Time-dependent risk of Fidelis lead failure.

The Medtronic Sprint Fidelis leads (models 6930, 6931, 6948, 6949) are 6.6-F bipolar high-voltage implantable cardioverter-defibrillator electrodes that were first introduced in September 2004. In October 2007, Fidelis leads were removed from the market. We sought to determine the time-dependent hazard of the Fidelis failure rate to date. A retrospective chart review was conducted in all patients who underwent implantation of a Sprint Fidelis lead (426 leads) at our center. We primarily implanted models 6931 and 6949. With 1,056 years of combined follow-up (average 2.3 +/- 1), 38 of 426 (8.92%) Sprint Fidelis leads failed (3.6%/year). The hazard of fracture increased exponentially over time by a power of 2.13 (95% confidence interval [CI] 1.98 to 2.27, p <0.001) and the 3-year survival was 90.8% (95% CI 87.4 to 94.3). If a Fidelis lead was functioning normally at 1 year, the chance it would survive another year was 97.4% (95% CI 95.7 to 99.1); if functioning at 2 years, the chance of surviving another year was 94.7% (95% CI 91.8 to 97.7); and if functioning at 3 years, the chance of surviving 1 more year was 86.7% (95% CI 78.8 to 95.5). Other commonly used implantable cardioverter-defibrillator leads showed no evidence of increased failure rates. In conclusion, to date, the hazard of Fidelis lead fracture is increasing exponentially with time and, based on our data, occurring at a higher rate than the latest manufacturer's performance update. Further accumulative data are needed because it remains unknown if the fracture rate will level off or continue to increase.

Clinical outcomes following IVUS-guided stent deployment in a community hospital.

OBJECTIVES: A discrepancy exists in the medical literature as to what effect intravascular ultrasound (IVUS)-guided stent deployment has on target vessel revascularization (TVR) at 6 months. The major endpoints of this study are the need for TVR, defined as clinically driven repeat interventional or surgical therapy of the index vessel at 6 months and major adverse cardiac events. METHODS: One hundred interventional stent cases (50 IVUS-guided, 50 non-IVUS guided) were randomly selected in a 6-month period (January to June 2001) for review by measurement of minimal luminal diameter (MLD) pre- and post-intervention. Seventy males and 30 females were distributed among the 2 groups. There were a total of 135 lesions (70 IVUS-guided, 65 non-IVUS guided) in the 2 groups. A 6-month follow-up chart review was performed following the initial stenting. RESULTS: At 6-month follow-up, there were 2 deaths in the IVUS-guided group and 3 deaths in the non-IVUS guided group (p=NS). All deaths were cardiovascular in nature. Post-procedure MLD was 3.58+/-0.08 mm for the IVUS-guided group and 2.88+/-0.09 mm for the non-IVUS guided group [t=5.7 (df, 133); p<0.001]. Ten of 70 IVUS-guided lesions (14.3%) and 3 of 65 non-IVUS guided lesions (4.2%) underwent TVR within the 6-month study period (Chi square=3.62; p=0.057). CONCLUSION: In this population, IVUS-guided stent deployment does not appear to reduce either the need for TVR or overall cardiovascular mortality at 6 months. The added expense of IVUS does not appear to be warranted.