Postmortem ICD interrogation in mode of death classification.

BACKGROUND: The definition of sudden death due to arrhythmia relies on the time interval between onset of symptoms and death. However, not all sudden deaths are due to arrhythmia. In patients with an implantable cardioverter defibrillator (ICD), postmortem device interrogation may help better distinguish the mode of death compared to a time-based definition alone. OBJECTIVE: This study aims to assess the proportion of "sudden" cardiac deaths in patients with an ICD that have confirmed arrhythmia. METHODS: We conducted a literature search for studies using postmortem ICD interrogation and a time-based classification of the mode of death. A modified QUADAS-2 checklist was used to assess risk of bias in individual studies. Outcome data were pooled where sufficient data were available. RESULTS: Our search identified 22 studies undertaken between 1982 and 2015 with 23,600 participants. The pooled results (excluding studies with high risk of bias) suggest that ventricular arrhythmias are present at the time of death in 76% of "sudden" deaths (95% confidence interval [CI] 67-85; range 42-88). CONCLUSION: Postmortem ICD interrogation identifies 24% of "sudden" deaths to be nonarrhythmic. Postmortem device interrogation should be considered in all cases of unexplained sudden cardiac death.

Is taking part in clinical trials good for your health? A cohort study.

AIMS: The prognosis of patients included in clinical trials is often better than might be anticipated from epidemiological data. Patients volunteering to take part in a study might be unrepresentative of the potential treatment population or the trial itself may confer benefit by offering closer supervision. METHODS AND RESULTS: A total of 2332 consecutive patients (average +/- SD age 70.1 +/- 10.8; 26% female) who presented to a community heart failure clinic were diagnosed as having heart failure due to left ventricular systolic dysfunction. All patients were asked whether they would be prepared to take part in clinical research projects at their initial visit. During a median follow-up in survivors of 55.7 months (interquartile range 30.4-74.3), 792 (34%) patients died. Agreeing to take part in clinical trials strongly predicted a good outcome (approximately halving the risk of death). In multivariate modelling, willingness to take part [hazard ratio (95% confidence intervals) 0.33 (0.26-0.40)] was a predictor of good outcome independent of age, severity of left ventricular dysfunction, renal function, sodium levels, drug use, and comorbidities. In a subset in whom N-terminal pro-B type natriuretic peptide (NT-proBNP) was available (n = 1256), agreeing to take part in trials remained an independent predictor of survival with log [NT-proBNP]. CONCLUSION: Those patients with chronic heart failure who express a willingness to take part in a clinical trial, appear to have a better prognosis than those who do not.