment program to prevent such consequences. Further research is required to explore the association of various factors with QTc prolongation, evaluate the impact of potential interventions on cardiac adverse events and also unravel the underlying mechanisms of QTc prolongation in this population. Funding: No grant funding. Declaration of Interest: Authors do not have any conflict of interests in regards to this study to disclose. Ethical Approval: The study design was approved by the ethics committee of the Ludwig Maximillian University (LMU) in Munich.