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Background Rate smoothing, which is available in some pacemakers and implantable cardioverter defibrillators (ICDs), has been used to prevent Torsades de Pointes in patients with long QT syndrome. Its efficacy in general ventricular arrhythmia prevention has not been determined. Objectives The purpose of the Ventricular Arrhythmia Suppression Trial (VAST) was to prospectively investigate whether rate smoothing could significantly reduce the incidence of ventricular tachyarrhythmias in a large, broad population of patients with ICDs. Methods Five hundred sixty-nine patients were enrolled at 57 participating centers and implanted with a commercially available Guidant ICD. A single-blinded crossover design was used in which each patient was randomized at implant to one of two treatment sequences: either rate smoothing on (RS On) followed by rate smoothing off (RS Off), or RS Off followed by RS On. This mode sequence was randomly determined and assigned in a 1:1 fashion using randomized permuted blocks by site. Each mode was followed for 6 months. Programming of rate smoothing was prescribed as 12% Down and 12% Up for the duration of the RS On period. Results Of enrolled patients, 281 were randomized to RS Off followed by RS On, and 288 to RS On followed by RS Off. With RS On, 75 (23%) patients experienced a reduction in arrhythmias, 76 (23%) saw an increase in arrhythmias, and the remaining 176 (54%) had no difference. No significant difference ( P = .58) in frequency of arrhythmias with RS On vs RS Off was found. Conclusion Rate smoothing does not result in a reduction in ventricular arrhythmias in a heterogenous population of patients receiving ICDs.

IMPACT (Improving Mood--Promoting Access to Collaborative Treatment) has a large body of evidence demonstrating its effectiveness for treating late-life depression in clients enrolled in a clinical research study, but little is known about how well the collaborative care model translates into treatment provided in a public mental health setting. This evaluation examines the influence of clinical and demographic characteristics in 112 older adults treated for late-life depression through publicly funded IMPACT in a large San Francisco Bay Area county. Depression severity decreased for 85% of clients between enrollment and treatments' end and 46% of clients realized a 50% reduction in symptom severity. Depression severity at enrollment, number of treatment sessions attended, ethnicity, and gender reliably predicted depression severity at the end of treatment. Men, clients attending more therapy sessions, and clients without substance abuse diagnoses had an increased likelihood of realizing a 50% reduction in symptoms. Results highlight the success of this evidence-based treatment program offered through the public mental health system but suggest that the demographic and clinical characteristics of the population being treated must be considered when adopting evidence-based practices.