Catheter ablation for atrial fibrillation (Afib) was associated with an improvement in patients’ quality of life (QOL), regardless of the ablation procedure, in the absence of recurring Afib episodes lasting more than 30 seconds, according to a secondary analysis of the Substrate and Trigger Ablation for Reduction of Atrial Fibrillation — Part II (STAR AF II) study.
“In this secondary analysis of the STAR AF II randomized clinical trial, we analyzed the change in QOL after catheter ablation for patients with persistent Afib. Ablation was associated with a 92% reduction in Afib burden,” Maria Terricabras, MD, Department of Cardiology, Southlake Regional Health Centre, University of Toronto, Newmarket, Ontario, Canada, and colleagues reported in JAMA Network Open. “Patients experienced a statistically significant improvement in QOL from baseline to 18 months.”
The researchers did not find a difference in QOL in patients with and without Afib recurrence episodes lasting more than 30 seconds, but when they defined the outcome as Afib burden reduction, they found that those with lower burden reduction post-procedure had less QOL improvement. “By multivariable analysis, Afib burden reduction of less than 70% was associated with lower QOL scores, and the association remained statistically significant after correction for baseline score,” Terricabras and colleagues wrote.
The researchers assessed QOL using the 36-item Short Form Health Survey (SF-36), which is a questionnaire given at baseline, and at 6, 12, and 18 months after ablation. “All patients underwent 12-lead electrocardiography and 24-hour Holter monitoring at baseline and at every follow-up visit; patients wore the Holter monitors at home between visits,” the study authors wrote.
There were 549 out of 589 patients in the STAR AF II trial who underwent ablation, at 35 centers in Europe, Canada, Australia, China, and South Korea from Nov. 2010 to July 2012.
The patients were treated with one of three ablation strategies — pulmonary vein isolation (PVI), PVI plus complex fractionated electrograms, or PVI plus linear lesions.
Of the 549 patients, 466 (85%) were included in the QOL assessments.
Most of the patients in the study were men (76%), the mean age of the participants was 60, and 76% of them had continuous Afib for 6 months or more before ablation.
Among the findings:
- A significant decrease in Afib burden, from a mean (SD) of 82% (36%) before ablation to 6.6% (23%) after ablation (P < .001).
- There were improvements in both the physical health component score (PCS) and the mental health component score (MCS) — (68.3 [20.7] to 82.5 [18.6]) and MCS (35.3 [8.6] to 37.5 [7.6]) 18 months after ablation (P<.05 for both).
- There were QOL improvements in all 3 study arms regardless of Afib recurrence — “for no recurrence, mean (SD) PCS increased from 66.5 (20.9) to 79.1 (19.4) and MCS from 35.3 (8.7) to 37.7 (7.7); for recurrence, mean (SD) PCS increased from 70.2 (20.4) to 86.4 (16.8) and MCS from 35.3 (8.6) to 37.1 (7.4) (P < .05 for all)” the study authors wrote.
- In terms of Afib burden reduction, “PCS was significantly less than in those with greater than 70% reduction, and only 3 of 8 subscales showed significant improvement.”
In an accompanying editorial, Stacey J. Howell, MD, and Eric C. Stecker, MD, MPH, both from the Electrophysiology Section, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, noted that these findings need to be set within the context of three trials that preceded this one — the Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial, the Catheter Ablation Compared With Pharmacological Therapy for Atrial Fibrillation (CAPT-AF) study, and the Comparison of Efficacy of Phased Multipolar versus Traditional Radiofrequency Ablation (CAPCOST) trial.
CABANA, like the current study, also found improvement in QOL in patients undergoing catheter ablation over medical therapy, Howell and Stecker pointed out; however, the study used several tools to assess QOL. CAPT-AF, which also used the SF-36 assessment, again found improved QOL in those undergoing ablation.
“CABANA and CAPT-AF investigators did not specifically study the relationship between improvement in QOL and Afib burden and/or recurrence and could not exclude placebo effect, given the absence of a sham-procedure group,” the editorialists wrote. “In addition to STAR AF II, this uncertainty was addressed by investigators in the just-published CAPCOST study, in which the relationship between Afib burden and QOL was evaluated among patients randomized to 1 of 2 catheter ablation techniques: a novel multielectrode technology versus conventional radiofrequency. Both STAR AF II and CAPCOST evaluated the association between Afib suppression and QOL only among patients undergoing ablation, eliminating placebo effect as a potential confounder. Like STAR AF II, patients in CAPCOST who had a low post-ablation Afib burden experienced improved QOL.”
The editorialists also noted that the current study does have limitations, including that only the SF-36 was used to assess quality of life, a tool used to determine QOL in the general population and which may not be sensitive to Afib. “Other assessment tools have been designed to evaluate QOL specifically among individuals with Afib ablation, including the Afib effect on Quality of Live questionnaire, the Mayo AF-Specific Symptom Inventory, and the AF Severity scale,” they wrote.
The editorialists also pointed out that Afib burden was determined only thorough intermittent ambulatory rhythm monitoring rather than “more rigorous methods… such as continuous monitoring using an implantable loop recorder.”
The study authors concurred with the assessment of the study limitations.
Nonetheless, Howell and Stecker noted that the current study “proves the direct association between symptom improvement and Afib suppression after ablation and validates the role of Afib burden assessment as an easily measurable surrogate for formal evaluation of QOL after ablation… STAR AF II reinforces our belief that for Afib ablation, nothing succeeds like success; reducing Afib burden by at least 70% leads to improved symptoms and quality of life.”
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Catheter ablation for atrial fibrillation (Afib) was associated with an improvement in patients’ quality of life (QOL), regardless of the ablation procedure, in the absence of recurring Afib episodes lasting more than 30 seconds.
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However, Afib burden reduction of less than 70% was associated with lower QOL scores, and the association remained statistically significant after correction for baseline score in this study.
Candace Hoffmann, Managing Editor, BreakingMED™
The study was funded by St. Jude Medical, Inc (now Abbott Laboratories)
Terracabras disclosed no relevant relationships.
Howell and Stecker had no relevant relationships to disclose.
Cat ID: 2
Topic ID: 74,2,2,913,192,925
