Comment on: Implication of pulmonary artery pressure monitoring during left ventricular assist device supports

We read with great interest the protocol design of HEMOVAD pilot study proposed by Veenis and colleagues, in which the feasibility and implication of pulmonary artery pressure (PAP) guidance with CardioMEMS in patients with left ventricular assist device (LVAD) is prospectively investigated. Our team recently demonstrated the implications of hemodynamic optimization in LVAD patients, with the observed association of abnormal hemodynamics and heart failure (HF) readmissions along with hemocompatibility-related adverse events. We fully agree that the PAP-guided adjustment of LVAD speed and medications would likely result in a reduction in HF readmissions, given the strongly positive studies previously published on the use of CardioMEMS in general HF cohorts. If the CardioMEMS device can be mechanistically linked to LVADs, the promising future of a smart pump, which can automatically adjust pump settings based on feedback from the CardioMEMS, would be a welcomed innovation. Unique hemodynamic challenges remain nevertheless in estimating the degree of ventricular unloading, as approximately half of clinically stable LVAD patients have decoupling between diastolic PAP and pulmonary capillary wedge pressure. Second, the assessment of right ventricular failure (RVF) by PAP monitoring alone might be challenging to accurately quantify. In patients with HF with reduced ejection fraction, out-of-proportion RVF can result from longstanding left-sided failure. However, the physiology of RVF during LVAD support is unique and complex. Increased right ventricular preload and anatomical changes experienced by the RV due to leftward shifting of the intraventricular septum both contribute maladaptive structure and function. Therefore, in patients with LVADs, RVF often exists in the absence of elevated left-sided filling pressures, and as a result, PAP monitoring alone might not be an appropriate method to assess for the presence of RVF. Central venous pressure monitoring in the context of PAP measurements would be the most optimal method to hemodynamically assess for RVF, although technology to accurately assess central venous pressure through minimally invasive yet durable means has yet to be developed. Using a combination of these assessments may also be useful in predicting potential LVAD-related adverse events, specifically gastrointestinal bleeding, which is known to be associated with RVF.