Anna Apostolo1, Stefania Paolillo2, Mauro Contini1, Carlo Vignati3, Vincenzo Tarzia4, Jeness Campodonico1, Massimo Mapelli1, Massimo Massetti5, Jonida Bejko4, Francesca Righini1, Tomaso Bottio4, Niccolò Bonini1, Elisabetta Salvioni1, Paola Gugliandolo1, Gianfranco Parati6, Carolina Lombardi7, Gino Gerosa4, Luca Salvi1, Francesco Alamanni1, Piergiuseppe Agostoni8. 1. Centro Cardiologico Monzino, Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy. 2. Istituto di Ricerca Diagnostica e Nucleare, Istituto di Ricovero e Cura a Carattere Scientifico, Naples, Italy. 3. Centro Cardiologico Monzino, Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy; Cardiovascular Section Department of Clinical Sciences and Community Health, University of Milano, Milan, Italy. 4. Cardiac Surgery Unit, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua, Italy. 5. Catholic University, Department of Cardiovascular Sciences, Gemelli Hospital, Rome, Italy. 6. Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Istituto Auxologico Italiano, Milan, Italy; Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy. 7. Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Istituto Auxologico Italiano, Milan, Italy. 8. Centro Cardiologico Monzino, Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy; Cardiovascular Section Department of Clinical Sciences and Community Health, University of Milano, Milan, Italy. Electronic address: piergiuseppe.agostoni@unimi.it.
Abstract
BACKGROUND: Increasing left ventricular assist device (LVAD) pump speed according to the patient's activity is a fascinating hypothesis. This study analyzed the short-term effects of LVAD speed increase on cardiopulmonary exercise test (CPET) performance, muscle oxygenation (near-infrared spectroscopy), diffusion capacity of the lung for carbon monoxide (Dlco) and nitric oxide (Dlno), and sleep quality. METHODS: We analyzed CPET, Dlco and Dlno, and sleep in 33 patients supported with the Jarvik 2000 (Jarvik Heart Inc., New York, NY). After a maximal CPET (n = 28), patients underwent 2 maximal CPETs with LVAD speed randomly set at 3 or increased from 3 to 5 during effort (n = 15). Then, at LVAD speed randomly set at 2 or 4, we performed (1) constant workload CPETs assessing O2 kinetics, cardiac output (CO), and muscle oxygenation (n = 15); (2) resting Dlco and Dlno (n = 18); and (3) nocturnal cardiorespiratory monitoring (n = 29). RESULTS: The progressive pump speed increase raised peak volume of oxygen consumption (12.5 ± 2.5 ml/min/kg vs 11.7 ± 2.8 ml/min/kg at speed 3; p = 0.001). During constant workload, from speed 2 to 4, CO increased (at rest: 3.18 ± 0.76 liters/min vs 3.69 ± 0.75 liters/min, p = 0.015; during exercise: 5.91 ± 1.31 liters/min vs 6.69 ± 0.99 liters/min, p = 0.014), and system efficiency (τ = 65.8 ± 15.1 seconds vs 49.9 ± 14.8 seconds, p = 0.002) and muscle oxygenation improved. At speed 4, Dlco decreased, and obstructive apneas increased despite a significant apnea/hypopnea index and a reduction of central apneas. CONCLUSIONS: Short-term LVAD speed increase improves exercise performance, CO, O2 kinetics, and muscle oxygenation. However, it deteriorates lung diffusion and increases obstructive apneas, likely due to an increase of intrathoracic fluids. Self-adjusting LVAD speed is a fascinating but possibly unsafe option, probably requiring a monitoring of intrathoracic fluids.
BACKGROUND: Increasing left ventricular assist device (LVAD) pump speed according to the patient's activity is a fascinating hypothesis. This study analyzed the short-term effects of LVAD speed increase on cardiopulmonary exercise test (CPET) performance, muscle oxygenation (near-infrared spectroscopy), diffusion capacity of the lung for carbon monoxide (Dlco) and nitric oxide (Dlno), and sleep quality. METHODS: We analyzed CPET, Dlco and Dlno, and sleep in 33 patients supported with the Jarvik 2000 (Jarvik Heart Inc., New York, NY). After a maximal CPET (n = 28), patients underwent 2 maximal CPETs with LVAD speed randomly set at 3 or increased from 3 to 5 during effort (n = 15). Then, at LVAD speed randomly set at 2 or 4, we performed (1) constant workload CPETs assessing O2 kinetics, cardiac output (CO), and muscle oxygenation (n = 15); (2) resting Dlco and Dlno (n = 18); and (3) nocturnal cardiorespiratory monitoring (n = 29). RESULTS: The progressive pump speed increase raised peak volume of oxygen consumption (12.5 ± 2.5 ml/min/kg vs 11.7 ± 2.8 ml/min/kg at speed 3; p = 0.001). During constant workload, from speed 2 to 4, CO increased (at rest: 3.18 ± 0.76 liters/min vs 3.69 ± 0.75 liters/min, p = 0.015; during exercise: 5.91 ± 1.31 liters/min vs 6.69 ± 0.99 liters/min, p = 0.014), and system efficiency (τ = 65.8 ± 15.1 seconds vs 49.9 ± 14.8 seconds, p = 0.002) and muscle oxygenation improved. At speed 4, Dlco decreased, and obstructive apneas increased despite a significant apnea/hypopnea index and a reduction of central apneas. CONCLUSIONS: Short-term LVAD speed increase improves exercise performance, CO, O2 kinetics, and muscle oxygenation. However, it deteriorates lung diffusion and increases obstructive apneas, likely due to an increase of intrathoracic fluids. Self-adjusting LVAD speed is a fascinating but possibly unsafe option, probably requiring a monitoring of intrathoracic fluids.
Authors: Julien Guihaire; Francois Haddad; Mita Hoppenfeld; Myriam Amsallem; Jeffrey W Christle; Clark Owyang; Khizer Shaikh; Joe L Hsu Journal: Can J Cardiol Date: 2019-11-09 Impact factor: 5.223
Authors: Richard Severin; Ahmad Sabbahi; Cemal Ozemek; Shane Phillips; Ross Arena Journal: Expert Rev Med Devices Date: 2019-09-06 Impact factor: 3.166