The Value of Physiotherapeutic Tests Next to Cardiopulmonary Exercise Test to Assess Exercise Capacity in Left Ventricular Assist Device Patients

Abstract

Purpose Quality of life in advanced heart failure patients treated with left ventricular assist device (LVAD) is largely determined by exercise capacity, for which cardiopulmonary exercise test (CPET) is the gold standard. The complexity of CPET frequently leads to inconclusive results due to functional impairment early after LVAD implantation. Physiotherapeutic tests have been opted as an alternative for CPET in LVAD patients. To evaluate the value of physiotherapeutic tests next to CPET in assessing exercise capacity after LVAD implantation. Methods Patients who underwent LVAD implantation between January 2015 and July 2019 in our center were included if both a regular CPET and physiotherapeutic tests were performed. At 3-6 months physiotherapeutic tests consisted of a 6-minute walking test (6MWT), measurement of maximal inspiratory pressure (MIP) and grip strength. After univariable analysis using Pearson correlation, stepwise multivariable linear regression was performed to assess the association of physiotherapeutic parameters with CPET. Results 147 patients received an LVAD of which 79 (53.7%) performed both CPET and any of the physiotherapeutic tests at 3-6 months. 6MWT, grip strength and MIP were significantly correlated with VO2 max, of which 6MWT was the strongest (R=0.55, p<0.001). Grip strength was moderately correlated to VO2 max (R=0.48, p<0.001), MIP correlated weakly (R=0.30, p=0.033). Stepwise multivariate analysis showed that the combination of 6MWT and grip strength were independently associated with VO2 max (R=0.65, adjusted R2=0.41, p<0.001; Table 1). MIP was not significantly associated with VO2max in the multivariate model, and was therefore excluded from our model. Conclusion Of the physiotherapeutic tests at 3-6 months after LVAD implantation, 6MWT was best correlated with VO2max. The combination of 6MWT and grip strength significantly improved the association with VO2max. Quality of life in advanced heart failure patients treated with left ventricular assist device (LVAD) is largely determined by exercise capacity, for which cardiopulmonary exercise test (CPET) is the gold standard. The complexity of CPET frequently leads to inconclusive results due to functional impairment early after LVAD implantation. Physiotherapeutic tests have been opted as an alternative for CPET in LVAD patients. To evaluate the value of physiotherapeutic tests next to CPET in assessing exercise capacity after LVAD implantation. Patients who underwent LVAD implantation between January 2015 and July 2019 in our center were included if both a regular CPET and physiotherapeutic tests were performed. At 3-6 months physiotherapeutic tests consisted of a 6-minute walking test (6MWT), measurement of maximal inspiratory pressure (MIP) and grip strength. After univariable analysis using Pearson correlation, stepwise multivariable linear regression was performed to assess the association of physiotherapeutic parameters with CPET. 147 patients received an LVAD of which 79 (53.7%) performed both CPET and any of the physiotherapeutic tests at 3-6 months. 6MWT, grip strength and MIP were significantly correlated with VO2 max, of which 6MWT was the strongest (R=0.55, p<0.001). Grip strength was moderately correlated to VO2 max (R=0.48, p<0.001), MIP correlated weakly (R=0.30, p=0.033). Stepwise multivariate analysis showed that the combination of 6MWT and grip strength were independently associated with VO2 max (R=0.65, adjusted R2=0.41, p<0.001; Table 1). MIP was not significantly associated with VO2max in the multivariate model, and was therefore excluded from our model. Of the physiotherapeutic tests at 3-6 months after LVAD implantation, 6MWT was best correlated with VO2max. The combination of 6MWT and grip strength significantly improved the association with VO2max.