Two-year results from a randomized clinical trial of revascularization in patients with intermittent claudication

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

Patient Related Outcomes After Receiving a Person Centred Nurse Led Follow Up Programme Among Patients Undergoing Revascularisation for Intermittent Claudication: A Secondary Analysis of a Randomised Clinical Trial

OBJECTIVE

The aim was to evaluate the effect of a person centred nurse led follow up programme on health related quality of life (HRQoL), health literacy, and general self efficacy compared with standard care for patients undergoing revascularisation for intermittent claudication (IC), and to describe factors associated with HRQoL one year after revascularisation.

METHODS

This was a secondary analysis of a randomised controlled trial. Patients with IC scheduled for revascularisation at two vascular surgery centres in Sweden between 2016 and 2018 were randomised to intervention or control. During the first year after surgery, the intervention group received a person centred follow up programme with three visits and two telephone calls with a vascular nurse, while the control group received standard follow up with two visits to a vascular surgeon or vascular nurse. Outcomes were HRQoL measured by VascuQol-6, health literacy, and general self efficacy measured by validated questionnaires.

RESULTS

Overall, 214 patients were included in the trial; this secondary analysis comprised 183 patients who completed the questionnaires. One year after revascularisation, HRQoL had improved with a mean increase in VascuQol-6 of 7.0 scale steps (95% CI 5.9 - 8.0) for the intervention and 6.0 scale steps (95% CI 4.9 - 7.0) for the control group; the difference between the groups was not significant (p = .18). In an adjusted regression analysis, the intervention was associated with higher VascuQoL-6 (2.0 scale steps, 95% CI 0.08 - 3.93). There was no significant difference between the groups regarding health literacy or general self efficacy. The prevalence of insufficient health literacy among all participants was 38.7% (46/119) at baseline and 43.2% (51/118) at one year.

CONCLUSION

In this study, a person centred, nurse led follow up programme had no significant impact on HRQoL, health literacy, or general self efficacy among patients undergoing revascularisation for IC. The prevalence of insufficient health literacy was high and should be addressed by healthcare givers and researchers.

Disease Specific Health Related Quality of Life in Patients With Chronic Limb Threatening Ischaemia Undergoing Revascularisation of Femoropopliteal Lesions

OBJECTIVE

Patients with chronic limb threatening ischaemia (CLTI) suffer from pain and non-healing ulcers, which impact negatively on both their physical and mental health. While maintaining and improving quality of life is a principal aim with all treatments, little is known about the health related quality of life (HRQoL) of CLTI patients and how revascularisation procedures impact on HRQoL endpoints. The aim of this study was to investigate disease specific HRQoL before and after revascularisation in patients with CLTI undergoing femoropopliteal revascularisation.

METHODS

HRQoL was prospectively analysed in 190 CLTI patients with main atherosclerotic target lesions in the femoropopliteal segment, who were planned for endovascular or open revascularisation. The choice of revascularisation method was made by the vascular team, represented by both open and endovascular expertise. The Vascular Quality of Life (VascuQoL) questionnaire was used to assess disease specific HRQoL before revascularisation and one month, one year, and two years after the procedure. Main endpoints were mean VascuQoL score changes, effect sizes of observed changes and the proportion reaching a minimally important difference (half a standard deviation change from baseline) during two years after revascularisation.

RESULTS

Patient reported VascuQoL scores were low at baseline (mean 2.68, 95% CI 1.18 - 4.17). After revascularisation, the mean VascuQoL score improved statistically significantly over time, with the largest improvement observed after one year (difference from baseline 2.02, 95% CI 1.75 - 2.29; p < .001). No differences in HRQoL change over time were observed between patients treated with endovascular approaches compared with bypass surgery. Approximately half the patients reached the minimally important threshold at one year (53%), which was largely maintained also at two years (41%).

CONCLUSION

While CLTI profoundly affected HRQoL, a large and clinically meaningful HRQoL increase was observed after revascularisation. This confirms the value of CLTI revascularisation on HRQoL and underlines the importance of including patient reported outcomes when evaluating revascularisation procedures in CLTI patients.

Reprint of: Early peripheral vascular interventions for claudication are associated with higher rates of late interventions and progression to chronic limb threatening ischemia

OBJECTIVE

Despite societal guidelines that peripheral vascular intervention (PVI) should not be the first-line therapy for intermittent claudication, a significant number of patients will undergo PVI for claudication within 6 months of diagnosis. The aim of the present study was to investigate the association of early PVI for claudication with subsequent interventions.

METHODS

We evaluated 100% of Medicare fee-for-service claims to identify all beneficiaries with a new diagnosis of claudication from January 1, 2015 to December 31, 2017. The primary outcome was late intervention, defined as any femoropopliteal PVI performed >6 months after the claudication diagnosis (through June 30, 2021). Kaplan-Meier curves were used to compare the cumulative incidence of late PVI for claudication patients with early (≤6 months) PVI vs those without early PVI. A hierarchical Cox proportional hazards model was used to evaluate the patient- and physician-level characteristics associated with late PVIs.

RESULTS

A total of 187,442 patients had a new diagnosis of claudication during the study period, of whom 6069 (3.2%) had undergone early PVI. After a median follow-up of 4.39 years (interquartile range, 3.62-5.17 years), 22.5% of the early PVI patients had undergone late PVI vs 3.6% of those without early PVI (P < .001). Patients treated by high use physicians of early PVI (≥2 standard deviations; physician outliers) were more likely to have received late PVI than were patients treated by standard use physician of early PVI (9.8% vs 3.9%; P < .001). Patients who had undergone early PVI (16.4% vs 7.8%) and patients treated by outlier physicians (9.7% vs 8.0%) were more likely to have developed CLTI (P < .001 for both). After adjustment, the patient factors associated with late PVI included receipt of early PVI (adjusted hazard ratio [aHR], 6.89; 95% confidence interval [CI], 6.42-7.40) and Black race (vs White; aHR, 1.19; 95% CI, 1.10-1.30). The only physician factor associated with late PVI was a majority of practice in an ambulatory surgery center or office-based laboratory, with an increasing proportion of ambulatory surgery center or office-based laboratory services associated with significantly increased rates of late PVI (quartile 4 vs quartile 1; aHR, 1.57; 95% CI, 1.41-1.75).

CONCLUSIONS

Early PVI after the diagnosis of claudication was associated with higher late PVI rates compared with early nonoperative management. High use physicians of early PVI for claudication performed more late PVIs than did their peers, especially those primarily delivering care in high reimbursement settings. The appropriateness of early PVI for claudication needs critical evaluation, as do the incentives surrounding the delivery of these interventions in ambulatory intervention suites.

Early peripheral vascular interventions for claudication are associated with higher rates of late interventions and progression to chronic limb threatening ischemia

OBJECTIVE

Despite societal guidelines that peripheral vascular intervention (PVI) should not be the first-line therapy for intermittent claudication, a significant number of patients will undergo PVI for claudication within 6 months of diagnosis. The aim of the present study was to investigate the association of early PVI for claudication with subsequent interventions.

METHODS

We evaluated 100% of Medicare fee-for-service claims to identify all beneficiaries with a new diagnosis of claudication from January 1, 2015 to December 31, 2017. The primary outcome was late intervention, defined as any femoropopliteal PVI performed >6 months after the claudication diagnosis (through June 30, 2021). Kaplan-Meier curves were used to compare the cumulative incidence of late PVI for claudication patients with early (≤6 months) PVI vs those without early PVI. A hierarchical Cox proportional hazards model was used to evaluate the patient- and physician-level characteristics associated with late PVIs.

RESULTS

A total of 187,442 patients had a new diagnosis of claudication during the study period, of whom 6069 (3.2%) had undergone early PVI. After a median follow-up of 4.39 years (interquartile range, 3.62-5.17 years), 22.5% of the early PVI patients had undergone late PVI vs 3.6% of those without early PVI (P < .001). Patients treated by high use physicians of early PVI (≥2 standard deviations; physician outliers) were more likely to have received late PVI than were patients treated by standard use physician of early PVI (9.8% vs 3.9%; P < .001). Patients who had undergone early PVI (16.4% vs 7.8%) and patients treated by outlier physicians (9.7% vs 8.0%) were more likely to have developed CLTI (P < .001 for both). After adjustment, the patient factors associated with late PVI included receipt of early PVI (adjusted hazard ratio [aHR], 6.89; 95% confidence interval [CI], 6.42-7.40) and Black race (vs White; aHR, 1.19; 95% CI, 1.10-1.30). The only physician factor associated with late PVI was a majority of practice in an ambulatory surgery center or office-based laboratory, with an increasing proportion of ambulatory surgery center or office-based laboratory services associated with significantly increased rates of late PVI (quartile 4 vs quartile 1; aHR, 1.57; 95% CI, 1.41-1.75).

CONCLUSIONS

Early PVI after the diagnosis of claudication was associated with higher late PVI rates compared with early nonoperative management. High use physicians of early PVI for claudication performed more late PVIs than did their peers, especially those primarily delivering care in high reimbursement settings. The appropriateness of early PVI for claudication needs critical evaluation, as do the incentives surrounding the delivery of these interventions in ambulatory intervention suites.

Two-year results of endovascular therapy for femoropopliteal artery disease in Japan during the introduction of drug-eluting devices

Although various devices and strategies were introduced into endovascular therapy, factors associated with chronic outcomes remain unclear. Therefore, this study aimed to build preliminary data of Japanese femoropopliteal lesions in a period of transition from non-drug to drug technology. This research was a multicenter, prospective, and observational study. A total of 1003 consecutive patients with a mean age of 73.6 ± 8.3 years from 67 institutes were registered from February 2017 to June 2018 in Japan. In addition to the baseline data, angiographic findings affecting primary patency were studied. Lesion length was 16.4 ± 9.6 cm, and chronic total occlusion was found in 42%. Calcified lesions were found in 75% of patients. The 1-year and 2-year freedom from target lesion revascularization were 81% and 75%, respectively, and maximum walking distance showed improvement over the two years (pre; 234 m ± 211 m, 1-year; 402 m ± 241 m, 2-year; 428 m ± 231 m). The independent predictors for primary patency were pre-procedure ankle-brachial index, history of minor amputation, ostium lesion, and drug-coated balloon use. Angiographic analysis revealed that only lesion length and full cover stent were related to primary patency. Two-year freedom from target vessel revascularization was 75% in the Japanese transitional period of drug-eluting devices. Maximum walking distance was improved and well maintained for up to 2-year.

Revascularization of intermittent claudicants leads to more chronic limb-threatening ischemia and higher amputation rates

BACKGROUND

There is an increasing incidence of peripheral arterial disease (PAD). The most common symptomatic presentation of PAD is intermittent claudication (IC), reproducible leg pain with ambulation. The progression of symptoms beyond IC is rare, and a nonprocedural approach of smoking cessation, supervised exercise therapy, and best medical therapy can mitigate progression of IC. Despite the lack of limb- or life-threatening sequelae of IC, invasive treatment strategies of IC have experienced rapid growth. Within our health care system, PAD is treated by multiple disciplines with varying practice patterns, providing an opportunity to investigate the progression of IC based on treatment strategy. This study aims to compare PAD progression and amputation in patients with IC with and without revascularization.

METHODS

This institutional review board-approved, single institute retrospective study reviewed all patients with an initial diagnosis of IC between June 11, 2003, and April 24, 2019. Revascularization was defined as endovascular or open. Time to chronic limb-threatening ischemia (CLTI) diagnosis and amputation were stratified by revascularization status using the Kaplan-Meier method. The association between revascularization status and each of CLTI progression and amputation using multivariable Cox regression, adjusting for demographic and clinical potential confounding variables was assessed.

RESULTS

We identified 1051 patients who met the inclusion criteria. Of these patients, 328 had at least one revascularization procedure and 723 did not. The revascularized group was younger than the nonrevascularized group (60.3 years vs 62.1 years; P = .013). There was no significant difference in sex or comorbidities in the two groups other than a higher rate of diabetes mellitus type 2 (32.3% vs 16.3%; P < .001) and COPD (4.3% vs 1.7%; P = .017) in the revascularized group. Multivariable Cox regression found revascularization of patients with IC to be significantly associated with the progression to CLTI (hazard ratio, 2.9; 95% confidence interval, 2.0-4.2) and amputation (hazard ratio, 4.5; 95% confidence interval, 2.2-9.5). These findings were also demonstrated in propensity-matched cohorts of 218 revascularized and 340 nonrevascularized patients.

CONCLUSIONS

Revascularization of patients with IC is associated with an increased rate of progression to CLTI and increased amputation rates. Given these findings, further studies are required to identify which, if any, patients with IC benefit from revascularization procedures.

Long-Term Results of Distal Bypass for Intermittent Claudication

BACKGROUND

Distal bypass (DB) is the optimal treatment for patients with critical limb ischemia (CLI). However, effectiveness of DB for patients with intermittent claudication (IC) remains uncertain. This study aimed to analyze long-term results of DB for IC patients (IC-DB) compared with those of DB for CLI patients (CLI-DB).

METHODS

Patients undergoing DB from January 2009 to July 2018 at a single institution were retrospectively reviewed. Operative details, primary and secondary patency, amputation free survival rate (AFS), and long-term exercise capacity using Barthel index were analyzed.

RESULTS

Out of 302 DB (245 patients), 49 IC-DB were performed in 43 patients: 38 males, mean age 70.3 ± 8.0 years, diabetes mellitus 51%, chronic renal failure with hemodialysis 7%. The Great saphenous vein was used in 47 limbs, the small saphenous vein in 1, and the arm vein in 1. These grafts were bypassed in a non-reversed fashion for 35 limbs, in an in-situ fashion in 9, and in a reversed fashion in 5. The mean operative time was 173 min. The mean follow-up was 25 ± 26 months. Primary and secondary patency of IC-DB was 79% and 94% at 1 year, 71% and 90% at 3 years, 65% and 90% at 5 years, which were significantly higher than those of CLI-DB (primary patency: P = .007, secondary patency: P = .025). AFS of IC-DB and CLI-DB was 100% and 77% at 1 year, 93% and 52% at 3 years, and 90% and 43% at 5 years (IC-DB vs. CLI-DB, p < .0001). Barthel index of IC-DB unchanged at discharge (median 100) and at the last visit (median 100), showing daily activity was maintained adequately.

CONCLUSIONS

DB could offer a promising approach for patients with IC because of durable graft patency, acceptable AFS, and maintenance of daily activity.

Absence of Long-Term Benefit of Revascularization in Patients With Intermittent Claudication: Five-Year Results From the IRONIC Randomized Controlled Trial

BACKGROUND

The long-term benefit of revascularization for intermittent claudication is poorly understood. The aim of this study was to investigate the long-term effectiveness and cost-effectiveness compared with a noninvasive approach.

METHODS

The IRONIC trial (Invasive Revascularization or Not in Intermittent Claudication) randomized patients with mild-to-severe intermittent claudication to either revascularization + best medical therapy + structured exercise therapy (the revascularization group) or best medical therapy + structured exercise therapy (the nonrevascularization group). The health-related quality of life short form 36 questionnaire was primary outcome and disease-specific health-related quality of life (vascular quality of life questionnaire) and treadmill walking distances were secondary end points. Health-related quality of life has previously been reported superior in the revascularization group at 1- and 2-year follow-up. In this study, the 5-year results were determined. The cost-effectiveness of the treatment options was analyzed from a payer/healthcare standpoint.

RESULTS

Altogether, 158 patients were randomized in a 1:1 ratio. Regarding the primary end point, no intergroup differences were observed for the short form 36 sum or domain scores from baseline to 5 years, except for the short form 36 role emotional domain score, with greater improvement in the nonrevascularization group (n=116, P=0.007). No intergroup differences were observed in the vascular quality of life questionnaire total and domain scores (n=116, NS) or in treadmill walking distances (n=91, NS). A revascularization strategy resulted in almost twice the cost per patient compared with a noninvasive treatment approach ($13 098 versus $6965, P=0.02).

CONCLUSIONS

After 5 years of follow-up, a revascularization strategy had lost its early benefit and did not result in any long-term improvement in health-related quality of life or walking capacity compared to a noninvasive treatment strategy. Revascularization was not a cost-effective treatment option from a payer/healthcare point of view.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01219842.

Supervised Exercise Therapy and Revascularization for Intermittent Claudication: Network Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

The aim of this study was to perform a comprehensive meta-analysis comparing all therapeutic modalities for intermittent claudication (IC), including best medical therapy (BMT) alone, percutaneous angioplasty (PTA), supervised exercise therapy (SET), and PTA combined with SET, to establish the optimal first-line treatment for IC.

BACKGROUND

IC is a common health problem that limits physical activity, results in decreased quality of life (QoL) and is associated with poor cardiovascular outcomes. Previous meta-analyses have attempted to combine data from randomized trials; however, none have combined data from all possible treatment combinations or synthesized QoL outcomes.

METHODS

Following a systematic review of the published research (conducted in December 2018) that identified 37 published randomized trials, a network meta-analysis was performed combining all possible IC treatment strategies.

RESULTS

Overall, 2,983 patients with IC were included (mean weighted age 68 years, 54.5% men). Comparisons were performed between BMT (n = 688, 28 arms) versus SET (n = 1,189, 35 arms) versus PTA (n = 511, 12 arms) versus PTA plus SET (n = 395, 8 arms). Mean weighted follow-up was 12 months (95% confidence interval: 9 to 23 months). Compared with BMT alone, PTA plus SET outperformed other treatment strategies, with a maximum walking distance gain of 290 m (95% credible interval: 180 to 390 m; p < 0.001). A variety of QoL assessments using validated tools were reported in 15 trials; PTA plus SET was superior to other treatments (Cohen's D = 1.8; 95% credible interval: 0.21 to 3.4).

CONCLUSIONS

In addition to BMT, PTA combined with SET seems to be the optimal first-line treatment strategy for IC in terms of maximum walking distance and QoL improvement.

Cost-effectiveness of revascularization in patients with intermittent claudication

BACKGROUND

Revascularization is a treatment option for patients with intermittent claudication. However, there is a lack of evidence to support its long-term benefits and cost-effectiveness. The aim of this study was to compare the cost-effectiveness of revascularization and best medical therapy (BMT) with that of BMT alone.

METHODS

Data were used from the IRONIC (Invasive Revascularization Or Not in Intermittent Claudication) RCT where consecutive patients with mild-to-severe intermittent claudication owing to aortoiliac or femoropopliteal disease were allocated to either BMT alone (including a structured, non-supervised exercise programme) or to revascularization together with BMT. Inpatient and outpatient costs were obtained prospectively over 24 months of follow-up. Mean improvement in quality-adjusted life-years (QALYs) was calculated based on responses to the EuroQol Five Dimensions EQ-5D-3 L™ questionnaire. Cost-effectiveness was assessed as the cost per QALY gained.

RESULTS

A total of 158 patients were randomized, 79 to each group. The mean cost per patient in the BMT group was €1901, whereas it was €8280 in the group treated with revascularization in addition to BMT, with a cost difference of €6379 (95 per cent c.i. €4229 to 8728) per patient. Revascularization in addition to BMT resulted in a mean gain in QALYs of 0·16 (95 per cent c.i. 0·06 to 0·24) per patient, giving an incremental cost-effectiveness ratio of €42 881 per QALY.

CONCLUSION

The costs associated with revascularization together with BMT in patients with intermittent claudication were about four times higher than those of BMT alone. The incremental cost-effectiveness ratio of revascularization was within the accepted threshold for public willingness to pay according to the Swedish National Guidelines, but exceeded that of the UK National Institute for Health and Care Excellence guidelines.

Primary Stenting of the Superficial Femoral Artery in Patients with Intermittent Claudication Has Durable Effects on Health-Related Quality of Life at 24 Months: Results of a Randomized Controlled Trial

BACKGROUND

Intermittent claudication (IC) is commonly caused by lesions in the superficial femoral artery (SFA), yet invasive treatment is still controversial and longer term patient-reported outcomes are lacking. This prospective randomized trial assessed the 24-month impact of primary stenting with nitinol self-expanding stents compared to best medical treatment (BMT) alone in patients with stable IC due to SFA disease on health-related quality of life (HRQoL).

METHODS

One hundred patients with stable IC due to SFA disease treated with BMT were randomized to either stent (n = 48) or control (n = 52) group. HRQoL assessed by Short Form 36 Health Survey (SF-36) and EuroQoL 5-dimensions (EQ5D) 24 months after treatment were primary outcome measures. Walking Impairment Questionnaire, ankle-brachial index (ABI), and walking distance were secondary outcomes.

RESULTS

Significantly better SF-36 Physical Component Summary (P = 0.024) and physical domain scores such as Physical Function (P = 0.012), Bodily Pain (P = 0.002), General Health (P = 0.037), and EQ5D (P = 0.010) were reported in intergroup comparison between the stent and the control group. Both ABI (from 0.58 ± 0.11 to 0.85 ± 0.18; P < 0.001 in the stent group and from 0.63 ± 0.17 to 0.69 ± 0.18; P = 0.036 in the control group) and walking distance (from 170 ± 90 m to 616 ± 375 m; P < 0.001 in the stent group and from 209 ± 111 m to 331 ± 304 m; P = 0.006 in the control group) improved significantly in intragroup comparisons.

CONCLUSIONS

In patients with IC caused by lesions in the SFA, primary stenting compared to BMT alone was associated with significant improvements in HRQoL, ABI, and walking distance durable up to 24 months of follow-up. Clinical Trial Registration http://www.clinicaltrials.gov . Unique Identifier: NCT01230229.

Risk of major amputation in patients with intermittent claudication undergoing early revascularization

BACKGROUND

Revascularization is being used increasingly for the treatment of intermittent claudication and yet few studies have reported the long-term outcomes of this strategy. The aim of this study was to compare the long-term outcome of patients with intermittent claudication who underwent revascularization compared with a group initially treated without revascularization.

METHODS

Patients with symptoms of intermittent claudication and a diagnosis of peripheral arterial disease were recruited from outpatient clinics at three hospitals in Queensland, Australia. Based on variation in the practices of different vascular specialists, patients were either treated by early revascularization or received initial conservative treatment. Patients were followed in outpatient clinics using linked hospital admission record data. The primary outcome was the requirement for major amputation. Kaplan-Meier curves, Cox regression and competing risks analyses were used to compare major amputation rates.

RESULTS

Some 456 patients were recruited; 178 (39·0 per cent) underwent early revascularization and 278 (61·0 per cent) had initial conservative treatment. Patients were followed for a mean(s.d.) of 5·00(3·37) years. The estimated 5-year major amputation rate was 6·2 and 0·7 per cent in patients undergoing early revascularization and initial conservative treatment respectively (P = 0·003). Early revascularization was associated with an increased requirement for major amputation in models adjusted for other risk factors (relative risk 5·40 to 4·22 in different models).

CONCLUSION

Patients presenting with intermittent claudication who underwent early revascularization appeared to be at higher risk of amputation than those who had initial conservative treatment.

Assessment of Minimum Important Difference and Substantial Clinical Benefit with the Vascular Quality of Life Questionnaire-6 when Evaluating Revascularisation Procedures in Peripheral Arterial Disease

OBJECTIVES

Patient reported outcomes are increasingly used to assess outcomes after peripheral arterial disease (PAD) interventions. VascuQoL-6 (VQ-6) is a PAD specific health-related quality of life (HRQoL) instrument for routine clinical practice and clinical research. This study assessed the minimum important difference for the VQ-6 and determined thresholds for the minimum important difference and substantial clinical benefit following PAD revascularisation.

MATERIALS AND METHODS

This was a population-based observational cohort study. VQ-6 data from the Swedvasc Registry (January 2014 to September 2016) was analysed for revascularised PAD patients. The minimum important difference was determined using a combination of a distribution based and an anchor-based method, while receiver operating characteristic curve analysis (ROC) was used to determine optimal thresholds for a substantial clinical benefit following revascularisation.

RESULTS

A total of 3194 revascularised PAD patients with complete VQ-6 baseline recordings (intermittent claudication (IC) n = 1622 and critical limb ischaemia (CLI) n = 1572) were studied, of which 2996 had complete VQ-6 recordings 30 days and 1092 a year after the vascular intervention. The minimum important difference 1 year after revascularisation for IC patients ranged from 1.7 to 2.2 scale steps, depending on the method of analysis. Among CLI patients, the minimum important difference after 1 year was 1.9 scale steps. ROC analyses demonstrated that the VQ-6 discriminative properties for a substantial clinical benefit was excellent for IC patients (area under curve (AUC) 0.87, sensitivity 0.81, specificity 0.76) and acceptable in CLI (AUC 0.736, sensitivity 0.63, specificity 0.72). An optimal VQ-6 threshold for a substantial clinical benefit was determined at 3.5 scale steps among IC patients and 4.5 in CLI patients.

CONCLUSIONS

The suggested thresholds for minimum important difference and substantial clinical benefit could be used when evaluating VQ-6 outcomes following different interventions in PAD and in the design of clinical trials.