Ignite Creation Date:
2024-05-05 @ 4:52 PM
Last Modification Date:
2024-10-26 @ 9:25 AM
Study NCT ID:
NCT00338715
Status:
COMPLETED
Last Update Posted:
2011-02-08
First Post:
2006-06-19
Brief Title:
Effectiveness of Pulmonary Vein Isolation in Prevention of Atrial Fibrillation Following Heart Bypass Surgery
Sponsor:
Lawson Health Research Institute
Organization:
Lawson Health Research Institute
Study Overview
Official Title:
A Randomized Controlled Trial of Prophylactic Pulmonary Vein Isolation as Adjunct to Coronary Artery Bypass Grafting
Status:
COMPLETED
Status Verified Date:
2011-02
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Atrial fibrillation AF is an irregular heart rhythm that occurs in 30 to 40 of patients following heart surgery This irregular heart rhythm although often self-limiting can be cause for concern AF is associated with a two-fold increase in patient complications and mortality after heart surgery During AF the heart muscle does not contract properly causing the blood flow through the heart to slow down potentially forming clots A clot may then enter the blood stream and be carried to the brain possibly causing a stroke Patients in persistent AF require blood thinners to prevent strokes and this carries its own bleeding risks especially in elderly patients
Patients in AF after heart surgery spend twice as many days in the intensive care unit and 3 to 4 more days in the hospital hence the impact on hospital resources is quite significant Various medications are used to prevent AF after heart surgery but they are unable to completely prevent this complication and the medications have associated side effects In an effort to optimize the care of heart surgery patients strategies set on eliminating the onset of AF after surgery as opposed to trying to control AF with less than effective medications is a necessity
We are proposing a study to determine if isolating the misfiring areas that cause AF at the time of bypass surgery in high-risk patients will decrease the occurrence of AF following heart surgery Consenting patients will be randomized to one of two groups Group 1 will undergo bypass surgery plus the additional procedure of pulmonary vein isolation and Group 2 will undergo bypass surgery only without the additional procedure Four staff cardiac surgeons at the London Health Sciences Centre will perform all surgeries Patients will be seen postoperatively every six months and will be followed for a two-year period The occurrence of AF will be recorded as well as other complications and lengths of hospital stay We predict that the group with the additional pulmonary vein isolation procedure to prevent AF will have a much lower occurrence of this complication If this is found to be beneficial this will significantly decrease the complications and mortality associated with heart surgery This will have a profound effect in the delivery of care to patients with coronary artery disease and other forms of heart disease
Patients in AF after heart surgery spend twice as many days in the intensive care unit and 3 to 4 more days in the hospital hence the impact on hospital resources is quite significant Various medications are used to prevent AF after heart surgery but they are unable to completely prevent this complication and the medications have associated side effects In an effort to optimize the care of heart surgery patients strategies set on eliminating the onset of AF after surgery as opposed to trying to control AF with less than effective medications is a necessity
We are proposing a study to determine if isolating the misfiring areas that cause AF at the time of bypass surgery in high-risk patients will decrease the occurrence of AF following heart surgery Consenting patients will be randomized to one of two groups Group 1 will undergo bypass surgery plus the additional procedure of pulmonary vein isolation and Group 2 will undergo bypass surgery only without the additional procedure Four staff cardiac surgeons at the London Health Sciences Centre will perform all surgeries Patients will be seen postoperatively every six months and will be followed for a two-year period The occurrence of AF will be recorded as well as other complications and lengths of hospital stay We predict that the group with the additional pulmonary vein isolation procedure to prevent AF will have a much lower occurrence of this complication If this is found to be beneficial this will significantly decrease the complications and mortality associated with heart surgery This will have a profound effect in the delivery of care to patients with coronary artery disease and other forms of heart disease
Detailed Description:
Atrial fibrillation AF is a well recognized postoperative complication associated with cardiac surgery occurring in approximately 30 to 40 of patients AF occurs most frequently within 24 to 72 hours after surgery Even though postoperative AF is often a short-lived self-limiting complication it is associated with a two-fold increase in cardiovascular mortality and morbidity Patients are often symptomatic due to irregular andor rapid ventricular rates and complain of palpitations anxiety and diminished physical capacity Postoperative AF is associated with increased incidence of other complications and increased hospital length of stay and overall costs Patients may also develop congestive heart failure and hemodynamic instability as a result of this complication As a result of stasis in the left atrium the risk of thromboembolic complications is increased and the incidence of postoperative stroke is increased Patients with persistent AF have a 13-fold higher hospital stroke rate than patients without persistent AF Further morbidity is added in patients requiring anticoagulation if AF lasts greater than 48 hours Elderly patients requiring anticoagulation have a significantly increased risk of hemorrhagic complications The incidence of ventricular arrhythmias is also increased in patients in whom AF develops after cardiac operations
Postoperative AF has an immense impact on both the cardiac surgery patient and hospital resources One study determined that patients developing AF after cardiac surgery spend about twice as many days in the Intensive Care Unit as patients without AF and their hospital stay is extended by 3-4 daysStrategies aimed at preventing postoperative AF are necessary to optimize the postoperative care of patients undergoing open heart operations A large number of clinical trials have evaluated the effectiveness of various pharmacologic modalities in decreasing rates of AF following cardiac surgery A recent meta-analysis demonstrated that beta blockers sotalol and amiodarone all reduce the risk of postoperative AF with no marked difference between them However neither agent completely eliminated the occurrence of postoperative AF In the largest available beta blocker prevention trial metoprolol decreased the prevalence of postoperative AF from 39 to 31
The mechanism of AF following cardiac surgery is not well understood but possible etiologies include rapid firing from an ectopic focus and multiple reentrant circuits within the atria to propagate this rhythm It has been discovered that in chronic and paroxysmal AF the pulmonary veins and the surrounding ostial areas frequently contain focal triggers or re-entrant circuits critical to the initiation of AF In a study of 45 patients with frequent episodes of AF refractory to drug therapy 94 of ectopic beats responsible for instigating AF were located in the pulmonary veins Studies have shown that these foci are responsive to radiofrequency ablation Although it has never been used in the prevention of postoperative AF circumferential pulmonary vein ablation CPVA is a technique that has shown much success in the treatment of AF In CPVA radiofrequency lesions are created around the ostia of each pulmonary vein with the aim to electrically isolate these veins from the left atrium In one study 26 patients with resistant AF were treated with CPVA and 64 had sinus rhythm restoration during ablation In addition 85 of patients were free of AF at 9 months with 62 no longer requiring antiarrhythmic drugs and 23 taking drugs that had been ineffective before ablation Radiofrequency pulmonary vein isolation with electro-anatomic guidance is a safe and effective treatment of AF
Recently Medtronic has developed the Cardioblate BP and BP 2 Surgical Ablation System devices Minneapolis MN to perform pulmonary vein isolation to treat AF Vichol et al have demonstrated a mean ablation time of 152 seconds per lesion with the use of this device
It is clearly evident that postoperative AF increases morbidity length of hospital stay and costs associated with surgical coronary artery revascularization The current prophylactic agents are not completely effective at eliminating the occurrence of postoperative AF It has been shown that pulmonary vein isolation is an effective method of treating patients with chronic AF We propose a study to determine if performing pulmonary vein isolation with the Cardioblate BP 2 as an adjunct in those patients undergoing routine coronary artery bypass surgery who are at increased risk of developing postoperative AF will significantly reduce the occurrence of this complication
If pulmonary vein isolation is found to considerably decrease the incidence of postoperative AF the associated morbidity will also be decreased This will have a very profound effect in the delivery of care to patients with ischemic heart disease
Study QuestionPurpose
In patients at an increased risk of developing postoperative atrial fibrillation following coronary artery bypass grafting does pulmonary vein isolation with Cardioblate BP 2 result in a decreased incidence of postoperative atrial fibrillation when compared to those patients that do not have this adjunct procedure
Hypothesis
Pulmonary vein isolation with Cardioblate BP 2 will reduce the incidence of postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting who are at an increased risk of developing postoperative atrial fibrillation
Sample Size A sample size of 79 patients per group was calculated to detect a reduction in incidence of postoperative atrial fibrillation from 40 to 20 using a two-sided α 005 and a power of 80
Blinding-The patients outcome assessors and data analysts will be blinded to which group the patients belong Allocation concealment will be practiced and the randomization scheme will not be revealed Due to the nature of the intervention it is not possible to blind the surgeon performing the operation
Trial Implementation
After randomization is complete the baseline demographic characteristics of all patients will be recorded Those patients randomized to the control group will undergo coronary bypass grafting with cardiopulmonary bypass Those patients randomized to the experimental group will undergo coronary artery bypass grafting with cardiopulmonary bypass CABG and pulmonary vein isolation PVI Medtronics Cardioblate BP 2 will be used for the pulmonary vein isolation The following will take place for each patient
1 Will be transferred to the Cardiac Surgery Recovery Unit following surgery
2 Cardiac rhythm will be monitored with telemetry in the CSRU and on the floor until discharge home
3 All arrhythmias will be documented with regards to onset duration and immediate management - will be recorded by research assistant
4 All patients will be started on a beta blocker on POD 1 and will continue for minimum 2 years if tolerable - will be discontinued if any adverse effect ie heart block decreased cardiac output allergic reaction
5 All medications will be documented
6 After discharge home all complications and readmissions will be documented ie development of atrial fibrillation or other arrhythmia
7 Documentation of those patients requiring anticoagulation for persistent atrial fibrillation and duration and complications related to anticoagulation
8 Follow-up of patients by surgeons cardiologist and research assistant with ECG every 6 months for 2 years - patients will be asked to fill out questionnaire at each visit that may elicit any symptoms related to arrhythmias Outcomes Statistical Analysis All outcomes will be analyzed by a biostatistician blinded to allocation groups using the intention to treat principle The primary purpose of the data analyses is to determine whether pulmonary vein isolation reduces the incidence of postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting who are at high risk of developing postoperative atrial fibrillation The primary outcome will be compared between both groups with the Chi-square test All patients will be accounted for and we will aim for 100 follow-up for all patients
Postoperative AF has an immense impact on both the cardiac surgery patient and hospital resources One study determined that patients developing AF after cardiac surgery spend about twice as many days in the Intensive Care Unit as patients without AF and their hospital stay is extended by 3-4 daysStrategies aimed at preventing postoperative AF are necessary to optimize the postoperative care of patients undergoing open heart operations A large number of clinical trials have evaluated the effectiveness of various pharmacologic modalities in decreasing rates of AF following cardiac surgery A recent meta-analysis demonstrated that beta blockers sotalol and amiodarone all reduce the risk of postoperative AF with no marked difference between them However neither agent completely eliminated the occurrence of postoperative AF In the largest available beta blocker prevention trial metoprolol decreased the prevalence of postoperative AF from 39 to 31
The mechanism of AF following cardiac surgery is not well understood but possible etiologies include rapid firing from an ectopic focus and multiple reentrant circuits within the atria to propagate this rhythm It has been discovered that in chronic and paroxysmal AF the pulmonary veins and the surrounding ostial areas frequently contain focal triggers or re-entrant circuits critical to the initiation of AF In a study of 45 patients with frequent episodes of AF refractory to drug therapy 94 of ectopic beats responsible for instigating AF were located in the pulmonary veins Studies have shown that these foci are responsive to radiofrequency ablation Although it has never been used in the prevention of postoperative AF circumferential pulmonary vein ablation CPVA is a technique that has shown much success in the treatment of AF In CPVA radiofrequency lesions are created around the ostia of each pulmonary vein with the aim to electrically isolate these veins from the left atrium In one study 26 patients with resistant AF were treated with CPVA and 64 had sinus rhythm restoration during ablation In addition 85 of patients were free of AF at 9 months with 62 no longer requiring antiarrhythmic drugs and 23 taking drugs that had been ineffective before ablation Radiofrequency pulmonary vein isolation with electro-anatomic guidance is a safe and effective treatment of AF
Recently Medtronic has developed the Cardioblate BP and BP 2 Surgical Ablation System devices Minneapolis MN to perform pulmonary vein isolation to treat AF Vichol et al have demonstrated a mean ablation time of 152 seconds per lesion with the use of this device
It is clearly evident that postoperative AF increases morbidity length of hospital stay and costs associated with surgical coronary artery revascularization The current prophylactic agents are not completely effective at eliminating the occurrence of postoperative AF It has been shown that pulmonary vein isolation is an effective method of treating patients with chronic AF We propose a study to determine if performing pulmonary vein isolation with the Cardioblate BP 2 as an adjunct in those patients undergoing routine coronary artery bypass surgery who are at increased risk of developing postoperative AF will significantly reduce the occurrence of this complication
If pulmonary vein isolation is found to considerably decrease the incidence of postoperative AF the associated morbidity will also be decreased This will have a very profound effect in the delivery of care to patients with ischemic heart disease
Study QuestionPurpose
In patients at an increased risk of developing postoperative atrial fibrillation following coronary artery bypass grafting does pulmonary vein isolation with Cardioblate BP 2 result in a decreased incidence of postoperative atrial fibrillation when compared to those patients that do not have this adjunct procedure
Hypothesis
Pulmonary vein isolation with Cardioblate BP 2 will reduce the incidence of postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting who are at an increased risk of developing postoperative atrial fibrillation
Sample Size A sample size of 79 patients per group was calculated to detect a reduction in incidence of postoperative atrial fibrillation from 40 to 20 using a two-sided α 005 and a power of 80
Blinding-The patients outcome assessors and data analysts will be blinded to which group the patients belong Allocation concealment will be practiced and the randomization scheme will not be revealed Due to the nature of the intervention it is not possible to blind the surgeon performing the operation
Trial Implementation
After randomization is complete the baseline demographic characteristics of all patients will be recorded Those patients randomized to the control group will undergo coronary bypass grafting with cardiopulmonary bypass Those patients randomized to the experimental group will undergo coronary artery bypass grafting with cardiopulmonary bypass CABG and pulmonary vein isolation PVI Medtronics Cardioblate BP 2 will be used for the pulmonary vein isolation The following will take place for each patient
1 Will be transferred to the Cardiac Surgery Recovery Unit following surgery
2 Cardiac rhythm will be monitored with telemetry in the CSRU and on the floor until discharge home
3 All arrhythmias will be documented with regards to onset duration and immediate management - will be recorded by research assistant
4 All patients will be started on a beta blocker on POD 1 and will continue for minimum 2 years if tolerable - will be discontinued if any adverse effect ie heart block decreased cardiac output allergic reaction
5 All medications will be documented
6 After discharge home all complications and readmissions will be documented ie development of atrial fibrillation or other arrhythmia
7 Documentation of those patients requiring anticoagulation for persistent atrial fibrillation and duration and complications related to anticoagulation
8 Follow-up of patients by surgeons cardiologist and research assistant with ECG every 6 months for 2 years - patients will be asked to fill out questionnaire at each visit that may elicit any symptoms related to arrhythmias Outcomes Statistical Analysis All outcomes will be analyzed by a biostatistician blinded to allocation groups using the intention to treat principle The primary purpose of the data analyses is to determine whether pulmonary vein isolation reduces the incidence of postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting who are at high risk of developing postoperative atrial fibrillation The primary outcome will be compared between both groups with the Chi-square test All patients will be accounted for and we will aim for 100 follow-up for all patients
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| 11973 | None | None | None |