Effects of the left ventricular assist device on the compliance and distensibility of the carotid artery

We investigated the impact of continuous-flow left ventricular assist devices (LVAD) on the carotid elastic properties. Carotid artery parameters (diameter distensibility (DD), cross-sectional distensibility (CSD), diameter compliance (DC), cross-sectional compliance (CSC), and incremental elastic modulus (IEM)) were measured in a cross-sectional study using a standard ultrasound with a 10-MHz linear array probe. Measurements (mean ± SEM) were made in separate groups at various clinical time points: prior to LVAD surgery (baseline; 13 male/3 female; age 48 ± 3 years), 1 week following LVAD placement (acute; 12 male/2 female; age 47 ± 3 years), approximately 24 weeks following LVAD surgery (chronic; 13 male/2 female; age 52 ± 3 years), and in a group of healthy subjects (controls; 9 male/1 female; age 51 ± 4 years). Distensibility properties were lower (P < 0.05) in the acute (DD 2.3 % ± 0.4 %; CSD 4.7 % ± 0.8 %) and chronic (DD 2.2 % ± 0.4 %; CSD 4.5 ± 0.9 %) compared with the baseline (DD 5.9 % ± 0.7 %; CSD 12.2 % ± 1.5 %) and control (DD 5.8 % ± 0.6 %; CSD 11.9 % ± 1.3 %) groups. Compliance properties were lower (P < 0.05) in the chronic (DC 4.4 ± 0.7 mm/mmHg × 10^-3; CSC 1.2 ± 0.2 mmHg^-1 × 10^-3) compared with acute (DC 9.0 ± 1.6 mm/mmHg × 10^-3; CSC 2.6 ± 0.4 mmHg^-1 × 10^-3) and baseline (DC 11.1 ± 1.1 mm/mmHg × 10^-3; CSC 3.3 ± 0.4 mmHg^-1 × 10^-3) groups. The compliance properties in the control (DC 8.3 ± 0.8 mm/mmHg × 10^-3; CSC 2.4 ± 0.2 mmHg ^-1 × 10^-3) group were not different from any of the patient groups. The IEM was higher (P < 0.05) in the chronic (6908 ± 1269 mmHg) compared with acute (2739 ± 412 mmHg), baseline (1849 ± 177 mmHg), and control (2349 ± 241 mmHg) groups. Chronic continuous-flow LVAD support is associated with lower carotid artery compliance and distensibility, which may place further strain on the left ventricle.