A Halifax-led clinical trial shows that catheter ablation is a better treatment for recurrent ventricular tachycardia (VT) than increased drug therapy. The international study was published today in the New England Journal of Medicine.
Ventricular tachycardia is a life-threatening heart condition that affects about 50,000 Canadians. VT 鈥� which is caused by heart scar (often from heart attacks) 鈥� can be difficult to manage. And until this trial, doctors didn鈥檛 know if high doses of antiarrhythmic drugs or a procedure led to better patient outcomes.
鈥淰entricular tachycardia is a rapid heartbeat that often causes sudden death,鈥� says Dr. John Sapp (pictured left), the study鈥檚 principal investigator and professor of cardiology at AV俱乐部 Medical School. 鈥淰T caused by heart attack scar can be very difficult to deal with, and can have quite a severe impact on both survival and quality of life.鈥�
Catheter ablation is a technique used to treat the dangerous heart rhythms by inserting wires into the heart to cauterize short circuits.
鈥淪ometimes we use medication to manage VT. Sometimes we use catheter ablation,鈥� says Dr. Sapp, director of the Heart Rhythm Service at the QEII Health Sciences Centre, where the study was coordinated. 鈥淯ntil now, we really didn鈥檛 know what the best treatment was when our first-line drug therapy didn鈥檛 work as well as we鈥檇 hoped.鈥�
For most, surgery better than high doses of drugs
The clinical trial involved 259 patients who had prior heart attacks, implantable cardioverter defibrillators, and recurrent VT.
鈥淗eart rhythm researchers and patients who live with VT worked together to discover that catheter ablation is a better option for most,鈥� says Dr. Sapp.
鈥淚n this trial, we studied arrhythmias that weren鈥檛 responding to medication. The patients who had ablation still remained on low doses of antiarrhythmic drugs, but we discovered that this was a better approach than just raising the drug doses.鈥�
Treatment decisions will still need to be individualized, and catheter ablation might not be for everyone.
鈥淎blation carries a bit more up front procedural risk, but high doses of the medications we use in an attempt to control VT tend to cause more issues in the long-term,鈥� says Dr. Sapp. 鈥淭he higher the dose, and the longer the strong antiarrhythmic drugs are administered, the higher the risk of adverse side effects.鈥�
The study was funded by the Canadian Institutes of Health Research, with additional support from St. Jude Medical and Biosense Webster.