Abstract
Introduction
Left Ventricular Assist Devices (LVAD) improve survival and functional capacity in patients with advanced heart failure (HF). However, there are potential complications.
Purpose
We sought to determine parameters of exercise intolerance in a group of patients with the HeartWare LVAD (HVAD) compared to a group of HF patients.
Methods
This was a single-centre parallel prospective group-study. Briefly, echocardiograms, right heart catheterisation (RHC) and cardiopulmonary exercise tests were performed in forty-two patients admitted for a heart transplant assessment between August2017 and October2018.Of them 20 belonged to the HVAD group and 22 to the HF group.
Results
In our study, HVAD patients had a better exercise capacity than HF patients, although no significant differences were noted (14.0±5.0 ml/kg/min vs 11.3±3.9 ml/kg/min, p=0.06). To determine exercise tolerance, both HVAD and HF groups were subdivided into 2 groups based on the median peak exercise oxygen consumption (peakVO2) for that group. The table shows the comparison between preserved and non-preserved exercise tolerance in HF and HVADpatients. First of all, in the HVADgroup, all resting RHC pressures were significantly lower in the preserved exercise capacity group. However, in HFpatients there were no statistically significant differences between both subgroups in right-sided pressures, but Thermodilution exercise-induced change in cardiac output (ΔCO) and cardiac index (ΔCI) was significantly higher in the patients with preserved exercise tolerance. Secondly, in the HVADgroup the right ventricle was significantly larger in the reduced exercise tolerance subgroup. Moreover, patients with lower peak VO2 had more significant tricuspid regurgitation. Nevertheless, in HFpatients none of the echocardiographic parameters were related to the exercise capacity.
HF HVAD > Median Peak V02 < Median Peak V02 p > Median Peak V02 < Median Peak V02 p Thermodilution CO, l/min: • Rest 4.3±1.0 4.4±1.8 0.82 4.8±0.8 4.2±1.2 0.21 • Exercise 5.6±1.7 4.8±1.8 0.36 7.1±3.2 4.8±0.8 0.05 • ΔCO 1.26±1.0 0.26±0.7 0.02 2.2±2.5 0.4±0.7 0.05 Right Atrium pressure, mmHg 7.0±4.5 6.8±4.10 0.92 4.3±3.2 10.6±6.40 0.02 Mean Pulmonary Artery pressure, mmHg 26.4±12.6 26.5±10.9 0.97 16.8±5.4 30.5±12.5 0.01 Tricuspid Regurgitation, n (%): • None 1 (9) 1 (9) 1 (12) 0 (0) • Mild 7 (64) 8 (73) 7 (88) 4 (44) • Moderate 2 (18) 0 (0) 0 (0) 4 (44) • Severe 1 (9) 2 (18) 0.36 0 (0) 1 (12) 0.03 Right Ventricle Basal Diastolic Diameter, cm 4.0±1.0 4.1±1.0 0.83 3.7±0.5 4.4±0.5 0.02
Conclusion
Right-sided parameters in the echocardiogram and RHC pressures discriminate between preserved and non-preserved exercise capacity in HVADpatients, but not in HFpatients. In these last patients only ΔCO and ΔCI were statistically correlated with peak exercise oxygen consumption
Acknowledgement/Funding
N. Bouzas-Cruz would like to thank the Spanish Society of Cardiology (Sociedad Española de Cardiología), for her research grant and fellowship
Stochastic Modeling and Dynamic Analysis of the Cardiovascular System with Rotary Left Ventricular Assist Devices
