A Prospective, Multicentre Randomised Controlled Trial Comparing Catheter Ablation Versus Antiarrhythmic Drugs in Patients With Structural Heart Disease Related Ventricular Tachycardia: The CAAD-VT Trial Protocol.

IMPORTANCE: Randomised trials have shown that catheter ablation (CA) is superior to medical therapy for ventricular tachycardia (VT) largely in patients with ischaemic heart disease. Whether this translates to patients with all forms and stages of structural heart disease (SHD-e.g., non-ischaemic heart disease) is unclear. This trial will help clarify whether catheter ablation offers superior outcomes compared to medical therapy for VT in all patients with SHD. OBJECTIVE: To determine in patients with SHD and spontaneous or inducible VT, if catheter ablation is more efficacious than medical therapy in control of VT during follow-up. DESIGN: Randomised controlled trial including 162 patients, with an allocation ratio of 1:1, stratified by left ventricular ejection fraction (LVEF) and geographical region of site, with a median follow-up of 18-months and a minimum follow-up of 1 year. SETTING: Multicentre study performed in centres across Australia. PARTICIPANTS: Structural heart disease patients with sustained VT or inducible VT (n=162). INTERVENTION: Early treatment, within 30 days of randomisation, with catheter ablation (intervention) or initial treatment with antiarrhythmic drugs only (control). MAIN OUTCOMES, MEASURES, AND RESULTS: Primary endpoint will be a composite of recurrent VT, VT storm (≥3 VT episodes in 24 hrs or incessant VT), or death. Secondary outcomes will include each of the individual primary endpoints, VT burden (number of VT episodes in the 6 months preceding intervention compared to the 6 months after intervention), cardiovascular hospitalisation, mortality (including all-cause mortality, cardiac death, and non-cardiac death) and LVEF (assessed by transthoracic echocardiography from baseline to 6-, 12-, 24- and 36-months post intervention). CONCLUSIONS AND RELEVANCE: The Catheter Ablation versus Anti-arrhythmic Drugs for Ventricular Tachycardia (CAAD-VT) trial will help determine whether catheter ablation is superior to antiarrhythmic drug therapy alone, in patients with SHD-related VT. TRIAL REGISTRY: Australian New Zealand Clinical Trials Registry (ANZCTR) TRIAL REGISTRATION ID: ACTRN12620000045910 TRIAL REGISTRATION URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377617&isReview=true.

Early Catheter Ablation Versus Initial Medical Therapy for Ventricular Tachycardia Storm.

BACKGROUND: Ventricular tachycardia (VT) storm is associated with significantly increased morbidity, mortality, and exponential healthcare utilization. Although catheter ablation (CA) may be curative, there are limited data directly comparing outcomes of early CA with initial medical therapy. METHODS: We compared outcomes of patients presenting with VT storm treated with initial CA versus those treated with initial medical therapy during their first storm presentation in an observational study. Retrospective data from the host institution from January 2014 to April 2020 of 129 patients with their first VT storm presentation were analyzed (58 underwent initial CA, 71 underwent treatment with initial medical therapy). Outcomes were compared in follow-up. RESULTS: Median time to initial CA was 6 days. Over a median follow-up of 702 days, patients who underwent initial CA compared with those treated with initial medical therapy had significantly less: (i) VA recurrence (43% versus 92%; P=0.002); (ii) VT storm recurrence (28% versus 73%; P<0.001); (iii) composite end point of death, heart transplant, VT storm recurrence, and VT-related hospitalization (47% versus 89%; P=0.002); (iv) iatrogenic complications (at 12 months: 17% versus 45%; P<0.001); (v) cardiovascular-related hospitalizations (50% versus 89%; P=0.01); (vi) total number of hospitalizations (median 1 versus 4; P<0.001); and (vi) cumulative days in hospital (median 0.5 versus 18; P<0.001). There were no intraprocedural deaths in patients treated with early CA. CONCLUSION: In an observational setting in which patients presenting with storm, early CA appears superior to initial medical therapy in terms of VT recurrence, storm recurrence, iatrogenic complications, cardiovascular hospitalizations, and cumulative days in hospital in follow-up.

Comparison of 6 and 7 French guiding catheters for percutaneous coronary intervention: results of a randomised trial with a vascular ultrasound endpoint.

OBJECTIVE: To perform a randomized, ultrasound controlled trial to define the procedural and clinical advantages and limitations of 6 French (Fr) compared with 7 Fr transfemoral coronary intervention in the stenting era. BACKGROUND: The use of 7 Fr guiding catheters may facilitate Percutaneous Coronary Intervention (PCI), but may be associated with increased vascular complications when compared with 6 Fr catheters. METHODS: Patients undergoing PCI considered suitable for either a 6 or 7 Fr sheath and guiding catheter system were included. All vascular sheaths were removed with assisted manual compression. Femoral vascular ultrasounds were performed prior to hospital discharge and interpreted by a vascular surgeon blinded to treatment assignment. The primary endpoint was a composite of significant vascular complications including major haematoma, retroperitoneal haematoma, pseudoaneurysm, arterio-venous fistula, or femoral venous or arterial thrombosis. RESULTS: During the study, 414 patients (mean age 61+/-11 years, 27% females) were randomly assigned to 6 Fr or 7 Fr sheath groups. The incidence of major vascular complications was 5.7% in the 6 Fr group and 3.9% in the 7 Fr group (P=0.383). There was no significant difference in procedural or angiographic success between the groups. The use of contrast volume was higher in the 7 Fr group (157+/-58 ml vs. 144+/-58 ml; P=0.029). There was a trend toward better operator satisfaction with the 7 Fr guide (P=0.08). CONCLUSIONS: This prospective, randomized trial indicates no reduction in major peripheral vascular complications with the use of smaller guiding catheters in PCI. There was less contrast used in the 6 Fr group, which may benefit some patient subsets, however operators tended to prefer the larger 7 Fr system. The target coronary anatomy and need for complex device intervention should mandate the choice of guiding catheter size, not a perceived impact on vascular complications.