Mark, Daniel B.

Background: Evaluation of obese patients with suspected CAD is challenging because obesity is a CV risk factor, but adiposity itself may mimic symptoms of CAD and reduce the accuracy of diagnostic testing. Optimal testing strategies in obese patients are not known. Methods: Patients with stable symptoms suggestive of cardiac ischemia from the PROMISE trial (n=9230) were classified according to BMI. Providers specified a functional test modality prior to stratified randomization to functional (stress testing) or anatomical (CTA) testing. We assessed relationships between BMI, physician’s preference of functional test, test positivity and results of catheter angiography (cath) using logistic regression. Results: Providers were more likely to choose SPECT over other functional tests as BMI increased (OR 1.04 per unit increase in BMI above 27, p<0.001). In patients with BMI ≥ 35 vs. < 35, the rate of positivity with CTA was similar (10% vs. 12%; see Table). The same was true for stress echo and stress ECG (positivity 8-13%, p>0.8 for both). In contrast, SPECT was significantly more likely to be positive in those with BMI ≥ 35 vs. <35 (18% vs. 13%; p=0.001). The likelihood of finding obstructive CAD at cath did not differ with BMI ≥ 35 vs. <35 in patients having CTA (59% vs. 52%, p=0.22), but among SPECT patients, positivity was only 29% with BMI ≥ 35 compared to 52% with BMI < 35 (p=0.005; Table). Conclusions: Increasing levels of obesity were associated with stronger physician preference for SPECT over other noninvasive tests. In patients receiving SPECT, higher levels of obesity were associated with a higher rate of positive results, but a lower cath yield for obstructive CAD. In contrast, in patients receiving CTA, positivity rates and cath yield did not vary by BMI. Obesity appears to significantly influence provider decision-making with regard to noninvasive test choice, probability of abnormal test results and probability of finding obstructive disease at cath.

Background Women with atrial fibrillation (AF) demonstrate more AF‐related symptoms and worse quality of life (QOL). Whether increased use of ablation in women reduces sex‐related QOL differences is unknown. Sex‐related outcomes for ablation versus drug therapy was a prespecified analysis in the CABANA (Catheter Ablation Versus Antiarrhythmic Drug Therapy for Atrial Fibrillation) trial. Methods and Results Symptoms were assessed periodically over 60 months with the Mayo AF‐Specific Symptom Inventory (MAFSI) frequency score, and QOL was assessed with the Atrial Fibrillation Effect on Quality of Life (AFEQT) summary and component scores. Women had lower baseline QOL scores than men (mean AFEQT scores 55.9 and 65.6, respectively). Ablation patients improved more than drug therapy patients with similar treatment effect by sex: AFEQT 12‐month mean adjusted treatment difference in women 6.1 points (95% CI, 3.5–8.6) and men 4.9 points (95% CI, 3.0–6.9). Participants with baseline AFEQT summary scores <70 had greater QOL improvement, with a mean treatment difference at 12 months of 7.6 points for women (95% CI, 4.3–10.9) and 6.4 points for men (95% CI, 3.3–9.4). The mean adjusted difference in MAFSI frequency score between women randomized to ablation versus drug therapy at 12 months was −2.5 (95% CI, −3.4 to −1.6); for men, the difference was −1.3 (95% CI, −2.0 to −0.6). Conclusions Compared with drug therapy for AF, ablation resulted in more QOL improvement in both sexes, primarily driven by improvements in those with lower baseline QOL. Ablation did not eliminate the AF‐related QOL gap between women and men. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT00911508.

Background: In the CABANA trial (Catheter Ablation vs Antiarrhythmic Drug Therapy for Atrial Fibrillation), catheter ablation did not significantly reduce the primary end point of death, disabling stroke, serious bleeding, or cardiac arrest compared with drug therapy by intention-to-treat, but did improve the quality of life and freedom from atrial fibrillation recurrence. In the heart failure subgroup, ablation improved both survival and quality of life. Cost-effectiveness was a prespecified CABANA secondary end point. Methods: Medical resource use data were collected for all CABANA patients (N=2204). Costs for hospital-based care were assigned using prospectively collected bills from US patients (n=1171); physician and medication costs were assigned using the Medicare Fee Schedule and National Average Drug Acquisition Costs, respectively. Extrapolated life expectancies were estimated using age-based survival models. Quality-of-life adjustments were based on EQ-5D–based utilities measured during the trial. The primary outcome was the incremental cost-effectiveness ratio, comparing ablation with drug therapy on the basis of intention-to-treat, and assessed from the US health care sector perspective. Results: Costs in the first 3 months averaged $20 794±SD 1069 higher with ablation compared with drug therapy. The cumulative within-trial 5-year cost difference was $19 245 (95% CI, $11 360–$27 170) and the lifetime mean cost difference was $15 516 (95% CI, –$2963 to $35,512) higher with ablation than with drug therapy. The drug therapy arm accrued an average of 12.5 life-years (LYs) and 10.7 quality-adjusted life-years (QALYs). For the ablation arm, the corresponding estimates were 12.6 LYs and 11.0 QALYs. The incremental cost-effectiveness ratio was $57 893 per QALY gained, with 75% of bootstrap replications yielding an incremental cost-effectiveness ratio < $100 000 per QALY gained. With no quality-of-life/utility adjustments, the incremental cost-effectiveness ratio was $183 318 per LY gained. Conclusions: Catheter ablation of atrial fibrillation was economically attractive compared with drug therapy in the CABANA Trial overall at present benchmarks for health care value in the United States on the basis of projected incremental QALYs but not LYs alone.

Abstract Aims Influence of atrial fibrillation (AF) type on outcomes seen with catheter ablation vs. drug therapy is incompletely understood. This study assesses the impact of AF type on treatment outcomes in the Catheter Ablation vs. Antiarrhythmic Drug Therapy for Atrial Fibrillation Trial (CABANA). Methods and results CABANA randomized 2204 patients ≥65 years old or &lt;65 with at least one risk factor for stroke to catheter ablation or drug therapy. Of these, 946 (42.9%) had paroxysmal AF (PAF), 1042 (47.3%) had persistent AF (PersAF), and 215 (9.8%) had long-standing persistent AF (LSPAF) at baseline. The primary endpoint was a composite of death, disabling stroke, serious bleeding, or cardiac arrest. Symptoms were measured with the Mayo AF-Specific Symptom Inventory (MAFSI), and quality of life was measured with the Atrial Fibrillation Effect on Quality of Life (AFEQT). Comparisons are reported by intention to treat. Compared with drug therapy alone, catheter ablation produced a 19% relative risk reduction in the primary endpoint for PAF {adjusted hazard ratio [aHR]: 0.81 [95% confidence interval (CI): 0.50, 1.30]}, and a 17% relative reduction for PersAF (aHR: 0.83, 95% CI: 0.56, 1.22). For LSPAF, the ablation relative effect was a 7% reduction (aHR: 0.93, 95% CI: 0.36, 2.44). Ablation was more effective than drug therapy at reducing first AF recurrence in all AF types: by 51% for PAF (aHR: 0.49, 95% CI: 0.39, 0.62), by 47% for PersAF (aHR: 0.53, 95% CI: 0.43,0.65), and by 36% for LSPAF (aHR 0.64, 95% CI 0.41,1.00). Ablation was associated with greater improvement in symptoms, with the mean difference between groups in the MAFSI frequency score favouring ablation over 5 years of follow-up in all subgroups: PAF had a clinically significant −1.9-point difference (95% CI: −1.2 to −2.6); PersAF a −0.9 difference (95% CI: −0.2 to −1.6); LSPAF a clinically significant difference of −1.6 points (95% CI: −0.1 to −3.1). Ablation was also associated with greater improvement in quality of life in all subgroups, with the AFEQT overall score in PAF patients showing a clinically significant 5.3-point improvement (95% CI: 3.3 to 7.3) over drug therapy alone over 5 years of follow-up, PersAF a 1.7-point difference (95% CI: 0.0 to 3.7), and LSPAF a 3.1-point difference (95% CI: -1.6 to 7.8). Conclusion Prognostic treatment effects of catheter ablation compared with drug therapy on the primary and major secondary clinical endpoints did not differ consequentially by AF subtype. With regard to decreases in AF recurrence and improving quality of life, ablation was more effective than drug therapy in all three AF type subgroups. ClinicalTrials.gov Identifier NCT00911508

Background: Patients evaluated for coronary artery disease have a range of symptoms and underlying risk. The relationships between patient-described symptoms, clinician conclusions, and subsequent clinical management and outcomes remain incompletely described. Methods: In this secondary analysis, we examined the association between 4 types of presenting symptoms (substernal/left-sided chest pain, other chest/neck/arm pain, dyspnea, and other symptoms) and patient risk, noninvasive test results, clinical management, and outcomes for stable outpatients randomized in the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial. Multivariable regression models were used to evaluate differences in noninvasive test result, all-cause death/myocardial infarction/unstable angina hospitalization and cardiovascular death/myocardial infarction by symptom type. Results: Among 9996 patients, most presented with chest pain (47.2% substernal, 29.2% other), followed by dyspnea (14.9%), and other symptoms (8.7%). Patients with dyspnea were older (median age 63 versus 60, P ≤0.02) with higher baseline risk (78.2% with atherosclerotic cardiovascular disease >7.5% versus 67.6%, P ≤0.02). Using patients with substernal chest pain as a reference, there was no difference in noninvasive test positivity across symptom groups (all P >0.05), but test-positive patients with dyspnea (adjusted odds ratio, 0.66 [95% CI, 0.51–0.85]) or other symptoms (adjusted odds ratio, 0.65 [95% CI, 0.47–0.90]) were less likely to be referred for cardiac catheterization. While symptom type alone was not associated with outcomes, symptom presentation with chest pain or dyspnea did modify the association between a positive noninvasive test and clinical outcome (interaction P =0.025 for both all-cause death/myocardial infarction/unstable angina hospitalization and cardiovascular death/MI). Conclusions: Among low-risk outpatients evaluated for coronary artery disease, typicality of symptoms was not closely associated with higher baseline risk but was related to differences in processes of care and the prognostic value of a positive test. Adverse events were not associated with clinician risk estimates or symptoms alone. These unexpected findings highlight the limitation of relying solely on symptom presentation or clinician risk estimation to evaluate patients for suspected coronary artery disease. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01174550.

Objective To evaluate informal physician judgement versus pretest probability scores in estimating risk in patients with suspected coronary artery disease (CAD). Methods We included 4533 patients from the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial. Physicians categorised a priori the pretest probability of obstructive CAD (≥70% or ≥50% left main); Diamond-Forrester (D-F) and European Society of Cardiology (ESC) pretest probability estimates were calculated. Agreement was calculated using the κ statistic; logistic regression evaluated estimates of pretest CAD probability and actual CAD (as determined by CT coronary angiography), and clinical outcomes were modelled using Cox proportional hazard models. Results Physician estimates agreed poorly with D-F (κ 0.16; 95% CI 0.14 to 0.18) and ESC (κ 0.04; 95% CI 0.02 to 0.05). Actual obstructive CAD was significantly more prevalent in both the high-likelihood (OR 3.30; 95% CI 2.30 to 4.74) and the intermediate-likelihood (OR 1.43; 95% CI 1.16 to 1.76) physician-estimated groups versus the low-likelihood group; ESC similarly differentiated between the three groups (OR 9.07; 95% CI 2.87 to 28.70; and OR 3.87; 95% CI 1.22 to 12.28). However, using D-F, only the high-probability group differed (OR 2.49; 95% CI 1.74 to 3.54). Only physician estimates were associated with a higher incidence of adjusted death/myocardial infarction/unstable angina hospitalisation in the high-probability versus low-probability group (HR 2.68; 95% CI 1.52 to 4.74); neither pretest probability score provided prognostic information. Conclusions Compared with D-F and ESC estimates, physician judgement more accurately identified obstructive CAD and worse patient outcomes. Integrating physician judgement may improve risk prediction for patients with stable chest pain. Trial registration number NCT01174550 .

Background: Observational data suggest that catheter ablation may be safe and effective to treat younger and older patients with atrial fibrillation. No large, randomized trial has examined this issue. This report describes outcomes according to age at entry in the CABANA trial (Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation). Methods: Patients with atrial fibrillation ≥65 years of age, or <65 with ≥1 risk factor for stroke, were randomly assigned to catheter ablation versus drug therapy. The primary outcome was a composite of death, disabling stroke, serious bleeding, or cardiac arrest. Secondary outcomes included all-cause mortality, the composite of mortality or cardiovascular hospitalization, and recurrence of atrial fibrillation. Treatment effect estimates were adjusted for baseline covariables using proportional hazards regression models. Results: Of 2204 patients randomly assigned in CABANA, 766 (34.8%) were <65 years of age, 1130 (51.3%) were 65 to 74 years of age, and 308 (14.0%) were ≥75 years of age. Catheter ablation was associated with a 43% reduction in the primary outcome for patients <65 years of age (adjusted hazard ratio [aHR], 0.57 [95% CI, 0.30–1.09]), a 21% reduction for 65 to 74 years of age (aHR, 0.79 [95% CI, 0.54–1.16]), and an indeterminate effect for age ≥75 years of age (aHR, 1.39 [95% CI, 0.75–2.58]). Four-year event rates for ablation versus drug therapy across age groups, respectively, were 3.2% versus 7.8%, 7.8% versus 9.6%, and 14.8% versus 9.0%. For every 10-year increase in age, the primary outcome aHR increased (ie, less favorable to ablation) an average of 27% (interaction P value=0.215). A similar pattern was seen with all-cause mortality: for every 10-year increase in age, the aHR increased an average of 46% (interaction P value=0.111). Atrial fibrillation recurrence rates were lower with ablation than with drug therapy across age subgroups (aHR 0.47, 0.58, and 0.49, respectively). Treatment-related complications were infrequent for both arms (<3%) regardless of age. Conclusions: We found age-based variations in clinical outcomes for catheter ablation compared with drug therapy, with the largest relative and absolute benefits of catheter ablation in younger patients. No prognostic benefits for ablation were seen in the oldest patients. No differences were found by age in treatment-related complications or in the relative effectiveness of catheter ablation in preventing recurrent atrial arrhythmias. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT00911508.

Background: The CABANA trial (Catheter Ablation Versus Antiarrhythmic Drug Therapy for Atrial Fibrillation) was a randomized, prospective trial of left atrial catheter ablation versus drug therapy for treatment of atrial fibrillation (AF). As part of CABANA, a prospective imaging substudy was conducted. The main objectives were to describe the patterns of changes in the dimensions of the left atrium and pulmonary veins (PVs), and the relationship between these changes with treatment assignment and clinical outcomes. Methods: Computed tomography or magnetic resonance imaging was acquired at baseline and follow-up in 121 ablation (median follow-up 101 days) and 85 drug patients (median follow-up 97 days). Left atrial volume index, mean PV ostial diameter, and ostial diameters of each PV separately were computed. We examined the relationship between the change from baseline to follow-up with subsequent clinical outcomes (composite of death, disabling stroke, serious bleeding, or cardiac arrest [CABANA primary end point], total mortality or cardiovascular hospitalization, first AF recurrence after the 90-day blanking period, first AF/atrial flutter/atrial tachycardia after the 90-day blanking period) using Cox proportional-hazards models. Results: The median (25th to 75th) change from baseline for left atrial volume index was −7.8 mL/m 2 (−16.4 to 0.2), ablation arm and −3.5 mL/m 2 (−11.4 to 2.6), drug therapy arm. The left atrial volume index decreased in 52.9% of ablation patients versus 40.0% of drug therapy patients. Change for mean PV was −2.7 mm (−4.2 to −1.3) in the ablation arm versus −0.1 mm (−1.5 to 0.8) in the drug therapy arm. Changes in left atrium and PV dimensions had no consistent relationship with the risk of developing the study primary end point. Reductions in left atrial volume index, and in mean PV diameter were associated with decreased risk of AF recurrence. Conclusions: Ablation patients demonstrated more frequent and larger atrial structural changes compared with drug patients. These changes suggest a critical relationship between structural features and AF generation.

Background: In patients with heart failure and atrial fibrillation (AF), several clinical trials have reported improved outcomes, including freedom from AF recurrence, quality of life, and survival, with catheter ablation. This article describes the treatment-related outcomes of the AF patients with heart failure enrolled in the CABANA trial (Catheter Ablation Versus Antiarrhythmic Drug Therapy for Atrial Fibrillation). Methods: The CABANA trial randomized 2204 patients with AF who were ≥65 years old or <65 years old with ≥1 risk factor for stroke at 126 sites to ablation with pulmonary vein isolation or drug therapy including rate or rhythm control drugs. Of these, 778 (35%) had New York Heart Association class >II at baseline and form the subject of this article. The CABANA trial’s primary end point was a composite of death, disabling stroke, serious bleeding, or cardiac arrest. Results: Of the 778 patients with heart failure enrolled in CABANA, 378 were assigned to ablation and 400 to drug therapy. Ejection fraction at baseline was available for 571 patients (73.0%), and 9.3% of these had an ejection fraction <40%, whereas 11.7% had ejection fractions between 40% and 50%. In the intention-to-treat analysis, the ablation arm had a 36% relative reduction in the primary composite end point (hazard ratio, 0.64 [95% CI, 0.41–0.99]) and a 43% relative reduction in all-cause mortality (hazard ratio, 0.57 [95% CI, 0.33–0.96]) compared with drug therapy alone over a median follow-up of 48.5 months. AF recurrence was decreased with ablation (hazard ratio, 0.56 [95% CI, 0.42–0.74]). The adjusted mean difference for the AFEQT (Atrial Fibrillation Effect on Quality of Life) summary score averaged over the entire 60-month follow-up was 5.0 points, favoring the ablation arm (95% CI, 2.5–7.4 points), and the MAFSI (Mayo Atrial Fibrillation-Specific Symptom Inventory) frequency score difference was –2.0 points, favoring ablation (95% CI, –2.9 to –1.2). Conclusions: In patients with AF enrolled in the CABANA trial who had clinically diagnosed stable heart failure at trial entry, catheter ablation produced clinically important improvements in survival, freedom from AF recurrence, and quality of life relative to drug therapy. These results, obtained in a cohort most of whom had preserved left ventricular function, require independent trial verification. Registration: URL: https://www.clinicaltrials.gov/ct2/show/NCT00911508 ; Unique identifier: NCT0091150.