Safety of chronic anticoagulation therapy after endovascular abdominal aneurysm repair (EVAR).
OBJECTIVE
Current data supporting the effect of anticoagulation drug use on aneurysm sealing and the durability of endovascular abdominal aneurysm repair (EVAR) are conflicting. This study assessed the safety of chronic anticoagulation therapy after EVAR.


METHODS
Records of 1409 consecutive patients having elective EVAR during 1997-2011 who were prospectively followed were reviewed. Survival, reintervention, conversion, and endoleak rates were analyzed in patients with and without chronic anticoagulants. Cox proportional hazards models were used to estimate the effect of anticoagulation therapy on outcomes.


RESULTS
One-hundred and three (7.3%) patients were on chronic anticoagulation drugs (80 on vitamin K antagonists) at the time of EVAR. An additional 46 patients started on anticoagulants after repair were identified. Patients on chronic anticoagulation therapy at repair (mean age 73.6 years; 91 males) had more frequent cardiac disease (74.8% vs. 44.2%; p < 00001), but no other differences in demographic and major baseline comorbidities with respect to the others. At baseline, mean abdominal aortic aneurysm (AAA) diameter was 56.43 mm vs. 54.65 mm (p = .076) and aortic neck length 26.54 mm vs. 25.21 mm (p = .26) in patients with and without anticoagulants, respectively. At 5 years, freedom from endoleak rates were 55.5% vs. 69.9% (p < .0001), and freedom from reintervention/conversion rates were 69.4% vs. 82.4% (p < .0001) in patients with (including those with delayed drug use) and without chronic anticoagulants, respectively. Controlling for covariates with the Cox regression method, at a mean follow-up of 64.3 ± 45.2 months after EVAR, use of anticoagulation drugs was independently associated with an increased risk of endoleak (odds ratio, OR 1.6; 95% confidence interval, CI: 1.23-2.07; p < .0001) and reintervention or late conversion rates (OR 1.8; 95% CI: 1.31-2.48; p < .0001).


CONCLUSIONS
The safety of anticoagulation therapy after EVAR is debatable. Chronic anticoagulation drug use risks exposure to a poor long-term outcome. A critical and balanced decision-making approach should be applied to patients with AAA and cardiac disease who may require prolonged anticoagulation treatment.
Unit of Vascular and Endovascular Surgery, Hospital S. Maria Misericordia, Perugia, Italy. Electronic address: plderango@gmail.com.
P
P
De Rango
Unit of Vascular and Endovascular Surgery, Hospital S. Maria Misericordia, Perugia, Italy.
F
F
Verzini
Unit of Vascular and Endovascular Surgery, Hospital S. Maria Misericordia, Perugia, Italy.
G
G
Parlani
Unit of Vascular and Endovascular Surgery, Hospital S. Maria Misericordia, Perugia, Italy.
E
E
Cieri
Unit of Vascular and Endovascular Surgery, Hospital S. Maria Misericordia, Perugia, Italy.
G
G
Simonte
Unit of Vascular and Endovascular Surgery, Hospital S. Maria Misericordia, Perugia, Italy.
L
L
Farchioni
Unit of Vascular and Endovascular Surgery, Hospital S. Maria Misericordia, Perugia, Italy.
G
G
Isernia
Unit of Vascular Surgery, Dept. of Cardiosciences, Hospital S. Camillo - Forlanini, Rome, Italy.
P
P
Cao
D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects*; D017544:Aortic Aneurysm, Abdominal / Q000401:mortality / Q000601:surgery*; D057867:Endoleak / Q000453:epidemiology; D057510:Endovascular Procedures; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D011183:Postoperative Complications / Q000453:epidemiology; D011184:Postoperative Period; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D014859:Warfarin / Q000009:adverse effects
D000925:Anticoagulants; D014859:Warfarin
Anticoagulation; Chronic anticoagulant; Conversion; EVAR; Endoleak; Endovascular abdominal aortic aneurysm repair; Reintervention; Warfarin