Long-term clinical effectiveness of supervised exercise therapy versus endovascular revascularization for intermittent claudication from a randomized clinical trial

Long-term outcomes of a randomized clinical trial of supervised exercise, percutaneous transluminal angioplasty or combined treatment for patients with intermittent claudication due to femoropopliteal disease

BACKGROUND

The aim was to compare the long-term outcomes of percutaneous transluminal angioplasty (PTA), a supervised exercise programme (SEP) and combined treatment (PTA + SEP) in patients with intermittent claudication owing to femoropopliteal disease.

METHODS

Patients recruited to an RCT comparing these treatments were invited for long-term follow-up from 2010 to 2011. Indicators of limb ischaemia were recorded (ankle : brachial pressure index (ABPI) and treadmill walking distances). Duplex ultrasound imaging was also done. Patients completed Short Form 36 and VascuQol quality-of-life (QoL) questionnaires.

RESULTS

Of 178 patients initially recruited to the trial, 139 were alive at the time of follow-up (PTA 46, SEP 47, PTA + SEP 46). Assessments were completed for 111 patients. Median time to follow-up was 5·2 (i.q.r. 3·8-7·4) years. Sixty-nine patients (62·2 per cent) were symptomatic; 18 (16·2 per cent) had experienced a major cardiovascular event since their last follow-up visit. Improvement was observed in ABPI in all groups. QoL outcomes were inconsistent across individual groups. PTA and PTA + SEP groups had a significantly higher ABPI than the SEP group. No significant difference was observed in treadmill walking distances, QoL outcomes, restenosis rates, and new ipsilateral and contralateral lesions on duplex imaging. Patients in all groups required reinterventions (PTA 14, SEP 10, PTA + SEP 6). The total number of reinterventions was higher after PTA (29) compared with SEP (17) and PTA + SEP (9), but failed to reach statistical significance.

CONCLUSION

PTA, SEP and combined treatment were equally effective long-term treatment options for patients with claudication owing to femoropopliteal disease. The addition of a SEP to PTA can reduce the rate of symptomatic restenosis and reintervention. Registration number: NCT00798850 (http://www.clinicaltrials.gov).

Cost-effectiveness of supervised exercise therapy compared with endovascular revascularization for intermittent claudication

Background

Current guidelines recommend supervised exercise therapy (SET) as the preferred initial treatment for patients with intermittent claudication. The availability of SET programmes is, however, limited and such programmes are often not reimbursed. Evidence for the long-term cost-effectiveness of SET compared with endovascular revascularization (ER) as primary treatment for intermittent claudication might aid widespread adoption in clinical practice.

Methods

A Markov model was constructed to determine the incremental costs, incremental quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratio of SETversus ER for a hypothetical cohort of patients with newly diagnosed intermittent claudication, from the Dutch healthcare payer's perspective. In the event of primary treatment failure, possible secondary interventions were repeat ER, open revascularization or major amputation. Data sources for model parameters included original data from two RCTs, as well as evidence from the medical literature. The robustness of the results was tested with probabilistic and one-way sensitivity analysis.

Results

Considering a 5-year time horizon, probabilistic sensitivity analysis revealed that SET was associated with cost savings compared with ER (−€6412, 95 per cent credibility interval (CrI) –€11 874 to –€1939). The mean difference in effectiveness was −0·07 (95 per cent CrI −0·27 to 0·16) QALYs. ER was associated with an additional €91 600 per QALY gained compared with SET. One-way sensitivity analysis indicated more favourable cost-effectiveness for ER in subsets of patients with low quality-of-life scores at baseline.

Conclusion

SET is a more cost-effective primary treatment for intermittent claudication than ER. These results support implementation of supervised exercise programmes in clinical practice.

Comparison of Use of Short Form-36 Domain Scores and Patient Responses for Derivation of Preference-Based SF6D Index to Calculate Quality-Adjusted Life Years in Patients with Intermittent Claudication

BACKGROUND

The short form 36 (SF36) questionnaire is used for assessment of generic quality of life. Responses to the individual question in SF36 are also used for calculation of the SF6D index score. This score is used for calculation of quality adjusted-life years (QALYs) in economical analyses. As the individual patient questionnaires are not always available for performing systematic reviews and meta-analyses, a new formula has been developed for derivation of SF6D index score from the reported SF36-domain scores. This study aimed to evaluate the validity of this formula for use in patients with intermittent claudication.

METHODS

A retrospective review of a prospectively collected database of a randomized controlled trial was performed. A total of 178 patients were recruited. Clinical indicators of ischemia were recorded. All patients completed SF36 questionnaires. Response and domain-based SF6D scores (R-SF6D and D-SF6D) and QALYs were calculated. Correlation and agreement analysis were performed.

RESULTS

Response rate was 88% (n = 781) over a 1-year follow-up period. Domain-based SF6D score (mean, 0.684; standard deviation [SD] 0.110) was significantly higher (paired t-test, P = 0.001) than the response-based score (mean, 0.627; SD, 0.110) with a mean difference of 0.056 (95% confidence interval, 0.053-0.060). Mean QALY calculated using D-SF6D score (0.503; SD, 0.116) was also significantly higher than the QALY calculated from the R-SF6D score (0.467; SD, 0.121). Bland-Altman comparison showed strong agreement (limit of agreement -0.167 to 0.054) between the 2 methods with equal variances (Pitman's test, P = 0.629). D-SF6D scores showed stronger correlation with clinical indicators of ischemia (r = 0.246-0.602) compared with that of R-SF6D scores (r = 0.233-0.549).

CONCLUSIONS

Domain-based estimation of SF6D score is a valid and reliable method with strong agreement to the gold standard response-based scores in claudicants. However, adjustments may be required in studies using a mixture of D-SF6D and R-SF6D scores for QALY calculation.

Advances in our understanding of the influence of gender on patient outcomes with peripheral arterial disease co-occurring with diabetes

Peripheral arterial disease is an important predictor of cardiovascular morbidity and mortality. Patients with peripheral arterial disease are at a higher risk of myocardial infarction and stroke. The well-known coronary artery disease risk factors such as diabetes, hypertension, smoking and dyslipidemia are also risk factors for peripheral arterial disease. Hyperglycemia is an important mediator in the pathogenesis of this disease in diabetics, more so in women. The morbidity and poor outcomes associated with peripheral arterial disease in women are emerging. Women are more likely to present at an older age are often asymptomatic and have poorer outcomes with revascularization. Women experience specific sex-related challenges in the various diagnostic methods which could lead to a delay in diagnosis. This is a group which needs close attention and aggressive risk factor modification.

The LIBERTY study: Design of a prospective, observational, multicenter trial to evaluate the acute and long-term clinical and economic outcomes of real-world endovascular device interventions in treating peripheral artery disease

BACKGROUND

Most peripheral artery disease (PAD) clinical device trials are supported by commercial manufacturers and designed for regulatory device approval, with extensive inclusion/exclusion criteria to support homogeneous patient populations. High-risk patients with advanced disease, including critical limb ischemia (CLI), are often excluded leading to difficulty in translating trial results into real-world clinical practice. As a result, physicians have no direct guidance regarding the use of endovascular devices. There is a need for objectively assessed studies to evaluate clinical, functional, and economic outcomes in PAD patient populations.

STUDY DESIGN

LIBERTY is a prospective, observational, multicenter study sponsored by Cardiovascular Systems Inc (St Paul, MN) to evaluate procedural and long-term clinical and economic outcomes of endovascular device interventions in patients with symptomatic lower extremity PAD. Approximately 1,200 patients will be enrolled and followed up to 5 years: 500 patients in the "Claudicant Rutherford 2-3" arm, 600 in the "CLI Rutherford 4-5" arm, and 100 in the "CLI Rutherford 6" arm. The study will use 4 core laboratories for independent analysis and will evaluate the following: procedural and lesion success, rates of major adverse events, duplex ultrasound interpretations, wound status, quality of life, 6-minute walk test, and economic analysis. The LIBERTY Patient Risk Score(s) will be developed as a clinical predictor of outcomes to provide guidance for interventions in this patient population.

CONCLUSION

LIBERTY will investigate real-world PAD patients treated with endovascular revascularization with rigorous study guidelines and independent oversight of outcomes. This study will provide observational, all-comer patient clinical data to guide future endovascular therapy.

The Completeness of Intervention Descriptions in Randomised Trials of Supervised Exercise Training in Peripheral Arterial Disease

Research supports the use of supervised exercise training as a primary therapy for improving the functional status of people with peripheral arterial disease (PAD). Several reviews have focused on reporting the outcomes of exercise interventions, but none have critically examined the quality of intervention reporting. Adequate reporting of the exercise protocols used in randomised controlled trials (RCTs) is central to interpreting study findings and translating effective interventions into practice. The purpose of this review was to evaluate the completeness of intervention descriptions in RCTs of supervised exercise training in people with PAD. A systematic search strategy was used to identify relevant trials published until June 2015. Intervention description completeness in the main trial publication was assessed using the Template for Intervention Description and Replication checklist. Missing intervention details were then sought from additional published material and by emailing authors. Fifty-eight trials were included, reporting on 76 interventions. Within publications, none of the interventions were sufficiently described for all of the items required for replication; this increased to 24 (32%) after contacting authors. Although programme duration, and session frequency and duration were well-reported in publications, complete descriptions of the equipment used, intervention provider, and number of participants per session were missing for three quarters or more of interventions (missing for 75%, 93% and 80% of interventions, respectively). Furthermore, 20%, 24% and 26% of interventions were not sufficiently described for the mode of exercise, intensity of exercise, and tailoring/progression, respectively. Information on intervention adherence/fidelity was also frequently missing: attendance rates were adequately described for 29 (38%) interventions, whereas sufficient detail about the intensity of exercise performed was presented for only 8 (11%) interventions. Important intervention details are commonly missing for supervised exercise programmes in the PAD trial literature. This has implications for the interpretation of outcome data, the investigation of dose-response effects, and the replication of protocols in future studies and clinical practice. Researchers should be mindful of intervention reporting guidelines when attempting to publish information about supervised exercise programmes, regardless of the population being studied.

Comparing Supervised Exercise Therapy to Invasive Measures in the Management of Symptomatic Peripheral Arterial Disease

Peripheral arterial disease (PAD) is associated with considerable morbidity and mortality. Consensus rightly demands the incorporation of supervised exercise training (SET) into PAD treatment protocols. However, the exact role of SET particularly its relationship with intervention requires further clarification. While supervised exercise is undoubtedly an excellent tool in the conservative management of mild PAD its use in more advanced disease as an adjunct to open or endovascular intervention is not clearly defined. Indeed its use in isolation in this cohort is incompletely reported. The aim of this review is to clarify the exact role of SET in the management of symptomatic PAD and in particular to assess its role in comparison with or as an adjunct to invasive intervention. A systematic literature search revealed a total 11 randomised studies inclusive of 969 patients. All studies compared SET and intervention with monotherapy. Study results suggest that exercise is a complication-free treatment. Furthermore, it appears to offer significant improvements in patients walk distances with a combination of both SET and intervention offering a superior walking outcome to monotherapy in those requiring invasive measures.

Lower-extremity arterial revascularization: Is there any evidence for diabetic foot ulcer-healing?

The presence of peripheral arterial disease (PAD) is an important consideration in the management of diabetic foot ulcers. Indeed, arteriopathy is a major factor in delayed healing and the increased risk of amputation. Revascularization is commonly performed in patients with critical limb ischaemia (CLI) and diabetic foot ulcer (DFU), but also in patients with less severe arteriopathy. The ulcer-healing rate obtained after revascularization ranges from 46% to 91% at 1 year and appears to be improved compared to patients without revascularization. However, in those studies, healing was often a secondary criterion, and there was no description of the initial wound or its management. Furthermore, specific alterations associated with diabetes, such as microcirculation disorders, abnormal angiogenesis and glycation of proteins, can alter healing and the benefits of revascularization. In this review, critical assessment of data from the literature was performed on the relationship between PAD, revascularization and healing of DFUs. Also, the impact of diabetes on the effectiveness of revascularization was analyzed and potential new therapeutic targets described.

Treatment of intermittent claudication

Stop smoking. Exercise under supervision