Kaplan-Meier analysis of freedom from extraction or death in patients with an Accufix J retention wire atrial permanent pacemaker lead: a potential management tool.
Morbidity (36 cases) and mortality (6 cases) have been reported in patients with Accufix J retention wire atrial leads. This has resulted in ongoing patient fluoroscopic monitoring as well as lead extractions. The estimated implanted worldwide population is 40,860. Estimating the size of the remaining population at risk is an important tool for assessing patient management guidelines.


RESULTS
The Kaplan-Meier method can be used to calculate the cumulative probability of remaining free of extraction and death for patients based on implant duration. The individual Kaplan-Meier curves for lead extraction and patient survival can also be computed. Based on the Multicenter Study (MCS) population of 2,298 patients, the probability that a patient is alive with the lead still implanted at 5 years implant duration is 52.5%. The event-free survival rate at 5 years implant duration is 81.3%. The corresponding probability of remaining free from injury due to the J-wire is 99.9% at 5 years implant duration. Assuming similar rates of death and extraction, these results can be extrapolated to the world wide population.


CONCLUSIONS
The management of Accufix patients must consider patient longevity, the probability of J-wire morbidity/mortality, and the probability of extraction complication morbidity/mortality. The probability of remaining at risk as a function of time from implant can be calculated from the events known in the MCS patient population. These event-free survival estimates can be used to identify subsets of the population at greater or lesser risk based on various clinical parameters.
Kawanishi
D T
DT
Accufix Research Institute, Englewood, Colorado, USA. DTKawanishi@msn.com
Brinker
J A
JA
Reeves
R
R
Kay
G N
GN
Gross
J
J
Pioger
G
G
Petitot
J C
JC
Esler
A
A
Grunkemeier
G
G
D018572:Disease-Free Survival; D004567:Electrodes, Implanted / Q000009:adverse effects* / Q000706:statistics & numerical data; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data; D006801:Humans; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data*; D011358:Product Surveillance, Postmarketing; D018570:Risk Assessment