Catheter Ablation of Atrial Fibrillation in Octogenarians
The desire to take medicine is perhaps the greatest feature which distinguishes man from animals."
"One of the first duties of the physician is to educate the masses not to take medicine."
—Sir William Osler
Atrial fibrillation (AF) is the most common, sustained cardiac rhythm disorder and is increasing dramatically in prevalence as our population ages. As an individual gets older, especially if there is associated cardiovascular disease, the likelihood of AF increases. The majority of the AF patients that are encountered in clinical practice are older than the typical patients seen in the AF ablation trials and cardiovascular comorbidities are common. Although not acutely life threatening, AF is associated with increased mortality, morbidity, and hospitalizations. Furthermore, the presence of AF in Medicare-aged patients is also associated with substantially more cardiovascular and noncardiovascular costs implying a less favorable clinical course for individuals with AF in comparison with propensity score matched controls without AF. The treatment of AF patients has centered around 3 non-mutually exclusive principles: (1) prevention of stroke and systemic embolism, (2) ventricular rate control during AF, and (3) rhythm control in selected patients.
There is no controversy that the use of antithrombotic therapy in appropriate AF patients is a correct strategy to reduce the risk of stroke and systemic embolism. The choice of a rate control or rhythm control disease management strategy, however, is variable and somewhat controversial. There is an emphasis on rate control for most AF patients on the primary care side unless symptoms persist despite adequate rate control; in contrast, the option of either rate or rhythm control is promoted on the specialty side. Guideline recommendations for AF are made on the basis of an evaluation of safety, efficacy, and the available data. It is noteworthy that variations exist in regard to rhythm control recommendations for antiarrhythmic therapy and catheter ablation of AF based on essentially the same data by the respective specialty societies and nations. Catheter ablation of AF is part of the rhythm control armamentarium. Since the report of potentially curable AF, catheter ablation of AF and rhythm control strategies, in general, have been progressively and increasingly applied in AF patients.
The use of catheter ablation of AF has increased dramatically since 1998 and is now a routine procedure in most major medical centers. Initially beginning with relatively young patients </- 65 years of age without major comorbidities, AF ablation is being increasingly performed in the elderly. The procedure has evolved to include septuagenarians and more recently octogenarians. In this issue of the Journal, Santangeli et al. present safety and outcomes data on the largest group of octogenarians (n = 103 pts) reported to date. In this retrospective, observational study of catheter ablation of AF in octogenarians (mean age 85), the procedure was found to have a similar rate of success in comparison with younger patients without any significant difference in procedural complications. After a mean follow-up of 18 months, 69% of octogenarians were free of AF without antiarrhythmic drugs after a single procedure versus 71% in those less than 80 years of age (P = 0.65). The success rate increased to 87% after 2 procedures. The experience of the authors is reflected by the large number of AF ablations (n = 2,754) performed over the past 4 years. The cumulative reported experience with octogenarians, however, is only 3.7% of the total ablation population.
Unless there is a change in upcoming AF ablation updates, the AF ablation guidelines advocate a more conservative approach in octogenarians and older as the data are limited. Although the data reported in this study are significant in describing the safety and efficacy of catheter ablation in this cohort of octogenarians even in comparison with the overall younger population, there remains a paucity of data on these aged patients. Published reports of similarly aged patients including this study do not describe the average octogenarian with AF. Reported patients are highly selected on multiple factors including referral bias, patient characteristics, and proceduralist selection of the individual for ablation. This report of the real world experience of 2,754 patients yielded an octogenarian population of 103 patients that were other than age and thus more CHADS2 scores of >/- 2 essentially nearly as "healthy" as the 2,651 patients (mean age 62) based on Charlson Comorbidity index scores that were not significantly different. The patients reported in this study are highly selected and not typical of the multitude of octogenarians with AF so the data must be interpreted with such considerations in mind.
The 2011 ACC/AHA/HRS AF focused update upgraded catheter ablation of AF to a Class I indication for symptomatic, paroxysmal AF patients who have failed treatment with an antiarrhythmic drug and have normal or mildly dilated left atria, normal or mildly reduced left ventricular ejection fraction, and no severe pulmonary disease. In contrast, the European and Canadian recommendations remain a Class IIa indication for ablation. Further recommendations in the US update included Class IIa indications for persistent AF and Class IIb indications for paroxysmal AF with significant left atrial enlargement or left ventricular dysfunction. In a systematic review, the single procedure success rate of catheter ablation of AF was only 57% and the multiple procedure success rate was 71% when not taking antiarrhythmic drugs. A survey report on the worldwide experience of 182 centers and 16,309 patients yielded a success rate of 70% without antiarrhythmics after a mean of 1.3 procedures per patient. Unfortunately, the recurrence rate of those thought to be cured of AF after catheter ablation over a 5-year period is significant. If we look specifically at the octogenarians who undergo catheter ablation of AF, those that are selectively offered and undergo the procedure appear to do comparably well from both an efficacy and safety perspective.
Data from the report in this issue of the Journal add to the data on the potential benefit of applying catheter ablation of AF in a highly selected cohort of octogenarians. Before expanding the use of invasive procedures in such patients, clinicians should consider the limited amount of experience in octogenarians and an evaluation of other alternatives to therapy. An assessment of cardiovascular outcomes and treatment goals beyond the rhythm (AF) should be a priority, especially in the elderly in association with cardiovascular comorbidities. Patients undergoing catheter ablation of AF are increasingly becoming older with more nonparoxysmal AF and more underlying heart disease. Specifically, the use of catheter ablation of AF is growing tremendously in the Medicare-aged population with substantial implications for cost of care.
In the very elderly with asymptomatic or minimally symptomatic AF, many clinicians would argue that rate control is the preferred strategy. One could also argue that the mean age of >/- 85 would be very elderly and advocate rate over rhythm strategies. Given reports of comparable efficacy and a satisfactory safety profile of AF ablation in some octogenarians, one could consider more widespread use of catheter ablation in this population. However, real world data present a somewhat different picture in the overall assessment of comparative effectiveness evaluation. Shah presented data on the outcomes of catheter ablation of AF in all adult patients (n = 4,156) in California who had a first AF ablation from 2005 to 2008. The main findings revealed a significant periprocedural complication rate of 5.1%, a 30-day rehospitalization rate of 9.4%, and 10 deaths (0.24%) within 30 days of the index hospitalization. By the end of the first year postablation, there was an overall 40% hospital readmission rate overall with 22% of patients admitted for recurrent atrial arrhythmias or repeat ablation. These results occurred in a population with a mean age of 62 years. There were 97 patients >/- 85 years old, which would represent the 2nd largest report of octogenarians and older, and the complication rate was roughly doubled (10.3%). A comparative look at patients (mean age 62) admitted to the hospital with a primary diagnosis of AF resulted in a 11% readmission rate over 1 year after the index hospitalization. The comparative data presented by Shah et al. postablation in a similarly aged population thus raise some concerns from a quality and outcomes perspective because of a high rate of adverse events.
All societal guidelines recommend catheter ablation of AF for treatment of symptoms refractory to medical therapy. The strongest recommendation for ablation or "medicine" is for more effective rhythm control of paroxysmal AF at 12 months when used as a second line therapy in younger patients with no significant structural heart disease. In this systematic review of 108 AF ablation studies, fewer than 5% of patients suffered a serious complication, but the level of evidence was felt to be low for adverse events to be uncommon. So how do we approach the octogenarian with AF looking for our medical recommendations?
Ideally, it would be of value to have a large, randomized, controlled trial of catheter ablation versus medical therapy in any group of patients, let alone the elderly, where endpoints of the trial would include more than AF recurrence, symptoms, and procedural complications. Data concerning other treatment surrogates such as cardiovascular outcomes, cost, hospitalizations, and mortality would be helpful. The ongoing CABANA Trial (NCT00578617) should hopefully provide some answers in an older population with CV risk factors. Until such data are available, one must keep in mind what the treatment goals are for the octogenarian patient, especially those beyond arrhythmia recurrence. Despite the likely excellent functional and health status of an octogenarian undergoing catheter ablation of AF, "old is old" and octogenarians are different than the mid-50- to 60-year-old patient traditionally undergoing AF ablation. Even in octogenarians, highly symptomatic AF not responsive to medical therapy should be a consideration in highly selected patients, although until more robust data are available, especially in regard to long-term cardiovascular outcomes, the role of the physician may be better directed to different options of "medicine." The threshold to offer catheter ablation of AF should be higher than in the more traditional, younger, and healthier cohort of AF ablation candidates.
The soon-to-be-released AF ablation consensus document in the Spring of 2012 will include class and level of grades of indications for catheter ablation of AF. Likely, as the data support, the strongest indication will be for those AF patients with symptomatic, paroxysmal AF who have failed antiarrhythmic therapy. I do not expect clear age-based guidelines, which although important, is not the only discriminating feature for discerning appropriateness or effectiveness. The debate over AF treatment options, however, whether it is rate control, antiarrhythmic therapy, or catheter ablation in octogenarians will soon have to involve cost, health care reform, and economic constraints. Data driven treatment goals with an eye toward cardiovascular outcomes will be more relevant. Future guidelines should address the heterogeneity of AF and the impact of age, cardiovascular comorbidities, clinical outcomes, and cost. AF can be viewed as more than one disease depending on many factors, including age, patient characteristics, and type of AF. Choose and prescribe the "medicine" wisely.
Editorial Comment
The desire to take medicine is perhaps the greatest feature which distinguishes man from animals."
"One of the first duties of the physician is to educate the masses not to take medicine."
—Sir William Osler
Atrial fibrillation (AF) is the most common, sustained cardiac rhythm disorder and is increasing dramatically in prevalence as our population ages. As an individual gets older, especially if there is associated cardiovascular disease, the likelihood of AF increases. The majority of the AF patients that are encountered in clinical practice are older than the typical patients seen in the AF ablation trials and cardiovascular comorbidities are common. Although not acutely life threatening, AF is associated with increased mortality, morbidity, and hospitalizations. Furthermore, the presence of AF in Medicare-aged patients is also associated with substantially more cardiovascular and noncardiovascular costs implying a less favorable clinical course for individuals with AF in comparison with propensity score matched controls without AF. The treatment of AF patients has centered around 3 non-mutually exclusive principles: (1) prevention of stroke and systemic embolism, (2) ventricular rate control during AF, and (3) rhythm control in selected patients.
There is no controversy that the use of antithrombotic therapy in appropriate AF patients is a correct strategy to reduce the risk of stroke and systemic embolism. The choice of a rate control or rhythm control disease management strategy, however, is variable and somewhat controversial. There is an emphasis on rate control for most AF patients on the primary care side unless symptoms persist despite adequate rate control; in contrast, the option of either rate or rhythm control is promoted on the specialty side. Guideline recommendations for AF are made on the basis of an evaluation of safety, efficacy, and the available data. It is noteworthy that variations exist in regard to rhythm control recommendations for antiarrhythmic therapy and catheter ablation of AF based on essentially the same data by the respective specialty societies and nations. Catheter ablation of AF is part of the rhythm control armamentarium. Since the report of potentially curable AF, catheter ablation of AF and rhythm control strategies, in general, have been progressively and increasingly applied in AF patients.
The use of catheter ablation of AF has increased dramatically since 1998 and is now a routine procedure in most major medical centers. Initially beginning with relatively young patients </- 65 years of age without major comorbidities, AF ablation is being increasingly performed in the elderly. The procedure has evolved to include septuagenarians and more recently octogenarians. In this issue of the Journal, Santangeli et al. present safety and outcomes data on the largest group of octogenarians (n = 103 pts) reported to date. In this retrospective, observational study of catheter ablation of AF in octogenarians (mean age 85), the procedure was found to have a similar rate of success in comparison with younger patients without any significant difference in procedural complications. After a mean follow-up of 18 months, 69% of octogenarians were free of AF without antiarrhythmic drugs after a single procedure versus 71% in those less than 80 years of age (P = 0.65). The success rate increased to 87% after 2 procedures. The experience of the authors is reflected by the large number of AF ablations (n = 2,754) performed over the past 4 years. The cumulative reported experience with octogenarians, however, is only 3.7% of the total ablation population.
Unless there is a change in upcoming AF ablation updates, the AF ablation guidelines advocate a more conservative approach in octogenarians and older as the data are limited. Although the data reported in this study are significant in describing the safety and efficacy of catheter ablation in this cohort of octogenarians even in comparison with the overall younger population, there remains a paucity of data on these aged patients. Published reports of similarly aged patients including this study do not describe the average octogenarian with AF. Reported patients are highly selected on multiple factors including referral bias, patient characteristics, and proceduralist selection of the individual for ablation. This report of the real world experience of 2,754 patients yielded an octogenarian population of 103 patients that were other than age and thus more CHADS2 scores of >/- 2 essentially nearly as "healthy" as the 2,651 patients (mean age 62) based on Charlson Comorbidity index scores that were not significantly different. The patients reported in this study are highly selected and not typical of the multitude of octogenarians with AF so the data must be interpreted with such considerations in mind.
The 2011 ACC/AHA/HRS AF focused update upgraded catheter ablation of AF to a Class I indication for symptomatic, paroxysmal AF patients who have failed treatment with an antiarrhythmic drug and have normal or mildly dilated left atria, normal or mildly reduced left ventricular ejection fraction, and no severe pulmonary disease. In contrast, the European and Canadian recommendations remain a Class IIa indication for ablation. Further recommendations in the US update included Class IIa indications for persistent AF and Class IIb indications for paroxysmal AF with significant left atrial enlargement or left ventricular dysfunction. In a systematic review, the single procedure success rate of catheter ablation of AF was only 57% and the multiple procedure success rate was 71% when not taking antiarrhythmic drugs. A survey report on the worldwide experience of 182 centers and 16,309 patients yielded a success rate of 70% without antiarrhythmics after a mean of 1.3 procedures per patient. Unfortunately, the recurrence rate of those thought to be cured of AF after catheter ablation over a 5-year period is significant. If we look specifically at the octogenarians who undergo catheter ablation of AF, those that are selectively offered and undergo the procedure appear to do comparably well from both an efficacy and safety perspective.
Data from the report in this issue of the Journal add to the data on the potential benefit of applying catheter ablation of AF in a highly selected cohort of octogenarians. Before expanding the use of invasive procedures in such patients, clinicians should consider the limited amount of experience in octogenarians and an evaluation of other alternatives to therapy. An assessment of cardiovascular outcomes and treatment goals beyond the rhythm (AF) should be a priority, especially in the elderly in association with cardiovascular comorbidities. Patients undergoing catheter ablation of AF are increasingly becoming older with more nonparoxysmal AF and more underlying heart disease. Specifically, the use of catheter ablation of AF is growing tremendously in the Medicare-aged population with substantial implications for cost of care.
In the very elderly with asymptomatic or minimally symptomatic AF, many clinicians would argue that rate control is the preferred strategy. One could also argue that the mean age of >/- 85 would be very elderly and advocate rate over rhythm strategies. Given reports of comparable efficacy and a satisfactory safety profile of AF ablation in some octogenarians, one could consider more widespread use of catheter ablation in this population. However, real world data present a somewhat different picture in the overall assessment of comparative effectiveness evaluation. Shah presented data on the outcomes of catheter ablation of AF in all adult patients (n = 4,156) in California who had a first AF ablation from 2005 to 2008. The main findings revealed a significant periprocedural complication rate of 5.1%, a 30-day rehospitalization rate of 9.4%, and 10 deaths (0.24%) within 30 days of the index hospitalization. By the end of the first year postablation, there was an overall 40% hospital readmission rate overall with 22% of patients admitted for recurrent atrial arrhythmias or repeat ablation. These results occurred in a population with a mean age of 62 years. There were 97 patients >/- 85 years old, which would represent the 2nd largest report of octogenarians and older, and the complication rate was roughly doubled (10.3%). A comparative look at patients (mean age 62) admitted to the hospital with a primary diagnosis of AF resulted in a 11% readmission rate over 1 year after the index hospitalization. The comparative data presented by Shah et al. postablation in a similarly aged population thus raise some concerns from a quality and outcomes perspective because of a high rate of adverse events.
All societal guidelines recommend catheter ablation of AF for treatment of symptoms refractory to medical therapy. The strongest recommendation for ablation or "medicine" is for more effective rhythm control of paroxysmal AF at 12 months when used as a second line therapy in younger patients with no significant structural heart disease. In this systematic review of 108 AF ablation studies, fewer than 5% of patients suffered a serious complication, but the level of evidence was felt to be low for adverse events to be uncommon. So how do we approach the octogenarian with AF looking for our medical recommendations?
Ideally, it would be of value to have a large, randomized, controlled trial of catheter ablation versus medical therapy in any group of patients, let alone the elderly, where endpoints of the trial would include more than AF recurrence, symptoms, and procedural complications. Data concerning other treatment surrogates such as cardiovascular outcomes, cost, hospitalizations, and mortality would be helpful. The ongoing CABANA Trial (NCT00578617) should hopefully provide some answers in an older population with CV risk factors. Until such data are available, one must keep in mind what the treatment goals are for the octogenarian patient, especially those beyond arrhythmia recurrence. Despite the likely excellent functional and health status of an octogenarian undergoing catheter ablation of AF, "old is old" and octogenarians are different than the mid-50- to 60-year-old patient traditionally undergoing AF ablation. Even in octogenarians, highly symptomatic AF not responsive to medical therapy should be a consideration in highly selected patients, although until more robust data are available, especially in regard to long-term cardiovascular outcomes, the role of the physician may be better directed to different options of "medicine." The threshold to offer catheter ablation of AF should be higher than in the more traditional, younger, and healthier cohort of AF ablation candidates.
The soon-to-be-released AF ablation consensus document in the Spring of 2012 will include class and level of grades of indications for catheter ablation of AF. Likely, as the data support, the strongest indication will be for those AF patients with symptomatic, paroxysmal AF who have failed antiarrhythmic therapy. I do not expect clear age-based guidelines, which although important, is not the only discriminating feature for discerning appropriateness or effectiveness. The debate over AF treatment options, however, whether it is rate control, antiarrhythmic therapy, or catheter ablation in octogenarians will soon have to involve cost, health care reform, and economic constraints. Data driven treatment goals with an eye toward cardiovascular outcomes will be more relevant. Future guidelines should address the heterogeneity of AF and the impact of age, cardiovascular comorbidities, clinical outcomes, and cost. AF can be viewed as more than one disease depending on many factors, including age, patient characteristics, and type of AF. Choose and prescribe the "medicine" wisely.
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