Lactate Dehydrogenase Levels after aortic valve replacement: What do they tell us?

Introduction: Lactate dehydrogenase (LDH) is a standard postoperative marker for hemolysis in the presence of paravalvular leakage (PVL) after aortic valve replacement (AVR). LDH is elevated in certain valves by a fluttering phenomenon. Previous studies suggested a correlation between microparticles (MP) and LDH elevation after AVR. We analyze the postoperative relevance of LDH after AVR with transapical transcatheter aortic valves (TA-TAV) or rapid deployment valves (RDV).

Method: We retrospectively analyzed the data from patients who received an AVR with RDV and TA-TAV groups between 2015-2018. We compared PVL and LDH levels before and after surgery, transvalvular gradients, heart block that required pacemaker implantation, and 30-day mortality.

Results: 138 consecutive patients were selected: 79 patients in the RDV group (37 Sorin Perceval valve, 42 Edwards Intuity valves) and 59 in the TA-TAV group (Edwards Sapien valve). TA-TAV-group were older (median 10 years) and with higher incidence of PVL (Odds ratio 11, 95% CI from 2.5 - 73.2, p-value 0.04)). TA-TAV-Group showed lower levels of LDH despite higher rates of PVL while the Perceval valve trended towards higher LDH values. Additionally, the RDV group showed an increased arrhythmia profile (p=0.0041) although the results show lower incidence in pacemaker implantation (95 % CI 0.05 - 1.65, p=0.635). 30-day mortality was similar between groups.

Conclusion: Our data do not support the association between hemolysis and PVL despite elevated LDH in suture-free valves. LDH could be a marker of extreme heart muscle output or fluttering phenomena and not a marker of hemolysis after sutureless AVR.