Heart Transplantation and Ventricular Assist Devices 
Heart transplantation and VAD patients face unprecedented challenges during the coronavirus disease 2019 (COVID-19) pandemic. These populations are at increased risk for acquiring COVID-19 infection. For heart transplant (HT) clinicians, the global pandemic has unique implications for patients, including those on the waiting list and transplant recipients.
Many centres have inactivated most of their HT waiting list, reserving active transplant status for only those patients with a presumed waiting list mortality of 1 to 2 weeks, thus limiting transplant to patients in tiers 1 or 2 of the new heart allocation policy. For listed patients who are hospitalized without a strict contraindication to durable left ventricular assist device implantation, LVAD as a bridge to transplant may be a viable strategy to get at-risk patients home and out of the hospital, minimizing their exposure to COVID-19. Left ventricular assist device implants should not be performed in elective cases because of resource constraints and potential for nosocomial infection.
The COVID-19 pandemic has had far-reaching implications for donor selection, organ procurement, waiting-list candidates, and transplant programmes.[30] Given the limitations of current testing and risks for asymptomatic transmission and infection, the HT community must be careful to select uninfected donors. As the pandemic continues to evolve, a centre’s transplant volume may require staged reduction to meet ITU bed, staffing, and medical equipment needs of the majority nontransplant population.
Important decisions have already appeared about actively listed patients. At any given time, a significant portion of patients are waiting in-hospital for HT. These patients are at higher risk for contracting the virus compared with others waiting at home. If they subsequently contract COVID-19, they are at risk for more severe infection because of their underlying health conditions, and risk delisting. For listed patients, transplant centres should highlight the waiting list mortality risk–benefit ratio and provide institutional updates.
Left ventricular assist device patients are affected by long‐standing cardiovascular diseases and subjected to variations of the normal cardiovascular physiology, thus requiring an even closer monitoring during the COVID‐19 outbreak. Potential deleterious effects of such a situation can be a delayed recognition of LVAD‐related complications, misdiagnosis of COVID‐19, and impaired social and psychological well‐being for patients and families.
LVAD patients are at increased risk of COVID‐19 infection for several reasons including most LVAD patients share the same risk factors for COVID‐19 infection and represent a very vulnerable population. These patients may manifest impaired immunity with increased risk for opportunistic infections[1] and activation or enhanced release of the inflammatory cytokines in COVID‐19 may augment the pre‐existing myocardial injury.[31]This “functionally immunocompromised state” increases susceptibility to complications from opportunistic infections.
Due to the general reorganization of healthcare resources in many hospitals, elective LVAD implantations have been reduced to allow for a higher availability of intensive care beds. Consequently, only patients classified as INTERMACS profile 1 and 2 are being considered for LVAD implantation.
With suspension of elective surgeries there is a potential morbidity and mortality increase in LVAD candidates waiting for implantation. Furthermore, there is a risk that the close connection between LVAD patients and their treating centres becomes looser with increased LVAD‐related complications and impaired well‐being. Patients undergoing HT/LVAD evaluation experiencing delays in listing and/or surgery can develop worsening nutritional, functional, or hemodynamic status. LVAD supported patients with the indication of bridge to transplantation might decline an offer to undergo heart transportation because of the fear of being infected from the donor or because they fear they will not get the optimal care from the overstressed healthcare system. Although delay of these procedures may not immediately affect clinical outcomes, there are important long-term and indirect implications for patients with HF.
While it is important to prevent COVID‐19, the routine care should not be discontinued to avoid severe complications both on clinical and psychological sides. Therefore, specific LVAD management algorithms should be implemented by every implanting and referring LVAD centre to aim for early diagnosis and treatment of COVID‐19 or LVAD complications.
COVID-19 can create a prothrombotic environment in some patients resulting in acute pulmonary embolism which may lead to acute right ventricular failure. Early recognition of right ventricular dysfunction and early intervention in patients who are hypotensive can be lifesaving. The Impella RP is a temporary heart pump that provides right ventricular circulatory support for patients who develop right side ventricular failure or decompensation caused by COVID-19 complications, including pulmonary embolus. For critically ill patients the Impella RP can be rapidly deployed in a matter of minutes using a minimally invasive technique in the cardiac catheterization laboratory or operating room.
In LVAD patients with COVID-19 developing right ventricular (RV) failure, medical management is the mainstay of therapy. Management should be focused on volume management and optimization of RV preload, reduction in RV afterload, improvement in the contractile state of the right ventricle and optimization of cardiac rhythm.[32] Regulation of the LVAD parameters is equally as important. Device speeds are chosen to obtain satisfactory haemodynamic goals without inappropriate left ventricular unloading, maintaining a rightward or neutral position of the interventricular septum and limiting cardiac output while maintaining an adequate mean arterial pressure. Vasodilatation or low systemic perfusion pressures may result in inappropriate unloading of the left ventricle and can contribute to leftward septal shift and suction events which impair LVAD output and RV function and may additionally trigger ventricular arrhythmias.
Serum lactate dehydrogenase (LDH) is a recognized biomarker for early recognition of lung injury and assessment of severity in COVID‐19.[18] In addition, a change in biomarker levels may be useful in grading COVID‐19 severity in LVAD patients. Increase in LDH in LVAD patients may raise specific concerns of haemolysis or LVAD thrombosis and concomitant stroke. Infection, itself, acts as a trigger for inflammatory response predisposing to pump thrombosis, ischaemic or haemorrhagic stroke in LVAD patients.[33]
In patients with acute hypoxaemic respiratory failure due to COVID‐19, prone ventilation may be effective in COVID‐19‐related severe ARDS (improving lung mechanics and gas exchange). However, it may be problematic in HF patients on LVAD support as prone positioning could result in complications such as compression of outflow graft and driveline, impaired venous return from increased thoracic pressure, hardware malpositioning, and worsening right ventricular (RV) haemodynamics. However, the probability of impaired functioning of the LVAD by rotation or mechanical compression seems to be very low.