Influence of Stent-Graft Fabrics on Aortic Stiffness after EVAR: Preliminary Results of a Prospective Cohort-Study

BACKGROUND: Endovascular aneurysm repair (EVAR) is a safe and durable treatment for aortic diseases but its effect on cardiovascular efficiency it is not well known yet. According to literature, EVAR leads to a worsening of Aortic Stiffness (AoS) with possible cardiac function modifications over time. The aim of the study was to evaluate the possible effect of different endograft fabric on AoS. METHODS: Patients candidate to EVAR were enrolled. Carotid-femoral Pulse Wave Velocity (cf-PWV) and echocardiography data were collected at preoperative time and after one year. Principal data assessed were: cardiac geometry data, arterial elastance (Ea), ventricular elastance (Ees) and their coupling (Ea/Ees), ratio of early ventricular filling to atrial systole (E/A) and ratio of trans-mitral early velocity peak to early diastolic mitral anulus velocity (E/E'). Systolic (SBP) and diastolic blood pressure (DBP) were evaluated. All data were compared between two groups: endograft with expanded polytetrafluoroethylene (ePTFE) and with polyester. RESULTS: Forty-two patients were recruited: fourteen of ePTFE-group and twenty-eight of Polyester-group. Thirty-five patients ended the follow-up. Cf-PWV (13.4 +/- 3.7 vs. 17.6 +/- 7; P=0.014) and Ea (1.4 +/- 0.3 vs. 1.8 +/- 0.4; P=0.007) increased significantly only in polyester-group. SBP increased in ePTFE-group (127.9 +/- 17 vs. 157.1 +/- 20.3; P=0.001) and in Polyester-group (137.9 +/- 14.2 vs. 152.4 +/- 15.5; P=0.001) and DBP increased in ePTFE-group (68.6 +/- 8.4 vs. 77.9 +/- 5.8; P=0.004). The E/A ratio decreased significantly in ePTFE-group (0.9 +/- 0.3 vs. 0.7 +/- 0.2; P=0.031) and in Polyester-group (0.8 +/- 0.2 vs. 0.7 +/- 0.2; P=0.003). Ventricular elastance grew of 0.3 mmHg/ml/m(2) in ePTFE-group. Data regarding cardiac geometry did not change significantly. CONCLUSIONS: Aortic stiffness increases after EVAR, mostly in patients with a polyester-covered device. Both groups show index of possible initial diastolic disfunction. Further investigation is needed to validate our results.