Heart Transplant Under Sizing is Associated with Adverse Early Hemodynamics but Does Not Affect Survival

Abstract

Purpose Guidelines recommend against significant > 30% size mismatch in heart transplantation (HT). However this approach is controversial in general and not well established in patients with left ventricular assist devices (LVAD). We investigated the effect of size mismatch on hemodynamics (HD) post HT and one year survival. Methods Retrospective analysis of HT patients from 04/07 to 09/17. Donor information was retrieved from UNOS Donor Net database. Recipients were divided in three groups based on Recipient to Donor Weight Ratio (RDWR): (1) in range (0.7-1.3); (2) undersized donor heart (>1.3); and oversized donor heart (<0.7). Post-HT outcomes were analyzed including HD at 1 week, 1 month and 6 months. Subgroup analysis for LVAD patients was done. Results 288 consecutive patients were identified (mean age 53±11 years, 76% male) and grouped based on RDWR: 18 oversized (0.55 ± 0.10), 191 in range (1.01 ± 0.16) and 79 undersized (1.53 ± 0.19) p<0.001. Importantly the recipient-to-donor left ventricular end diastolic diameters ratios were similar between the groups (Table). Despite under sizing there were was no significant difference in 1-year survival between the groups (Figure). The percentage of undersized HT was almost identical between the overall cohort and LVAD subgroup (27.4 and 27.5%). Notably patients with under sizing had significantly higher filling pressures and lower cardiac index 1 week post HT (Table). The same results were applicable to patients bridged with LVAD. Conclusion HT under sizing negatively affects early hemodynamics post HT but does not affect 1-year survival in the overall cohort and LVAD patients. Guidelines recommend against significant > 30% size mismatch in heart transplantation (HT). However this approach is controversial in general and not well established in patients with left ventricular assist devices (LVAD). We investigated the effect of size mismatch on hemodynamics (HD) post HT and one year survival. Retrospective analysis of HT patients from 04/07 to 09/17. Donor information was retrieved from UNOS Donor Net database. Recipients were divided in three groups based on Recipient to Donor Weight Ratio (RDWR): (1) in range (0.7-1.3); (2) undersized donor heart (>1.3); and oversized donor heart (<0.7). Post-HT outcomes were analyzed including HD at 1 week, 1 month and 6 months. Subgroup analysis for LVAD patients was done. 288 consecutive patients were identified (mean age 53±11 years, 76% male) and grouped based on RDWR: 18 oversized (0.55 ± 0.10), 191 in range (1.01 ± 0.16) and 79 undersized (1.53 ± 0.19) p<0.001. Importantly the recipient-to-donor left ventricular end diastolic diameters ratios were similar between the groups (Table). Despite under sizing there were was no significant difference in 1-year survival between the groups (Figure). The percentage of undersized HT was almost identical between the overall cohort and LVAD subgroup (27.4 and 27.5%). Notably patients with under sizing had significantly higher filling pressures and lower cardiac index 1 week post HT (Table). The same results were applicable to patients bridged with LVAD. HT under sizing negatively affects early hemodynamics post HT but does not affect 1-year survival in the overall cohort and LVAD patients.