Peripheral artery disease is an independent predictor of mortality after implantable cardioverter-defibrillator implantation in patients with severe left ventricular dysfunction.

The impact of peripheral artery disease (PAD) on survival in implantable cardioverter defibrillator (ICD) patients is poorly understood. Thus, we assessed the risk of PAD in our adult ICD patients with left ventricular dysfunction (ejection fraction [EF] ≤35%). Survival was estimated with Kaplan-Meier method and compared by the log-rank test; a Cox proportional hazards model assessed the effects of clinical variables on survival. Average age and EF of 1399 patients were 67.0 ± 12.1 years and 23.8% ± 7.2%, respectively. The ICD patients with PAD had significantly worse survival than those without (unadjusted P < .0001). The multivariate predictors of survival at implant were (hazard ratio, HR [95% confidence interval]) age (HR 1.05 [1.04-1.07] P < .0001), PAD (HR 2.07 [1.53-2.80] P < .0001), class III/IV heart failure (HR 1.36 [1.06-1.76] P = .016), creatinine 1.4-2.0 mg/dL (HR 1.36 [1.05-1.76] P = .019), and creatinine ≥2.0 mg/dL (HR 2.01 [1.42-2.85] P < .0001). The PAD is an independent predictor of mortality and should be considered in the preimplant risk assessment.

Early fatigue fractures in the IS-1 connector leg of a small-diameter ICD lead: value of returned product analysis for improving device safety.

BACKGROUND: Conductor fractures may affect the performance of implantable cardioverter-defibrillator leads. During routine surveillance of returned product analyses (RPAs) in the Food and Drug Administration's Manufacturers and User Facility Device Experience database, we found a number of conductor fractures in small diameter implantable cardioverter-defibrillator leads manufactured by St Jude Medical, Inc (SJM, Sylmar, CA). OBJECTIVES: To determine the location and cause of these fractures and to catalog their clinical signs and consequences. METHODS: We searched the FDA's Manufacturers and User Facility Device Experience database on April 11, 2013. SJM provided information and data it collected independently. RESULTS: Our search found 59 leads with fractures in the IS-1 leg. Most fractures were in leads implanted in 2008-2009; no fractures were found in leads implanted after 2010. Outer coil conductor fractures accounted for the majority (51 of 59, 86%). Oversensing and noise were common signs, and 81% of the patients received inappropriate shocks. SJM's RPAs found that the fractures were due to inadequate strain relief and redesigned the IS-1 leg by shortening the crimp bore. Younger age and subpectoral implants appeared to be associated with these fractures. SJM stated the incidence is low (0.040%) and has not seen further fractures of this type in leads with the modified crimp. CONCLUSIONS: SJM's small diameter leads that were manufactured before 2011 are prone to early outer coil fatigue fractures in the IS-1 leg. The failure mechanism appears to have been mitigated by a design change. RPA is important for improving device safety.