Protocol for a prospective, longitudinal cohort study on the effect of arterial disease level on the outcomes of supervised exercise in intermittent claudication: the ELECT Registry

The Effect of Arterial Disease Level on Outcomes of Supervised Exercise Therapy for Intermittent Claudication: A Prospective Cohort Study

OBJECTIVE

To assess whether level of arterial obstruction determines the effectiveness of SET in patients with IC.

BACKGROUND DATA

Guidelines advocate SET before invasive treatment for IC, but early revascularization remains widespread, especially in patients with aortoiliac disease.

METHODS

Patients were recruited from 10 Dutch centers between October 2017 and October 2018. Participants received SET first, followed by endovascular or open revascularization in case of insufficient effect. They were grouped according to level of stenosis (aortoiliac, femoropopliteal, multilevel, or rest group with no significant stenosis). Changes from baseline walking performance (maximal and functional walking distance on a treadmill test, 6-minute walk test) and vascular quality of life questionnaire-6 at 3 and 6 months were compared, after multivariate adjustment for possible confounders. Freedom from revascularization was estimated with Kaplan-Meier analysis.

RESULTS

Some 267 patients were eligible for analysis (aortoiliac n = 70, 26%; femoropopliteal n = 115, 43%; multilevel n = 69, 26%; rest n = 13, 5%). No between group differences in walking performance or vascular quality of life questionnaire-6 were found. Mean improvement in maximal walking distance after 6 months was 439 m [99% confidence interval (CI) 297-581], 466 m (99% CI 359-574), 353 m (99% CI 210-496), and 403 m (99% CI 58-749), respectively (P = 0.40). Freedom from intervention was 73.9% for aortoiliac disease and 88.6% for femoropopliteal disease (hazard ratio 2.46, 99% CI 0.96 - 6.30, P = 0.013).

CONCLUSIONS

Short-term effectiveness of SET for IC is not determined by the location of stenosis. Although aortoiliac disease patients improved walking performance and health-related quality of life similarly compared to other arterial disease level groups, they underwent revascularization more often.

Supervised Exercise Therapy is Effective for Patients With Intermittent Claudication Regardless of Psychological Constructs

OBJECTIVE

According to current guidelines, supervised exercise therapy (SET) is the treatment of choice for intermittent claudication (IC). Little is known about the potential consequences of psychological factors on the effectiveness of treatment. The aim of this study was to determine possible associations between a set of psychological constructs and treatment outcomes, and to investigate whether self efficacy increased after SET.

METHODS

This was a substudy of the ELECT Registry, a multicentre Dutch prospective cohort study in patients with IC receiving primary SET. A complete set of validated questionnaires scoring extraversion, neuroticism, conscientiousness, anxiety, depression, self control, optimism, and self efficacy was obtained in 237 patients (median age 69 years, 40% female). Anxiety and depression were dichotomised using established cutoff scores, whereas other scores were analysed as continuous measures. Multiple linear regression analyses determined possible associations between these independent variables and maximum and functional walking distances (MWD and FWD, respectively), Six Minute Walk Test (6MWT), and VascuQol-6 (dependent variables). Self efficacy during 12 months of SET was analysed using a linear mixed model.

RESULTS

Neuroticism and anxiety were associated with lower overall VascuQol-6 scores (estimate -1.35 points [standard error (SE) 0.57; p = .018] and -1.98 points [SE 0.87, p = .023], respectively). Optimism and self efficacy demonstrated higher overall 6MWT (5.92 m [SE 2.34; p = .012] and 1.35 m [SE 0.42; p = .001], respectively). Self control was associated with lower overall log MWD (-0.02 [SE 0.01; p = .038] and log FWD (-0.02 [SE 0.01; p = .080), whereas self efficacy had a higher overall log MWD (0.01 [SE 0.003; p = .009]) and log FWD (0.01 [SE 0.003; p = .011]). Depressive patients with IC demonstrated a greater improvement in 6MWT during follow up (17.56 m [SE 8.67; p = .044]), but this small effect was not confirmed in sensitivity analysis. Self efficacy did not increase during follow up (0.12% [SE 0.49; p = .080]).

CONCLUSIONS

The beneficial effects of SET occur regardless of the psychological constructs, supporting current guidelines recommending a SET first strategy in each patient with IC.

A Comparison of Health Status and Quality of Life in Patients with Intermittent Claudication

BACKGROUND

Patient reported outcome measures (PROMs) such as health status (HS) and quality of life (QOL) are frequently used interchangeably while they represent different outcomes. Whether a discrepancy exists in patients with intermittent claudication (IC) in changes over time between HS and QOL is unclear. This study aimed to investigate the strength and the direction of the association between HS and QOL over time in patients with IC that underwent supervised exercise therapy (SET).

MATERIAL AND METHODS

Patients were part of the ELECT multi-center prospective cohort study. One goal of this study was to obtain data on HS and QOL at different time intervals of patients with IC that underwent SET. HS (VascuQOL-6) and QOL (WHOQOL-BREF) were completed at baseline, 3 months, and 6 months follow up. Pearson's correlation coefficients and the associated common variances (R²) were calculated to measure the strength and the direction of the association between HS and QOL in changes between baseline and follow-up moments.

RESULTS

In total, 177 patients were included in data analyses. Only changes in physical QOL and overall QOL had a small correlation with changes over time in HS, at both 3- and 6 months follow up (respectively R²=.14; P < 0.001 and R² = 0.12; P < 0.001 for physical QOL and R² = 0.18; P < 0.001 and R² = 0.13; P < 0.001 for overall QOL).

CONCLUSIONS

This study showed that HS and QOL provide different outcomes in patients with IC that underwent SET. Future studies should be aware of these differences before PROMs are being incorporated as an outcome measure in clinical studies.

A Comparison of Quality of Life in Elderly Patients with Intermittent Claudication and Chronic Limb-Threatening Ischemia

BACKGROUND

Intermittent claudication (IC) and chronic limb-threatening ischemia (CLTI) are both associated with a decreased health status and possibly quality of life (QOL). A better understanding of the differences in QOL between patients with IC and CLTI could be of additional value in shared decision-making. The aim of this study was to compare the QOL at baseline between patients with IC and patients with CLTI.

METHODS

The study population was based on 2 study cohorts, 1 cohort consisted of patients with IC (ELECT registry) and the other cohort of patients with CLTI (KOP-study). Patients with an age of ≥70 years were included. QOL at baseline was measured by the WHOQOL-BREF questionnaire. Nonresponders were excluded from data analyses. Student's t-tests and analysis of covariance (ANCOVA) analyses were used to compare QOL between the 2 groups. Outcomes of the ANCOVA analyses were expressed as estimated marginal means.

RESULTS

In total, 308 patients were included, 115 patients with IC and 193 patients with CLTI. Patients with CLTI were older (median age 80 years vs. 75 years, P < 0.001) and had more comorbidities. Patients with IC had a statistically significant higher QOL regarding physical health (mean 13.7 [standard deviation (SD) 2.3] vs. 10.8 [SD 2.8], P < 0.001), psychological health (mean 15.3 [SD 2.1] vs. 14.1 [SD 2.4], P < 0.001), environment (mean 16.3 [SD 2.4] vs. 15.5 [SD 2.0], P < 0.002), and the overall domain (mean 3.5 [SD 0.7] vs. 3.1 [SD 0.9], P < 0.001). After correcting for the confounding effect of age and sex, patients with IC still had a statistically significant higher QOL in the physical, psychological, environment, and overall domain.

CONCLUSIONS

Patients with IC had a significantly higher QOL in the physical, psychological, environment, and overall domains of the WHOQOL-BREF questionnaire compared with patients with CLTI. This underlines the importance of strategies that reduce disease progression as disease progression is associated with a decrease in QOL.