Cardiac hemodynamic response to the 6-minute walk test in patients with intestinal carcinoma undergoing bevacizumab treatment

Abstract

Background: Exercise capacity is evaluated using the 6-minute walk test (6MWT) in various cardiovascular diseases. Bevacizumab (BEV) has been associated with significant risk of cardiovascular complications. The aim of this study was to investigate BEV-related influences on cardiac hemodynamic response to 6MWT. Methods: We prospectively studied 24 patients with intestinal carcinoma to assess the hemodynamic response during 6MWT, of whom eight underwent BEV treatment. Obtained data was analyzed to identify hemodynamic differences between BEV and non-BEV treated patients. Results: Twenty-four patients with stage IV intestinal carcinoma consented to assessment after the completion of three cycles of BEV-combined chemotherapy (age, 46.4±16.7 years) or standard chemotherapy alone (age, 56.4±13.7 years). In comparison with non-BEV treated patients, BEV-treated patients walked less (484.3±42.4 vs. 503.0±48.2, P=0.339). These two groups manifested similar hemodynamic response during the 6MWT. The change of hemodynamic parameters at 1 minute after completion of 6MWT was defined as hemodynamic parameter recovery. BEV-treated patients had significantly lower change of left cardiac work index (LCWi), cardiac index (CI), cardiac output (CO) and stroke volume (SV) after 6MWT. Interestingly, in BEV-treated patients CI change after 6MWT was predominantly related to the decrease in SV instead of heart rate (HR) as suggested by a higher standardized beta coefficient (0.883 vs. 0.657) and semi-partial correlations (0.821 vs. 0.677). Conclusions: Estimation of hemodynamic response to 6MWT is feasible, and may provide useful information of myocardial damage in BEV-treated patients.