HFSA: Catheter ablation versus drug therapy for VT

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BOSTON—Catheter ablation may have the ability to reduce the recurrence of ventricular tachycardia (VT), however, which is the best option for these arrhythmia patients: drug therapy or ablation? William G. Stevenson, MD, director of the clinical cardiac electrophysiology program at Brigham and Women’s Hospital in Boston, asked during a Sept. 19 presentation at the 15th annual Heart Failure Society of America (HFSA) scientific meeting.

“What is the reason to suppress ventricular arrhythmias?” asked Stevenson. “To prevent ICD [implantable cardioverter-defibrillator] shocks," he said.

He said that ICDs can terminate VT after it occurs; however, ICDs cannot prevent VT.

“ICD shocks reduce a patients' quality of life,” Stevenson offered. “Ventricular tachycardia is associated with an increased risk of death and heart failure hospitalizations in patients with an ICD, even when the ICD promptly stops the occurrence of ventricular tachycardia within 20 seconds.

“Is VT a prognostic marker or does it directly contribute to mortality and heart failure?” asked Stevenson. “Or is there something about the recurrence about the arrhythmia and ICD shock that may contribute directly to mortality?” Stevenson said that these data are not yet known.

Risk increases when patients experience an instance of ventricular tachycardia. Which tactic is better to fix these types of arrhythmias: ablation or drug therapy?

Stevenson referred to the OPTIC trial that enrolled 412 ICD patients, who had spontaneous VT and a left ventricular ejection fraction of at least 40 percent. Patients were randomized to receive a beta-blocker, sotalol or a beta-blocker plus amiodarone; 80 percent of patients within the study had MI.

During the trial, spontaneous arrhythmias cropped up in 45 percent of patients administered a beta-blocker and only 13 percent of patients administered the combination beta-blocker and amiodarone. However, adverse effects of drug therapy led to the discontinuation of therapy. In fact, 19.2 percent of patients administered amiodarone plus beta-blocker discontinued drug therapy and 23 percent of those administered sotalol (Betapace) discontinued therapy due to adverse events.

Overall, drug withdrawal in all VT trials is 29 percent when amiodarone is administered, Stevenson offered.

When deciding whether catheter ablation or drug therapy is your best bet in VT patients, one must first decipher whether the VT is polymorphic or monomorphic, Stevenson said.

“Substrate guided ablation is useful for mapping and ablation during stable sinus rhythm for instances of ventricular tachycardia that are hemodynamically unstable,” Stevenson offered. While catheter ablation techniques have been shown to reduce VT recurrence, there are complications, including a mortality rate of 3 percent. However, Stevenson said that this 3 percent rate is not surprising and “if you can’t get a patient's VT under control it’s obviously not going to end well.”

Additionally, Stevenson noted that catheter ablation for recurrent sustained monomorphic VT can reduce ICD therapies in more than 70 percent of patient cases.

“So, how do you decide whether to use catheter ablation or drug therapy?” Stevenson asked.

While he concluded that ablation may be a good option for patients with cases of monomorphic VT, he said it will be imperative to have access to an experienced center. Additionally, he said that the procedure may be useful for patients with incessant or frequent VT or for those who are at an increased risk for drug toxicities.

On the other hand, drug therapy may be preferred in patients with cases of polymorphic VT that are persistent or if one does not have access to an experienced center. Stevenson concluded that patient selection will play the most important role in this decision.