The effects of nordic walking, high-intensity interval training, and moderate-to-vigorous intensity continuous training on arterial stiffness in patients with coronary artery disease
Authors: R Marcal I , Cotie L , Ribeiro I , Reed J 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): The investigator-initiated research was supported by the Innovations Fund of the Alternate Funding Plan for the Academic Health Sciences Centres of the Ministry of Ontario (PIs: Pipe, Reed) and Heart and Stroke Foundation of Canada (PI: Reid).

Background
Coronary artery disease (CAD) is a leading cause of mortality worldwide. Arterial stiffness, a process associated with aging, arteriosclerosis, and arterial remodeling, is a strong and independent predictor of cardiovascular and all-cause mortality in patients with CAD. Moderate-to-vigorous intensity continuous training (MICT) has been shown to improve arterial stiffness parameters, including pulse wave velocity (PWV, i.e., the speed at which arterial pressure waves travel along the aorta and large arteries) and augmentation index (AIx: i.e., aortic pressure waveform) in the CAD population. Yet, the role of alternative exercise training approaches on arterial stiffness in patients with CAD has not been elucidated. Our recent study demonstrated greater improvements following Nordic walking (NW) compared to high-intensity interval training (HIIT) and MICT in functional capacity, quality of life, and depression severity in patients with CAD. No previous trial has compared the efficacy of NW, HIIT, and MICT in improving arterial stiffness in patients with CAD. Alternatives to traditional MICT, such as NW and HIIT, may provide superior understudied benefits on vascular health in patients with CAD.

Purpose
We compared the effects of 12 weeks of NW, HIIT, and MICT on arterial stiffness in patients with CAD.

Methods
Patients with CAD were randomly assigned to: (1) NW (walking with NW poles at a resting heart rate [RHR] + 20–40 bpm), (2) HIIT (aerobic exercise equipment: 4 × 4-min of high-intensity work periods at 85%–95% peak HR), or (3) MICT (aerobic exercise equipment: RHR + 20–40 bpm) twice weekly for 12 weeks. At baseline and week 12, aortic stiffness parameters were measured using a non-invasive device by stroke volume (SV), total vascular resistance (TVR), AIx with and without normalization for a HR of 75 bpm (AIX@75), and PWV. Linear mixed-effects models with repeated measures were used to compare groups over time.

Results
A total of 130 patients with CAD (aged 61 ± 7 years; male: 85%) were randomized to NW (n = 43), HIIT (n = 43), or MICT (n = 44). Table 1 shows that significant main effects of time were observed for SV (∆: 5.485 m/L, F = 8.530, p = 0.004), with a time × group interaction (F = 3.710, p = 0.027) revealing a greater improvement in SV following NW compared to HIIT (F = 5.748, p = 0.019) and MICT (F = 5.494, p = 0.022). A significant time × group interaction (F = 3.700, p = 0.028) was observed in AIx@75, with a greater reduction following NW than MICT (F = 7.388, p = 0.008). No significant differences were observed in TVR, AIx, and PWV.

Conclusion
Our findings show that NW facilitated greater improvements in SV and AIx@75 parameters of arterial stiffness, an important predictor of future cardiovascular events, when compared to HIIT and MICT in patients with CAD. NW may be considered as an alternative exercise training to improve vascular health in those with CAD.