Abstract
Background
Inducible left ventricular outflow tract obstruction (LVOTO) is not infrequently encountered in liver transplant (LT) candidates undergoing cardiac workup. While the impact of LVOTO on adverse cardiovascular haemodynamics is well reported, it is unclear whether it predisposes to perioperative cardiovascular complications following LT.
Purpose
To investigate the effect of inducible left ventricular outflow tract obstruction on perioperative cardiovascular complications in a modern cohort of liver transplant patients.
Methods
Consecutive patients undergoing dobutamine stress echocardiography (DSE) were evaluated from a quaternary LT centre between 2010 and 2017. Inducible LVOTO was defined as LVOT gradient ≥36mmHg. Perioperative major adverse cardiovascular events (MACE) at 30 days and all-cause death were recorded from a prospectively maintained transplantation database and augmented by electronic medical record review.
Results
We evaluated 560 patients who underwent DSE as part of a workup for LT. Of these, 319 progressed to transplant. Inducible LVOTO was observed in 68 patients (21.3%). A higher baseline cardiac output (7.7 L/min vs 7.0 L/min, p=0.002) predicted for development of inducible LVOTO. Seventy-seven patients (4.1%) experienced a MACE including five deaths, 19 cases of heart failure, 11 cardiac arrests, 10 acute coronary syndromes and 46 cases of arrhythmias (VT/AF). Overall MACE occurred in 17/68 patients (25.0%) with LVOTO and 60/251 patients (23.9%) without LVOTO (p=0.85). However, there was a significantly increased risk of resuscitated perioperative cardiac arrest in patients with LVOTO (7.4% vs 2.4%, p=0.04). Patients with LVOTO also required significantly greater volumes of fluid intra-operatively (8.37L vs. 6.71L, p=0.043).
Cardiac Arrest in LT Patients with LVOTO
Conclusions
Inducible LVOTO is a frequent finding occurring in 21.3% of LT candidates. Despite higher intraoperative fluid resuscitation, LVOTO increased the risk of a perioperative cardiac arrest. Further studies are required to confirm these findings and to assess whether patients with LVOTO undergoing liver transplantation may benefit from heightened perioperative surveillance.
Norepinephrine-associated left ventricular outflow tract obstruction and systolic anterior movement
