Effects of intravenous dofetilide in patients with frequent premature ventricular contractions: a clinical trial

Role of dofetilide in patients with ventricular arrhythmias

BACKGROUND OR PURPOSE

To assess effectiveness of dofetilide in reducing the burden of ventricular arrhythmias (VAs).

BACKGROUND

Prior small sample studies show that dofetilide has benefit in reducing VA. However, large sample investigations with long-term follow-up are lacking.

METHODS

Two hundred seventeen consecutive patients admitted between January 2015 and December 2021 for dofetilide initiation for control of VA were assessed. Dofetilide was successfully started in 176 patients (81%) and had to be discontinued in the remaining 41 patients (19%). Dofetilide was initiated for control of ventricular tachycardia (VT) in 136 patients (77%), whereas 40 (23%) patients were initiated on dofetilide for reducing the burden of premature ventricular complexes (PVCs).

RESULTS

The mean follow-up was 24 ± 7 months. In total, among the 136 VT patients, 33 (24%) died, 11 (8%) received a left ventricular assist device (LVAD), and 3 (2%) received a heart transplant during follow-up. Dofetilide was discontinued in 117 (86%) patients due to lack of sustained effectiveness during follow-up. Dofetilide use was associated with similar odds of the composite outcome of all-cause mortality/LVAD/heart transplant (OR: 0.97, 0.55-4.23) in patients with ischemic cardiomyopathy (ICM) compared to those with non-ischemic cardiomyopathy (NICM). Dofetilide did not reduce PVC burden during follow-up in the 40 patients with PVCs (mean baseline PVC burden: 15%, at 1-year follow-up: 14%).

CONCLUSIONS

Dofetilide use was less effective in reducing VA burden in our cohort of patients. Randomized controlled studies are needed to confirm our findings.

Infrequent intraprocedural premature ventricular complexes: implications for ablation outcome

BACKGROUND

Frequent premature ventricular complexes (PVCs) can be eliminated with an ablation procedure. Ablation success rates have been reported to be in the 80% range. Reasons for failure of ablation have not been described in detail. The purpose of this study was to determine whether the paucity of PVCs at the beginning of the ablation procedure affects the outcome.

METHODS

Catheter ablation was attempted in a consecutive series of 194 patients (age: 50 ± 14 years, 91 male, ejection fraction: 56.4 ± 8.4%) with frequent idiopathic PVCs. Based on receiver operator characteristics (ROC) analysis, patients were divided into 2 groups: Patients with frequent PVCs (≥32 PVCs within the first 30 minutes of the procedure: n = 135 [70%]); and patients with infrequent PVCs (<32 PVCs within the first 30 minutes of the procedure: n = 59 [30%]). Procedural outcomes were compared at 3 months postablation. A successful ablation was defined as a ≥80% reduction in the PVC burden compared to baseline.

RESULTS

A successful procedure was performed in 148 patients (76%) resulting in a decrease in the PVC burden from 19.1 ± 13.6% to 0.38 ± 0.98%(P < 0.0001). Patients with frequent intraprocedural PVCs had a higher success rate than patients with infrequent intraprocedural PVCs (85% vs. 56%, P = 0.0001). Administration of sedation was no different in the 2 groups. The paucity of PVCs was independent of the site of origin in predicting procedural failure (OR: 6.9, 95% CI: 3.0-16.2 P = 0.0001).

CONCLUSION

Paucity of PVCs at the beginning of an ablation procedure is associated with a lower ablation success rate independent of the site of origin.