Stroke Risk and AF Ablation With Anticoagulant by ECG
Stroke Risk and AF Ablation With Anticoagulant by ECG
All patients who underwent pulmonary vein isolation procedures for atrial fibrillation at the University of Pennsylvania Health System from 2000 to 2009 with 1 year of follow-up were included in the present study. Patient characteristics, including CHADS2 score, anticoagulant use, and the incidence of stroke, TIA, or significant bleeding were entered into our patient database based upon direct patient interviews and review of their medical records.
Our ablation strategy has been previously described in detail. To summarize, the predominant procedure included antral PV isolation with documented entrance and exit block coupled with ablation of identified arrhythmogenic nonpulmonary vein foci. In selected patients only the subset of pulmonary veins clearly identified as arrhythmogenic were targeted. Repeat ablation procedures performed for recurrence of atrial fibrillation were performed with the same ablation strategy unless manifest right or left atrial flutters were documented, in which case they were targeted using standard techniques.
Following their ablation procedure, all patients were discharged with 30-day trans-telephonic monitors (TTMs) to identify early recurrence of atrial arrhythmias. Repeat 30-day TTMs were routinely performed at 6 and 12 months postprocedure or prior to the discontinuation of antiarrhythmic drugs or warfarin. In selected patients, TTMs were performed following the discontinuation of antiarrhythmic drugs to assess for arrhythmia recurrence. In addition, trans-telephonic monitoring was repeated when patients experienced transient symptoms that could be consistent with arrhythmia recurrence.
Beginning at their 6-week postablation visit, all patients were taught life-long twice daily self-assessment of their pulse rate and pulse stability. The ability to demonstrate accurate pulse assessment was revisited at subsequent visits. Patients were instructed to call for changes or irregularities in their pulse that could be consistent with atrial fibrillation or atrial flutter recurrence.
Over the course of follow-up, recurrences of atrial fibrillation assessed by any means were managed per the treating electrophysiologist consistent with the wishes of the patient. Typically, this treatment consisted of one or more of the following: cardioversion (for sustained episodes), adjustment or initiation of antiarrhythmic drug therapy, and/or repeat ablation.
Following their ablation, all patients were discharged on warfarin (only available OAC at the time of this cohort) at a dose intended to maintain an INR of 2–3. The timing of any subsequent discontinuation of warfarin was at the discretion of the treating electrophysiologist but was consistently based upon the following factors: CHADS2 score, prior persistent atrial fibrillation, and freedom from recurrent atrial arrhythmias by our monitoring protocol. The decisions to discontinue OAC was primarily driven by the presence of any atrial fibrillation and in general discouraged if patients had a CHADS2 of ≥ 2. In general, our group remains conservative and if left atrial size was >5.0 cm we would strongly advise against stopping OAC. A patient's inability or unwillingness to adequately assess their own pulse and/or the documentation of any AF during monitoring or failure to undergo monitoring precluded the discontinuation of warfarin in CHADS2 ≥ 1. Use of anticoagulation in CHADS2 = 0 was based on physician preference.
Recurrent atrial fibrillation among patients who had previously discontinued warfarin led to the prompt reinitiation of warfarin.
All patients were seen routinely at 6 weeks, 6 months and 1-year postablation. An echocardiogram was routinely performed at the 6-week visit before the decision or not to continue oral anticoagulation. Left atrial function and dimension assessed at this echocardiogram were incorporated into the decision-making regarding the discontinuation of warfarin. Thereafter patients were typically seen at 6- to 12-month intervals. For those patients unable to adhere to this follow-up schedule, telephone follow-up was performed. At each follow-up visit, arrhythmia recurrence was ascertained, as was an updated CHADS2 score. The incidence of stroke, TIA, or major bleeding was captured either upon routine office visit or via telephone encounter with the patient, patient's family or referring physician. Stroke was defined as a neurologic deficit lasting longer than 24 hours due to cerebrovascular emboli based upon neurologic evaluation and/or cerebral imaging with CT or MRI. A TIA was defined as a neurologic deficit lasting less than 24 hours presumed to be due to cerebrovascular emboli based upon neurologic evaluation. Major bleeding was defined as bleeding severe enough to require hospitalization, transfusion or that resulted in permanent disability.
Categorical variables are expressed as percentages. The Student's t-test and Pearson's chi-square test were used to compare continuous and dichotomous variables, respectively, between groups. Analyses were performed using SPSS software (version 16.0, SPSS Inc., Chicago, IL, USA). A P value < 0.05 was considered statistically significant.
Methods
Study Population
All patients who underwent pulmonary vein isolation procedures for atrial fibrillation at the University of Pennsylvania Health System from 2000 to 2009 with 1 year of follow-up were included in the present study. Patient characteristics, including CHADS2 score, anticoagulant use, and the incidence of stroke, TIA, or significant bleeding were entered into our patient database based upon direct patient interviews and review of their medical records.
Ablation Strategy
Our ablation strategy has been previously described in detail. To summarize, the predominant procedure included antral PV isolation with documented entrance and exit block coupled with ablation of identified arrhythmogenic nonpulmonary vein foci. In selected patients only the subset of pulmonary veins clearly identified as arrhythmogenic were targeted. Repeat ablation procedures performed for recurrence of atrial fibrillation were performed with the same ablation strategy unless manifest right or left atrial flutters were documented, in which case they were targeted using standard techniques.
Postablation Monitoring Strategy
Following their ablation procedure, all patients were discharged with 30-day trans-telephonic monitors (TTMs) to identify early recurrence of atrial arrhythmias. Repeat 30-day TTMs were routinely performed at 6 and 12 months postprocedure or prior to the discontinuation of antiarrhythmic drugs or warfarin. In selected patients, TTMs were performed following the discontinuation of antiarrhythmic drugs to assess for arrhythmia recurrence. In addition, trans-telephonic monitoring was repeated when patients experienced transient symptoms that could be consistent with arrhythmia recurrence.
Beginning at their 6-week postablation visit, all patients were taught life-long twice daily self-assessment of their pulse rate and pulse stability. The ability to demonstrate accurate pulse assessment was revisited at subsequent visits. Patients were instructed to call for changes or irregularities in their pulse that could be consistent with atrial fibrillation or atrial flutter recurrence.
Over the course of follow-up, recurrences of atrial fibrillation assessed by any means were managed per the treating electrophysiologist consistent with the wishes of the patient. Typically, this treatment consisted of one or more of the following: cardioversion (for sustained episodes), adjustment or initiation of antiarrhythmic drug therapy, and/or repeat ablation.
Postablation Anticoagulation Strategy
Following their ablation, all patients were discharged on warfarin (only available OAC at the time of this cohort) at a dose intended to maintain an INR of 2–3. The timing of any subsequent discontinuation of warfarin was at the discretion of the treating electrophysiologist but was consistently based upon the following factors: CHADS2 score, prior persistent atrial fibrillation, and freedom from recurrent atrial arrhythmias by our monitoring protocol. The decisions to discontinue OAC was primarily driven by the presence of any atrial fibrillation and in general discouraged if patients had a CHADS2 of ≥ 2. In general, our group remains conservative and if left atrial size was >5.0 cm we would strongly advise against stopping OAC. A patient's inability or unwillingness to adequately assess their own pulse and/or the documentation of any AF during monitoring or failure to undergo monitoring precluded the discontinuation of warfarin in CHADS2 ≥ 1. Use of anticoagulation in CHADS2 = 0 was based on physician preference.
Recurrent atrial fibrillation among patients who had previously discontinued warfarin led to the prompt reinitiation of warfarin.
Follow-up
All patients were seen routinely at 6 weeks, 6 months and 1-year postablation. An echocardiogram was routinely performed at the 6-week visit before the decision or not to continue oral anticoagulation. Left atrial function and dimension assessed at this echocardiogram were incorporated into the decision-making regarding the discontinuation of warfarin. Thereafter patients were typically seen at 6- to 12-month intervals. For those patients unable to adhere to this follow-up schedule, telephone follow-up was performed. At each follow-up visit, arrhythmia recurrence was ascertained, as was an updated CHADS2 score. The incidence of stroke, TIA, or major bleeding was captured either upon routine office visit or via telephone encounter with the patient, patient's family or referring physician. Stroke was defined as a neurologic deficit lasting longer than 24 hours due to cerebrovascular emboli based upon neurologic evaluation and/or cerebral imaging with CT or MRI. A TIA was defined as a neurologic deficit lasting less than 24 hours presumed to be due to cerebrovascular emboli based upon neurologic evaluation. Major bleeding was defined as bleeding severe enough to require hospitalization, transfusion or that resulted in permanent disability.
Statistics
Categorical variables are expressed as percentages. The Student's t-test and Pearson's chi-square test were used to compare continuous and dichotomous variables, respectively, between groups. Analyses were performed using SPSS software (version 16.0, SPSS Inc., Chicago, IL, USA). A P value < 0.05 was considered statistically significant.
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