Atrial Substrate Modification With Aggressive Blood Pressure Lowering to Prevent AF

Atrial Fibrillation Clinical Trial

— SMAC AF  

Official title:

Atrial Substrate Modification With Aggressive Blood Pressure Lowering to Prevent AF

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00438113
• Other study ID #: RP-001
• Status: Completed
• Phase: Phase 4
• First received: February 7, 2007
• Last updated: June 19, 2017
• Start date: December 2009
• Est. completion date: September 2016

Study information

• Verified date: June 2017
• Source: Nova Scotia Health Authority
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Atrial fibrillation (AF) is a very common arrhythmia causing many symptoms resulting in numerous hospitalizations. Catheter ablation is a technique that has evolved significantly to improve symptomatic recurrences, but does not offer a 100% cure rate. We hypothesize that the use of aggressive BP lowering will reduce the rate of recurrent AF after catheter ablation for AF. We plan a randomized clinical trial of aggressive BP lowering versus standard BP control to investigate this.

Description:

Background: Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with significant morbidity, necessitating treatment. Radiofrequency ablation for atrial fibrillation/flutter has evolved significantly and is the closest we have come to a 'cure' for these dysrhythmias. Recurrence of atrial fibrillation in those who have undergone radiofrequency ablation as treatment AF is up to 40% at one year and higher in those with persistent AF. Hypertension is a potent risk factor for AF, but recent studies have demonstrated that even modest increases in BP may lead to a higher incidence of AF. There is no clinical trial evidence to date that has investigated aggressive BP control in patients post radiofrequency ablation for AF to prevent recurrent AF.

Objective: We propose to determine if aggressive BP control reduces recurrent AF post ablation.

Hypothesis: Aggressive BP lowering will reduce the incidence of recurrent AF post ablation.

Research Plan:

Study Design. This will be a randomized open label trial in patients who are post catheter ablation for atrial fibrillation. Randomization to either aggressive BP lowering or standard BP control will occur three to six months prior to the procedure.

Study Population. Patients will be included if they have persistent or high burden paroxysmal (refractory to class 1 or 3 antiarrhythmic medication) and intend to have a catheter ablation procedure for AF.

Followup. Patients will be followed at 3 month intervals for the first year, then every 6 months to a maximum of 30 months or the common study end date has been reached (1 year post randomization for the last patient enrolled).

Statistical Analysis. Kaplan-Meier analysis of the primary outcome will be performed. A Cox proportional hazards model will be constructed to assess the effect of variables chosen a priori on the primary outcome.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 184
• Est. completion date: September 2016
• Est. primary completion date: September 2016
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Documented systolic blood pressure greater than or equal to 130 mmHg

• Undergoing planned catheter ablation for persistent AF (lasting > 7 days and < 365 days or requiring electrical or chemical cardioversion) OR High burden paroxysmal AF > 6 months (greater than or equal to 3 symptomatic episdes in past 6 months and refractory or inteolerant to at least 1 class 1 or 3 antiarrhythmic)

Exclusion Criteria:

• Permanent atrial fibrillation

• Contraindication to Accupril or any other ACE-I

• Women of child-bearing potential

• Life expectancy less than 1 year

• Less than 18 years of age

• Unable to give informed consent

• Known moderate to several renal dysfunction (eGFR < 30 ml/min/1.73m2)

• Prior AF catheter ablation

Related Conditions & MeSH terms

• Atrial Fibrillation

Intervention

Drug:
• Aggressive Blood Pressure control
Aggressive Blood Pressure therapy, alone or combination therapy, to reach a target BP equal to or less than 120/80 mmHg

Locations

Country	Name	City	State
Canada	QE II Health Sciences Centre	Halifax	Nova Scotia

Sponsors (2)

Lead Sponsor	Collaborator
Nova Scotia Health Authority	Nova Scotia Health Research Foundation

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Time to symptomatic AF/atrial tachycardia (AT)/atrial flutter (AFl) lasting > 30 seconds more than 3 months post ablation.	This has been altered since the inception of the study to include atrial tachycardia and atrial flutter, as there have been changes to how ablation is performed since the study began. Specifically, the STAR AF2 study found that PVI is similar to PVI in addition to either complex fractionated electrogram ablation or PVI in addition to linear ablation. Given this, the occurrence of AT/AFL was thought to be iatrogenic and occur as a consequence of various ablation strategies, rather than to the substrate, hence was excluded from the primary endpoint. Given the change in strategy of ablation, the inclusion of AT/AFl in the primary outcome is now necessary as it may reflect change in substrate, rather than ablation strategy, as previously thought. In addition, from a patient perspective, the occurence of AT/AFl is indistinguishable from a symptoms point of view.	at least 3 months post catheter ablation
Secondary	Any recurrent atrial fibrillation/atrial tachycardia/atrial flutter post randomization		up to 30 months post randomization
Secondary	Recurrent atrial fibrillation/atrial tachycardia/atrial flutter (symptomatic or asymptomatic) post ablation		up to 30 months post randomization
Secondary	atrial fibrillation/atrial tachycardia/atrial flutter burden (pre and post ablation)		up to 30 months post randomization
Secondary	Generic and disease specific quality of life		12 months
Secondary	Correlation of BNP and CRP and recurrence of atrial fibrillation/atrial tachycardia/atrial flutter		12 months
Secondary	Recurrent AF ablation therapy		up to 30 months post randomization
Secondary	Visits to the ER or hospitalization for atrial arrhythmia		up to 30 months post randomization
Secondary	Thromboembolic events		up to 30 months post randomization