Pressure-dimension index: A novel “morphologic-functional” index of
right ventricle that predicts short-term survival after left ventricular
assist device implantation
Abstract
Background: Right ventricular failure (RVF) after left ventricular
assist device (LVAD) implantation is a major cause of postoperative
morbidity and mortality. Despite the availability of multiple imaging
parameters, none of these parameters had adequate predictive accuracy
for post-LVAD RVF. Aim: To study whether right ventricular
pressure-dimension index (PDI), which is a novel echocardiographic index
that combines both morphologic and functional aspects of the right
ventricle, is predictive of post-LVAD RVF and survival. Methods: 49
cases that underwent elective LVAD implantation were retrospectively
analyzed using data from an institutional registry. PDI was calculated
by dividing systolic pulmonary artery pressure to the square of the
right ventricular minor diameter. Cases were categorized according to
tertiles. Results: Patients within the highest PDI tertile
(PDI>3.62 mmHg/cm2) had significantly higher short-term
mortality (42.8%) and combined short-term mortality and definitive RVF
(50%) compared to other tertiles (p<0.05 for both, log-rank p
for survival to 15th day 0.014), but mortality was similar across
tertiles in the long-term follow up. PDI was an independent predictor of
short-term mortality (HR:1.05–26.49, p=0.031) and short-term composite
of mortality and definitive RVF (HR:1.37–38.87, p=0.027). Conclusions:
Increased PDI is a marker of an overburdened right ventricle. Heart
failure patients with a high PDI is at risk for short-term mortality
following LVAD implantation.