16.1 Evidence review
All patients with non-ischaemic cardiomyopathy should be treated as potential bridge-to-recovery candidates. Despite having the potential effect of myocardial hypertrophy, the addition of the beta-2 adrenergic agonist clenbuterol to standard HF therapy has not been shown to be effective in promoting recovery. At the time of LT-MCS implantation, potential myocardial recovery and device weaning should be anticipated [71]. Significant heart valve diseases that will not improve after LT-MCS implantation should be addressed, and the prevention of adhesions that facilitate device explantation should be considered [71]. Myocardial tissue that is typically retrieved during apical coring should undergo histological processing to identify treatable forms of myocarditis and assess the possibility of myocardial recovery.
To identify myocardial recovery, a standardized screening protocol should be used [393]. Accordingly, patients should undergo routine echocardiographic screening during outpatient visits at regular intervals. Specifically, ventricular function, shape and dimensions should be assessed in a quantitative manner [393]. In the setting of sinus rhythm and complete ventricular remodelling (left ventricular end-diastolic diameter ≤55 mm; left ventricular ejection fraction ≥45%), patients should be evaluated with echocardiography at reduced pump speed for weaning eligibility. If the findings are favourable and sustained, the patients may progress to invasive testing [393], which may include right heart catheterization with the pump speed reduced to the lowest possible level for 15 min. Some centres have stopped using the LVAD and balloon-occluded the outflow graft [406, 407]. Thresholds for device explantation are cardiac index >2.6 l/min/m2, pulmonary artery wedge pressure (mean) <16 mmHg, right atrial pressure (mean) <10 mmHg [393, 406]. Adequate anticoagulation must be ensured.
Different strategies for LT-MCS explant have been described. Depending on the individual patient’s situation and surgical preference, isolated removal of the pump and driveline or complete device explantation might be appropriate [408]. In patients in critical condition or patients with a high surgical risk (e.g. frailty), ligation of the outflow graft through the subxyphoidal approach or coiling in the catheterization laboratory with cutting of the driveline below the skin without pump explantation might be advisable (decommissioning) [409]. However, this technique necessitates lifelong anticoagulation because the inflow cannula remains in the ventricle. Complete system explantation should be the standard approach for patients with device infection [408].
After LT-MCS explant for myocardial recovery, patients should receive lifelong treatment by HF specialists to target medical therapy and identify recurrence of HF.