Vascular Remodeling on Intermediate and Long-Term left Ventricular Assist Device (LVAD) Support Under Nonpulsatile versus Pulsatile Blood Flow

Background: Although long-term LVAD support becomes more and more common in end-stage heart failure patients, so far, little is known about the functional and morphological changes in the vascular system caused by nonpulsatile blood flow. There is evidence that prolonged pulselessness affects the functional and structural characteristics of the vascular system.

Methods: A total of 59 patients on continuous-flow (CF) LVAD-support were included in the study between 15 and 2455 days after implantation. Among them, 30 patients presented with nonpulsatile flow, whereas 29 patients were diagnosed with pulsatile flow. The right brachial artery was sonographically examined in all patients. Pulsatility was defined by noninvasively estimated blood pressure amplitude, echocardiographically assessed opening of the aortic valve as well as pulsatile flow determined by vascular duplex. Dimensions of vessel wall layers and lumen diameters were estimated such as absolute and relative intima and media thickness. Intima and media areas were calculated. Results were analyzed using the Students t-tests and Spearman-Rho tests.

Results: LVAD patients with nonpulsatile arterial flow showed a trend towards a larger intima area compared to patients with pulsatile flow (5.39 ± 0.34 vs. 4.94 ± 0.26 mm²; p = ns). With increasing time on support, there was a tendency for the intima thickness to increase in patients with nonpulsatile flow, whereas in patients with pulsatile flow, there was a tendency for the intima thickness to decrease. The relative intima thickness in relation to the total vessel wall correlated significantly with the duration of implantation (r=0.389; p = 0.034).

Conclusion: Long-term nonpulsatile flow during CF-LVAD support leads to a significant increase in relative intima thickness over time. Possible implications are the consecutive development of atherosclerosis as well as the increasing fragility of the arterial vessels, with an impact on subsequent surgical procedures, such as heart transplantation. Further histological studies are required to assess long-term morphological changes

Publication History

Article published online:
13 February 2024