Aortic valve surgery and left ventricular assist device: lights and shadows. Letter regarding the article ‘Survival following a concomitant aortic valve procedure during left ventricular assist device surgery: an ISHLT Mechanically Assisted Circulatory Support (IMACS) Registry analysis’

We read with interest the paper by Veenis et al.1 concerning the effect on outcome of an aortic valve (AoV) procedure during left ventricular assist device (LVAD) implantation in patients enrolled in the ISHLT Mechanically Assisted Circulatory Support (IMACS) Registry. They conclude that concomitant aortic surgery represents per se an independent predictor of mortality. Such finding is not surprising, since we can imagine that this population in whom aortic disease might participate in heart failure genesis too is basally more seriously ill. Nevertheless, we would like to ask some enlightenments about corollary results: if the harmfulness of a mild insufficiency treatment is comprehensible, the fact that survival in patients with moderate-to-severe aortic regurgitation fails to be affected by surgical abstention or correction appears poorly perceptive and almost contrasting, considering its deleterious haemodynamic influence on ventricular unloading and assistance functioning.2 Moreover, LVAD pumping induces progressive ascending aorta dilatation (especially in proximal outflow implantation), a condition potentially capable of exacerbating a pre-existent AoV regurgitation enhancing a detrimental short-circuiting ventricular loop.3 Did some patients experience aneurysm development? Taking into account these elements, we believe that at least a slight negative effect on mid/long-term outcome should have arisen, since long-lasting AoV incompetence increased intolerance is reported in right ventricular failing LVAD recipients2 (nearly 40% of the population if we include both moderate and severe dysfunctions): how do the authors explain such apparent discrepancy? Another issue deserving attention is why the largest survival gap occurs in the first three postoperative months: in our opinion, this reflects a relationship with surgical trauma and prolonged cross-clamp time which could play a detrimental effect onto right ventricular performance. Furthermore, physiologically speaking, we may argue that after the failing-aortic group becomes used to the new haemodynamic situation a turning point is passed. Do the authors agree with this interpretation? How many patients underwent preoperative Impella support? In particular, Impella 5.0 can sometimes result in AoV damage4 whose entity may be underestimated prior to LVAD implantation, contributing to the big extent of significant aortic regurgitation diagnosis made in the operating room requiring an unplanned procedure with subsequent increased risk of adverse outcome. A last striking element stands out: more than 12% of deaths in AoV repair patients are attributable to major infections, almost the double compared to the replacement group: since in this procedure no or scarce additional material is employed and endocarditis rate is known to be negligible,5 what rational justification may be advocated?