Invasive Hemodynamic Red Flags To Left Ventricular Assist Device Implantation

J INVASIVE CARDIOL 2020;32(12):E375-E376. 

Key words: cardiac imaging, echocardiography, positron emission tomography

Right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation occurs in approximately 20% of patients, and is associated with significant morbidity and mortality. Available risk scores are complex, and combine laboratory, echocardiographic, clinical, and invasive hemodynamic parameters; they are modest at best at predicting postimplant RVF. Reliable identification of patients at high risk for RVF upfront using simple and easy-to-remember data is key. We present a case demonstrating the valuable information that an invasive hemodynamic assessment can provide, with focus on the pressure tracings, and 4 parameters identified as hemodynamic red flags to LVAD implant.

A 51-year-old man with suspected cardiac sarcoid presented for advanced heart failure therapy evaluation. Imaging showed biventricular systolic dysfunction and right > left heart chamber enlargement (Figure 1A), as well as diffuse fluoro-deoxyglucose uptake in all chambers (Figure 1B).

Right heart catheterization revealed elevated and equalized pressures, narrow right ventricular and pulmonary artery pulse pressure, no pulmonary hypertension, prominent right atrial Y descent (Figure 2), and a low cardiac index of 1.55 L/min/m². Hemodynamic red flags are shown in Table 1. This suggested a diseased right ventricle (myopathic and not expected to improve with LV unloading) at high risk for post-LVAD severe RVF. The patient was urgently listed, and underwent successful cardiac transplantation. The explanted heart had diffuse non-necrotizing granulomata, consistent with sarcoidosis. 

No single hemodynamic variable reliably predicts post-LVAD RVF. A comprehensive approach is needed to understand RV loading conditions and contractility. Pulmonary artery pulsatility index (PAPi) incorporates the pulmonary artery pulse pressure and right atrial pressure (surrogates for contractility and RV loading conditions, respectively). A low right atrial pressure to pulmonary capillary wedge pressure ratio usually indicates RV dysfunction due to elevated left-sided filling pressures. RV stroke work index assesses RV contractility. A low value suggests impaired systolic force, resulting in a low pulmonary artery pressure. A deeper nadir of the right atrial Y descent relative to the X descent indicates a less distensible RV, unable to maintain a low central venous pressure without compromising RV output.

From the University of Texas Southwestern Medical Center, Dallas, Texas.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

The authors report that patient consent was provided for publication of the images used herein.

Manuscript accepted March 11, 2020.

Address for correspondence: Faris G. Araj, MD, Professional Office Bldg. 2 Suite 600, 5939 Harry Hines Blvd, Dallas, TX 75390-9252. Email: faris.araj@utsouthwestern.edu