Membrane active non cardiac drugs and the risk of cardiac arrest

From a poster presentation at AHA 2016:

Introduction: Drugs may increase risk of ventricular tachycardia/fibrillation (VT/VF) and sudden cardiac arrest (SCA) in susceptible individuals by blocking cardiac ion channels. This also applies to drugs prescribed for non-cardiac conditions (non-cardiac drugs) if these drugs possess such properties. A well-known example is non-cardiac drugs that block cardiac potassium channels and cardiac repolarization. These drugs may cause excessive QT-interval prolongation and VT/VF in individuals with reduced repolarization reserve (e.g., Long QT syndrome). Similarly, non-cardiac drugs that block cardiac sodium channels and cardiac depolarization increase VT/VF risk in individuals with reduced depolarization reserve (e.g., Brugada syndrome). We hypothesized that non-cardiac depolarization blocking drugs (DB-drugs) are associated with increased VT/VF risk in the general population.

Methods and results: A community based case-control study was performed. Cases were out-of-hospital SCA victims with documented VT/VF included in the ARREST study in June 2005 - December 2009…

We included 1787 SCA cases (mean age 66 years, 77% male) and matched them to 7666 non-SCA controls. Non-cardiac DB-drugs were used by 81 cases (4.5%) and 249 controls (3.2%), and were associated with a 41% increased SCA risk (ORadj: 1.41 [95% CI: 1.10-1.83] P less than 0.05). Use of two or more DB-drugs was associated with a 5.6-fold risk (OR: 5.63 [1.95-16.23] P less than 0.05)…

Conclusion: Current use of non-cardiac DB-drugs is associated with increased risk of SCA, especially when two or more DB-drugs are used simultaneously.