The following is a summary of “Pulmonary Capillary Recruitment Is Attenuated Post Left Ventricular Assist Device Implantation,” published in the July 2023 issue of the Cardiovascular Disease by Kim et al.
There is a limited understanding of pulmonary physiology and function following the implantation of a continuous flow-left ventricular assist device (CF-LVAD). Hence, this study aimed to examine the impact of CF-LVAD on pulmonary circulation by evaluating pulmonary capillary blood volume and alveolar-capillary conductance, alongside assessing pulmonary function in individuals suffering from heart failure. A total of seventeen individuals diagnosed with severe cardiac insufficiency who were planned to undergo CF-LVAD (continuous flow left ventricular assist device) placement using either HeartMate II or III from Abbott in Abbott Park, IL, or Heart Ware from Medtronic in Minneapolis, MN, were included in this research.
The patients underwent pulmonary function testing, assessing lung volumes and flow rates. Additionally, unique measures of pulmonary physiology were taken using a rebreathing technique to determine the diffusing capacity of the lungs for carbon monoxide (DLCO) and the diffusing capacity of the lungs for nitric oxide. These measurements were obtained before and 3 months after the implantation of a CF-LVAD. Following the implementation of a CF-LVAD, no significant alterations were observed in pulmonary function (P >0.05). In terms of lung diffusing capacity, there was no observed alteration in alveolar volume (VA) (P = 0.47); however, DLCO exhibited a significant decrease (P = 0.04).
After adjusting for ventilation-perfusion mismatch, the diffusing capacity of the lungs for carbon monoxide corrected for alveolar volume (DLCO/VA) tended to decrease (P = 0.08). In the context of the alveolar-capillary component, there was a significant decrease in capillary blood volume (Vc) (P = 0.04) and a tendency towards a reduction of alveolar-capillary membrane conductance (P = 0.06). Nevertheless, no alteration was observed in the alveolar-capillary membrane conductance/Vc (P= 0.92). In summary, following the implantation of a CF-LVAD, there is a notable reduction in Vc, likely attributed to pulmonary capillary derecruitment. This reduction ultimately leads to a decrease in lung diffusing capacity.