This Week in JAMA

ICDs and Sudden Death in Hypertrophic Cardiomyopathy


Some data suggest that implantable cardioverter-defibrillators (ICDs) reduce the risk of sudden cardiac death among patients with hypertrophic cardiomyopathy. In an analysis of data from 506 patients with hypertrophic cardiomyopathy and an ICD, Maron and colleagues (SEE ARTICLE) assessed the incidence and efficacy of ICD intervention to terminate ventricular tachycardia/fibrillation and the relationship between an ICD intervention and risk markers for sudden cardiac death. During a mean 3.7-year follow-up, the authors found that ICD interventions appropriately terminated ventricular tachycardia/fibrillation in 103 patients, 88% of whom had no or only mild symptoms of their cardiomyopathy. Among patients who received an ICD for primary prevention, there was no relationship between appropriate ICD discharge and the presence of 1 or more risk markers for sudden cardiac death. In an editorial, Nishimura and Ommen (SEE ARTICLE) discuss identification of patients who are likely to benefit from ICD implantation.


Efficacy of Hip Protectors to Prevent Hip Fractures

Results of previous clinical trials assessing the efficacy of external hip protectors to prevent hip fractures among the frail elderly have been inconclusive, possibly because of limitations in study design. In a clinical trial designed to address these limitations, Kiel and colleagues (SEE ARTICLE) investigated the efficacy of an energy-absorbing/energy-dispersing hip protector to prevent hip fractures in nursing home residents who consistently wore the hip protector on either the left or right hip. The authors report that adherence to the study protocol was 73.8%, but after 20 months of follow-up, hip fracture rates did not differ for protected vs unprotected hips. In an editorial, Kannus and Parkkari (SEE ARTICLE) discuss issues related to research involving external hip protectors to prevent fractures.

Trends in the Use of Pulmonary Artery Catheters

Evidence that use of the pulmonary artery catheter is associated with increased mortality has accumulated in the past decade, but whether rates of utilization have declined is not clear. In a time trend analysis using national data for adult inpatients, Wiener and Welch (SEE ARTICLE) found that use of the pulmonary artery catheter decreased by two-thirds between 1993 and 2004. In an editorial, Rubenfeld and colleagues (SEE ARTICLE) discuss the implications for physician training and clinical care associated with limited use of pulmonary artery catheters.


Data Transformation and Reliability of Meta-analyses

When performing a meta-analysis of data from clinical trials that used different scales to record outcomes of a similar nature—for example, pain intensity ratings recorded on 2 different scales—the data must be transformed to a uniform scale, such as the standardized mean difference (SMD). To assess the reliability of these data transformations, Gøtzsche and colleagues identified 27 meta-analyses that reported a result as an SMD, randomly selected 2 trials from each meta-analysis, abstracted the trial data, and independently recalculated SMDs. The authors found erroneous SMD estimates in 10 of the meta-analyses (37%) and other serious errors in an additional 7 meta-analyses.

Source:jama.ama-assn.org