Mortality, stroke, and heart failure in atrial fibrillation cohorts after ablation versus propensity-matched cohorts.

BACKGROUND: We sought to determine from key clinical outcomes whether catheter ablation of atrial fibrillation (AF) is associated with increased survival. METHODS AND RESULTS: Using routinely collected hospital data, ablation patients were matched to two control cohorts using direct and propensity score methodology. Four thousand nine hundred ninety-one ablation patients were matched 1:1 with general AF controls without ablation. Five thousand four hundred seven ablation patients were similarly matched to controls who underwent cardioversion. We examined the rates of ischemic stroke or transient ischemic attack (stroke/TIA), heart failure hospitalization, and death. Matched populations had very similar comorbidity profiles, including nearly identical CHA2DS2-VASc risk distribution (p=0.6948 and p=0.8152 vs general AF and cardioversion cohorts). Kaplan-Meier models showed increased survival after ablation for all outcomes compared with both control cohorts (p<0.0001 for all outcomes vs general AF, p=0.0087 for stroke/TIA, p<0.0001 for heart failure, and p<0.0001 for death vs cardioversion). Cox regression models also showed improved survival after ablation for all outcomes compared with the general AF cohort (hazard ratio [HR]=0.4, 95% confidence interval [95% CI]: 0.3-0.6, p<0.0001 for stroke/TIA; HR=0.4, 95% CI: 0.2-0.6, p<0.0001 for heart failure; HR=0.1, 95% CI: 0.1-0.1, p<0.0001 for death) and the cardioversion cohort (HR=0.6, 95% CI: 0.4-0.9, p=0.0111 for stroke/TIA; HR=0.4, 95% CI: 0.3-0.6, p<0.0001 for heart failure; HR=0.3, 95% CI:0.2-0.5, p<0.0001 for death). CONCLUSIONS: Catheter ablation of AF was associated with very significant reductions in mortality, stroke/TIA, and heart failure compared with a matched general AF population and a matched population who underwent cardioversion. Potential confounding of outcomes was minimized by very tight cohort matching.

Stroke rates before and after ablation of atrial fibrillation and in propensity-matched controls in the UK.

BACKGROUND: We sought to determine whether catheter ablation of atrial fibrillation (AF) is associated with reduced occurrence of ischemic cerebrovascular events. METHODS AND RESULTS: Using routinely collected hospital data, ablation patients were matched to two control cohorts via direct and propensity score matching. A total of 4,991 ablation patients were matched 1:1 to general AF controls with no ablation, and 5,407 ablation patients were similarly matched to controls who underwent cardioversion. Yearly rates of ischemic stroke or transient ischemic attack (stroke/TIA) before and after an index date were compared between cohorts. Index date was defined as the first ablation, the first cardioversion, or the second AF event in the general AF cohort. Matched populations had very similar demographic and comorbidity profiles, including nearly identical CHA2DS2-VASc risk distribution (p-values 0.6948 and 0.8152 vs general AF and cardioversion cohorts). Statistical models of stroke/TIA risk in the preindex period showed no difference in annual event rates between cohorts (mean±standard error 0.30% ± 0.08% ablation vs 0.28% ± 0.07% general AF, p=0.8292; 0.37% ± 0.09% ablation vs 0.42% ± 0.08% cardioversion, p=0.5198). Postindex models showed significantly lower annual rates of stroke/TIA in ablation patients compared with each control group over 5 years (0.64% ± 0.11% ablation vs 1.84% ± 0.23% general AF, p<0.0001; 0.82% ± 0.15% ablation vs 1.37% ± 0.18% cardioversion, p=0.0222). CONCLUSION: Matching resulted in cohorts having the same baseline risks and rates of ischemic cerebrovascular events. After the index date, there were significantly lower yearly event rates in the ablation cohort. These results suggest the divergence in outcome rates stems from variance in the treatment pathways beginning at the index date.

The Effects of Catheter Ablation Therapy on Medication Use and Expenditures in Patients with Atrial Fibrillation.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia encountered in clinical practice. Catheter ablation has become an important treatment option for many AF patients. Catheter ablation has been hypothesized to reduce the need for continued medical therapy for patients with AF, but there are few empirical data which demonstrate this. Objective: The objective of this study was to estimate the impact of catheter ablation on antiarrhythmic drug (AAD) utilization and total drug expenditures among AF patients. Methods: A retrospective analysis using the Truven Health Analytics MarketScan® Research Database was performed. Patients with AF and a catheter ablation procedure who had continuous enrollment in the database 6 months prior to their first ablation and a minimum of 1-year follow-up post first ablation were compared to AF patients who were treated with AADs and not ablation. Propensity matching was used to account for baseline differences between groups, and multivariable regression models adjusted for patient characteristics and baseline healthcare resource utilization. Sub-analyses were performed for patients age ≥65. Results: AF patients treated with catheter ablation had significantly lower AAD utilization and total prescription drug costs than those treated with AADs only. These results persisted for the subset of patients age ≥65. The effects were strongest in the matched sample, where approximately 30% of ablation patients discontinued use of rhythm medication after receiving catheter ablation. Per-patient total medication expenditures were reduced by $800 to $1,200 per year in the matched sample. Conclusion: Catheter ablation for AF reduced AAD utilization and total prescription drug expenditures in a sustainable fashion up to 3 years post ablation. This reduction was consistent and significant in both the non-Medicare and Medicare populations.

Acute safety outcomes in younger and older patients with atrial fibrillation treated with catheter ablation.

PURPOSE: Catheter ablation for atrial fibrillation (AF) has been demonstrated to be safe and effective in subsets of patients with AF, but primarily in patients age <65. This study compared acute safety in patients age ≥65 vs. those <65 who have undergone catheter ablation for AF. METHODS: A retrospective analysis of data from two Thomson Reuters MarketScan® research databases was performed on 5,947 patients who underwent catheter ablation for treatment of AF. Acute safety was measured as a composite endpoint of procedure-related adverse events coded ≤7 days post-procedure. A logistic regression model was fitted to this endpoint, using age (<65, ≥65) and relevant covariates. Peri-procedural mortality rates were examined among patients with inpatient ablation procedures, where death rates could be determined by discharge status. RESULTS: The acute safety event rate was nearly identical between both groups. This finding persisted after adjusting for covariates in the logistic regression model (p = 0.6648). There were no peri-procedural mortalities among the 3,575 index ablation procedures performed in an inpatient setting. CONCLUSION: Acute safety of catheter ablation for AF in patients ≥65 was consistent with that of younger patients. A prior history of hypertension and stroke was associated with a high risk for complications with AF ablation. These findings in a large, real world population may have implications for Medicare patients with AF.

Health outcomes with catheter ablation or antiarrhythmic drug therapy in atrial fibrillation: results of a propensity-matched analysis.

BACKGROUND: Patients with atrial fibrillation (AF) face significant risks of stroke and heart failure. The objective of this study was to determine whether AF ablation reduces the long-term risk of stroke or heart failure compared with antiarrhythmic drug therapy. METHODS AND RESULTS: A coding algorithm was used to identify AF patients treated with catheter ablation (n=3194) or antiarrhythmic drugs without ablation (n=6028) between 2005 and 2009 using The MarketScan Research Database from Thomson Reuters From this sample, 801 pairs were propensity matched, based on 15 demographic and clinical characteristics and baseline medication use. Rates of stroke/transient ischemic attack (TIA) and heart failure hospitalizations for up to 3 years were examined. Patients treated with catheter ablation had a significantly lower rate of stroke or TIA (3.4% per year) than a group of patients with AF managed with antiarrhythmic drugs only (5.5% per year), with an unadjusted hazard ratio of 0.62 (95% CI, 0.44-0.86; P=0.005). The rates for heart failure hospitalization were 1.5% per year in the ablation group and 2.2% per year in the antiarrhythmic drug group, with an unadjusted hazard ratio of 0.69 (95% CI, 0.42-1.15; P=0.158). These results were minimally altered in Cox proportional hazards models, which further adjusted for potential confounders not well balanced by the propensity matching. CONCLUSIONS: In a large propensity-matched community sample, AF ablation was associated with a reduced risk of stroke/TIA and no significant difference in heart failure hospitalizations compared with antiarrhythmic drug therapy. These findings require confirmation with randomized study designs.

Healthcare utilization and expenditures in patients with atrial fibrillation treated with catheter ablation.

AIM: The aim was to estimate the impact of catheter ablation on short- and long-term healthcare utilization and expenditures among atrial fibrillation (AF) patients in general and Medicare populations. METHODS: Data were analyzed from The MarketScan(®) Databases. MarketScan data contain deidentified patient-level records from employer-sponsored and public health insurance plans. Multivariable regression models for utilization and expenditures were built for all patients, with subanalyses performed for patients ≥65 years. Results were compared to preablation figures and reported for 5 time groups, based on duration of available postablation follow-up: 6-12 months; 12-18 months; 18-24 months; 24-30 months; and 30-36 months. RESULTS: A total of 3,194 patients were identified who had undergone catheter ablation for treatment of AF, had continuous enrollment in the database 6 months prior to first ablation, and had at least 1-year follow-up postablation. Compared to the 6 months prior to ablation, there were significant reductions in the number of outpatient appointments, inpatient days, and emergency room visits in the total study population and in the subset ≥65 years. There was a statistically significant (P < 0.01) decrease in total healthcare expenditures across 4 of the 5 6-month time periods, with annual savings ranging from $3,300 to $9,200. For patients ≥65 years, annual savings ranged from $3,200 to $9,200. Drug utilization also significantly declined (P < 0.01), with average annual medication savings ranging from $670 to $890, and from $740 to $880 for patients ≥65 years. CONCLUSION: Catheter ablation for AF reduced healthcare utilization and expenditures up to 3 years postablation. This reduction was consistent, significant, and had implications for general and Medicare populations.

Economic impact to employers of treatment options for cardiac arrhythmias in the US health system.

OBJECTIVE: To measure relative employer-sponsored postablation costs for cardiac arrhythmias (CA), specifically atrial fibrillation (AF). METHODS: Regression-Controlled Employee/Spouse Database study (2001 to 2008) comparing CA patients with and without ablation and AF patients with and without ablation. Regression-adjusted monthly medical, pharmacy, sick leave, and short-term disability costs were calculated 11 months before index to 36 months after index (first ablation date or average date for nonablation patients). Relative pre/postindex comparisons between ablation and nonablation cohorts were calculated and time until ablation procedure cost recovery extrapolated. RESULTS: Few CA (280 of 11,291; 2.48%) and AF (93 of 3062; 3.04%) patients received ablation. Ablation cohorts cost less than nonablation cohorts postablation. Estimated total ablation-period costs were recovered 38 to 50 months postablation, including employee absence payment recovery within 18 months. CONCLUSION: Current ablation use in employer-sponsored health plans may improve health care and absence costs over time.

The burden of atrial fibrillation and other cardiac arrhythmias in an employed population: associated costs, absences, and objective productivity loss.

OBJECTIVE: To establish the burden of atrial fibrillation (AF) and other cardiac arrhythmias (CA) in an employed population. METHODS: Regression model analysis comparing objective work output, employee turnover, comorbidity prevalence, total health benefit (health care, drug, sick leave, disability, workers' compensation) costs, and absence days for AF versus Non-AF and CA versus Non-CA cohorts, while controlling for differences in patient characteristics. RESULTS: Cohort sizes were 1403 (AF), 323,333 (Non-AF), 4497 (CA), and 318,917 (Non-CA) employees. Annual AF benefit costs exceeded Non-AF costs by $3958. CA costs exceeded Non-CA costs by $2897. AF and CA cohorts had significantly more sick leave and short-term disability absence days than Non-AF and Non-CA cohorts, respectively. Annual CA work output was significantly lower than Non-CA output. CONCLUSIONS: AF and CA place significant cost, absence, and productivity burdens on employers.