Outflow graft obstruction after left ventricular assist device implantation: a retrospective, single-centre case series

Aims: Outflow graft obstruction is a poorly described complication following left ventricular assist device (LVAD) surgery. We sought to define the incidence of LVAD outflow graft obstruction and assess clinical outcomes with a percutaneous treatment strategy. Methods and results: From January 2012 to October 2020, 322 patients with LVAD were managed at our institution. Patients with LVAD outflow graft obstruction were identified by cardiac computed tomography with angiography and invasive haemodynamic assessment and were subsequently treated with percutaneous intervention. Poisson regression was used to analyse time-dependent differences in the incidence of LVAD outflow graft obstruction. Kaplan–Meier analysis was used to estimate survival. Twenty patients (6.2%) developed haemodynamically significant LVAD outflow graft obstruction at a rate of 0.03 events per patient-year. Outflow graft obstruction presented a median of 33 (26–49) months after surgery. Patients presented with low estimated LVAD pump flow (95%), heart failure (90%), or both (85%), and 59% developed cardiogenic shock prior to intervention. The most common aetiology identified by cardiac computed tomography with angiography was external compression of the outflow graft (78%). On presentation, the median peak gradient in the outflow graft was 78 (64–100) mmHg. Outflow graft stenting was 100% successful with no in-hospital mortality, and it reduced the peak outflow graft gradient to 10 (2–17) mmHg (P < 0.001). Outflow graft stenting was durable with two patients (10%) requiring a repeat procedure over a median follow-up of 13 (7–20) months and did not impact survival. Conclusions: Left ventricular assist device outflow graft obstruction is a relatively common and underappreciated cause of recurrent heart failure and LVAD dysfunction. Outflow graft stenting can be achieved with low morbidity and provides a long-term solution to this complication.