| Autor: |
Hydren JR; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah., Gifford JR; Department of Exercise Sciences, Brigham Young University, Provo, Utah., Jarrett CL; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah., Park SH; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah., Shields KL; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah., Broxterman RM; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah., Kithas AC; Department of Internal Medicine, University of Utah, Salt Lake City, Utah., Bisconti AV; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah., Thurston TS; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah., Ratchford SM; Department of Health and Exercise Science, Appalachian State University, Boone, North Carolina., Wray DW; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.; Department of Internal Medicine, University of Utah, Salt Lake City, Utah., Stehlik J; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah., Selzman CH; Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah., Drakos SG; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah., Richardson RS; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.; Department of Internal Medicine, University of Utah, Salt Lake City, Utah. |
| Abstrakt: |
Vascular function is further attenuated in patients with chronic heart failure implanted with a continuous-flow left ventricular assist device (LVAD), likely due to decreased arterial pulsatility, and this may contribute to LVAD-associated cardiovascular complications. However, the impact of increasing pulsatility on vascular function in this population is unknown. Therefore, 15 LVAD recipients and 15 well-matched controls underwent a 45-min, unilateral, arm pulsatility treatment, evoked by intermittent cuff inflation/deflation (2-s duty cycle), distal to the elbow. Vascular function was assessed by percent brachial artery flow-mediated dilation (%FMD) and reactive hyperemia (RH) (Doppler ultrasound). Pretreatment, %FMD (LVAD: 4.0 ± 1.7; controls: 4.2 ± 1.4%) and RH (LVAD: 340 ± 101; controls: 308 ± 94 mL) were not different between LVAD recipients and controls; however, %FMD/shear rate was attenuated (LVAD: 0.10 ± 0.04; controls: 0.17 ± 0.06%/s -1 , P < 0.05). The LVAD recipients exhibited a significantly attenuated pulsatility index (PI) compared with controls prior to treatment (LVAD: 2 ± 2; controls: 15 ± 7 AU, P < 0.05); however, during the treatment, PI was no longer different (LVAD: 37 ± 38; controls: 36 ± 14 AU). Although time to peak dilation and RH were not altered by the pulsatility treatment, %FMD (LVAD: 7.0 ± 1.8; controls: 7.4 ± 2.6%) and %FMD/shear rate (LVAD: 0.19 ± 0.07; controls: 0.33 ± 0.15%/s -1 ) increased significantly in both groups, with, importantly, %FMD/shear rate in the LVAD recipients being restored to that of the controls pretreatment. This study documents that a localized pulsatility treatment in LVAD recipients and controls can recover local vascular function, an important precursor to the development of approaches to increase systemic pulsatility and reduce systemic vascular complications in LVAD recipients. |
