Reproducibility of heart rate recovery in patients with intermittent claudication

Background: Postexercise heart rate recovery (HRR) is a non-invasive tool for cardiac autonomic function assessment. Reproducibility of HRR has been established in healthy subjects; however, no study has evaluated this reproducibility in clinical populations who may present autonomic dysfunction. Patients with peripheral artery disease and intermittent claudication (IC) often present altered cardiac autonomic function and HRR could be an interesting tool for evaluating autonomic responses to interventions in this population. Therefore, the reproducibility of HRR should be determined in this specific population. Objective: To determine the reproducibility of HRR indices in patients with IC. Methods: Nineteen men with IC underwent two repeated maximal treadmill tests. Raw HR and relative HRR (difference to exercise peak) indices measured at 30, 60, 120, 180, 240 and 300s of recovery were evaluated. The presence of systematic bias was assessed by comparing test and retest mean values via paired t-test. Reliability was assessed by intraclass correlation coefficient (ICC), and agreement by typical error (TE), coefficient of variation (CV) and minimal detectable difference (MDD). Results: There were no significant differences between the test and retest values of all raw HR and relative HRR indices (P ≥ 0·05), except for HR120s (P = 0·032). All indices exhibited excellent reliability (ICC ≥ 0·78). Raw HR and relative HRR indices showed TEs ≤ 6·4 bpm and MDDs ≤ 17·8 bpm. In addition, all indices showed CVs ≤ 13·2%, except HRR30s (CV = 45·6%). Conclusions: The current results demonstrated that most HRR indices were highly reproducible with no systematic error, excellent reliability and good agreement in patients with IC following maximal graded exercise

Association of time spent in physical activities and sedentary behaviors with carotid-femoral pulse wave velocity: A systematic review and meta-analysis

Background and aims: Increased arterial stiffness is linked to increased risk of cardiovascular disease and mortality. Studies have reported conflicting results regarding the relationship between arterial stiffness and time spent in sedentary behavior (SB) and physical activity (PA). The objective of this systematic review and meta-analysis was to assess the relationship between objectively measured light PA (LPA), moderate to vigorous PA (MVPA), and SB with the gold standard measurement of arterial stiffness, carotid-femoral pulse wave velocity (cfPWV). Methods: PubMed, Scopus, and Web of Science were searched for relevant studies published until November 2016. Studies reporting the correlation of objectively measured PA and SB with cfPWV in human adults >18 years old were included in this analysis. Correlation coefficients (CCs) were converted to Z scores via Fisher's z values for the analysis of summary effects, using a random-effects model. Results: Twelve studies were included in the systematic review. The meta-analysis showed a negative correlation between cfPWV and LPA (CC -0.16; 95% CI: −0.29 to −0.03; p=0.02) and MVPA (CC -0.16; 95% CI: −0.26 to −0.06; p<0.01), and a positive relationship between cfPWV and SB (CC 0.23; 95% CI: 0.12 to 0.35; p<0.01). Conclusions: Time spent in light and moderate physical activities is associated with lower arterial stiffness, while time spent in SB is related to higher arterial stiffness. It suggests that PA at any intensity is favorable for arterial stiffness, whereas SB leads to increased arterial stiffness. Considering that cfPWV has an independent prognostic value, these associations may have important clinical implications

Remote ischemic preconditioning in patients with intermittent claudication

OBJECTIVE: Remote ischemic preconditioning (RIPC) is a phenomenon in which a short period of sub-lethal ischemia in one organ protects against subsequent bouts of ischemia in another organ. We hypothesized that RIPC in patients with intermittent claudication would increase muscle tissue resistance to ischemia, thereby resulting in an increased ability to walk. METHODS: In a claudication clinic, 52 ambulatory patients who presented with complaints of intermittent claudication in the lower limbs associated with an absent or reduced arterial pulse in the symptomatic limb and/or an ankle-brachial index <0.90 were recruited for this study. The patients were randomly divided into three groups (A, B and C). All of the patients underwent two tests on a treadmill according to the Gardener protocol. Group A was tested first without RIPC. Group A was subjected to RIPC prior to the second treadmill test. Group B was subjected to RIPC prior to the first treadmill test and then was subjected to a treadmill test without RIPC. In Group C (control group), both treadmill tests were performed without RIPC. The first and second tests were conducted seven days apart. Brazilian Clinical Trials: RBR-7TF6TM. RESULTS: Group A showed a significant increase in the initial claudication distance in the second test compared to the first test. CONCLUSION: RIPC increased the initial claudication distance in patients with intermittent claudication; however, RIPC did not affect the total walking distance of the patients