Long-term outcome after ICD and CRT implantation and influence of remote device follow-up: the ALTITUDE survival study.

BACKGROUND: Outcome data for patients receiving implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy-defibrillator (CRT-D) devices treated outside of clinical trials are lacking. No clinical trial has evaluated mortality after device implantation or after shock therapy in large numbers of patients with implanted devices that regularly transmit device data over a network. METHODS AND RESULTS: Survival status in patients implanted with ICD and CRT devices across the United States from a single manufacturer was assessed. Outcomes were compared between patients followed in device clinic settings and those who regularly transmit remote data collected from the device an average of 4 times monthly. Shock delivery and electrogram analysis could be ascertained from patients followed on the network, enabling survival after ICD shock to be evaluated. One- and 5-year survival rates in 185,778 patients after ICD implantation were 92% and 68% and were 88% and 54% for CRT-D device recipients. In 8228 patients implanted with CRT-only devices, survival was 82% and 48% at 1 and 5 years, respectively. For the 69,556 ICD and CRT-D patients receiving remote follow-up on the network, 1- and 5-year survival rates were higher compared with those in the 116,222 patients who received device follow-up in device clinics only (50% reduction; P<0.0001). There were no differences between patients followed on or off the remote network for the characteristics of age, gender, implanted device year or type, and economic or educational status. Shock therapy was associated with subsequent mortality risk for both ICD and CRT-D recipients. CONCLUSIONS: Survival after ICD and CRT-D implantation in patients treated in naturalistic practice compares favorably with survival rates observed in clinical trials. Remote follow-up of device data is associated with excellent survival, but arrhythmias that result in device therapy in this population are associated with a higher mortality risk compared with patients who do not require shock therapy.

Sudden death in epilepsy: can any lessons be learned from convulsive therapy?

Convulsive therapy (chemically or electrically induced) has been used since the mid-1930s. Initially it had a high mortality rate, but this has been falling slowly in response to refinements in technique (introduction of muscle paralysis during the seizure, brief intravenous general anesthesia and, more recently, the acceptance that adequate ventilation and oxygenation are necessary during the procedure). Mortality during convulsive therapy has been ascribed to both cardiac and respiratory causes (particularly acute arrhythmias and pulmonary edema). There is some evidence that supporting respiration during and after the convulsion has reduced mortality significantly, such that electrical convulsive therapy is now a very low-risk procedure, even in the very elderly. This gives tenuous support for the view that death in epileptic seizures may be of respiratory origin.