Bridging with surgically placed microaxial left ventricular assist devices: a high-volume centre experience.

Objectives: The Impella 5.0 and 5.5 have largely superseded non-ambulatory temporary mechanical support devices; yet, clinical outcomes are predominantly limited to small series: this study presents the experience of a high-volume centre.

Methods: An institutional clinical registry was used to identify all patients with cardiogenic shock who underwent Impella 5.0 or 5.5 implantation from January 2014 to March 2022. The primary outcome was survival to device explantation.

Results: The study cohort comprised 221 patients, including 146 (66.1%) Impella 5.0 and 75 (33.9%) Impella 5.5 patients. The primary aetiology was non-ischaemic cardiomyopathy (50.7%, n = 112), ischaemic cardiomyopathy (23.1%, n = 51) and acute myocardial infarction (26.2%, n = 58). Patients were prospectively classified according to strategy as bridge to transplant (47.5%, n = 105), bridge to durable device (13.6%, n = 30) or bridge to recovery (38.9%, n = 86). Patients were predominantly Interagency Registry for Mechanically Assisted Circulatory Support profile 1 or 2 (95.0%, n = 210). The median bridging duration was 14 (range 0-137) days. Device exchange, Ischaemic stroke and ipsilateral arm ischaemia occurred in 8.1% (n = 18), 2.7% (n = 6) and 1.8% (n = 4) of patients, respectively. Compared to the 75 most recent Impella 5.0 patients, Impella 5.5 patients (n = 75) had lower rates of device exchange (4.0%, n = 3 vs 13.3%, n = 10, P = 0.04). Overall, 70.1% (n = 155) of patients survived to Impella explantation.

Conclusions: The Impella 5.0 and 5.5 provide safe and effective temporary mechanical support in appropriately selected patients with cardiogenic shock. The newer device generation may have a lower requirement for device exchange as compared to its predecessor.