By Todd J. Cohen, MD¹ and Daniel Kersten²
¹Director of Electrophysiology
²Member of the PAIDLESS team
Department of Medicine, Winthrop University Hospital
Mineola, New York
The Pacemaker and Implantable Defibrillator Lead Survival Study (PAIDLESS) gathers retrospective information from a large single-center implanting hospital over a 15.6 year period (from February 1, 1996 to December 31, 2011). In total, there were 4078 leads implanted, across all major United States manufacturers, in 3802 patients. The PAIDLESS study examined a variety of patient, operator, and lead characteristics, along with implant approaches, in order to determine their relationship with lead failure and patient mortality.
First, and possibly most importantly, this study revealed an association between recalled leads and overall mortality. Specifically, the mortality rate was higher in patients who had recalled leads implanted (Medtronic Sprint Fidelis, St. Jude Medical Riata, or St. Jude Medical Riata ST leads) than patients with non-recalled leads implanted (P=.01). However, the mortality rate was not significantly different when comparing Medtronic and St. Jude Medical recalled leads (P=.67).
Second, PAIDLESS demonstrated that Boston Scientific and St. Jude Medical leads had significantly better survival than Medtronic leads (P>.001 and P=.01, respectively). Further analysis demonstrated that Boston Scientific and St. Jude Medical lead survival rates were not significantly different (P=.80).
Third, Kaplan-Meier analysis demonstrated that recalled leads fail sooner than non-recalled leads (P=.01). Recalled Medtronic leads failed sooner than recalled St. Jude Medical leads (P<.001). In addition, failure of recalled St. Jude Medical leads and failure of all non-recalled leads was not significantly different (P=.45).
Finally, multivariate Cox regressions were performed on all the patient, operator, lead characteristics, and implant approaches which were found to have a P-value <.25 and that were not co-linear. The resulting model revealed that younger age, prior percutaneous coronary interventions, baseline rhythm (other than atrial fibrillation and atrial flutter), lead insulation with a combination of polyurethane and silicone, a second defibrillation coil, and recalled status were all linked to lead failure.
The PAIDLESS team has compiled a robust set of unique data points and developed a versatile database that can analyze a multitude of clinical questions. Working with the Winthrop team and its skilled biostatistician, we will be reporting on the effects of a number of factors on lead failure and mortality in the near future. So please stay tuned, more to come!
Cohen TJ, Asheld WJ, Germano J, Islam S, Patel D. A Comparative Study of Defibrillator Leads at a Large-Volume Implanting Hospital: Results From the Pacemaker and Implantable Defibrillator Leads Survival Study (“PAIDLESS”). J INVASIVE CARDIOL 2015;27(6):292-300.