Institutional Volume and Initial Results for Endovascular Treatment for Chronic Occlusive Lower-Extremity Artery Disease: A Report From the Japanese Nationwide Registry

PURPOSE

Chronic total occlusion (CTO) remains as a major target for endovascular treatment (EVT) in improving symptomatic lower-extremity artery disease (LEAD). However, despite the technical demand and learning curve for the procedure, volume-outcome relationship of EVT targeted for CTO in symptomatic LEAD remains unclear.

MATERIALS AND METHODS

Data were obtained from a nationwide registry for EVT procedures limited to the Japanese Association of Cardiovascular Intervention and Therapeutics between January 2018 and December 2020 from 660 cardiovascular centers in Japan. In total, 96 099 patients underwent EVT for symptomatic LEAD, and 41 900 (43.6%) underwent CTO-targeted EVTs during the study period. Institutional volume was classified into quartiles. The association of institutional volumes with short-term outcomes was explored using the generalized linear mixed model using a logit link function, in which, interinstitution variability was used as a random effect.

RESULTS

The median institutional volume for all EVT cases per quartile was 29, 68, 125, and 299 cases/year for the first, second, third, and fourth quartiles, respectively. With each model analysis, the adjusted odds ratios (ORs) for technical success were significantly lower in patients who underwent EVT in institutions within the first quartile (<52 cases/year) than in the other quartiles (P < .01, respectively). On the contrary, the adjusted ORs for procedural complications were significantly higher in the first and second quartiles than in the third and fourth quartiles (P < .01, respectively).

CONCLUSION

In contemporary Japanese EVT practice, a higher institutional volume but not operator volume was associated with a higher technical success rate and a lower procedural complication rate in patients with symptomatic LEAD involving CTO lesions.

CLINICAL IMPACT

EVT for CTO lesions is still challenging for clinicians because of difficulties of wire/devise crossing or high procedural complications rate. Our study demonstrated that a higher institutional volume but not operator volume was associated with a higher technical success rate and a lower procedural complication rate in patients with symptomatic LEAD involving CTO lesions. In contemporary Japanese practice, a higher institutional experience has better impacts on short-term clinical outcomes. Future research should determine the relationship between institutional volume and long-term clinical outcomes.

Impact of Institutional Volume on Critical In-Hospital Complications Adjusted for Patient- and Limb-Related Characteristics: An Analysis of a Nationwide Japanese Registry of Endovascular Interventions for PAD

PURPOSE

To investigate the incidence and clinical predictors, including institutional annual case volume, of critical in-hospital complications after endovascular therapy (EVT) for peripheral artery disease (PAD).

MATERIALS AND METHODS

The data were extracted from the nationwide registry of peripheral interventions in Japan [Japanese EVT (J-EVT)] between 2012 and 2017. A total of 92,224 EVT cases either for chronic limb-threatening ischemia (CLTI) or intermittent claudication were included in the analysis. The primary outcome measure was critical in-hospital complications, which were defined as a composite of urgent surgery and in-hospital death within 30 days after EVT. The institutional volume was classified into quartiles. The association of institutional volume, as well as baseline characteristics, with the critical in-hospital complications was explored using a multivariable logistic regression model with multiple imputation for missing data. Results are presented as the adjusted odds ratio (OR) with the 95% confidence intervals (CI).

RESULTS

The estimated prevalence of critical in-hospital complications was 0.3% (95% CI 0.3% to 0.4%). The following 10 patient- and limb-related characteristics were identified as independent risk factors for critical in-hospital complications: (1) female sex (OR 1.75, 95% CI 1.36 to 2.25), (2) age ≥75 years (OR 1.60, 95% CI 1.06 to 2.40), (3) CLTI (OR 2.12, 95% CI 1.47 to 3.05), (4) nonambulatory status (OR 1.66, 95% CI 1.23 to 2.24), (5) regular dialysis (OR 1.35, 95% CI 1.02 to 1.77), (6) cerebrovascular disease (OR 1.76, 95% CI 1.33 to 2.33), (7) urgent revascularization (OR 5.10, 95% CI 3.64 to 7.13), (8) aortoiliac TASC II D lesion (OR 3.65, 95% CI 2.51 to 5.33), (9) femoropopliteal TASC II D lesion (OR 1.77, 95% CI 1.24 to 2.52), and (10) infrapopliteal TASC D lesion (OR 1.52, 95% CI 1.08 to 2.13). In addition, the 4th quartile of the institutional volume (≥158 cases/year), but not the 2nd or 3rd quartile, had a significantly and independently lower risk of critical in-hospital complications than the 1st quartile (OR 0.13, 95% CI 0.07 to 0.23).

CONCLUSION

After EVT for symptomatic PAD, 0.3% of the population encountered critical in-hospital complications. A higher institutional volume was significantly associated with a lower risk of critical in-hospital complications.

Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

GUIDELINE SUMMARY

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Global vascular guidelines on the management of chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Prognostic Impact of Revascularization in Poor-Risk Patients With Critical Limb Ischemia: The PRIORITY Registry (Poor-Risk Patients With and Without Revascularization Therapy for Critical Limb Ischemia)

OBJECTIVES

The authors sought to investigate the prognostic impact of revascularization for poor-risk CLI patients in real-world settings.

BACKGROUND

Critical limb ischemia (CLI) is often accompanied with various comorbidities, and frailty is not rare in the population. Although previous studies suggested favorable outcomes of revascularization for CLI patients, those studies commonly included the healthier, that is, less frail patients.

METHODS

This was a multicenter prospective observational study, registering patients who presented with CLI and who required assistance for their daily lives because of their disability in activities of daily living (ADL) and/or impairment of cognitive function. Revascularization was either planned (revascularization group) or not planned (non-revascularization group). The primary endpoint was 1-year survival, and was compared between the revascularization and non-revascularization groups, using the propensity score-matching method.

RESULTS

Between January 2014 and April 2015, a total of 662 patients were registered, of those 100 non-revascularization patients were included. A total of 625 patients (94.4%) completed the 1-year follow-up. Death was observed in 223 patients (33.7%). After propensity score matching, the 1-year survival rate was 55.9% in the revascularization group versus 51.0% in the non-revascularization group, with no significant difference (p = 0.120). In the subgroups alive at 1 year after revascularization, health-related quality of life was significantly improved compared with baseline, whereas ADL scores were unchanged from baseline and still remained significantly worse than before CLI onset.

CONCLUSIONS

The 1-year overall survival rate was not significantly different between the revascularization and non-revascularization groups in poor-risk CLI patients. (Poor-Risk Patients With and Without Revascularization Therapy for Critical Limb Ischemia; [PRIORITY Registry]; UMIN000012871).