Pedal arterial calcification score is associated with the risk of major amputation in chronic limb-threatening ischemia

Influence of a Novel Morphology-Driven Classification on Limb Salvage after Isolated Tibial Intervention for Chronic Limb Threatening Ischemia

BACKGROUND

Infra-popliteal interventions for chronic limb-threatening ischemia (CLTI) can be impacted by the morphology of the tibial vessels. The aim of this study was to examine the impact of a novel morphology-driven classification on the outcomes of isolated tibial intervention for CLTI.

METHODS

A database of patients undergoing isolated tibial interventions for CLTI at a single center between 2010 and 2020 was retrospectively queried. Patients with isolated Infra-popliteal disease were identified, and their anatomy was scored as present or absent for lesion calcification (1 point), target vessel diameter<3.0 mm (1 point), lesion length>300mm (1 point) and poor pedal runoff score (1 point). Patients were then divided into three groups: low-risk (0 or 1 points), moderate-risk (2 points), and high-risk (3 or 4 points). Intention to treat analysis by the patient was performed. Limb-based patency (the absence of reintervention, occlusion, critical stenosis (>70%), or hemodynamic compromise with ongoing symptoms of CLTI as it related to the patency of the preoperatively determined target artery pathway) was assessed. Patient-orientated outcomes of amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; Above ankle amputation of the index limb or major re-intervention (new bypass graft, jump/interposition graft revision) were evaluated.

RESULTS

1607 patients (55% male, average age 60 years, 3846 vessels) underwent tibial intervention for CLTI. The majority of the patients were diabetic and of Hispanic. origin Morphologically, 27%, 31%, and 42% of the vessels were categorized as low risk, moderate risk, and high risk, respectively. There was a significant worsening of the infra-popliteal Global Limb Anatomic Staging System (GLASS) grading as the morphological risk increased. The 30-day major adverse cardiac events (MACE) were equivalent across the groups and were under the stated objective performance goal (OPG) of ≤10%. In contrast, both the 30-day MALE and the 30-day Major Amputations were significantly different across the groups, with the low-risk group remaining under the OPG of ≤9% and ≤4%, respectively, while the moderate-risk and high-risk exceeded the goal threshold. For the OPG. Freedom from MALE was 60±5%, 46±5%, and 22±9% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± SEM; p =0.008. Overall amputation-free survival (AFS) was 55±5%, 37±6%, and 18±7% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± SEM; p=0.003).

CONCLUSIONS

Tibial anatomic morphology impacts isolated tibial endovascular intervention with adverse morphology associated with poorer short and long-term outcomes. Risk stratification based on anatomic predictors should be an additional consideration as one intervenes on infra-popliteal vessels for CLTI.

Pedal medial arterial calcification influences the outcomes of isolated infra-malleolar interventions for chronic limb-threatening ischemia

OBJECTIVE

Inframalleolar disease is present in most diabetic patients presenting with tissue loss. Inframalleolar (pedal) artery disease and pedal medial arterial calcification (pMAC) are associated with major amputation in patients with chronic limb-threatening ischemia (CLTI). This study aimed to examine the impact of pMAC on the outcomes after isolated inframalleolar (pedal artery) interventions.

METHODS

A database of lower extremity endovascular intervention for patients with tissue loss between 2007 and 2022 was retrospectively queried. Patients with CLTI were selected, and those undergoing isolated inframalleolar intervention on the dorsalis pedis and medial and lateral tarsal arteries and who had foot x-rays were identified. X-rays were assessed blindly for pMAC and scored on a scale of 0 to 5. Patients with concomitant superficial femoral artery and tibial interventions were excluded. Intention to treat analysis by the patient was performed. Amputation-free survival (survival without major amputation) was evaluated.

RESULTS

A total of 223 patients (51% female; 87% Hispanic; average age, 66 years; 323 vessels) underwent isolated infra-malleolar intervention for tissue loss. All patients had diabetes, 96% had hypertension, 79% had hyperlipidemia, and 63% had chronic renal insufficiency (55% of these were on hemodialysis). Most of the patients had Wound, Ischemia, and foot Infection (WIfI) stage 3 disease and had various stages of pMAC: severe (score = 5) in 48%, moderate (score = 2-4) in 31%, and mild (score = 0-1) in 21% of the patients. Technical success was 94%, with a median of one vessel treated per patient. All failures were in severe pMAC. Overall, major adverse cardiovascular events was 0.9% at 90 days after the procedure. Following the intervention, most patients underwent a planned forefoot amputation (single digit, multiple digits, ray amputation, or trans-metatarsal amputation). WIfI ischemic grade was improved by 51%. Wound healing at 3 months was 69%. Those not healing underwent below-knee amputations. The overall 5-year amputation-free survival rate was 35% ± 9%. The severity of pMAC was associated with decreased AFS.

CONCLUSIONS

Increasing severity of pMAC influences the technical and long-term outcomes of infra-malleolar intervention in diabetes. Severe pMAC is associated with amputation and should be considered as a variable in the shared decision-making of diabetic patients with CLTI.

Transcatheter Arterialization of the Deep Veins for Limb Salvage

Critical limb-threatening ischemia is the most advanced stage of peripheral arterial disease, and patients with this problem represent a group at very high risk of limb loss. Until recently, patients with severe disease in the foot that was unreconstructable through the arterial system were relegated to treatment with wound care, pain management, and ultimately often faced major amputation. In recent investigations into the use of a percutaneous approach to venous arterialization, transcatheter arterialization of the deep veins has been evaluated as a mechanism to improve oxygen delivery to the foot in patients faced with the prospect of limb loss. Identifying patients who would benefit from this approach and a critical evaluation of the technique are provided along with expected outcomes. While the procedure remains in its infancy, early outcomes are promising, and continued advancement and improvement will further enhance options for these patients.

Pedal medial arterial calcification in diabetic foot ulcers: A significant risk factor of amputation and mortality

AIMS

Pedal medial arterial calcification (MAC) is frequently observed in individuals with diabetic foot ulcers (DFUs). However, the impact of pedal MAC on individuals with DFUs remains uncertain. The main aim of this study was to evaluate the association between pedal MAC with amputation and mortality outcomes.

METHODS

A prospective, observational cohort study was conducted at West China Hospital from January 2012 to December 2021. Logistic regression analyses, Kaplan-Meier survival method, and Cox proportional hazards models were employed to evaluate the relationship between pedal MAC and amputation as well as mortality.

RESULTS

A total of 979 patients were enrolled in the study. Peripheral artery disease (PAD) was observed in 53% of patients with DFUs, and pedal MAC was found in 8%. Over a median follow-up of 46 (23-72) months, foot amputation was performed on 190 patients, and mortality occurred in 246 patients. Pedal MAC showed a significant association with amputation both in unadjusted analysis (odds ratio [OR] = 2.98, 95% confidence interval [CI] = 1.86-4.76, p < .001) and after adjusting sex, age, albumin levels, hemoglobin levels, and diabetic retinopathy status (OR 2.29, 95% CI 1.33-3.93, p = .003). The risk of amputation was found to be twofold higher in individuals with PAD and pedal MAC compared to those with PAD alone (OR 2.05, 95% CI 1.10-3.82, p = .024). Furthermore, the presence of pedal MAC was significantly associated with an increased risk of mortality (p = .005), particularly among individuals with DFUs but without PAD (HR 4.26, 95% CI 1.90-9.52, p < .001), rather than in individuals presenting with both DFUs and PAD.

CONCLUSION

The presence of pedal MAC is significantly associated with both amputation and mortality in individuals with DFUs. Moreover, pedal MAC could provide additional value to predict amputation other than PAD.

An ultrasound-based femoral artery calcification score

Objective

Duplex ultrasound (US) of the lower extremities is commonly used to assess patients with lower extremity atherosclerosis. Arterial calcification can often be visualized in these images; however, efforts to quantify its extent have been limited. We, thus, sought to develop a new scoring system to measure calcification on duplex US studies of the femoral artery and correlate it with standard computed tomography (CT)-based methods. We then made preliminary attempts to correlate US-based femoral artery calcification scores with limb-specific outcomes in patients with peripheral arterial disease.

Methods

Patients who underwent CT evaluation of the lower extremities and arterial duplex US of either lower extremity within 6 months of each examination were included in the study. CT-based calcium scores of the femoral artery were generated using calcium scoring software. To determine the US score, five standard arterial segments (ie, common femoral artery, proximal superficial femoral artery [SFA], mid-SFA, distal SFA, and above the knee popliteal artery) were scored using a scale of 0 to 2 (0, a completely normal vessel segment; 1, a vessel with hyperechoic irregularities of the vessel wall; and 2, clear anechoic shadowing). The available scores were then averaged to yield a single femoral calcium score for each leg. Predictors of femoral calcification scores were then assessed and compared with the CT-based methods. The correlation between the US- and CT-based femoral calcification was assessed, and then the association between the US-based femoral calcification score and limb outcomes was evaluated.

Results

A total of 113 patients met the inclusion criteria and were included in the final analysis. US-based calcification scores were increased in patients with diabetes, renal failure, and the presence of chronic limb threatening ischemia similar to CT-based femoral calcification. The US- and CT-based calcification scores showed a moderate to strong correlation (r = 0.64). An elevated US-based femoral artery calcification score was associated with decreased amputation-free survival.

Conclusions

A novel US-based method shows promise as a simple method for quantifying the extent of femoral artery calcification in patients with peripheral arterial disease. The US-based method correlates with standard CT-based methods. Preliminary studies show that it could be useful for predicating outcomes for patients with peripheral arterial disease.

Clinical implications of diverse calcification patterns in endovascular therapy for femoral-popliteal arterial occlusive disease

OBJECTIVE

The aim of this study was to investigate whether intimal arterial calcification (IAC) and medial arterial calcification (MAC) are correlated with the various clinical outcomes following endovascular therapy (EVT) for peripheral arterial disease (PAD).

METHODS

This single-center retrospective study comprised 154 consecutively hospitalized individuals with PAD who underwent EVT for de novo femoral-popliteal calcific lesions from January 2016 to July 2021. The predominant calcification patterns of IAC and MAC were assessed using a semi-quantitative computed tomography scoring system. The Kaplan-Meier method and Cox regression were conducted to evaluate the correlations between calcification patterns and medium- to long-term outcomes.

RESULTS

The distribution of calcification patterns was as follows: IAC in 111 patients (72%) and MAC in 43 patients (28%). No remarkable variation was noted between the IAC and MAC groups regarding age (P = .84) and gender (P = .23). The MAC group indicated lower rates of 4-year primary patency, assisted primary patency, secondary patency, and amputation-free survival (AFS) compared with the IAC group (24% ± 7% vs 40% ± 6%; P = .003; 30% ± 8% vs 51% ± 6%; P = .001; 51% ± 8% vs 65% ± 5%; P = .004; and 43% ± 9% vs 76% ± 5%; P < .001, respectively). There was no significant difference in the rate of freedom from clinically driven target lesion revascularization between the MAC and IAC groups (63% ± 10% vs 73% ± 5%; P = .26). Stepwise multivariable Cox regression analysis demonstrated that MAC was associated with poor patency (hazard ratio, 1.81; 95% confidence interval, 1.12-2.93; P = .016) and AFS (hazard ratio, 2.80; 95% confidence interval, 1.52-5.16; P = .001).

CONCLUSIONS

Compared with IAC, MAC is independently associated with lower medium- to long-term patency and AFS after EVT for de novo femoral-popliteal occlusive lesions.

Medial arterial calcification score is associated with increased risk of major limb amputation

OBJECTIVE

The pedal medial arterial calcification (MAC) score has been associated with risk of major limb amputation in patients with chronic limb-threatening ischemia. This study aimed to validate the pedal MAC scoring system in a multi-institutional analysis to validate its usefulness in limb amputation risk prediction.

METHODS

A multi-institution, retrospective study of patients who underwent endovascular or open surgical infrainguinal revascularization for chronic limb-threatening ischemia was performed. MAC scores of 0 to 5 were assigned based on visible calcified arteries on foot X ray then trichotomized (0-1, 2-4, 5) for analysis. The primary outcome was major limb amputation at 6 months. Adjusted Kaplan-Meier models were used to analyze time-to-major amputation across groups.

RESULTS

There were 176 patients with 184 affected limbs (mean age, 66 years; 61% male; 60% White), of whom 97% presented with a wound. The MAC score was 0 in 41%, 1 in 9%, 2 in 13%, 3 in 11%, 4 in 13%, and 5 in 13% of the limbs. There were 26 major amputations (14%) and 16 deaths (8.7%) within 6 months. Patients with MAC 5 had a significantly higher risk of major limb amputation than both the 0 to 1 and 2 to 4 groups (P = .001 and P = .044, respectively), and lower overall amputation-free survival (log-rank P = .008).

CONCLUSIONS

Pedal MAC score is a reproducible and generalizable measure of inframalleolar arterial disease that can be used with Wound, Ischemia, and foot Infection staging to predict major limb amputation in patients with chronic limb-threatening ischemia.

Hybrid superficial venous arterialization and endovascular deep venous arterialization

We report on two venous arterialization (VA) techniques for treatment of CLTI in patients traditionally considered as having no treatment options for standard arterial endovascular or surgical bypass procedures. Screening and the preprocedural workup findings are outlined as deciding factors in determining a patient's fitness for the two techniques, with a focus on careful preprocedure arterial duplex ultrasound and assessment for vein suitability. Cardiac and infection screening are also factors in determining patient suitability for VA. In addition, radiographic assessment for the presence of medial artery calcification, which is used as a marker of technical difficulty and is a predictor of poor outcomes, is required. Ultimately, anatomic factors are used to determine the decision between hybrid superficial VA and or endovascular deep VA. Those with an occluded anterior tibial artery and suitable great saphenous vein are prioritized to hybrid superficial VA, and those with an occluded posterior tibial artery to endovascular deep VA. Both procedures are described in detail in this report of vascular and surgical techniques.

A Systematic Review and Meta-Analysis on Sex-Based Disparities in Patients with Chronic Limb Threatening Ischemia Undergoing Revascularization

BACKGROUND

This systematic review and meta-analysis sought to describe the prognostic implications of sex on the clinical outcomes of patients undergoing interventions for chronic limb threatening ischemia (CLTI).

METHODS

Studies were systematically searched across 7 databases from inception to August 25, 2021 and rerun on October 11, 2022. Studies focusing on patients with CLTI undergoing open surgery, endovascular treatment (EVT), or hybrid procedures were included if sex-based differences were associated with a clinical outcome. Two independent reviewers screened studies for inclusion, extracted data, and assessed risk of bias using the Newcastle-Ottawa scale. Primary outcomes included inpatient mortality, major adverse limb events (MALE), and amputation-free survival (AFS). Meta-analyses were performed using random effects models and reported pooled odds ratio (pOR) and 95% confidence interval (CI).

RESULTS

A total of 57 studies were included in the analysis. A meta-analysis of 6 studies demonstrated that female sex was associated with statistically higher inpatient mortality compared to male sex undergoing open surgery or EVT (pOR, 1.17; 95% CI: 1.11-1.23). Female sex also demonstrated a trend toward increased limb loss in those undergoing EVT (pOR, 1.15; 95% CI: 0.91-1.45) and open surgery (pOR 1.46; 95% CI: 0.84-2.55). Female sex also had a trend toward higher MALE (pOR, 1.06; 95% CI, 0.92-1.21) in 6 studies. Finally, female sex had a trend toward worse AFS (pOR, 0.85; 95% CI, 0.70-1.03) in 8 studies.

CONCLUSIONS

Female sex was significantly associated with higher inpatient mortality and a trend toward higher MALE following revascularization. Female sex trended toward worse AFS. The reasons for these disparities are likely multifaceted on patient, provider, and systemic levels and should be explored to identify solutions for decreasing these health inequities across this vulnerable patient population.

Presenting limb severity is associated with long-term outcomes after infrainguinal revascularization for chronic limb-threatening ischemia

OBJECTIVE

The SVS Wound, Ischemia, foot Infection (WIfI) limb staging system was established to estimate risk of major amputation in chronic limb-threatening ischemia (CLTI) and better stratify outcomes comparisons. There is little data on treatment outcomes beyond 1 year based on presenting WIfI stage.

METHODS

This is a single-institution retrospective study of 413 patients who underwent infrainguinal revascularization for CLTI (2011-2021) with data available for WIfI staging. Patient characteristics and outcomes were gathered from the electronic medical record. Data were analyzed based on presenting WIfI stage and initial treatment received at our center.

RESULTS

Presenting WIfI stages were 1 to 2 (23%), 3 (27%), and 4 (50%). Index revascularization approach was endoluminal (59%), autogenous vein bypass (29%), or non-autogenous bypass (13%). Operative mortality within 30 days was 2.9% and was not associated with WIfI stage or revascularization approach. Median limb follow-up time was 502 days (interquartile range [IQR], 112-1256 days), and median survival follow-up time was 932 days (IQR, 343-1770 days). Major amputation or death occurred in 19% and 46% of patients at median times of 119 days (IQR, 28-314 days) and 739 days (IQR, 204-1475 days), respectively. WIfI stage was independently associated with major amputation (P = .001), as was initial revascularization approach (P = .01). In a Cox proportional hazards model, factors independently associated with major amputation were male sex (hazard ratio [HR], 1.4; 95% confidence interval [CI], 1.04-2.0; P = .03), diabetes (HR, 1.8; 95% CI, 1.3-2.5; P = .001), WIfI stage 4 (HR, 2.3; 95% CI, 1.5-3.5; P < .001), and non-autogenous bypass (HR, 2.9; 95% CI, 2.1-4.2; P < .001). In a Cox proportional hazards model for mortality, independently associated factors were age (HR, 1.04; 95% CI, 1.02-1.05; P < .001), end-stage renal disease (HR, 2.8; 95% CI, 1.9-4.0; P < .001), congestive heart failure (HR, 1.9; 95% CI, 1.4-2.5; P < .001), chronic obstructive pulmonary disease (HR, 1.5; 95% CI, 1.1-2.1; P = .02), and WIfI stage 4 (HR, 1.6; 95% CI, 1.04-2.2; P = .03). Among those presenting with WIfI stage 4 limbs, Kaplan-Meier estimated rates of freedom from major amputation or death at 2 years were 71% ± 3.7% and 68% ± 3.5%, respectively. In an inverse propensity weighted Cox proportional hazards model, non-white race (HR, 1.5; 95% CI, 1.01-2.2; P = .047), diabetes (HR, 2.0; 95% CI, 1.2-3.3; P = .008), Global Anatomic Staging System infrapopliteal grade (HR, 1.2; 95% CI, 1.05-1.3; P = .005), non-autogenous bypass (HR, 3.2; 95% CI, 1.9-5.3; P < .001), and endoluminal revascularization (HR, 2.6; 95% CI, 1.6-4.3; P < .001) were independently associated with major amputation in the WIfI stage 4 subgroup.

CONCLUSIONS

Presenting WIfI stage is strongly associated with long-term risks of major amputation and death following infrainguinal revascularization for CLTI and should be used to stratify outcomes comparisons. Effective revascularization is critical in WIfI stage 4 disease, and autogenous vein bypass provides durable long-term limb preservation.

Severe inframalleolar disease is an independent predictor of adverse limb outcomes after endovascular revascularization in chronic limb-threatening ischemia

OBJECTIVE

In the present study, we evaluated the effects of inframalleolar (IM) disease on the occurrence of major adverse limb events (MALE) in patients undergoing endovascular revascularization for chronic limb-threatening ischemia (CLTI).

METHODS

Patients who had undergone endovascular revascularization for CLTI between January 2015 and December 2019 at two university-affiliated hospitals were reviewed retrospectively. Patients with severe IM disease (pedal score of 2) were compared with those with mild to moderate IM disease (score of 0 or 1) using the Global Vascular Guidelines. The primary outcome was MALE (open revascularization, acute leg ischemia, major amputation). The secondary outcomes were mortality, reintervention, major adverse cardiac events, and perioperative complications ≤30 days after endovascular revascularization, primary limb-based patency, and the occurrence of any limb event (defined as any amputation, acute leg ischemia, or open revascularization). Kaplan-Meier estimates were used to compare the primary outcome, and the Cox proportion hazard model was used to assess the effects of IM disease.

RESULTS

The study included 167 limbs in 149 patients (36% female; mean age, 74 ± 12 years). Severe IM disease was identified in 71 limbs (43%). No differences were found in the baseline characteristics, except for a higher prevalence of dyslipidemia in the patients with severe IM disease (66% vs 43%; P = .003). Most patients in both groups had had a WIfI (Wound, Ischemia, foot Infection) score of 4 (severe IM disease, 64%; vs mild to moderate IM disease, 57%; P = .462) and GLASS (global limb anatomic severity scale) III anatomy (severe IM disease, 54%; vs mild to moderate IM disease, 48%; P = .752). The Kaplan-Meier estimates showed that severe IM disease was associated with lower freedom from MALE (69% vs 82%; P = .026). The Cox proportion hazard regression model showed that severe IM disease was an independent predictor of increased MALE and amputation risk (hazard ratio, 1.715; 95% confidence interval, 1.015-2.896; P = .044) after adjusting for covariates. During follow-up, patients with severe IM disease had had mortality (27% vs 31%; P = .567) and reintervention (42% vs 38%; P = .608) similar to those for patients with mild to moderate IM disease. Primary limb-based patency was also similar (79% vs 84%; P = .593) at a mean follow-up of 3.8 ± 0.8 years.

CONCLUSIONS

Severe IM disease was prevalent in 43% of limbs that had undergone endovascular revascularization for CLTI and was associated with lower freedom from MALE. Severe IM disease also independently increased the hazard of adverse limb outcomes and amputations in patients with CLTI by >70%, highlighting its importance as a measure of foot perfusion.

Multidisciplinary approach to decreasing major amputation, improving outcomes, and mitigating disparities in diabetic foot and vascular disease

Major nontraumatic lower extremity amputation (LEA) is a morbid complication of longstanding or poorly controlled diabetes and/or end-stage peripheral artery disease. Incidence of major LEAs consistently declined during the 1990s and 2000s, but rates have plateaued or increased in many regions during the past decade. Marked racial, ethnic, socioeconomic, and geographic disparities in risk of LEA persist and are related to inequalities in access to care and differential rates of attempted limb preservation. Multidisciplinary diabetic foot care (MDFC) is increasingly recognized as a necessary model for optimal management of patients with diabetic foot and vascular disease. This article reviews the role of MDFC in reducing major LEAs and the specific ways in which MDFC can mitigate disparities in care delivery and limb preservation outcomes. Access to MDFC among vulnerable populations remains a significant barrier to systematic reduction in major LEAs.

Lower-extremity pressure, staging, and grading thresholds to identify chronic limb-threatening ischemia

INTRODUCTION

The Society for Vascular Surgery Threatened Limb Classification System ('WIfI') is used to predict risk of limb loss and identify peripheral artery disease in patients with foot ulcers or gangrene. We estimated the diagnostic sensitivity of multiple clinical and noninvasive arterial parameters to identify chronic limb-threatening ischemia (CLTI).

METHODS

We performed a single-center review of 100 consecutive patients who underwent angiography for foot gangrene or ulcers. WIfI stages and grades were determined for each patient. Toe, ankle, and brachial pressure measurements were performed by registered vascular technologists. CLTI severity was characterized using Global Limb Anatomic Staging System (GLASS stages) and angiosomes. Medial artery calcification in the foot was quantified on foot radiographs.

RESULTS

GLASS NA (not applicable), I, II, and III angiographic findings were seen in 21, 21, 23, and 35 patients, respectively. A toe-brachial index < 0.7 and minimum ipsilateral ankle-brachial index < 0.9 performed well in identifying GLASS II and III angiographic findings, with sensitivity rates 97.8% and 91.5%, respectively. The diagnostic accuracy rates of noninvasive measures peaked at 74.7% and 89.3% for identifying GLASS II/III and GLASS I+ angiographic findings, respectively. The presence of medial artery calcification significantly diminished the sensitivity of most noninvasive parameters.

CONCLUSIONS

The use of alternative noninvasive arterial testing parameters improves sensitivity for detecting PAD. Abnormal noninvasive results should suggest the need for diagnostic angiography to further characterize arterial anatomy of the affected limb. Testing strategies with better accuracy are needed.

Medial artery calcification in peripheral artery disease

Medial artery calcification (MAC) is a distinct, highly regulated process that is often identified in small and mid-sized arteries of the lower extremities. It is associated with advanced age, diabetes, and chronic kidney disease. MAC often occurs in conjunction with atherosclerotic occlusive disease in lower extremity arteries, and when seen together or in isolation, long-term limb outcomes are negatively affected. In patients with peripheral artery disease (PAD), the extent of MAC independently correlates with major amputation and mortality rates, and it predicts poor outcomes after endovascular interventions. It is associated with increased arterial stiffness and decreased pedal perfusion. New endovascular methods aimed at treating calcified lower-extremity lesions may improve our ability to treat patients with limb-threatening ischemia. Although recent developments have increased our understanding of the mechanisms contributing to MAC, further investigations are needed to understand the role of medial calcification in PAD, and to develop strategies aimed at improving patient outcomes.