Sudden death or cardiac arrest occurs when the heart goes into a fatal heart rhythm called ventricular tachycardia (VT). These fatal rhythms almost invariable occur due to underlying scar tissue in the heart from a variety of heart diseases. Cardiac arrest survivors receive a specialised form of pacemaker, called an implanted cardiac defibrillator (ICD) placed under the skin that automatically delivers an internal shock if VT recurs, thereby aborting otherwise inevitable sudden death. However, ICDs do not prevent VT from occurring in the first place, they only treat VT when it occurs. Cardiac arrest survivors will experience recurrent VT at an annual rate of 30-50 per cent/year. Recurrent shocks are painful, cause tremendous psychological trauma and lead to increased risk of death. They also lead to frequent hospital visits, and exponential health care utilisation.
Recurrent VT can be treated with strong doses of anti-arrhythmic (AAD) medications but these tend to be minimally effective, and with potent side effects. An alternative is to perform a cardiac ablation (CA) procedure that entails electrical wires navigated up through the veins to the heart, to identify, cauterise and thus destroy the electrical short circuits causing VT. Some studies have shown that CA is highly effective in curing VT, reducing VT burden and improving quality of life in patients with scar tissue due to coronary heart disease (blocked arteries). It is unknown if CA is just as effective for a large population of patients who have scar related to genetic (familial) disease, or infection or inflammation of the heart (termed non-ischemic cardiomyopathy). This group is important as the incidence of non-ischemic cardiomyopathy is rising; such patients tend to be young (30-60 years), and are very likely to experience toxic side effects from AAD and thus stand to gain the most benefit from CA. This research proposal is for a randomised trial that will examine if CA is superior to AAD in the treatment of VT in patients with non-ischemic cardiomyopathy.
Results of this study will be disseminated through clinicians at scientific meetings/publication in journals (and via their social media channels), and by engagement of Sydney Health Partners, NSW Agency for Clinical Innovation and major national/international cardiac societies. Findings will lead to major practice and policy change nationally and globally. Engagement with patients and the general public will be via novel e-health social media channels such as Facebook and Twitter, as well as involvement of charitable foundations.