Cost effectiveness of focal impulse and rotor modulation guided ablation added to pulmonary vein isolation for atrial fibrillation.

BACKGROUND: Although ablation with focal impulse and rotor modulation (FIRM), as an adjunct to pulmonary vein isolation (PVI), has been shown to decrease atrial fibrillation (AF) recurrence, cost-effectiveness has not been assessed. OBJECTIVE: We aimed to evaluate the cost effectiveness of FIRM-guided ablation when added to PVI in a mixed AF population. METHODS AND RESULTS: We used a Markov model to estimate the costs, quality-adjusted survival, and cost effectiveness of adding FIRM ablation to PVI. AF recurrence rates were based on 3-year data from the CONFIRM trial. Model inputs for event probabilities and utilities were obtained from literature review. Costs were based on Medicare reimbursement, wholesale acquisition costs, and literature review. Three-year total costs FIRM+PVI versus PVI alone were $27,686 versus $26,924. QALYs were 2.338 versus 2.316, respectively, resulting in an incremental cost-effectiveness ratio (ICER) of $34,452 per QALY gained. Most of the cost (65-81%) was related to the index ablation procedure. Lower AF recurrence generated cost offsets of $4,266, primarily due to a reduced need for medications and repeat ablation. Probabilistic sensitivity analysis demonstrated ICER below $100,000/QALY in 74% of simulations. CONCLUSION: Based on data from the CONFIRM study, the addition of FIRM to PVI does have the potential to be cost-effective due to higher quality-adjusted life years and lower follow-up costs. Value is sensitive to the incremental reduction in AF recurrence, and FIRM may have the greatest economic value in patients with greater AF symptom severity. Results from ongoing randomized trials will provide further clarity.

Ablation of paroxysmal atrial fibrillation using a second-generation cryoballoon catheter or contact-force sensing radiofrequency ablation catheter: A comparison of costs and long-term clinical outcomes.

INTRODUCTION: Although noninferiority of cryoballoon ablation (CBA) and radiofrequency catheter ablation for antral pulmonary vein isolation (APVI) has been reported in patients with paroxysmal atrial fibrillation (PAF), it is not clear whether contact force sensing (CF-RFA) and CBA with the second-generation catheter have similar procedural costs and long-term outcomes. The objective of this study is to compare the long-term efficacy and cost implications of CBA and CF-RFA in patients with PAF. METHODS AND RESULTS: A first APVI was performed in 146 consecutive patients (age: 63 ± 10 years, men: 95 [65%], left atrial diameter: 42 ± 6 mm) with PAF using CBA (71) or CF-RFA (75). Clinical outcomes and procedural costs were compared. The mean procedure time was significantly shorter with CBA than with CF-RFA (98 ± 39 vs. 158 ± 47 minutes, P < 0.0001). Despite a higher equipment cost in the CBA than the CF-RFA group, the total procedure cost was similar between the two groups (P = 0.26), primarily driven by a shorter procedure duration that resulted in a lower anesthesia cost. At 25 ± 5 months after a single ablation procedure, 51 patients (72%) in the CBA, and 55 patients (73%) in the CF-RFA groups remained free from atrial arrhythmias without antiarrhythmic drug therapy (P = 0.84). CONCLUSIONS: The procedure duration was approximately 60 minutes shorter with CBA than CF-RFA. The procedural costs were similar with both approaches. At 2 years after a single procedure, CBA and CF-RFA have similar single-procedure efficacies of 72-73%.

Cost-Effectiveness and Clinical Effectiveness of the Risk Factor Management Clinic in Atrial Fibrillation: The CENT Study.

BACKGROUND: Atrial fibrillation (AF) imposes a substantial cost burden on the healthcare system. Weight and risk factor management (RFM) reduces AF burden and improves the outcomes of AF ablation. OBJECTIVES: This study sought to evaluate the cost and clinical effectiveness of integrating RFM into the overall management of AF. METHODS: Of 1,415 consecutive patients with symptomatic AF, 825 patients had body mass index ≥27 kg/m2. After screening for exclusion criteria, the final cohort comprised 355 patients: 208 patients who opted for RFM and 147 control subjects and were followed by 3 to 6 monthly clinic review, 7-day Holter monitoring, and AF Symptom Score. A decision analytical model calculated the incremental cost-effectiveness ratios of cost per unit of global well-being gained and unit of AF burden reduced. RESULTS: There were no differences in baseline characteristics or follow-up duration (p = NS). Arrhythmia-free survival was better in the RFM compared with control subjects (Kaplan-Meier: 79% vs. 44%; p < 0.001). At follow-up, RFM group had less unplanned specialist visits (0.19 ± 0.40 vs. 1.94 ± 2.00; p < 0.001), hospitalizations (0.74 ± 1.3 vs. 1.05 ± 1.60; p = 0.03), cardioversions (0.89 ± 1.50 vs. 1.51 ± 2.30; p = 0.002), emergency presentations (0.18 ± 0.50 vs. 0.76 ± 1.20; p < 0.001), and ablation procedures (0.60 ± 0.69 vs. 0.72 ± 0.86; p = 0.03). Antihypertensive (0.53 ± 0.70 vs. 0.78 ± 0.60; p = 0.04) and antiarrhythmic (0.26 ± 0.50 vs. 0.91 ± 0.60; p = 0.003) use declined in RFM. The RFM group had an increase of 0.1930 quality-adjusted life years and a cost saving of $12,094 (incremental cost-effectiveness ratios of $62,653 saved per quality-adjusted life years gained). CONCLUSIONS: A structured physician-directed RFM program is clinically effective and cost saving.

Design, Challenges, and Implications of Quality Improvement Projects Using the Electronic Medical Record: Case Study: A Protocol to Reduce the Burden of Postoperative Atrial Fibrillation.

Postoperative atrial fibrillation (POAF) is a frequent complication of cardiac surgery, which results in increased morbidity, mortality, length of stay, and hospital costs. We developed and followed a process map to implement a protocol to decrease POAF: (1) identify stakeholders and form a working committee, (2) formal literature and guideline review, (3) retrospective analysis of current institutional data, (4) data modeling to determine expected effects of change, (4) protocol development and implementation into the electronic medical record, and (5) ongoing review of data and protocol adjustment. Retrospective analysis demonstrated that POAF occurred in 29.8% of all cardiovascular surgery cases. Median length of stay was 2 days longer (P<0.001), and median total variable costs $2495 higher (P<0.001) in POAF patients. Modeling predicted that up to 60 cases of POAF and >$200 000 annually could be saved. A clinically based electronic medical record tool was implemented into the electronic medical record to aid preoperative clinic providers in identifying patients eligible for prophylactic amiodarone. Initial results during the 9-month period after implementation demonstrated a reduction in POAF in patients using the protocol, compared with those who qualified but did not receive amiodarone and those not evaluated (11.1% versus 38.7% and 38.8%; P=0.022); however, only 17.3% of patients used the protocol. A standardized methodological approach to quality improvement and electronic medical record integration has potential to significantly decrease the incidence of POAF, length of stay, and total variable cost in patients undergoing elective coronary artery bypass graft and valve surgeries. This framework for quality improvement interventions may be adapted to similar clinical problems beyond POAF.

Cost-effectiveness of cryoballoon ablation for the management of paroxysmal atrial fibrillation.

AIMS: Cryoballoon ablation is an established treatment option for the management of patients with atrial fibrillation. We sought to evaluate the cost-effectiveness of cryoablation, compared with second-line anti-arrhythmic drug (AAD) therapy in patients with paroxysmal atrial fibrillation (PAF), from a UK payer perspective. METHODS AND RESULTS: We developed a state-transition (Markov) model to calculate the total costs and quality-adjusted life-years (QALYs) associated with cryoablation and AAD therapy in patients with PAF. A 5-year horizon was used for the base-case. Data from a recent study of cryoballoon ablation in patients with PAF were used to model short-term health outcomes and costs, together with longer term external evidence to populate subsequent time periods. Total discounted costs were £21 162 and £17 627 for the cryoballoon ablation and AAD arms, respectively. Total QALYs of 3.565 and 3.404 therefore led to an incremental cost-effectiveness ratio of £21 957 per QALY gained. Sensitivity analysis suggested that the key drivers of the results were the model time horizon, the costs of follow-up care in patients with recurrent AF, and the costs of the ablation procedure. CONCLUSION: Cryoballoon ablation provides increased quality-adjusted life expectancy compared with AAD at reasonable additional cost, representing good value for money in patients with PAF.

Amiodarone is a cost-neutral way of preventing atrial fibrillation after surgery for lung cancer.

OBJECTIVES: Our aim was to estimate the costs and health benefits of routinely administered postoperative amiodarone as a prophylactic agent in reducing the risk of atrial fibrillation in patients undergoing surgery for lung cancer. METHODS: This was a cost-effectiveness study, based on the randomized, controlled, double-blinded PASCART study, using avoidance of atrial fibrillation as the measure of benefit. Two hundred and fifty-four eligible, consecutively enrolled patients, undergoing surgery for lung cancer at the department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Denmark, were included and randomized to receive either 300 mg of amiodarone or placebo (5% aqueous dextrose solution), administered intravenously over 20 min immediately after surgery, followed by 600 mg of amiodarone/placebo orally twice per day (8 a.m. and 6 p.m.) for the first five postoperative days. RESULTS: In the amiodarone group there were 11 cases of atrial fibrillation, compared with 38 in the control group (P < 0.001). There were no differences in the length of hospital stay or resources used. The mean total costs per patient were equal and amounted to €7288 per patient (P = 0.23). There were no signs of adverse developments referable to amiodarone in this prophylactic regime. CONCLUSIONS: For patients undergoing surgery for lung cancer, routine use of postoperative prophylactic intravenous bolus and five subsequent days of oral amiodarone therapy reduces the risk of atrial fibrillation in a cost-neutral manner.

Economic modelling of diagnostic and treatment pathways in National Institute for Health and Care Excellence clinical guidelines: the Modelling Algorithm Pathways in Guidelines (MAPGuide) project.

BACKGROUND: National Institute for Health and Care Excellence (NICE) clinical guidelines (CGs) make recommendations across large, complex care pathways for broad groups of patients. They rely on cost-effectiveness evidence from the literature and from new analyses for selected high-priority topics. An alternative approach would be to build a model of the full care pathway and to use this as a platform to evaluate the cost-effectiveness of multiple topics across the guideline recommendations. OBJECTIVES: In this project we aimed to test the feasibility of building full guideline models for NICE guidelines and to assess if, and how, such models can be used as a basis for cost-effectiveness analysis (CEA). DATA SOURCES: A 'best evidence' approach was used to inform the model parameters. Data were drawn from the guideline documentation, advice from clinical experts and rapid literature reviews on selected topics. Where possible we relied on good-quality, recent UK systematic reviews and meta-analyses. REVIEW METHODS: Two published NICE guidelines were used as case studies: prostate cancer and atrial fibrillation (AF). Discrete event simulation (DES) was used to model the recommended care pathways and to estimate consequent costs and outcomes. For each guideline, researchers not involved in model development collated a shortlist of topics suggested for updating. The modelling teams then attempted to evaluate options related to these topics. Cost-effectiveness results were compared with opinions about the importance of the topics elicited in a survey of stakeholders. RESULTS: The modelling teams developed simulations of the guideline pathways and disease processes. Development took longer and required more analytical time than anticipated. Estimates of cost-effectiveness were produced for six of the nine prostate cancer topics considered, and for five of eight AF topics. The other topics were not evaluated owing to lack of data or time constraints. The modelled results suggested 'economic priorities' for an update that differed from priorities expressed in the stakeholder survey. LIMITATIONS: We did not conduct systematic reviews to inform the model parameters, and so the results might not reflect all current evidence. Data limitations and time constraints restricted the number of analyses that we could conduct. We were also unable to obtain feedback from guideline stakeholders about the usefulness of the models within project time scales. CONCLUSIONS: Discrete event simulation can be used to model full guideline pathways for CEA, although this requires a substantial investment of clinical and analytic time and expertise. For some topics lack of data may limit the potential for modelling. There are also uncertainties over the accessibility and adaptability of full guideline models. However, full guideline modelling offers the potential to strengthen and extend the analytical basis of NICE's CGs. Further work is needed to extend the analysis of our case study models to estimate population-level budget and health impacts. The practical usefulness of our models to guideline developers and users should also be investigated, as should the feasibility and usefulness of whole guideline modelling alongside development of a new CG. FUNDING: This project was funded by the Medical Research Council and the National Institute for Health Research through the Methodology Research Programme [grant number G0901504] and will be published in full in Health Technology Assessment; Vol. 17, No. 58. See the NIHR Journals Library website for further project information.

Resource utilization and outcomes in patients with atrial fibrillation: a case control study.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained disorder of cardiac rhythm. Various new anticoagulation and antiarrythmic treatments are being investigated for the treatment of AF. Before novel treatments can be used widely in actual clinical practice, the cost effectiveness of such novel treatments may need to be determined. OBJECTIVE: The objectives of the study were to describe resource utilization for AF and control patients, and estimate the incidence of mortality. METHODS: This case control study evaluated 6 months of primary and secondary care resource utilization and mortality rates for patients within the period 01 April 2001 to 31 March 2006. Cases included 15 373 adults with a record of AF in the General Practice Research Database (GPRD) within the study period. The index date was randomly selected between 6 months after the AF record and end of data collection. Cases were matched to controls by age, gender, general practice and time. RESULTS: AF patients had significantly higher resource utilization than controls. Resource utilization increased with greater National Institute for Clinical Excellence (NICE) stroke risk strata (graded as low, moderate or high based on associated risk factors). Both current warfarin and aspirin users had higher resource utilization than control patients. Resource utilization remained high amongst AF patients who discontinued therapy. The mortality rate was significantly higher in AF patients than controls, deaths due to circulatory system disease were increased 4-fold and cancer deaths were doubled. All-cause and circulatory mortality rates, as well as rates of clinical outcomes, were related to the NICE stroke risk schema. CONCLUSIONS: There was large heterogeneity in resource utilization between AF patients, although overall, this was still higher than controls without AF. Higher resource utilization was evident in patients at higher risk of stroke, and remained where antithrombotic therapy was discontinued. The mortality risk in AF was increased substantially, both for cardiovascular and non-cardiovascular causes of death, indicating a large unmet medical need.

Landiolol hydrochloride for prevention of atrial fibrillation after coronary artery bypass grafting: new evidence from the PASCAL trial.

OBJECTIVE: Atrial fibrillation occurs frequently after cardiac surgery and not only prolongs hospitalization but also influences the prognosis. We investigated whether landiolol hydrochloride, an ultrashort-acting beta-blocker, could reduce postoperative atrial fibrillation in a randomized controlled trial. METHODS: The subjects were 140 patients undergoing coronary artery bypass grafting at the Nihon University School of Medicine. The primary end point was occurrence/non-occurrence of atrial fibrillation up to 1 week postoperatively. Logistic regression analysis was performed to investigate risk factors for atrial fibrillation among preoperative, perioperative, and postoperative variables. RESULTS: Atrial fibrillation occurred in 7 patients (10%) in the landiolol group versus 24 patients (34.3%) in the placebo group; the landiolol group had a significantly lower incidence (P = .0006). Postoperative heart rate was significantly lower in the landiolol group than in the placebo group. On returning to the intensive care unit, the landiolol group had significantly lower inflammatory and ischemic parameters. Medical costs were also significantly lower in the landiolol group. Multivariate analysis revealed that significant risk factors for atrial fibrillation were a European System for Cardiac Operative Risk Evaluation of 10 or more, preoperative non-use of angiotensin receptor blockers, and non-use of landiolol. CONCLUSIONS: Postoperative atrial fibrillation was reduced by treatment with landiolol hydrochloride. Amelioration of ischemia, an anti-inflammatory effect, and inhibition of sympathetic hypertonia by landiolol presumably reduced the occurrence of atrial fibrillation. Hypotension or bradycardia did not develop in any of the patients, indicating the safety of this beta-blocker. These findings suggest that landiolol hydrochloride could be useful in the perioperative management of patients undergoing cardiac surgery.

[Cost-benefit analysis of concomitant atrial fibrillation management in Spain]. / Análisis de coste-utilidad del manejo de la fibrilación auricular concomitante en España.

OBJECTIVES: Atrial fibrillation (AF) is the most common arrhythmia in clinical practice; this disorder is a risk factor for stroke and is associated with substantial morbidity and mortality. Our objective was to develop a cost-utility analysis of the different treatment alternatives in patients aged 40 years old or more with concomitant AF with valve disease in Spain, from the National Health System perspective. METHODS: An economic evaluation through a Markov model with four health states (sinus rhythm, AF, dependent stroke, death) was developed to simulate the evolution of a cohort of 1,000 patients receiving each treatment alternative in addition to mitral valve surgery (drug therapy, surgical ablation and catheter ablation). The time horizon was 5 years, with a cycle length of 3 months. Data on costs and effects were obtained from the published literature and expert opinion and were discounted at 3.5%. A sensitivity analysis was developed to determine the robustness of the results. RESULTS: The quality-adjusted life years (QALY) gained were 3.29, 3.89, and 3.83, respectively, for the alternatives of no ablation, surgical ablation and catheter ablation. The costs per patient were 5,770euro, 10,034euro and 11,289euro, respectively. The surgical ablation cost/QALY rate compared with no ablation was 7,145euro. Surgical ablation was dominant versus catheter ablation. The probabilistic sensitivity analysis showed that the results were robust. CONCLUSIONS: Surgical ablation is a cost-effective treatment option in patients with concomitant AF, with a cost-effectiveness ratio under the efficiency threshold commonly accepted in Spain.

Patterns and predictors of discontinuation of rhythm-control drug therapy in patients with newly diagnosed atrial fibrillation.

STUDY OBJECTIVE: To assess patterns and predictors of discontinuation of rhythm-control drug therapy in managed care patients with newly diagnosed atrial fibrillation and the direct medical costs of atrial fibrillation in these patients. DESIGN: Retrospective cohort study. DATA SOURCE: PharMetrics Patient-Centric Database. PATIENTS: A total of 3549 adults with a new diagnosis of atrial fibrillation between April 1, 2002, and March 31, 2006, and who had at least one claim for rhythm-control drug therapy within 6 months of the initial diagnosis. MEASUREMENTS AND MAIN RESULTS: Discontinuation (defined as a gap in rhythm-control drug therapy coverage [days' supply] > or = 30 days) was assessed after the initiation of rhythm-control therapy. Among the 3549 patients included in the analysis, 2688 (75.7%) discontinued initial rhythm-control therapy in the first 12 months, with a median time to discontinuation of 89 days. Significant predictors of rhythm-control therapy discontinuation included cardiac arrest (odds ratio [OR] 2.24, 95% confidence interval [CI] 1.04-4.83), history of coronary artery bypass graft surgery (OR 2.03, 95% CI 1.02-4.05), valvular heart disease (OR 1.67, 95% CI 1.33-2.09), ischemic heart disease (OR 1.44, 95% CI 1.13-1.82), and severity of illness (Charlson Comorbidity Index score; OR 1.09, 95% CI 1.01-1.17). Over 12 months, 661 (18.6%) of the 3549 patients had a hospital stay and 285 (8.0%) had an emergency department visit that were related to atrial fibrillation. Total annual atrial fibrillation-related costs/patient were $6165: $3872 for inpatient costs, $1503 for outpatient costs, and $790 for pharmacy costs. CONCLUSION: Initial rhythm-control drug therapy is associated with a high rate of discontinuation, especially early in therapy. Such rates of discontinuation will likely have an impact on the effectiveness of disease management and the quality of care in patients with atrial fibrillation.

Intravenous magnesium sulphate and sotalol for prevention of atrial fibrillation after coronary artery bypass surgery: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical and cost-effectiveness of magnesium sulphate compared with sotalol, and to assess the clinical effectiveness of magnesium sulphate compared with placebo in the prevention of atrial fibrillation (AF) in patients who have had a coronary artery bypass graft (CABG). DATA SOURCES: Major electronic databases were searched from December 2003 to May 2007. REVIEW METHODS: Selected studies were assessed, subjected to data extraction using a standard template and quality assessment using published criteria. A simple short-term economic model was developed, informed by a systematic review of economic evaluations and populated with data from a review of costing/resource-use studies and other published studies. The cost-effectiveness of magnesium sulphate as prophylaxis was estimated for a set of base-case assumptions and the robustness of these results was assessed using deterministic and probabilistic sensitivity analysis. RESULTS: Twenty-two papers met the inclusion criteria reporting 15 trials which all compared magnesium sulphate with placebo or control. They ranged in size from 15 to 176 patients randomised, and were conducted in Europe, the USA and Canada. The standard of reporting was generally poor, with details of key methodological attributes difficult to elucidate. No trials were identified that specifically aimed to compare magnesium sulphate with sotalol. Of 1070 patients in the pooled magnesium group, 230 (21%) developed postoperative AF, compared with 307 of 1031 (30%) patients in the placebo or (control) group. Meta-analysis using a fixed-effects model generated a pooled odds ratio (OR) that was significantly less than 1.0 [OR=0.65, 95% confidence interval (CI) 0.53 to 0.79, test for overall effect p<0.0001], but with statistically significant heterogeneity (I2=63.4%, p=0.0005). Two randomised controlled trials (RCTs) were notable as they had relatively lower ORs in favour of magnesium sulphate. When these were removed from the analyses the pooled OR remained statistically significant, but heterogeneity no longer remained significant. These two studies tended to impart a highly significant reduction in the odds of AF to whichever subgroup they were analysed in. When studies were ordered by total duration of prophylaxis, an apparent relationship between duration and odds of AF was evident, with decreasing odds of AF as duration of prophylaxis increased. This was confirmed by linear regression analysis (R2=0.743, p<0.001). When the data were grouped into three classes according to duration, a statistically significant intervention effect was only present for the longest duration (OR=0.12, 95% CI 0.06 to 0.23, p=0.00001). Statistically significant intervention effects were associated with the initiation of prophylaxis 12 hours or more before surgery (OR 0.26; 95% CI 0.16 to 0.44, test for overall effect p=0.00001, fixed-effects model) and less than 12 hours before surgery or during the surgery itself (OR=0.73, 95% CI 0.56 to 0.97, test for overall effect p = 0.03, fixed-effects model), but not when prophylaxis was initiated at the end of surgery or postsurgery (OR=0.85, 95% CI 0.59 to 1.22, p=0.37, fixed-effects model). When studies were ordered by total dose of intravenous magnesium sulphate (<25 g), the odds of AF were independent of the dose. A notable exception was that for a total dose of 9 g magnesium sulphate; here the odds of AF were significantly reduced relative to the control group, although this may be explained by the fact that these studies had excluded patients who were on antiarrhythmic drugs and so may have been at higher risk of AF. Sixty-three potentially relevant references about cost-effectiveness were identified, but no economic evaluations of intravenous magnesium alone as prophylaxis against AF following CABG, compared with sotalol as prophylaxis or no prophylaxis, were identified. Studies reporting resource use by patients with AF following CABG suggest that while AF significantly increased inpatient stays, by up to 2.3 days in the intensive care unit (ICU) and 3.4 days on the ward, differences in length of stay and costs between patients receiving prophylaxis and those not receiving prophylaxis were not statistically significant. In the base-case analysis, magnesium sulphate prophylaxis resulted in 0.081 fewer cases of AF at an incremental cost of 2.55 pounds sterling. The incremental cost-effectiveness ratio (ICER) was 32 pounds sterling per AF case avoided. The estimated difference in average length of stay between the prophylaxis and no-prophylaxis strategies was only 0.24 days, despite a large assumed difference of 3 days for patients experiencing AF in each group (1 extra day in the ICU and 2 extra days on the ward). In a deterministic sensitivity analysis the greatest variation in ICERs was observed for input parameters relating to the baseline risk of AF following CABG and the effectiveness of prophylaxis, cost of prophylaxis and the resource consequences of postoperative AF. The largest ICER (2092 pounds sterling) in the sensitivity analysis was associated with increasing the length of patients' preoperative stay. In the base case it was assumed that admission routines would be identical under both strategies. However, patients receiving prophylaxis by intravenous infusion may have longer preoperative stays. In a probabilistic analysis the majority of the simulations were associated with improved outcomes (in this case fewer cases of AF), but also higher costs. Prophylaxis was the dominant strategy (better outcome at lower cost) in about 41% of the simulations using the base-case assumptions. Under an alternative scenario where patients receiving prophylaxis are admitted for longer before their operation, to receive their initial infusion, the proportion of simulations where prophylaxis dominates fell to around 5%. The probability of being cost-effective was 99% at a willingness to pay (WTP) threshold of 2000 pounds sterling per AF case avoided and 100% at a WTP threshold of 5000 pounds sterling per AF case avoided under the base-case assumptions. Under the alternative scenario of longer preoperative stays the probability of being cost-effective at these two threshold values fell to 48% and 93%, respectively. It is unclear what the appropriate decision threshold should be, given that this model used intermediate rather than final outcomes. CONCLUSIONS: No RCTs were identified that specifically aimed to compare intravenous magnesium with sotalol as prophylaxis for AF in patients undergoing CABG. Intravenous magnesium, compared with placebo or control, is effective in preventing postoperative AF, as confirmed by a statistically significant intervention effect based on pooled analysis of 15 RCTs. It was also found that AF was less likely to occur when a longer duration of prophylaxis was used, and the earlier that prophylaxis is started; however, this finding was associated with two RCTs that had more favourable results than the other trials. No clear relationship between dose and AF was observed, although a lower constant dose rate was associated with the lowest odds of AF. Further research should investigate the relationship between dose, dose rate, duration of prophylaxis, timing of initiation of therapy and patient characteristics, such as degree of risk for AF. This will provide stronger evidence for the optimum delivery of intravenous magnesium in patients undergoing CABG. In the base-case analysis in the economic model, magnesium sulphate prophylaxis reduced the number of postoperative AF cases at a modest increase in cost. The results of the economic analysis are highly sensitive to variation in certain key parameters. Prophylaxis is less likely to be a cost-effective option if it requires changes in admission routines that result in longer preoperative stays than would be the case without prophylaxis.

Amiodarone cost effectiveness in preventing atrial fibrillation after coronary artery bypass graft surgery.

BACKGROUND: The purpose of this study was to estimate the costs and health benefits of routinely administered postoperative amiodarone as prevention of atrial fibrillation for patients undergoing coronary artery bypass grafting (CABG) for stable angina. METHODS: This cost-effectiveness study was based on a randomized, controlled, double-blind trial (the RASCABG study) using avoidance of atrial fibrillation as the measure of benefit at the Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Skejby, Denmark. Two hundred and fifty eligible consecutively enrolled CABG patients were included to receive either 300 mg amiodarone or placebo (5% aqueous dextrose solution) administered intravenously over 20 minutes followed by 600 mg amiodarone/placebo orally twice a day (8 am and 8 pm) for the first 5 postoperative days. RESULTS: In the amiodarone group, there were 14 cases of atrial fibrillation compared with 32 in the control group (p < 0.01) whereas there were no differences in the length of stay. The mean total cost per patient was 7,639 euros in the amiodarone group and 7,814 euros in the placebo group (p < 0.01). CONCLUSIONS: Routine use of postoperative prophylactic intravenous bolus and subsequent 5 days of oral amiodarone therapy after coronary artery bypass grafting reduces the risk of atrial fibrillation and decreases the total costs of care by 175 euros per patient.

Risk-stratified evaluation of amiodarone to prevent atrial fibrillation after cardiac surgery.

BACKGROUND: Amiodarone prophylaxis (AMP) reduces the prevalence of postoperative atrial fibrillation (POAF) after cardiac surgery. We investigated the impact of AMP on the frequency and duration of POAF, the intensive care unit and hospital length of stay, and its cost-effectiveness in a risk-stratified cohort. METHODS: A retrospective, observational analysis of 509 patients who underwent cardiac surgery in 2003 was performed. Data sources included The Society of Thoracic Surgeons national database; medical and medication administration records; and the activity-based cost data from our institution. Risk stratification for POAF was determined using a validated risk index. Cost-effectiveness was determined from the hospital's perspective. RESULTS: The mean patient age was 63 years, 27% were female, 80% underwent coronary artery bypass grafting, and 29% underwent valve surgery. When a risk-stratified evaluation was made, 50% of patients were at an elevated risk for having POAF develop. When compared with nonprophylaxed patients, those receiving AMP (59%) experienced less POAF (31% vs 22%; p = 0.027) and shorter durations of POAF (4.7 vs 2.7 days; p = 0.025). In the elevated-risk group, AMP clinically (but not significantly) reduced length of stay in the intensive care unit (101 vs 68 hours; p > 0.05) and post-procedural hospital length of stay (9.7 vs. 7.9 days, p > 0.05). In the elevated-risk group, AMP was robustly cost-effective in reducing POAF. CONCLUSIONS: Amiodarone prophylaxis reduced the prevalence and duration of POAF. Baseline risk for POAF was a major determinant of the overall cost-effectiveness of AMP. The greatest cost savings with AMP was seen in patients at an elevated risk for POAF. These findings suggest the need for risk stratification when prescribing AMP.

Radiofrequency catheter ablation of supraventricular tachycardia in children and adolescents : feasibility and cost-effectiveness in a low-income country.

The objective of this study is to provide results and costs of catheter ablation in children and adolescents in a low-income country. Reports from first-world countries have demonstrated the cost-effectiveness of radiofrequency catheter ablation (RFCA) compared to medical treatment of supraventricular tachycardia (SVT). The study included 28 patients younger than 18 years of age with SVT in a pediatric cardiology unit in Guatemala. All patients underwent RFCA. Clinical outcome and cost-effectiveness of RFCA compared to continued medical treatment were the end points. Twenty-four patients had successful ablation (85.7%). Mean age at RFCA was 11.42 +/- 3.49 years. Three patients underwent a second ablation, increasing the success rate to 96.4%. One remaining patient is awaiting a second procedure. At a mean follow-up of 13.69 +/- 7.16 months, all 27 patients who had a successful ablation remained in sinus rhythm. Mean cost per procedure was 4.9 times higher than that of medical treatment. However, the estimated cost of catheter ablation equal that of medical therapy after 5.1 years and is 3.4 times less after 20 years. Radiofrequency catheter ablation of SVT in children and adolescents is safe and cost-effective compared to medical therapy. Resources must be judiciously allocated, especially in low-income countries, to treat the largest number of pediatric patients.

Pharmacological management of atrial fibrillation following cardiac surgery.

Atrial fibrillation (AF) is the most common complication following coronary artery bypass graft surgery (CABG). Post-CABG AF occurs most commonly on the second postoperative day and declines in incidence thereafter. A number of risk factors have been found to be associated with a higher frequency of post-CABG AF. These risk factors include advanced age, a prior history of AF, hypertension, and heart failure. Postoperative complications--including low cardiac output, use of an intra-aortic balloon pump, pneumonia, and prolonged mechanical ventilation--are also associated with higher rates of post-CABG AF. Post-CABG AF increases the risk of stroke, and the length and cost of hospitalization. Prophylactic administration of conventional beta-adrenoceptor antagonists (beta-blockers) or sotalol produces a consistent and significant reduction in the incidence of post-CABG AF; however, results with prophylactic amiodarone or magnesium are less consistent. Termination of post-CABG AF, once it occurs, can be accomplished with a number of antiarrhythmic agents. Ibutilide has been the most widely studied agent for this indication. Sotalol is not indicated for cardioversion of AF and has not been studied in the post-CABG setting. Electrical cardioversion and biatrial pacing have also been used to terminate post-CABG AF. Ventricular rate is best controlled with beta-blockers and calcium channel antagonists. Esmolol has a rapid onset of action and is easily titrated to effect. Digoxin can control the ventricular rate, but has a slow onset of action. There are limited data available to guide decisions regarding the optimal management of post-CABG AF.

Effect of prophylactic amiodarone on clinical and economic outcomes after cardiothoracic surgery: a meta-analysis.

BACKGROUND: Two previous meta-analyses of amiodarone for prevention of postoperative atrial fibrillation (POAF) after cardiothoracic surgery did not evaluate total hospital cost, concluded that data on stroke are incomplete, and did not evaluate the effect of clinical heterogeneity between trials. OBJECTIVE: To conduct a meta-analysis examining amiodarone's prophylactic impact on cardiothoracic surgery POAF, length of stay (LOS), stroke, and total costs. METHODS: Three reviewers conducted a systematic literature search of MEDLINE, EMBASE, CINAHL, and the Cochrane Library (1966-SEPTEMBER 2004). Studies were included if they met the following criteria: (1) randomized controlled trial versus placebo/routine treatment, (2) coronary artery bypass graft and/or valvular surgery, (3) Jadad score > or = 3, (4) reported data on incidence of POAF or stroke, LOS, or total costs, (5) used electrocardiographic/Holter monitoring, and (6) monitored subjects for > or = 2 days. A random-effects model was utilized. Subgroup and sensitivity analyses were conducted. RESULTS: Fifteen trials were identified, including 1512 and 1429 patients in the amiodarone and control groups, respectively. Amiodarone reduced POAF (OR 0.50; 95% CI 0.42 to 0.60) and decreased stroke (n = 8 studies), LOS (n = 10), and total costs (n = 6) (OR 0.47; 95% CI 0.23 to 0.96; -0.73 days, 95% CI -0.95 to -0.51; and -dollar 1619, 95% CI -3395 to 156, respectively). Surgery type, beta-blocker use, route of administration, use of a fixed-effects model, or exclusion of unblinded/unpublished studies did not affect the overall results. No statistical heterogeneity was observed for any endpoint evaluated (p > 0.22 for all comparisons). CONCLUSIONS: Prophylactic treatment with amiodarone decreases patients' risk of POAF and stroke while reducing LOS.

Regression methods for cost-effectiveness analysis with censored data.

A system of seemingly unrelated regression equations is proposed for prognostic factor adjustment and subgroup analysis when comparing two groups in a cost-effectiveness analysis with censored data. Because of the induced dependent censoring on costs and quality-adjusted survival, inverse probability weighting is employed for parameter estimation. The method is illustrated with data from two recent examples using both survival time and quality-adjusted survival time as the measures of effectiveness.

Economic analysis of intravenous plus oral amiodarone, atrial septal pacing, and both strategies to prevent atrial fibrillation after open heart surgery.

STUDY OBJECTIVES: To compare the cost-effectiveness of intravenous plus oral amiodarone, atrial septal pacing, and both strategies combined to prevent atrial fibrillation after open heart surgery. Secondary objectives were to compare the cost-effectiveness of amiodarone versus no amiodarone and of pacing versus no pacing, and to compare hospitalization costs of the various strategies. DESIGN: Piggyback cost analysis of a randomized, 2 x 2 factorial trial. SETTING: Urban academic hospital. PATIENTS: One hundred and sixty patients with coronary artery and/or valvular disease. INTERVENTION: Patients were randomized to receive amiodarone or matching placebo and then further randomized to receive atrial septal pacing or no pacing. MEASUREMENTS AND MAIN RESULTS: The economic analysis was conducted from a hospital perspective. Charges were converted to costs using cost:charge ratios. For the cost-effectiveness analysis, a joint distribution of costs and effectiveness was performed using the nonparametric bootstrap method. Amiodarone plus pacing significantly decreased the frequency of atrial fibrillation after open heart surgery, compared with amiodarone alone, pacing alone, and placebo. Total costs (mean+/-SD) were $27,026+/-30,226 for the placebo group, $22,725+/-17,661 for the amiodarone group, $33,868+/-60,309 for the pacing group, and $18,697+/-8174 for the amiodarone plus pacing group (p=0.27). In the joint distribution cost-effectiveness analysis, when compared with placebo, the probability of lower cost but higher effect (superiority) was 67% for amiodarone, 15% for pacing, and 97% for amiodarone plus pacing. In the multivariate analysis, preoperative beta-blockers and amiodarone were negatively associated with hospital costs (p<0.05). CONCLUSIONS: Data suggest that both amiodarone alone and the combination of amiodarone plus pacing are cost-effective compared with placebo. Additional comparative studies of these strategies are warranted to confirm these findings.