Does Left Ventricular Apical Histology Taken During Ventricular Assist Device Insertion Alter Diagnosis in Severe Heart Failure Patients

Background: Ventricular assist devices (VAD) are established therapy as bridge to cardiac transplantation (BTT) in patients with severe heart failure (HF). Heartware® VAD (HVAD) insertion offers the unique ability to correlate core biopsy myocardial histologic changes with clinical diagnosis prior to transplantation. Methods: A retrospective analysis of medical and pathologic records in 45 patients who received HVAD insertion as BTT between November 2011-February 2017 was performed. 39 patients proceeded to cardiac transplantation. Histology from explanted hearts were available for comparison with LV core biopsies obtained at HVAD implantation. HF aetiology was categorised. Medical records were reviewed to ascertain if histology impacted upon diagnosis or management after HVAD insertion. Results: Histology from 43 LV core biopsies were available. The aetiology of HF based on LV core biopsies were: DCM (n = 23; 53%) followed by ICM (n = 9; 21%), peri-partum cardiomyopathy (n = 3; 7%), chemotherapy induced CMP (n = 2; 5%), sarcoidosis (n = 1; 4%), hypertrophic cardiomyopathy (n = 1; 2%), giant cell myocarditis (n = 1; 2%) and possible autoimmune cause (n = 2; 5%). All HVAD histology results were concordant with clinical diagnosis. When compared to the histology from 39 explanted hearts at time of transplantation, 37/39 (95%) were in concordance. Of the 2 discordant cases one had DCM and non-specific inflammatory changes on HVAD histology but the explanted heart demonstrated granulomas consistent with sarcoidosis. The second partially discordant DCM case revealed mild lymphocytic myocarditis with background features of DCM. Conclusion: There was excellent concordance between clinical diagnosis of heart failure and LV histology at HVAD insertion and heart explant post transplantation.