Date Published: June 14, 2018
Publisher: Public Library of Science
Author(s): Bartosz Symonides, Andrzej Śliwczyński, Zbigniew Gałązka, Jarosław Pinkas, Zbigniew Gaciong, Carlos Zaragoza.
The aim of the study was to compare short and long-term mortality and readmissions in patients with non-ruptured abdominal aortic aneurysm (AAA) treated with endovascular aortic repair (EVAR) or open aneurysm repair (OAR).
Retrospective survival analysis based on prospectively collected medical records of the national Polish public health insurer.
In the National Health Fund database we identified all patients who underwent elective open or endovascular treatment of AAA between January 1st 2011 and March 22nd 2016. The data on mortality, selected concomitant diseases and readmissions were collected. A total of 7805 patients (mean age 70.9±8.1 yrs, 85.8% males) underwent OAR (n = 2336) or EVAR (n = 5469). A median follow up was 27.5 months (IQR range 10.0–38.4 months).
The primary outcome variable was all-cause mortality, secondary outcomes included 30-day mortality and readmissions. Kaplan–Meier (K-M), Cox proportional-hazards and propensity score analyses were performed for primary and secondary outcomes adjusting for repair type of AAA (OAR vs. EVAR), age, sex and concomitant diseases.
EVAR patients had higher all-cause mortality (6.4% vs. 4.6% P = 0.002, adjHR 1.34, 95%CI 1.07–1.67, P = 0.010) compared with OAR. The mortality risks for OAR patients decreased below those for EVAR patients after 9.9 months. Of all the tested confounding factors only age independently and significantly influenced long-term mortality. Readmissions occurred more often in EVAR than in OAR (16.5% vs. 8.4% P<0.001, adjHR 2.15, 95%CI 1.84–2.52, P<0.001) independently from other covariants. Survival and readmissions Kaplan-Meier curves remained statistically different between OAR and EVAR patients after propensity score matching. Survival benefit of EVAR over OAR disappeared early during the first year after procedure, particularly in patients below 70 years of age, accompanied by an increased frequency of readmissions of EVAR patients. Our data suggest re-evaluation of the strategy for AAA management in vascular units in the country.
Abdominal aortic aneurysm (AAA) is a common disease in the Western population, with a prevalence of 2% to 5% in men ≥ 65 years of age, with very high mortality rates related with AAA rupture . Recent Polish epidemiological studies revealed the prevalence of abdominal aortic aneurysm similar to other European countries . Endovascular repair of abdominal aneurysm (EVAR) has become the method of choice over open aneurysm repair (OAR) due to lower perioperative mortality found in randomized clinical trials (RCTs) [3,4]. However data from these trials revealed that survival advantage of EVAR disappears during long-term follow-up [5,6]. In the DREAM study two years after randomization the cumulative survival rates were 89.6% for OAR and 89.7% for EVAR. The advantage of EVAR over OAR regarding aneurysm-related death (5.7% vs. 2.1%) was entirely accounted for by events occurring in the perioperative period, with no significant difference in subsequent aneurysm-related mortality . In EVAR-1 study 4 years after randomization, all-cause mortality was similar in the two groups (about 28%), despite the fact that there was a persistent reduction in aneurysm-related deaths in the EVAR group (4% vs. 7%, p = 0.04). The proportion of patients with postoperative complications within 4 years of randomization was 41% in the EVAR group and 9% in the OAR group .
We used data collected by the National Health Fund (NHF), the only public and obligatory health insurer in Poland. In case of medical procedures related to the treatment of AAA, the NHF is practically the single payer that signs contracts with public and private healthcare providers.
A total of 7 805 patients underwent repair of AAA using open or endovascular method and were followed for a median of 27.5 months (IQR 10.0–38.4 months). EVAR was performed in 5469 of patients (70.1%) who were significantly older, with a higher incidence of concomitant disorders, as compared with 2336 patients treated with OAR. The demographic data are presented in Table 1, percentage of EVAR in consecutive years of study on S1 Fig.
Our analysis of 7805 patients treated for AAA with a median follow up 27.5 months revealed survival benefit of EVAR over OAR disappeared early during the first year after the procedure.
Our large-population based study of patients treated for unruptured AAA revealed significantly higher late mortality after EVAR than after OAR, particularly in patients below 70 years of age. Compared to other studies we have found lower short-term and long-term mortality in our cohort, which suggests lower cardiovascular risk in treated population. However, contrary to other studies, survival benefit of EVAR disappeared early during the first year after the procedure, accompanied by an increased frequency of readmissions of EVAR patients. Taking into consideration significant variations in the management of AAA, in particular low compliance with EVAR device guidelines  our data necessitate re-evaluation of the strategy for AAA management in vascular units in the country.