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.

Natural history and predictors of temporary epicardial pacemaker wire function in patients after open heart surgery.

STUDY OBJECTIVES: To assess the short-term reliability of temporary epicardial pacing wires in patients after open heart surgery and to determine the influence of preoperative factors on the performance of these wires. PATIENTS AND METHODS: In this prospective, longitudinal cohort study, 60 patients (41 men) with a mean age of 66.8 +/- 8.9 years were studied for 5.3 +/- 1.1 days postoperatively. Each patient's history, physical findings, hemodynamics and echocardiographic data were analyzed. Postoperatively, capture threshold, the electrogram amplitude and slew rate, and the lead impedance were determined daily in both chambers. RESULTS: Both atrial and ventricular thresholds increased significantly (p < 0.001) by the 4th postoperative day. The P-wave amplitudes were consistently less than half of the R-wave amplitudes. Both P- and R-wave amplitudes deteriorated significantly by the 2nd postoperative day (p < 0.001 and p < 0.02, respectively). Atrial and ventricular slew rates and lead impedance decreased significantly during the observation period (p < 0.002). CONCLUSION: Although both atrial and ventricular temporary epicardial leads are reliable for short-term use, their function deteriorates on a daily basis. Perioperative factors are generally not helpful in predicting the performance of temporary epicardial pacing wires.

Factors determining ICD implantation in drug therapy patients after termination of antiarrythmics versus implantable defibrillators trial.

Because of a significant survival benefit in the defibrillator arm of the Antiarrhythmics versus Implantable Defibrillator (AVID) Trial, patients in the antiarrhythmic drug (AAD) arm were advised to undergo ICD implantation. Despite this recommendation, ICD implantation in AAD patients was variable, with a large number of patients not undergoing ICD implantation. Patients were grouped by those who had been on AAD < 1 year (n = 111) and those on AAD > 1 year (n = 223). Multiple clinical and socioeconomic factors were evaluated to identify those who might be associated with a decision to implant an ICD. The primary reason for patients not undergoing ICD implantation was collected, as well as reasons for a delayed implantation, occurring later than 3 months from study termination. Of 111 patients on AAD for less than 1 year, 53 received an ICD within 3 months compared to 40/223 patients on AAD for more than 1 year (P < 0.001). Patient refusal was the most common reason to not implant an ICD in patients on drug < 1 year; physician recommendation against implantation was the most common in patients on drug > 1 year. Multivariate analysis showed ICD recipients on AAD < 1 year were more likely to be working and have a history of myocardial infarction (MI), while those on AAD > 1 year were more likely to be working, have a history of MI and ventricular fibrillation, and less likely to have experienced syncope, as compared to those who did not get an ICD. Having private insurance may have played a role in younger patients receiving an ICD.