Complications after hip arthroplasty and the association with hospital procedure volume.

BACKGROUND AND PURPOSE: It has been suggested that a higher procedure volume is associated with less complications after hip arthroplasty. In order to investigate the incidence of serious negative outcomes and a possible association with procedure volume, we performed a retrospective nationwide cohort study on total hip replacements in all Dutch hospitals. METHODS: All total hip replacements (n = 50,080) that were identified as primary intervention in all general and university medical centers between January 1, 2002 and October 1, 2004 were included. Primary endpoints of follow-up were mortality and complications during admission, and re-admission within 3 months due to complications. Variables that were assessed as potential risk factor were age, sex, duration of (preoperative) admission, specific diagnosis, acute/non-planned admission, co-morbidity, and hospital procedure volume. RESULTS: Age, sex, and comorbidity were associated with complications and mortality. Additionally, acute admission was a risk factor for mortality but not for complications. There was no linear trend indicating that decreasing volume led to an increasing number of complications, and no statistically sginificant effect for mortality was found. INTERPRETATION: After adjustment for several risk factors, we found that the hospitals performing most hip procedures every year had fewer complications during index admission, but that they did not have a lower mortality than groups performing fewer procedures. The lack of a linear trend may be explained by the fact that almost all Dutch hospitals perform a high number of hip arthroplasties each year.

A comparison of rate control and rhythm control in patients with recurrent persistent atrial fibrillation.

BACKGROUND: Maintenance of sinus rhythm is the main therapeutic goal in patients with atrial fibrillation. However, recurrences of atrial fibrillation and side effects of antiarrhythmic drugs offset the benefits of sinus rhythm. We hypothesized that ventricular rate control is not inferior to the maintenance of sinus rhythm for the treatment of atrial fibrillation. METHODS: We randomly assigned 522 patients who had persistent atrial fibrillation after a previous electrical cardioversion to receive treatment aimed at rate control or rhythm control. Patients in the rate-control group received oral anticoagulant drugs and rate-slowing medication. Patients in the rhythm-control group underwent serial cardioversions and received antiarrhythmic drugs and oral anticoagulant drugs. The end point was a composite of death from cardiovascular causes, heart failure, thromboembolic complications, bleeding, implantation of a pacemaker, and severe adverse effects of drugs. RESULTS: After a mean (+/-SD) of 2.3+/-0.6 years, 39 percent of the 266 patients in the rhythm-control group had sinus rhythm, as compared with 10 percent of the 256 patients in the rate-control group. The primary end point occurred in 44 patients (17.2 percent) in the rate-control group and in 60 (22.6 percent) in the rhythm-control group. The 90 percent (two-sided) upper boundary of the absolute difference in the primary end point was 0.4 percent (the prespecified criterion for noninferiority was 10 percent or less). The distribution of the various components of the primary end point was similar in the rate-control and rhythm-control groups. CONCLUSIONS: Rate control is not inferior to rhythm control for the prevention of death and morbidity from cardiovascular causes and may be appropriate therapy in patients with a recurrence of persistent atrial fibrillation after electrical cardioversion.

Corticosteroids and the risk of atrial fibrillation.

BACKGROUND: High-dose (pulse) corticosteroid therapy has been associated with the development of atrial fibrillation. This association, however, is mainly based on case reports. METHODS: To test the hypothesis that high-dose corticosteroid exposure increases the risk of new-onset atrial fibrillation, we performed a nested case-control study within the Rotterdam Study, a population-based cohort study among 7983 older adults. Cases were defined as persons with incident atrial fibrillation between July 1, 1991, and January 1, 2000. Their date of diagnosis was defined as the index date. All noncases within the Rotterdam Study who were alive and eligible on this index date were used as controls. Subsequently, we compared the proportion of cases and controls that received a corticosteroid prescription within 1 month preceding the index date. Corticosteroid exposure was categorized into high-dose exposure (oral or parenteral steroid at a daily dose > or =7.5 mg of prednisone equivalents) and low-intermediate-dose exposure (<7.5 mg of prednisone equivalents or inhaled corticosteroids). RESULTS: There were 385 eligible cases of new-onset atrial fibrillation during the study period. The risk of new-onset atrial fibrillation was significantly higher for persons who received a corticosteroid prescription within 1 month before the index date than for those without (odds ratio [OR], 3.75; 95% confidence interval [CI], 2.38-5.87). However, only high-dose corticosteroid use was associated with an increased risk (OR, 6.07; 95% CI, 3.90-9.42), whereas low-intermediate-dose use was not (OR, 1.42; 95% CI, 0.72-2.82). The association of atrial fibrillation with high-dose corticosteroid use was largely independent of the indication for corticosteroid therapy, since the risk of new-onset atrial fibrillation was not only increased in patients with asthma or chronic obstructive pulmonary disease (OR, 4.02; 95% CI, 2.07-7.81) but also in patients with rheumatic, allergic, or malignant hematologic diseases (OR, 7.90; 95% CI, 4.47-13.98). CONCLUSION: Our findings strongly suggest that patients receiving high-dose corticosteroid therapy are at increased risk of developing atrial fibrillation.

Drug-induced atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained rhythm disorder observed in clinical practice and predominantly associated with cardiovascular disorders such as coronary heart disease and hypertension. However, several classes of drugs may induce AF in patients without apparent heart disease or may precipitate the onset of AF in patients with preexisting heart disease. We reviewed the literature on drug-induced AF, using the PubMed/Medline and Micromedex databases and lateral references. Successively, we discuss the potential role in the onset of AF of cardiovascular drugs, respiratory system drugs, cytostatics, central nervous system drugs, genitourinary system drugs, and some miscellaneous agents. Drug-induced AF may play a role in only a minority of the patients presenting with AF. Nevertheless, it is important to recognize drugs or other agents as a potential cause, especially in the elderly, because increasing age is associated with multiple drug use and a high incidence of AF. This may contribute to timely diagnosis and management of drug-induced AF.

Effect of rate or rhythm control on quality of life in persistent atrial fibrillation. Results from the Rate Control Versus Electrical Cardioversion (RACE) Study.

OBJECTIVES: We studied the influence of rate control or rhythm control in patients with persistent atrial fibrillation (AF) on quality of life (QoL). BACKGROUND: Atrial fibrillation may cause symptoms like fatigue and dyspnea. This can impair QoL. Treatment of AF with either rate or rhythm control may influence QoL. METHOD: Quality of life was assessed in patients included in the Rate Control Versus Electrical Cardioversion for Persistent Atrial Fibrillation (RACE) study (rate vs. rhythm control in persistent AF). Rate control patients (n = 175) were given negative chronotropic drugs and oral anticoagulation. Rhythm control patients (n = 177) received serial electrocardioversion, antiarrhythmic drugs, and oral anticoagulation, as needed. Quality of life was studied using the Short Form (SF)-36 health survey questionnaire at baseline, one year, and the end of the study (after 2 to 3 years of follow-up). At baseline, QoL was compared with that of healthy control subjects. Patient characteristics related to QoL changes were determined. RESULTS: Mean follow-up was 2.3 years. At baseline, QoL was lower in patients than in age-matched healthy controls. At study end, under rate control, three subscales of the SF-36 improved. Under rhythm control, no significant changes occurred compared with baseline. At study end, QoL was comparable between both groups. The presence of complaints of AF at baseline, a short duration of AF, and the presence of sinus rhythm (SR) at the end of follow-up, rather than the assigned strategy, were associated with QoL improvement. CONCLUSIONS: Quality of life is impaired in patients with AF compared with healthy controls. Treatment strategy does not affect QoL. Patients with complaints related to AF, however, may benefit from rhythm control if SR can be maintained.

Antipsychotics and the risk of sudden cardiac death.

BACKGROUND: Antipsychotics have been associated with prolongation of the corrected QT interval and sudden cardiac death. Only a few epidemiological studies have investigated this association. We performed a case-control study to investigate the association between use of antipsychotics and sudden cardiac death in a well-defined community-dwelling population. METHODS: We performed a population-based case-control study in the Integrated Primary Care Information (IPCI) project, a longitudinal observational database with complete medical records from 150 general practitioners. All instances of death between January 1, 1995, and April 1, 2001, were reviewed. Sudden cardiac death was classified based on time between onset of cardiovascular symptoms and death. For each case, up to 10 random controls were matched for age, sex, date of sudden death, and practice. Exposure at the index date was categorized as 3 mutually exclusive groups of current use, past use, and nonuse. RESULTS: The study population comprised 554 cases of sudden cardiac death. Current use of antipsychotics was associated with a 3-fold increase in risk of sudden cardiac death. The risk of sudden cardiac death was highest among those using butyrophenone antipsychotics, those with a defined daily dose equivalent of more than 0.5 and short-term (

Apolipoprotein E epsilon4 allele is associated with left ventricular systolic dysfunction.

BACKGROUND: Apolipoprotein (APOE) epsilon4 allele has been associated with cardiac dysfunction in Alzheimer's disease and beta-thalassemia. We investigated the association between APOE genotypes and left ventricular dysfunction in a population of community-dwelling elderly subjects. METHODS: This study was performed in the Rotterdam Study, a population-based prospective cohort study among elderly subjects. For 2206 participants, a baseline echocardiogram and blood specimens for APOE typing were available. Cardiac dysfunction was considered present when fractional shortening was or=65 years. CONCLUSION: The APOE epsilon4 allele is an independent risk factor for cardiac dysfunction in elderly people. Besides well-known effects on atherosclerosis and cholesterol levels, there may be other mechanisms, such as apoptosis, through which this allele exerts negative effects on myocardial performance.

Prolonged QTc interval and risk of sudden cardiac death in a population of older adults.

OBJECTIVES: This study sought to investigate whether prolongation of the heart rate-corrected QT (QTc) interval is a risk factor for sudden cardiac death in the general population. BACKGROUND: In developed countries, sudden cardiac death is a major cause of cardiovascular mortality. Prolongation of the QTc interval has been associated with ventricular arrhythmias, but in most population-based studies no consistent association was found between QTc prolongation and total or cardiovascular mortality. Only very few of these studies specifically addressed sudden cardiac death. METHODS: This study was conducted as part of the Rotterdam Study, a prospective population-based cohort study that comprises 3,105 men and 4,878 women aged 55 years and older. The QTc interval on the electrocardiogram was determined during the baseline visit (1990 to 1993) and the first follow-up examination (1993 to 1995). The association between a prolonged QTc interval and sudden cardiac death was estimated using Cox proportional hazards analysis. RESULTS: During an average follow-up period of 6.7 years (standard deviation, 2.3 years) 125 patients died of sudden cardiac death. An abnormally prolonged QTc interval (>450 ms in men, >470 ms in women) was associated with a three-fold increased risk of sudden cardiac death (hazard ratio, 2.5; 95% confidence interval, 1.3 to 4.7), after adjustment for age, gender, body mass index, hypertension, cholesterol/high-density lipoprotein ratio, diabetes mellitus, myocardial infarction, heart failure, and heart rate. In patients with an age below the median of 68 years, the corresponding relative risk was 8.0 (95% confidence interval 2.1 to 31.3). CONCLUSIONS: Abnormal QTc prolongation on the electrocardiogram should be viewed as an independent risk factor for sudden cardiac death.

Mortality in patients with hypertension on angiotensin-I converting enzyme (ACE)-inhibitor treatment is influenced by the ACE insertion/deletion polymorphism.

BACKGROUND: The response to angiotensin-I converting enzyme (ACE)-inhibitor therapy is highly variable. Residual ACE activity during treatment, potentially modified by the ACE insertion/deletion (I/D) polymorphism, may explain part of this variability. We studied the possible interaction between ACE-inhibitor therapy in patients with hypertension and the ACE I/D polymorphism in incident heart failure and death. METHODS: We studied 3365 hypertensive participants of the population-based Rotterdam Study, without heart failure at baseline for whom ACE-genotyping was successful. Incident heart failure was defined according to established criteria. In addition, total and cardiovascular mortality were studied as endpoints. A Cox regression model with use of ACE-inhibitors defined as time-dependent covariates was used for data-analysis. Interaction was tested in this model assuming an allele-effect relationship. RESULTS: Although we could not demonstrate a beneficial effect of ACE-inhibitors, there was significant interaction between the ACE I/D polymorphism (II-ID-DD) and ACE-inhibitor use in the prediction of total and cardiovascular mortality. Mortality risk associated with treatment increased with the number of D alleles present; e.g. for total mortality in the II genotype group: RR=0.95 (95% CI 0.63-1.45), in the ID genotype group: RR=1.08 (95% CI 0.84-1.38) and in the DD genotype group: RR=1.61 (95% CI 1.18-2.18). No statistically significant interaction was found for incident heart failure. CONCLUSION: The results of our study suggest a relative resistance to ACE-inhibitor therapy in subjects with hypertension and the DD genotype compared to the II genotype, with the ID genotype in an intermediate position.

Oral antiarrhythmic drugs in converting recent onset atrial fibrillation.

AIM: This article reviews clinical studies on oral antiarrhythmic drugs in converting recent onset atrial fibrillation. An oral loading dose of an antiarrhythmic drug for cardioversion of atrial fibrillation could be an option, due to its simplicity, both for patients admitted to outpatient departments and for episodic treatment by self administration outside the hospital. The latter treatment strategy has recently been pointed out by the American College of Cardiology, the American Heart Association and the European Society of Cardiology as the 'pill in the pocket approach'. METHODS: Articles were identified by Medline 1966 to November 2001 and Embase 1966 to November 2001. Randomized studies of oral antiarrhythmic drugs versus placebo or comparative treatment, which are written in the English language, were selected. Non-randomized or non-comparative studies were selected if the results of an analysis to identify predictors for successful conversion are described. The review of clinical trials is followed by a description of pharmacokinetic parameters of the antiarrhythmic drugs. RESULTS: Studies meeting the inclusion criteria were on propafenone, flecainide, sotalol, amiodarone, quinidine, digoxin and verapamil. Conversion rates of a single oral loading dose of 600 mg propafenone varied between 37% and 41% at 4 h after ingestion. Propafenone was more effective than quinidine, amiodarone and placebo. A single oral dose of 300 mg flecainide restored sinus rhythm in 59% and 68% of patients at 3 h. Flecainide was more effective than amiodarone and placebo. Oral sotalol, digoxin and verapamil were not effective in converting atrial fibrillation to sinus rhythm. CONCLUSION: Propafenone and flecainide are effective in converting recent onset atrial fibrillation. No serious ventricular arrhythmia, other serious proarrhythmic effects or serious non cardiac adverse events were observed. Regular supraventricular tachyarrhythmias with 1:1 AV conduction were rare and were also observed in placebo treated patients. Propafenone and flecainide are more effective in patients with atrial fibrillation of less than 24 h. The association between cardioversion and patient characteristics are not consistent between studies. The pharmacokinetics of flecainide, with lower interindividual variability of absorption kinetics, no genetically determined formation of an active metabolite and a more rapid distribution to myocardial tissue, are more favourable for episodic treatment as compared to propafenone. Both flecainide and propafenone are safe in hospitalized patients. Out of hospital self administration of antiarrhythmic drugs, also described as the 'pill in the pocket approach', could be an option for selected patients, after the treatment has proven to be safe in hospital.

Rate control is more cost-effective than rhythm control for patients with persistent atrial fibrillation--results from the RAte Control versus Electrical cardioversion (RACE) study.

Aims To evaluate costs between a rate and rhythm control strategy in persistent atrial fibrillation. Methods and results In a prospective substudy of RACE (Rate control versus electrical cardioversion for persistent atrial fibrillation) in 428 of the total 522 patients (206 rate control and 222 rhythm control), a cost-minimisation and cost-effectiveness analysis was performed to assess cost-effectiveness of the treatment strategies. After a mean follow-up of 2.3+/-0.6 years, the primary endpoint (cardiovascular morbidity and mortality) occurred in 17.5% (36/202) of the rate control patients and in 21.2% (47/222) of the rhythm control patients. Mean costs per patient under rate control were euro 7386 and euro 8284 under rhythm control. Cost-effectiveness analysis showed that per avoided endpoint under rate control, the cost savings were euro 24944. Under rhythm control, more costs were generated due to electrical cardioversions, hospital admissions and anti-arrhythmic medication. Costs were higher in older patients, patients with underlying heart disease, those who reached a primary endpoint and women. Heart rhythm at the end of study, did not influence costs. Conclusions Rate control is more cost-effective than rhythm control for treatment of persistent atrial fibrillation. Underlying heart disease but not heart rhythm largely accounts for costs.