Depressive symptoms, right ventricular function, and muscular strength are associated with peak oxygen uptake in patients with implantable left ventricular assist devices

Abstract

Background: Left ventricular assist device (LVAD) implantation is among the most effective treatment options for patients with severe heart failure. Although previous studies have examined the factors related to peak oxygen uptake (peak VO₂ ), they were limited by the few patients involved and their focus on medical and physical functions. Therefore, this study comprehensively examined the factors associated with peak VO₂ , which is an important prognostic factor in patients with implantable LVADs.

Methods: Eighty-nine patients who underwent initial LVAD implantation and were eligible for cardiopulmonary exercise testing (CPX) between May 2014 and September 2021 were included. The patients' mean age was 48 ± 12 years, and 70% were males. Based on previous studies, the cut-off was set at 12 and 14 mL/kg/min for patients taking β-blocker and those not taking β-blockers, respectively. Furthermore, factors associated with peak VO₂ were examined using multivariate logistic regression analysis.

Results: The mean time from surgery to CPX administration was 73 ± 40 days. The high group had a higher cardiac index, right ventricular stroke work index (RVSWI), and isometric knee extensor muscular strength and lower Patient Health Questionnaire-9 (PHQ-9) and B-type natriuretic peptide values than the low group. Multivariate logistic regression analysis showed that RVSWI and KEMS were positively correlated, whereas PHQ-9 was negatively associated with peak VO₂ .

Conclusion: Right ventricular function, depressive symptoms, and lower limb muscular strength were associated with exercise capacity in patients with implantable LVADs.

Keywords: depressive symptoms; knee extensor muscular strength; left ventricular assist devices; peak oxygen uptake; right ventricular function.