Biomedical subjects

Humberto Vidaillet

Publications and source records attributed to Humberto Vidaillet.

12 recordsLinked to original sources

PubMed2005

Asymptomatic atrial fibrillation: demographic features and prognostic information from the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study.

BACKGROUND: Atrial fibrillation (AF) may occur without symptoms. Little is known about demographic features and prognostic information in patients with asymptomatic AF. METHODS: In the AFFIRM study, 4060 patients were randomized to either rhythm or rate control. At baseline, patients were identified as asymptomatic if they answered "no" to a 15-item questionnaire related to cardiac symptoms during AF in the 6 months before study entry. RESULTS: There were 481 (12%) asymptomatic patients at baseline. Compared with symptomatic patients, asymptomatic patients were more often men and had a lower incidence of coronary artery disease and congestive heart failure, but had more cerebrovascular events. Asymptomatic patients had a longer duration of AF, a lower maximum heart rate, and better left ventricular function. They received fewer cardiac medications and fewer therapies to maintain sinus rhythm. At 5 years, there was a trend for better survival in asymptomatic patients (81% vs 77%, P = .058), and they were more likely to be free from disabling stroke or anoxic encephalopathy, major bleeding, and cardiac arrest (79% vs 67%, P = .024). However, mortality and major events were similar after correction for baseline differences. CONCLUSIONS: Patients with asymptomatic AF have less serious heart disease but more cerebrovascular disease. Asymptomatic patients receive different therapies than symptomatic patients. However, the absence of symptoms and the differences in treatment does not confer a more favorable prognosis when differences in baseline clinical parameters are considered. Anticoagulation should be considered in these patients.

Aged↗

PubMed2005

Clinical factors associated with abandonment of a rate-control or a rhythm-control strategy for the management of atrial fibrillation in the AFFIRM study.

OBJECTIVE: The objective of the current study was to determine the clinical factors that were associated with abandonment of a rate-control or a rhythm-control strategy in patients with atrial fibrillation (AF). BACKGROUND: Although the AFFIRM Study demonstrated that outcomes are similar with a primary strategy of rate-control or rhythm-control for AF, there may be clinical or demographic factors associated with abandonment of the initial treatment strategy. Knowledge of these risk factors would be useful so that patients may be given appropriate initial therapy and, as appropriate, switched to alternative treatments earlier. METHODS: Patients in the AFFIRM Study were subdivided into those who were maintained on their initial treatment strategy versus those who abandoned initial treatment strategy for alternative therapies. We determined the clinical and demographic factors associated with change in initial treatment strategy. RESULTS: At 5 years the original treatment strategy was maintained in 85% of the patients in the rate-control arm versus 62% of those in the rhythm-control arm (P <.0001). Length of the qualifying episode of AF was associated with abandonment of both rhythm-control and rate-control strategies. Antiarrhythmic drug failure before randomization and a history of thyroid disease also were associated with abandonment of rhythm-control. Patients were more likely to maintain rate-control if they already had an implanted pacemaker or if they were older than 75 years, while an ejection fraction <30% was associated with abandonment of the rate-control strategy. CONCLUSIONS: In patients with AF, rhythm-control strategies are abandoned significantly more often than rate-control strategies. Patients with long durations of AF on presentation or previous antiarrhythmic drug failure might be considered for rate-control as initial treatment.

Age Factors↗

PubMed2005

Recent progress in the epidemiology of atrial fibrillation.

PURPOSE OF REVIEW: Atrial fibrillation is a common arrhythmia with serious health consequences. This review explores contributions to the characterization and control of atrial fibrillation made by recent epidemiologic efforts. RECENT FINDINGS: Topics included in this review include the classification and clinical progression of atrial fibrillation, the burden atrial fibrillation places on the individual and on the health care delivery system, temporal trends in the occurrence and effect of atrial fibrillation, and novel predictors and risk factors. In light of the clinically relevant classification system used in the 2001 American College of Cardiology/American Heart Association/European Society of Cardiology Practice Guidelines for atrial fibrillation, recent estimates of pattern-specific recurrence and progression rates are described, along with insights into the incidence and prognosis of primary and secondary atrial fibrillation. Important new studies from North America and Europe quantifying the alarming health care burden and economic effect of atrial fibrillation are summarized. A discussion of several novel risk factors recently found to be associated with the development of atrial fibrillation is also included. SUMMARY: Better characterization of the predictors, natural history, and clinical course of atrial fibrillation should ultimately support improvements in prevention, clinical decision making, and patient communication. A fuller comprehension of the current and future impact of atrial fibrillation can assist in planning health care delivery from the local facility to the international arena. Finally, there is a growing recognition that unraveling the complex interplay between atrial fibrillation and other associated diseases and their common risk factors may hold promise of deep insights into the fundamental nature of cardiovascular diseases.

Atrial Fibrillation↗

PubMed2005

Rate control versus rhythm control.

PURPOSE OF REVIEW: The results of five randomized clinical trials comparing rate control with rhythm control in the management of atrial fibrillation have been published recently. The purpose of this report is to review their main results and selected subanalyses and other related data to offer practical recommendations regarding the treatment of patients with this common arrhythmia. RECENT FINDINGS: In the aggregate, the five trials enrolled a total of 5175 subjects and accumulated 16,186 patient-years of follow-up. All these trials have had similar results in that each of them failed to demonstrate a clear advantage of the rhythm control approach over that of rate control. The largest of the studies, the Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) study, enrolled 79% of all the cases in the five trials and accounts for 88% of the cumulative follow-up experience and for 92% of all deaths. Among AFFIRM participants, antiarrhythmic drug use did not improve survival, stroke risk, quality of life, or functional capacity but was associated with increased resource use. In several of the trials, however, the presence of sinus rhythm was associated with improved outcomes. SUMMARY: The evidence is now overwhelming that for most patients with atrial fibrillation, rhythm control using currently available antiarrhythmic drugs is more expensive but not more effective than the rate control strategy in the prevention of major adverse events. Further research is needed to determine whether maintaining sinus rhythm by other means can improve outcomes.

Anti-Arrhythmia Agents↗

PubMed2004

A randomized, controlled trial of RSD1235, a novel anti-arrhythmic agent, in the treatment of recent onset atrial fibrillation.

OBJECTIVES: The purpose of this study was to determine the efficacy and safety of intravenous RSD1235 in terminating recent onset atrial fibrillation (AF). BACKGROUND: Anti-arrhythmic drugs currently available to terminate AF have limited efficacy and safety. RSD1235 is a novel atrial selective anti-arrhythmic drug. METHODS: This was a phase II, multi-centered, randomized, double-blinded, step-dose, placebo-controlled, parallel group study. Fifty-six patients from 15 U.S. and Canadian sites with AF of 3 to 72 h duration were randomized to one of two RSD1235 dose groups or to placebo. The two RSD1235 groups were RSD-1 (0.5 mg/kg followed by 1 mg/kg) or RSD-2 (2 mg/kg followed by 3 mg/kg), by intravenous infusion over 10 min; a second dose was given only if AF was present. The primary end point was termination of AF during infusion or within 30-min after the last infusion. Secondary end points included the number of patients in sinus rhythm at 0.5, 1, and 24 h post-last infusion and time to conversion to sinus rhythm. RESULTS: The RSD-2 dose showed significant differences over placebo in: 1) termination of AF (61% vs. 5%, p < 0.0005); 2) patients in sinus rhythm at 30 min (56% vs. 5%, p < 0.001); 3) sinus rhythm at 1 h (53% vs. 5%, p = 0.0014); and 4) median time to conversion to SR (14 vs. 162 min, p = 0.016). There were no serious adverse events related to RSD1235. CONCLUSIONS: RSD1235, a new atrial-selective anti-arrhythmic agent, appears to be efficacious and safe for converting recent onset AF to sinus rhythm.

Adult↗

PubMed2004

Cost-effectiveness of rhythm versus rate control in atrial fibrillation.

BACKGROUND: Atrial fibrillation is the most common type of sustained cardiac arrhythmia, but recent trials have identified no clear advantage of rhythm control over rate control. Consequently, economic factors often play a role in guiding treatment selection. OBJECTIVE: To estimate the cost-effectiveness of rhythm-control versus rate-control strategies for atrial fibrillation in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM). DESIGN: Retrospective economic evaluation. Nonparametric bootstrapping was used to estimate the distribution of incremental costs and effects on the cost-effectiveness plane. DATA SOURCES: Data on survival and use of health care resources were obtained for all 4060 AFFIRM participants. Unit costs were estimated from various U.S. databases. TARGET POPULATION: Patients with atrial fibrillation who were 65 years of age or who had other risk factors for stroke or death, similar to those enrolled in AFFIRM. TIME HORIZON: Mean follow-up of 3.5 years. PERSPECTIVE: Third-party payer. INTERVENTIONS: Management of patients with atrial fibrillation with antiarrhythmic drugs (rhythm control) compared with drugs that control heart rate (rate control). OUTCOME MEASURES: Mean survival, resource use, costs, and cost-effectiveness. RESULTS OF BASE-CASE ANALYSIS: A mean survival gain of 0.08 year (P = 0.10) was observed for rate control. Patients in the rate-control group used fewer resources (hospital days, pacemaker procedures, cardioversions, and short-stay and emergency department visits). Rate control costs 5077 dollars less per person than rhythm control. RESULTS OF SENSITIVITY ANALYSIS: Cost savings ranged from 2189 dollars o 5481 dollars per person. Rhythm control was more costly and less effective than rate control in 95% of the bootstrap replicates over a wide range of cost assumptions. LIMITATIONS: Resource use was limited to key items collected in AFFIRM, and the results are generalizable only to similar patient populations with atrial fibrillation. CONCLUSION: Rate control is a cost-effective approach to the management of atrial fibrillation compared with maintenance of sinus rhythm in patients with atrial fibrillation similar to those enrolled in AFFIRM.

Anti-Arrhythmia Agents↗

PubMed2004

Alternative endpoints for mortality in studies of patients with atrial fibrillation: the AFFIRM study experience.

OBJECTIVES: The purpose of this study was to examine possible alternatives for death, particularly hospitalization for cardiovascular reasons (CV hospitalization), as an endpoint in studies of atrial fibrillation (AF) using the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) database. BACKGROUND: AF is associated with increased mortality, but large numbers of patients are needed to demonstrate even a moderate effect of a therapy on mortality. METHODS: AFFIRM studied 4,060 patients with AF, randomized to either rate-control or rhythm-control strategy with death as the primary endpoint. RESULTS: Only CV hospitalization occurred more frequently than death. Like death, CV hospitalization was more frequent in the rhythm-control arm (46% vs 36%, P < .001) overall but not in a cohort that attempted to exclude those CV hospitalizations possibly related to treatment strategy (e.g., cardioversion, 24% vs 27%). In either model there was no interaction of CV hospitalization (analyzed as a time-dependent covariate) with treatment arm (P = .18 and P = .21, respectively). CV hospitalization was highly predictive of death in both treatment arms (P < .001) in either model, but after this event, there was no difference in time to death. A composite endpoint of CV hospitalization combined with death might increase power and reduce the size of trials of therapy for AF in such patients. CONCLUSIONS: In patients with AF such as those in the AFFIRM study, CV hospitalization has many attributes of a surrogate for mortality. More research on CV hospitalization, alone or as part of a composite endpoint, is warranted.

Aged↗

PubMed2004

Alternatives to warfarin for thromboembolism prophylaxis in nonrheumatic atrial fibrillation.

Decision-making regarding thromboembolism prophylaxis in atrial fibrillation remains a major clinical challenge. While evidence of the beneficial effect of anticoagulation for patients participating in clinical trials is well established, only half of eligible individuals in the general population are currently treated with warfarin. Using an evidence-based approach, this review covers major therapeutic approaches in practice today and many of those expected to be released in the near future. Pharmacologic agents evaluated include warfarin, aspirin, other antiplatelets agents, direct thrombin inhibitors and antiarrhythmic drugs. Nonpharmacologic treatments reviewed include surgical and catheter ablation, pacing, left atrial appendage ligation and occlusion methods, and atrial defibrillators.

Anticoagulants↗

PubMed2003

Patient with Sotos syndrome, Wolff-Parkinson-White pattern on electrocardiogram, and two right-sided accessory bypass tracts.

Sotos syndrome is a growth regulation disorder. Accessory conduction pathways, the anatomical structures responsible for Wolff-Parkinson-White syndrome, are thought to result from developmental failure to eradicate the remnants of the atrioventricular connections during cardiogenesis. Although the reported prevalence of congenital heart disease in Sotos syndrome is 10 times higher than in the general population, there are no reported cases with ventricular pre-excitation. We report a patient with Sotos syndrome with two distinct accessory atrioventricular bypass tracts documented by invasive electrophysiology testing and a curative catheter ablation procedure.

Adolescent↗

PubMed2002

A population-based study of mortality among patients with atrial fibrillation or flutter.

PURPOSE: To determine the mortality associated with atrial flutter and atrial fibrillation in the general population. SUBJECTS AND METHODS: Using the Marshfield Epidemiologic Study Area, a database that captures nearly all medical care and deaths among its 58,820 residents, we identified patients diagnosed with atrial flutter or atrial fibrillation from July 1, 1991, through June 30, 1995. Patients were followed prospectively and compared with a group of controls without these arrhythmias. RESULTS: A total of 4775 person-years of follow-up were completed in 577 patients and 577 controls. Compared with controls, mortality among patients with atrial fibrillation or flutter was nearly 7.8-fold higher at 6 months (95% confidence interval [CI]: 4.1 to 15) and 2.5-fold higher (95% CI: 2.0 to 3.1; P < 0.0001) at the last follow-up (mean [+/- SD] of 3.6 +/- 2.3 years; range, 1 day to 7.3 years). At 6 months, mortality among patients with atrial flutter alone was somewhat greater than in controls and less than one third that of those with atrial fibrillation (with or without atrial flutter) (P = 0.02). At the last follow-up, however, mortality was greater among patients with atrial flutter (hazard ratio [HR] = 1.7; 95% CI: 1.2 to 2.6; P = 0.007), atrial fibrillation (HR = 2.4; 95% CI: 1.9 to 3.1; P < 0.0001), or both atrial arrhythmias (HR = 2.5; 95% CI: 1.9 to 3.3; P < 0.0001) when compared with controls in models that adjusted for cardiovascular risk factors. CONCLUSION: In the general population, both atrial flutter and atrial fibrillation are independent predictors of increased late mortality. The relatively benign course during the 6-month period after the initial diagnosis of atrial flutter suggests that early diagnosis and treatment of these patients may improve their long-term survival.

Aged↗

PubMed2002

Frequency of symptomatic atrial fibrillation in patients enrolled in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study.

INTRODUCTION: The frequency of symptomatic paroxysmal atrial fibrillation (AF) may identify subsets with different characteristics. Because the approach to AF now is so varied, ranging from drug therapy to surgery and catheter ablation, the frequency of AF may have important therapeutic implications if the frequency identifies subsets with distinguishing features. METHODS AND RESULTS: The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Study is evaluating patients with AF who are at high risk for stroke. We evaluated the clinical characteristics of the patients in the AFFIRM Study in an attempt to identify features that might distinguish patients with infrequent and frequent AF occurrences. Patients were divided into five groups, based upon the historic frequency of occurrence of AF at the time the patients were enrolled in the study. Although statistically significant differences were present among the groups, no important differences were noted in clinical or echocardiographic characteristics that could differentiate patients with frequent episodes of AF from other patients in the AFFIRM population. CONCLUSION: In a large population of patients with AF at high risk for stroke, individual historic and echocardiographic characteristics failed to distinguish patients based on the frequency of AF. Those with frequent and infrequent AF were similar. Although AF frequency has been suggested as a marker of a focal etiology in young populations with little overt heart disease, it does not seem to be a distinguishing characteristic in older populations at high risk for stroke.

Age Factors↗

PubMed2002

Incidence of myocardial infarction in a general population: the Marshfield Epidemiologic Study Area.

BACKGROUND: Much of what is known about the occurrence of myocardial infarction (MI) in populations is derived from mortality data. International heart disease registries and recent population-based studies provide only limited incidence data from selected areas of the United States. METHODS: The Marshfield Epidemiologic Study Area (MESA), a defined geographic region where nearly all residents receive their health care from the Marshfield Clinic and affiliated hospitals, is a resource for estimating disease incidence in a general population. MI incidence rates and time trends from 1992 to 1998 were evaluated in MESA. RESULTS: A total of 1691 MESA residents had their first MI during the study period (age-adjusted rate, 292.4 per 100,000 per year). Rates in MESA were similar to some, and higher than other, incidence rates reported from US populations. About 20% of first MIs were detected only on death certificates. Overall incidence did not change much over time (-0.4% per year, P = 0.68), although rates declined 2.3% per year among women (P = 0.07). CONCLUSIONS: This is the first report of MI incidence in a general population from Wisconsin. The fairly steady incidence trend and the large number of incident events detected through death certificates demonstrate the continued need for primary prevention.

Adult↗