1. Introduction
Despite improvements in patient selection and management algorithms,
right ventricular failure (RVF) remains as a major cause of
postoperative morbidity and mortality following left ventricular assist
device (LVAD) implantation and seen in up to 13% - 51% of patients,
depending on the definition of RVF (1,2). Several clinical, imaging,
laboratory and catheterization parameters are available to predict
postoperative RVF with variable diagnostic accuracy (3). Of those,
transthoracic echocardiography (TTE) plays a pivotal role for
preoperative evaluation of the right ventricle (RV) as this is a widely
available modality that could be easily utilized at bedside and it
allows a comprehensive evaluation for the structural and functional
alterations in the RV (3). Numerous echocardiographic parameters were
studied as a possible “gold-standard” method to predict post-LVAD RVF,
though these variables rarely performed well beyond their initial study
cohort. A recent meta-analysis that included available echocardiographic
parameters has concluded that a qualitative analysis of the RV remains
as the best predictor of postoperative outcomes (3).
A major shortcoming of all available standalone parameters is that the
variable in question either evaluates structural (i.e. RV diameter or RV
to left ventricle (LV) ratio) or hemodynamic / functional (tricuspid
annular excursion, pulmonary artery pressure) changes in the RV. As a
result, other aspects of the RV structure or function is omitted and
therefore the parameter studied does not fully reflect alterations in
the RV. As such, an index that combines both structural and
hemodynamic/functional changes in the RV could theoretically be more
useful over existing parameters to predict post-LVAD RVF.
In the present analysis, we aimed to investigate the usefulness of RV
pressure-dimension index (PDI), a novel index that reflects both the
structural and functional changes in the RV, to predict post-LVAD
short-term and long-term mortality and RV failure. In addition,
correlation of PDI with available parameters of RV structure and
function was also investigated.