An economic analysis of amiodarone versus placebo for the prevention of atrial fibrillation after open heart surgery.

STUDY OBJECTIVE: To determine if the additional costs of oral amiodarone in patients undergoing open heart surgery would be offset by reductions in the frequency of atrial fibrillation. DESIGN: Piggyback cost analysis of the data from a randomized, double-blind, placebo-controlled trial. SETTING: Urban academic hospital. PATIENTS: Two hundred twenty elderly patients (> or = 60 yrs old) undergoing open heart surgery. INTERVENTION: Hospital costs of open heart surgery in patients given amiodarone for the prevention of atrial fibrillation and in prespecified subgroups were compared with those for patients given placebo (i.e., standard care with beta-blockers alone). MEASUREMENTS AND MAIN RESULTS: Total hospital costs incurred were $15,565 +/- $9832 and $16,126 +/- $8043 in the amiodarone and placebo groups, respectively (p=0.12). General ward, intensive care unit, operating room, pharmacy, and costs in all other departments were similar between the groups (p>0.05 for all comparisons). Because costs were similar but amiodarone was more effective than placebo, amiodarone was cost-effective compared with placebo. Amiodarone remained cost-effective compared with placebo regardless of the following subgroup characteristics: rapid or slow loading strategy, no history of atrial fibrillation or heart failure, age older than 70 years, and no tolerance to preoperative beta-blockers. Moreover, in the one-way sensitivity analysis, the findings remained robust to changes in effectiveness and cost of amiodarone. CONCLUSION: Routine prophylaxis with amiodarone is cost-effective compared with placebo. Future studies should examine the cost-effectiveness of selective prophylaxis, and primary cost-effectiveness studies should be conducted to validate these findings.     

Cost-effectiveness of amiodarone for prophylaxis of atrial fibrillation after cardiothoracic surgery

STUDY OBJECTIVE: To determine whether prophylactic amiodarone, dosed according to Atrial Fibrillation Suppression Trial (AFIST) I and II regimens, is a cost-effective strategy for prevention of postoperative atrial fibrillation. DESIGN: Cost-effectiveness analysis of retrospective cohort study. SETTING: Urban, academic hospital. PATIENTS: A total of 2046 patients who underwent cardiothoracic surgery between February 1, 1998, and October 31, 2003. Of these patients, 186 received amiodarone and 1860 served as controls. MEASUREMENTS AND MAIN RESULTS: Each patient who received prophylactic amiodarone using the AFIST I or II dosing strategies was matched for age, sex, history of valvular surgery, history of atrial fibrillation, beta-blocker intolerance, and receipt of preoperative digoxin therapy with 10 patients who did not receive prophylactic amiodarone. Occurrence of postoperative atrial fibrillation, total hospital costs, and both intensive care unit (ICU) and total hospital length of stay (LOS) were compared between groups. Nonparametric bootstrapping was conducted to examine study results as part of a quadrant analysis and to calculate confidence intervals for the incremental cost-effectiveness ratio. The ICU and total hospital LOS, and total costs for patients with and without postoperative atrial fibrillation were also compared. Fewer patients receiving prophylactic amiodarone developed postoperative atrial fibrillation compared with controls (23.1% vs 29.9%, p=0.05). Total hospital costs for the amiodarone group were 28% less than those for the control group (24,131 US dollars +/- 26,539 vs 33,518 US dollars +/- 40,892, p=0.002). Approximately 98% of the time, patients receiving amiodarone prophylaxis fell into the quadrant that showed superior efficacy and lower total costs. Patients who developed postoperative atrial fibrillation, compared with those who did not, regardless of amiodarone prophylaxis, had a longer mean +/- SD stay in the ICU (6.9 +/- 17.1 vs 3.7 +/- 7.9 days, p<0.001), a longer mean total hospital LOS (14.8 +/- 18.8 vs 10.2 +/- 10.4 days, p+/-0.001), and higher mean total hospital costs (41,574 US dollars +/- 54,721 vs 28,968 US dollars +/- 31,046, p<0.001). CONCLUSION: Prophylactic amiodarone was shown to reduce the occurrence of postoperative atrial fibrillation as well as total hospital costs in patients undergoing cardiothoracic surgery. In patients who developed postoperative atrial fibrillation, both ICU and total hospital LOS as well as total hospital costs were increased.     

Cost-effectiveness of amiodarone for prophylaxis of atrial fibrillation in coronary artery bypass surgery.

The cost-effectiveness of amiodarone prophylaxis of atrial fibrillation (AF) in patients undergoing coronary artery bypass grafting (CABG) was determined. A decision analysis using current hospital data and values from the literature was conducted. Under the base-case scenario, CABG patients received usual care (no prophylaxis) or 2 g of oral amiodarone hydrochloride over one to three days before surgery and 400 mg daily for seven days after surgery. Costs of hospitalization in the intensive care unit (ICU) and the cardiac step-down unit (SDU), cardioversion costs, electrocardiogram costs, drug costs, nursing administration charges, and pharmacy i.v. admixture charges were included. A sensitivity analysis using a Monte Carlo simulation and a one-way sensitivity analysis were performed. The mean cost per AF event avoided was lower in the amiodarone group ($15,750, 95% confidence interval [CI]: $15,591-$15,999) than the control group ($17,426,95% CI: $17,252-$17,600). A majority of the cost difference was due to the cost of hospitalization for patients without AF, the frequency of AF, and the cost of hospitalization in the SDU for patients with AF. For patients treated with amiodarone who did not develop AF, the cost difference was sensitive to changes in the cost of hospitalization and the efficacy of amiodarone. For patients who did develop AF, the cost difference was robust. Prophylaxis of AF with amiodarone in CABG patients was more cost-effective than usual care in the short term from a hospital perspective; the results were sensitive to changes in the cost of hospitalization of patients who did not develop AF and the efficacy of amiodarone.     

Cost effectiveness of ibutilide with prophylactic magnesium in the treatment of atrial fibrillation

BACKGROUND: In the Treatment with Ibutilide and Magnesium Evaluation (TIME) study, a retrospective multicentre cohort trial, prophylactic magnesium was found to improve the antiarrhythmic efficacy of ibutilide as demonstrated by an increase in the rate of successful chemical conversion and reduction in the need for direct current cardioversion (DCC). OBJECTIVE: The primary objective of this piggyback cost-effectiveness analysis of the TIME study was to compare the cost per successful conversion of atrial fibrillation (AF) for ibutilide in the presence and absence of magnesium prophylaxis. A secondary objective was to determine whether specific factors predict costs in the conversion of AF. METHOD: The study was conducted from the US hospital-payer perspective. Direct medical costs (USD, 2002 values) including drugs, intravenous admixture and administration, DCC, electrocardiographs and physicians' fees were obtained directly from the provider. Nonparametric bootstrapping was conducted to calculate confidence intervals for the incremental cost-effectiveness ratios. One-way sensitivity analysis was conducted varying efficacy, and drug, hospital and physician costs. Multivariate analysis was conducted to determine whether specific baseline factors were predictors of total cost. RESULTS: Total costs per patient were lower in the ibutilide plus magnesium group compared with ibutilide alone (USD1075 vs USD1201); however, the difference was not statistically significant (p = 0.116). Patients receiving ibutilide plus magnesium had lower DCC costs compared with those receiving ibutilide alone (USD261 vs USD399; p = 0.036), but higher magnesium-associated costs (USD0.50 vs USD0; p < 0.001). Bootstrapping revealed that the ibutilide plus magnesium strategy would result in lower costs and greater efficacy 93.4% of the time. These results remained robust to changes in both cost and efficacy. No baseline factors were found to be independent predictors of total costs. CONCLUSION: Our data suggest that adding prophylactic magnesium to ibutilide may be cost effective, from a US hospital-payer perspective, for the acute conversion of patients in AF or flutter compared with ibutilide alone.     

Conversion of recent-onset atrial fibrillation with intravenous amiodarone: a meta-analysis of randomized controlled trials.

STUDY OBJECTIVE: To evaluate efficacy and safety of intravenous amiodarone for conversion of recent-onset atrial fibrillation. DATA SOURCES: MEDLINE search of published, randomized, controlled trials assessing the efficacy and safety of intravenous amiodarone in recent-onset (< 7 days) atrial fibrillation, supplemented with searches of reference lists of identified articles and bibliographies of secondary and tertiary review articles. STUDY SELECTION: The identified trials were eligible for meta-analysis if they met the following criteria: patients had recent-onset atrial fibrillation; patients were randomized to intravenous amiodarone, placebo, or another antiarrhythmic agent; no other antiarrhythmic agent except digoxin was administered simultaneously with intravenous amiodarone or other active treatments; the number and percentage of conversions to sinus rhythm after treatment began were reported; and the number and type of adverse drug reactions occurring after treatment began were reported. RESULTS: Eighteen randomized controlled trials, including active control cohorts and placebo cohorts, met inclusion criteria. Atrial fibrillation was spontaneous in 13 trials, postoperative in 4, and combined spontaneous and postoperative in 1. A total of 550 patients received intravenous amiodarone, 451 received other antiarrhythmic therapy, and 202 received placebo. Unadjusted averages for cardioversion were as follows: intravenous amiodarone, 417 (76%) of 550 patients; other antiarrhythmics, 324 (72%) of 451 patients; and placebo, 121 (60%) of 202 patients. Pooled estimates of cardioversion for active cohort studies were 72.1% for intravenous amiodarone and 71.9% for other antiarrhythmics (p=0.84). Pooled estimates of cardioversion for placebo cohort studies were 82.4% for intravenous amiodarone and 59.7% for placebo (p=0.03). Unadjusted averages for adverse event rates were intravenous amiodarone, 94 (17%) of 550 patients; other antiarrhythmics, 63 (14%) of 451 patients; and placebo, 23 (11%) of 202 patients. Pooled estimates of adverse event rates for active cohort studies were 12.2% for intravenous amiodarone and 14.0% for other antiarrhythmics (p=0.64). Pooled estimates of adverse event rates for placebo cohort studies were 26.8% for intravenous amiodarone and 10.8% for placebo (p=0.02). The most common adverse drug reactions reported with intravenous amiodarone were infusion phlebitis, bradycardia, and hypotension. CONCLUSION: The efficacy and safety profile of intravenous amiodarone is similar to that of other antiarrhythmics for cardioversion of recent-onset atrial fibrillation. Intravenous amiodarone is significantly more effective than placebo but is associated with significantly higher frequency of adverse events, although most were not considered to be dose limiting.     

Effects of amiodarone on electrical and structural remodeling induced in a canine rapid pacing-induced persistent atrial fibrillation model

Structural in addition to electrical remodeling may be induced by persistent atrial fibrillation per se and make atrial fibrillation refractory to antiarrhythmic drug therapy. Matrix metalloproteinases (MMPs) contribute to structural remodeling in the interstitial space. Amiodarone is effective in treating persistent atrial fibrillation compared with other antiarrhythmic drugs. In mongrel dogs, right atrial pacing at 540 beats/min (bpm) was performed along with ventricular pacing at 100 bpm for 6 weeks after atrioventricular node ablation. Right atrial pacing at 400 bpm was continued for 4 weeks with (n=5) or without (n=5) oral amiodarone (30 mg/kg/day). In sham dogs, only ventricular pacing was done with (n=4) or without (n=6) amiodarone. In atrial pacing without amiodarone group, electrical remodeling characterized by monophasic action potential duration shortening, loss of action potential duration-rate adaptation and depressed conduction velocity and structural remodeling characterized by slightly but significantly increased interstitial fibrosis and enhanced MMP-2 activity compared with sham group were observed, and sustained atrial fibrillation was easily induced. In atrial pacing with amiodarone group, both electrical and structural remodeling were reversed and sustained atrial fibrillation was not induced. In sham group with amiodarone, action potential duration prolongation and depressed conduction velocity compared with sham without amiodarone were observed, but either increased fibrosis or enhanced MMP-2 activity was not observed. Not only electrical but structural remodeling were induced in a canine persistent atrial fibrillation model. Amiodarone reversed both of them, which may be related to its high efficacy in preventing recurrence of persistent atrial fibrillation.     

Cost comparisons of pharmacological strategies in open-heart surgery

Open-heart surgery (OHS) is performed to bypass occluded arteries, replace malfunctioning cardiac valves or correct congenital abnormalities. The average cost of OHS varies from $US25 057-$US79 795 (1997 values). The objective of this paper was to review economic studies of pharmacological strategies in open-heart surgery. Pharmacological strategies studied include the prevention of postoperative complications such as atrial fibrillation (AF), bleeding and infection. Modifications in anaesthetic technique have been attempted by using agents that promote early extubation. In addition, strategies for postoperative management of sedation, analgesia and AF and use of neuromuscular blockers have also been compared. The majority of studies in this area have been cost analyses with few cost-effectiveness studies performed. Prophylaxis against AF with amiodarone is associated with a reduction in AF and was cost-neutral compared with placebo. Compared with placebo, prevention of bleeding with antifibrinolytics reduces transfusion costs. In direct comparative studies, lysine analogues, due to lower drug acquisition costs, offset transfusion costs to a greater extent than aprotinin. However, safety concerns with the lysine analogues remain. Erythropoietin decreases transfusion requirements and is cost effective compared with no intervention when the cost of postoperative bacterial complications is included. First- and second-generation cephalosporins prevent postoperative infections. Based on drug acquisition cost, the first-generation agents are less expensive although when administration costs are included, both classes have similar costs. Modifications in anaesthetic technique with short-acting anaesthetic agents, results in higher drug costs although nursing and total hospital costs are typically reduced. For neuromuscular blockers, drug acquisition costs are lowest with pancuronium but administration costs and the cost of adverse events have not been included in existing analyses. Midazolam provides an equivalent level of postoperative sedation to propofol but the acquisition cost is lower. The combined use of propofol and midazolam warrants further investigation, as its use is associated with lower sedative agent costs compared with either agent alone. There is limited data on the economics of postoperative analgesia and the management of AF. As the majority of studies to date are partial cost analyses, additional studies that include length of stay and other hospitalisation data are warranted. In future, cost-effectiveness and cost-utility studies, which incorporate quality of life and the cost of adverse effects and other longer term costs, should be undertaken.     

联合用药对阵发性心房颤动患者疗效观察

目的 观察联合应用小剂量胺碘酮、螺内酯与厄贝沙坦对非瓣膜病阵发性心房颤动患者窦性心律的维持,对左心房内径、脑钠肽以及安全性的影响.方法 将142例非瓣膜病阵发性心房颤动按就诊顺序随机分为胺碘酮组(n=47),胺碘酮加螺内酯组(n=47),胺碘酮、厄贝沙坦、螺内酯组(联合用药组,n=48),3组均服用胺碘酮,胺碘酮加螺内酯组在应用胺碘酮基础上加用螺内酯,联合用药组在应用胺碘酮、螺内酯基础上加用厄贝沙坦,观察3组治疗6、12、18个月后的左心房内径、脑钠肽变化以及治疗3、6、12、18、24个月后的窦性心律维持率和安全性.结果 治疗6个月后3组左心房内径、脑钠肽值差异无统计学意义,但12个月后胺碘酮加螺内酯组、联合用药组的左心房内径、脑钠肽值明显小于胺碘酮组(P＜0.05),联合用药组左心房内径、脑钠肽值明显小于胺碘酮加螺内酯组(P＜0.05);治疗3、6个月后胺碘酮组窦性心律维持率低于胺碘酮加螺内酯组、联合用药组,治疗6个月后胺碘酮组和联合用药组之间差异有统计学意义(P＜0.05),治疗12个月后胺碘酮加螺内酯组、联合用药组的窦性心律维持率明显大于胺碘酮组(P＜0.05),联合用药组窦性心律维持率明显大于胺碘酮加螺内酯组(P＜0.05).结论 胺碘酮、螺内酯联合治疗非瓣膜病阵发性心房颤动维持实性心律的疗效优于单用胺碘酮,并能延缓左心房的扩大和脑钠肽值的升高,在胺碘酮、螺内酯基础上加用厄贝沙坦则使上述疗效进一步加强.

Abstract：

Objective To observe the effect and safety of amiodarone, spironolactone and irbesartan on sinus rhythm, left atrial internal diameter and brain natruretic peptide(BNP) for patients with nonvalvular paroxysmal atrial fibrillation(AF). Methods One hundred and forty-two patients with nonvalvular paroxysmal atrial fibrillation were divided into amiodarone group(n=47), amiodarone plus spironolactone group (n = 47 ) and amiodarone spironolactone plus irbesartan group ( Combined treatment group, n = 48 ). Three groups were treated with amiodarone.Amiodarone plus spironolactone group was treated with spironolactone in addition. Combined treatment group was treated with irbesartan based on amiodarone and spironolactone. Left atrial internal diameter and BNP were observed after 6 months, 12 months, 18 months respectively and the rate of maintenance of sinus rhythm was observed after 3months, 6 months, 12 months, 18 months, 24 months respectively. The safety of drugs was observed during this study. Results After 6 months treatments, left atrial internal diameter and BNP of three groups was no difference but left atrial internal diameter and BNP of amiodarone plus spironolactone group and Combined treatment group was less than that of amiodarone group after 12 months ( P ＜ 0.05 ). left atrial internal diameter and BNP of combined treatment group was less than those of amiodarone plus spironolactone group after 12 months ( P ＜ 0.05 ). After 3and 6 months treatments, the rate of maintenance of sinus rhythm of amiodarone group was lower than that in amiodarone plus spironolactone group and combined treatment group, but there was no statistically significance difference between amiodarone group and amiodarone plus spironolactone group, amiodarone plus spironolactone group andCombined treatment group. The rate of maintenance of sinus rhythmia of amiodarone group was statistically lower than that in combined treatment group (P＜0.05). After 12 months, The rate of mainterance of sinus rhythmia of amiodarone plus spironolactone group and Combined treatment group was more than that of amiodarone group (P＜0.05 ), and that of group Ⅲ was more than that of amiodarone plus spironolactone group ( P ＜ 0.05 ). Conclusions Therapeutic results of mainterance of sinus rhythmia is better with amiodarone plus spironolactone than with amiodarone lonely, and treatment with amiodarone plus spironolactone can suspend the enlargement of left atrial. This influence will strengthen if treated with irbesartan based on amiodarone and spironolactone.     

Amiodarone prophylaxis for atrial fibrillation after cardiac surgery: meta-analysis of dose response and timing of initiation

STUDY OBJECTIVE: To investigate a possible dose-response relationship between amiodarone and reduction in incidence of postoperative atrial fibrillation, and to determine whether pre- or postoperative initiation of amiodarone is superior. DESIGN: Meta-analysis of randomized controlled trials. DATA SOURCE: MEDLINE and EMBASE databases and the Cochrane Central Register of Controlled Trials for English-language reports published between 1966 and December 2005. MEASUREMENTS AND MAIN RESULTS: Of 23 identified randomized controlled trials of amiodarone prophylaxis of postoperative atrial fibrillation, 14 were included in the final analysis. These studies enrolled a total of 2864 patients. For each study, the total administered amiodarone dose--categorized as low (< 3000 mg), medium (3000-5000 mg), or high (> 5000 mg)--and preoperative versus postoperative initiation were aggregated by using meta-analytic techniques. The incidence of postoperative atrial fibrillation was significantly reduced by amiodarone compared with placebo (p<0.001). Although the odds of developing atrial fibrillation appeared to be somewhat higher in the low-dose group, no significant differences were noted in the odds ratios (ORs) of developing atrial fibrillation among the low-, medium-, and high-dose groups: OR 0.58, 95% confidence interval (CI) 0.44-0.77; OR 0.45, 95% CI 0.30-0.69; and OR 0.44, 95% CI 0.33-0.58; respectively (p=0.238). In addition, the ORs for atrial fibrillation development associated with preoperative and postoperative initiation of amiodarone were not significantly different (OR 0.50, 95% CI 0.39-0.63; and OR 0.48, 95% CI 0.37-0.63; respectively, p=0.862). CONCLUSION: Total amiodarone doses of 3000 mg or higher may be more effective than lower doses in reducing the rate of postoperative atrial fibrillation after cardiac surgery. Preoperative initiation of amiodarone appears to be unnecessary. These findings require confirmation in prospective, randomized trials.     

Impact of amiodarone on the ability of anterior fat pad retention to prevent postcoronary arterial bypass grafting atrial fibrillation incidence: a substudy of the AFIST III (Atrial Fibrillation Suppression Trial III)

Background: In the AFIST III (Atrial Fibrillation Suppressions Trial III), anterior fat pad (AFP) retention did not decrease the incidence of postoperative atrial fibrillation (POAF), but prophylaxis with amiodarone did. In order to examine the inter-relationship between amiodarone with AFP retention on POAF, we performed a planned subgroup analysis of AFIST III. Methods: Coronary artery bypass graft (CABG) patients were randomized to AFP maintenance or removal with prophylactic amiodarone used via the discretion of the caregiver. Patients were categorized into four groups: AFP retention alone, AFP retention plus amiodarone, AFP removal alone and AFP removal plus amiodarone. Multivariate logistic regression was used to calculate adjusted odds ratios with 95% confidence intervals for development of POAF. Results: Amiodarone was used in 28% of the 178 patients (mean age = 66 ± 10, 80% male, 5% previous atrial fibrillation) undergoing CABG surgery. The overall POAF occurrence rate, regardless of subgroup designation was 35.4%. On multivariate logistic regression, amiodarone plus AFP retention was associated with an 81% reduction in the odds of the patient developing POAF (p = 0.015). Amiodarone prophylaxis without AFP retention was associated with a 68% reduction (p = 0.040). Conclusion: Amiodarone prophylaxis with or without AFP retention is an independent negative predictor of POAF. Combining amiodarone with AFP retention may provide a synergistic effect in the prevention of POAF. Further studies are needed to validate the results of this study.     

Surveillance colonoscopy or chemoprevention with COX-2 inhibitors in average-risk post-polypectomy patients: a decision analysis

OBJECTIVES: Clinical trials are currently underway evaluating the efficacy of COX-2 inhibitors in decreasing the incidence of adenomas and colorectal carcinoma in 'average' risk individuals. AIM: To use decision analysis to compare the cost-effectiveness of celecoxib to surveillance colonoscopy in 'average' risk patients who had undergone prior adenoma resection. METHODS: A model of the natural history of adenomas after endoscopic polypectomy was constructed using probabilities from the literature. Cost estimates were obtained from available Medicare reimbursement rates and supplemented by the literature. Three strategies were evaluated: (i) no surveillance; (ii) colonoscopic surveillance; and (iii) celecoxib chemoprevention. We compared total costs and performed cost-effectiveness analysis between these strategies. The outcome measures were years of life saved and 'high-grade' adenoma prevented. Sensitivity analyses were performed on selected variables. RESULTS: Our base-case analysis assumed a 50% risk reduction in the incidence of adenomas among patients using celecoxib. No surveillance was associated with a cost of $1014 per patient, and colonoscopic surveillance with a cost of $1572 per patient, whereas celecoxib use was associated with a total cost of $11,503. Ten years after the index colonoscopy, 15% of patients in the no surveillance strategy developed 'high-grade' lesions compared to 13% of patients in the colonoscopic surveillance group and 6% in the celecoxib group. There was a small gain in years of life saved (0.006) favouring celecoxib over colonoscopic surveillance. The incremental cost-effectiveness ratio of celecoxib vs. colonoscopy was $141 871 per 'high-grade' adenoma prevented and $1,715,199 per year of life saved. The most important variables in determining the cost-effectiveness of celecoxib were its cost and its efficacy. CONCLUSION: Chemoprevention with COX-2 inhibitors in 'average-risk' postpolypectomy patients is a more expensive strategy compared to colonoscopic surveillance.     

胺碘酮与依那普利联合治疗阵发性心房颤动的临床研究

目的评价胺碘酮与依那普利联合治疗阵发性心房颤动（房颤）的临床疗效。方法将129例阵发性房颤随机分为胺碘酮组（Ⅰ组,n=64）和胺碘酮联合依那普利组（Ⅱ组,n=65）,治疗随访时间为1年,研究终点为房颤发作。比较两组治疗前、治疗后的左心房内径。计算两组治疗后窦性心律维持率。结果两组患者治疗前后左心房内径比较：治疗前分别为（35．21±1．76）mm、（35．84±1．69）mm,治疗后分别为（38．76±2．14）mm、（36．27-I-1．91）mm,治疗后IⅠ组患者左房内径明显小于Ⅰ组。两组患者窦性心律维持率的比较：治疗结束时,Ⅰ组患者窦性心律维持率为62．3％,Ⅱ组患者窦性心律维持率80．6％,两组患者比较有显著性差异。结论胺碘酮与依那普利联合治疗阵发性房颤维持窦性心律的疗效优于单用胺碘酮,对延缓左心房扩大有一定作用。     

心房不同部位起搏对阵发房颤患者心房激动时间的影响

目的　比较右心耳 (RAA)、冠状窦远端 (DCS)、右房双部位 (右心耳加冠状窦口 ,DSA)和双房 (右心耳加冠状窦远端 ,BiA)起搏对阵发房颤 (PAf)患者心房激动时间的影响。方法 2 2例接受心脏电生理评价试验的PAf患者在窦性心律下行心房不同部位起搏 ,同步记录 12 -导心电图 ,测量最大P波时限。结果与窦性P波时限相比 ,RAA起搏明显延长P波时限 (P <0 0 1) ,DCS、DSA及BiA起搏则明显缩短P波时限 (P <0 0 1)结论DCS、DSA及BiA起搏明显缩短心房激动时间 ,减少心房电活动的离散度 ,有利于PAf的防治     

Enalapril prevents perpetuation of atrial fibrillation by suppressing atrial fibrosis and over-expression of connexin43 in a canine model of atrial pacing-induced left ventricular dysfunction

Effects of enalapril on a canine model of atrial pacing-induced atrial fibrillation (AF) with rapid ventricular responses were determined. METHODS: Four weeks of atrial rapid pacing was performed on twenty-four beagles pretreated with placebo (Group I, n = 14) or enalapril 1 mg/kg (Group II, n = 10). Atrial effective refractory period (ERP), P-wave width, duration of AF, and left ventricular ejection fraction (LVEF) were evaluated every week. AF cycle length was determined by spectral analyses of fibrillation waves. Quantitative analysis of histology was added. RESULTS: After 4 weeks of pacing, P-wave width was longer in Group I than in Group II, and the duration of induced AF was significantly longer in Group I (59.6 +/- 66.3 seconds) than in Group II (3.6 +/- 3.4 seconds, P < 0.05). AF cycle length was longer in Group I than in Group II despite similar shortening of atrial ERP. Mean ventricular rate during rapid atrial pacing was not different between the two groups. LVEF similarly decreased in both groups. Interstitial fibrosis and expression of connexin43 was greater in Group I than in Group II (interstitial fibrosis, 9.2 +/- 8.4 versus 1.9 +/- 2.1%, P < 0.05; connexin43, 5.3 +/- 2.2 versus 1.1 +/- 1.1%, P < 0.05). CONCLUSIONS: Enalapril suppressed atrial pacing-induced AF with tachycardia-mediated cardiomyopathy by suppressing interstitial fibrosis, connexin43 over-expression and conduction delay.     

胺碘酮预防心脏手术后心房颤动效果Meta分析

目的：系统性评价胺碘酮预防心脏手术后心房颤动（房颤）的效果。方法：通过中英文电子数据库及手工检索的方式，收集胺碘酮与安慰荆比较预防心脏手术后房颤效果的随机对照临床试验，运用Meta分析法进行统计。结果：14篇文献符合纳入排除标准，应用固定效应模型合并结果，RR为0．66（95％CI：0．58-0.76）。亚组分析显示。胺碘酮首次给药时间和给药方式对房颤的预防作用没有影响。敏感度分析证实了Meta分析结果的稳定性。结论：与安慰剂相比。胺碘酮可以有效地降低心脏手术后房颤的发生率。     

Thromboembolic Prophylaxis in Moderate-Risk Patients Undergoing Elective Abdominal Surgery: Decision and Cost-Effectiveness Analyses

We conducted a retrospective, literature-based decision analysis to compare the cost-effectiveness of conventional low-dose heparin, dalteparin, and intermittent pneumatic compression (IPC) as thromboembolic prophylaxis to a no-prophylaxis option in patients at moderate risk of developing thromboembolic complications after major elective abdominal surgery. The analysis was conducted through an institutional perspective. Probability and incidence rate data were summarized from the literature. Cost data were obtained from the Detroit Medical Center's cost accounting systems and from national diagnosis-related group estimates. Mortality and complications avoided were the main outcome measures on which cost-effectiveness was based. Overall costs associated with conventional low-dose heparin, dalteparin, intermittent pneumatic compression, and no prophylaxis were $84, $122, $102, and $112, respectively, in the primary analysis, which included costs of labor. Corresponding cost-effectiveness ratios in terms of costs/complication-free patient were $86, $124, $103, and $118, respectively. Compared with no prophylaxis, incremental cost-effectiveness analysis in terms of cost/mortality avoided involved savings of $6087 and $3125 with conventional low-dose heparin and IPC, respectively, and expenses of $2857 with dalteparin. A secondary analysis excluding costs of labor showed similar results. The results of the study consistently showed conventional low-dose heparin to provide the most cost-effective thromboembolic prophylaxis of the methods considered in terms of reducing both morbidity and mortality in the patient population studied.     

Cost-effectiveness of computer-assisted training in cognitive-behavioral therapy as an adjunct to standard care for addiction

Aim

To determine the cost-effectiveness, from clinic and patient perspectives, of a computer-based version of cognitive-behavioral therapy (CBT4CBT) as an addition to regular clinical practice for substance dependence.

Participants, design and measurements

This cost-effectiveness study is based on a randomized clinical trial in which 77 individuals seeking treatment for substance dependence at an outpatient community setting were randomly assigned to treatment as usual (TAU) or TAU plus biweekly access to computer-based training in CBT (TAU plus CBT4CBT). The primary patient outcome measure was the total number of drug-free specimens provided during treatment. Incremental cost-effectiveness ratios (ICERs) and cost-effectiveness acceptability curves (CEACs) were used to determine the cost-effectiveness of TAU plus CBT4CBT relative to TAU alone. Results are presented from both the clinic and patient perspectives and are shown to be robust to (i) sensitivity analyses and (ii) a secondary objective patient outcome measure.

Findings

The per patient cost of adding CBT4CBT to standard care was $39 ($27) from the clinic (patient) perspective. From the clinic (patient) perspective, TAU plus CBT4CBT is likely to be cost-effective when the threshold value to decision makers of an additional drug-free specimen is greater than approximately $21 ($15), and TAU alone is likely to be cost-effective when the threshold value is less than approximately $21 ($15). The ICERs for TAU plus CBT4CBT also compare favorably to ICERs reported elsewhere for other empirically validated therapies, including contingency management.

Conclusions

TAU plus CBT4CBT appears to be a good value from both the clinic and patient perspectives.     

雷米普利和替米沙坦与胺碘酮联用治疗阵发性心房颤动的临床观察

目的探讨雷米普利和替米沙坦与小剂量胺碘酮联用对心功能正常的阵发性心房颤动（房颤）维持窦性心律的长期疗效。方法将180例阵发性房颤患者完全随机分为胺碘酮组（A组,61例）、胺碘酮＋雷米普利组（B组,59例）、胺碘酮＋替米沙坦组（C组,60例）,随访2年,比较3组治疗后6、12、18、24个月的窦性心律维持率以及治疗前、后的左心房内径。结果治疗12个月后,A组左心房内径大于B、C组（P〈0．05）,A组窦性心律维持率明显低于B、C组（P〈0．05）。试验终点时,A组的窦性心律维持率为58．62％,B组为77．78％,C组为78．57％（P〈0．05）。结论胺碘酮分别与雷米普利和替米沙坦配伍治疗阵发性房颤维持窦性心律具有相同的疗效,但优于单用胺碘酮,并能抑制左心房的扩大。     

门冬氨酸钾镁片加小剂量乙胺碘呋酮片治疗心房纤颤的临床分析

目的探讨胺碘酮片与门冬氨酸钾镁片联用治疗阵发性心房颤动（房颤）的有效性和安全性。方法78例发作频繁的阵发性房颤患者,男41例,女37例,平均年龄（57.8±11.2）岁。随机分为研究组和对照组,前者同时应用胺碘酮片和门冬氨酸钾镁片,后者仅服用胺碘酮片。随访时间为1年。结果研究组治疗1年的总有效率为77.5%（31/40）,显著高于对照组治疗1年的总有效率52.6%（20/38）,P〈0.05。结论和单纯应用胺碘酮片比较,胺碘酮片和门冬氨酸钾镁片联用能够显著提高预防阵发性房颤发作的效果,同时并未增加严重不良反应。     

Safety of amiodarone in the prevention of postoperative atrial fibrillation: a meta-analysis.

PURPOSE: A meta-analysis was conducted to assess the safety of amiodarone in the prevention of postoperative atrial fibrillation. METHODS: A search of the medical literature was conducted to identify randomized controlled trials of prophylactic amiodarone use in cardiothoracic surgery. Studies were independently reviewed by three investigators and selected for inclusion if they met the following three criteria: (1) randomized controlled trial of amiodarone versus placebo or routine treatment, (2) patients underwent coronary artery bypass graft or valvular surgery, and (3) reported data on the frequency of at least one of the following safety endpoints: bradycardia, hypotension, heart block, nausea, cerebral vascular accident, myocardial infarction, and death. Both random- and fixed-effects models were used to determine any significant associations between amiodarone and safety endpoints. RESULTS: Eighteen trials were analyzed. A total of 3408 patients were enrolled in these trials (1736 received amiodarone and 1672 received placebo). Amiodarone increased the odds of developing bradycardia (odds ratio [OR], 1.70; 95% confidence interval [CI], 1.05-2.74) and hypotension (OR, 1.62; 95% CI, 1.04-2.54). The administration of i.v. amiodarone, an average daily dose exceeding 1 g, and postoperative amiodarone administration were each associated with a greater likelihood of hemodynamic adverse effects. Amiodarone did not appear to affect other safety endpoints. CONCLUSION: Meta-analysis showed amiodarone to be associated with an increased risk of developing bradycardia and hypotension when used for the prophylaxis of postoperative atrial fibrillation. The greatest risk in the occurrence of these adverse events arose when using regimens containing i.v. amiodarone, initiating prophylaxis during the postoperative period, and using regimens with average daily doses exceeding 1 g.