ECMO and Valve surgeries
Outcomes for patients requiring EMCO for PCCS refractory to
maximal-inotropic support and IABP support in patients who have
undergone valve surgery have been analysed across few
studies6, 22, 23. Rastan et
al 6 carried out a study with a cohort of 517 patients
who required ECMO for PCCS, of which 14.3% had undergone isolated valve
surgery whilst 16.8% had undergone valve surgery in combination with
CABG. This study found that post-operative ECMO requirement following
mitral valve surgery was associated with a reduced survival rate when
compared to other cardiac procedures (OR 2.08; 95% CI 1.20-3.63;P= 0.010). Similarly, Onorati et al 22found that in patients undergoing aortic valve replacement for aortic
stenosis, post-operative ECMO was a predictor for early death as it was
associated with a greater 30-day mortality rate (OR 9.8; 95% CI
1.1-63.4; P =0.029) when compared to that of other cardiac
procedures. However, this study has not yet reached its 5-year endpoint,
meaning the reported findings are only preliminary.
More recently, the institution of ECMO with a TandemHeart (TH)
percutaneous Left VAD i.e. a TH-ECMO, was found to provide stabilisation
of patient haemodynamics and hypoxaemia in two patients with acute
severe mitral regurgitation (MR) associated with cardiogenic failure and
hypoxaemia23. Acute severe MR associated with
cardiogenic shock and hypoxaemia can only be definitively managed with
mitral valve surgery, but usually this surgery is associated with high
peri-operative mortality rates of 25-46%, a poor outcome due to
patients being haemodynamically unstable and having refractory
hypoxaemia. In this case series, the institution of TH-ECMO resulted in
prompt stabilisation of the patients’ haemodynamics and hypoxaemia which
in turn allowed them to have early surgical intervention to manage their
acute severe MR. This case series shows the potential survival benefit
of ECMO for acute severe MR associated with cardiogenic shock and
hypoxaemia. However, it is important to note that the study only
reported on two cases making the sample size far too small for results
to be statistically significant and the patients would need to be
followed up for a lengthier period of time to ascertain the longer-term
outcomes associated with ECMO use. Outcomes in patients who had ECMO
having undergone valve surgery are summarised in Table 4.
Whilst post-operative requirement following valve surgery may be
associated with worse prognosis when compared to people who did not
require ECMO post-valve surgery, it again does improve survival for
refractory PCCS when compared to without the use of MCS. It is unclear
when the best time to institute ECMO in patients undergoing
valve-surgery would be but based on the studies analysed, ECMO
institution was associated with increased mortality when inserted
post-operatively6, 22. By contrast in the case series
which showed improved outcomes for patients undergoing mitral valve
surgery, ECMO was inserted pre-operatively allowing for haemodynamic
stabilisation of patients before they underwent surgery which would
suggest that ECMO may be most useful when inserted pre-operatively
alongside inotropes in these patients23. However, more
work on the potential survival benefit of ECMO use pre-operatively in
patients undergoing valvular surgery is needed as only one paper has
shown improved outcomes.