Abstract
Background
The implantation of left ventricular assist devices (LVAD) has established its role in therapy for patients with end stage heart failure.
Benefits in survival as well as an improved quality of life, compared to optimized medical therapy (OMT) alone, has been proven.
There are limited data in the literature on the metabolic changes during exercise in LVAD patients, and in most studies no increase in peak oxygen consumption on cardiopulmonary exercise test (CPET) could be shown early after surgery. However, recent data suggests an improvement in peak oxygen uptake (VO2) as a late effect after rehabilitation.
To further investigate these findings we sought to analyse CPET data from patients before LVAD implantation as well as in the early and late follow up in correlation with hemodynamic changes at these times.
Methods
We collected and retrospectively analysed data of heart failure patients who had undergone LVAD implantation, and in whom a right heart catheterization, a cardiopulmonary exercise test and an echocardiography had been performed at time before, as well as 6 Months and 12 months after LVAD implantation, respectively.
Results
Data of 43 patients implanted with an LVAD between 2011 and 2017 were analysed. There was significant improvement in cardiac output (3,2 vs 4,3 L/min, p<0,001) and VE/VCO2 slope (46 vs 38, p=0,001) 6 months after LVAD implant as well as a significant reduction in PCWP (26 vs 11 mmHg, p<0,001), PAP mean (40 vs 22 mmHg, p<0,001), RA mean (12 vs 8 mmHg, p=0,002) and PVR (4,2 vs 2,5 WU, p<0,001). However, there was no significant increase in peak VO2 after 6 months.
12 months after LVAD implantation there were no further significant changes in cardiac output, intracardiac pressures or VE/VCO2 slope, which all remained similar to the 6 months follow up. However, at that point, a significant increase in peak VO2 was seen, compared to baseline (1060 vs 1410ml/min, p=0,001) and to 6 months after surgery (Figure 1).
Conclusion
Cardiac output increases in heart failure patients early after LVAD implantation. Consequently, permanent ventricular off loading results in the reduction of intracardiac pressures and improvement in the VE/VCO2 slope 6 months after surgery. However, a significant rise in peak oxygen consumption could only be noted 12 months after surgery, suggesting either a delayed long-term effect of improved hemodynamics or other causes such as enhanced mobility or training due to improved quality of life.
Monitoring functional capacity in heart failure
