Intravascular Lithotripsy for Peripheral Artery Calcification: 30-Day Outcomes From the Disrupt PAD III Observational Study

PURPOSE

Intravascular lithotripsy (IVL) has shown promising safety and effectiveness in calcified peripheral artery disease (PAD) in large trials and small real-world experiences. Real-world evidence from a larger cohort is lacking, so we aimed to evaluate the real-world acute performance of IVL in the treatment of calcified PAD.

MATERIALS AND METHODS

The Disrupt PAD III Observational Study (OS) is a prospective, multicenter, single-arm study. Patients with claudication or critical limb-threatening ischemia (CLTI) and at least moderate calcification were eligible. Independent predictors of procedural outcomes were assessed by multivariable analysis.

RESULTS

Between November 2017 and June 2021 across 30 global sites, 1373 patients with 1677 lesions (1531, 91.3% core lab evaluable) were enrolled. Diameter stenosis and lesion length was 80.6±17.6% and 93.5±74.3 mm, respectively. Target vessels included femoropopliteal (61%), iliac (15.8%), common femoral (10.7%), and infrapopliteal arteries (12.8%). Lesion characteristics included 31.1% chronic total occlusions (CTOs) and 19.3% long lesions (≥15 cm). At final assessment, residual stenosis was 23.8±11.3%, with 0.9% serious angiographic complications, no abrupt closures, distal embolization, no flow, or thrombotic events. Independent predictors of ≤30% residual stenosis were lesion length ≥15 cm (odds ratio [OR]=0.384), female sex (OR=1.850), age ≤75 years (OR=1.625), IVL balloon to artery ratio ≥1.0 (OR=1.538), and CTO lesions (OR=0.638). Lesion length ≥15 cm (OR=16.076) was an independent predictor of procedural complications.

CONCLUSIONS

The Disrupt PAD III OS represents the largest assessment of IVL periprocedural outcomes in calcified PAD. It confirmed excellent procedural safety and effectiveness in complex lesions across multiple peripheral vascular beds.

CLINICAL IMPACT

This final analysis of the PAD III OS represents the largest report of peripheral IVL utilization in daily clinical practice. The outcomes of this study indicate that previously reported procedural results in clinical trial settings can be translated to a broader patient population. Treatment with peripheral IVL in severely calcified stenotic lower limb lesions demonstrated consistent acute safety and stenosis reduction, even in complex patients across multiple vessel beds. In addition, the importance of proper IVL balloon sizing to achieve excellent acute stenosis reduction was confirmed by multivariate analysis.

Sex-Specific Analysis of Mid-Term Outcomes of Atherectomy-Assisted Endovascular Treatment in Severe Peripheral Arterial Disease

Background: Endovascular treatment of lower-extremity peripheral disease (PAD) is associated with higher complication rates and suboptimal outcomes in women. Atherectomy has shown favourable outcomes in calcified lesions, minimising the incidence of stent placement caused by recoil or flow-limiting dissection. To date, there are no published mid-term outcomes evaluating the performance of atherectomy differentiated by sex. This study aims to evaluate sex-specific outcomes and prognostic factors affecting the results of atherectomy-assisted endovascular treatment in severe PAD. Methods: A retrospective analysis was conducted at a single centre in Germany, initiated by physicians and not sponsored by industry, on patients presenting with Rutherford categories ranging from III to V and featuring de novo occlusive or stenotic lesions of the superficial femoral (SFA) and/or popliteal arteries. The intervention involved rotational atherectomy-assisted angioplasty utilising the Jetstream (Boston, US®) device. The point of interest of this study was postinterventional clinical improvement as well as mid-term outcomes, including primary patency, over a targeted 2-year follow-up period. Statistical analysis utilised Cox regression (survival analysis) to calculate hazard ratios according to sex category. Comparative survival analysis was performed using the log-rank test and visually represented through Kaplan-Meier curves. Risk factors associated with absence of clinical improvement were examined across both sex groups utilising the chi-square or Fisher exact test, as appropriate. Results: A total of 98 patients (103 limbs) were initially included, with >75% having moderate-to-severe lesion calcification (>50%). A total of 84 patients (97 limbs, 62 male and 35 female) proceeded to a 2-year follow-up (mean 16.4 months for males and 16.1 for females) after a successful index procedure. Age distribution, Rutherford class, diabetes, chronic kidney disease (CKD), target vessel, lesion type, and length were balanced among both groups. Similar primary patency rates, of 89% among female and 91% among male limbs, were observed (p = 0.471). Female patients exhibited a lower rate of clinical improvement based on the Rutherford scale in comparison to males (80.6% vs. 94.5%, p = 0.048). CDK was the only significant prognostic factor across pooled data (odds ratio for CKD: 15.15, p < 0.001). Conclusions: Rotational atherectomy showed comparably high rates of mid-term primary patency, with low rates of bailout stent placement. These findings highlight the beneficial use of atherectomy in female patients who are per se at risk for higher rates of complications during and after endovascular interventions.

Sex-specific analysis of intravascular lithotripsy for peripheral artery disease from the Disrupt PAD III observational study

OBJECTIVE

Endovascular therapy of lower extremity peripheral artery disease (PAD) is associated with higher complication rates and worse outcomes in women vs men. Although intravascular lithotripsy (IVL) has shown similarly favorable outcomes in men and women in calcified coronary arteries, there is no published safety and effectiveness data of peripheral IVL differentiated by sex. This study aims to evaluate sex-specific acute procedural safety and effectiveness following IVL treatment of calcified PAD.

METHODS

We performed a secondary analysis of the multicenter Disrupt PAD III Observational Study, which assessed short-term procedural outcomes of patients undergoing treatment of symptomatic calcified lower extremity PAD with the Shockwave peripheral IVL system. Adjudicated acute safety and efficacy outcomes were compared by sex using univariate analysis performed with the χ2 test or Fisher exact test, as appropriate.

RESULTS

A total of 1262 patients (29.9% women) were included, with >85% having moderate to severe lesion calcification. Women were older (74 vs 71 years; P < .001), had lower ankle-brachial index (0.7 vs 0.8; P = .003), smaller reference vessel size (5.3 vs 5.6 mm; P = .009), and more severe stenosis at baseline vs men (82.3% vs 79.8%; P = .012). Rates of diabetes, renal insufficiency, chronic limb-threatening ischemia, lesion length, and atherectomy use were similar in both groups. Residual stenosis after IVL alone was significantly reduced in both groups. Final residual stenosis was 21.9% in women and 24.7% in men (P = .001). Serious angiographic complications were infrequent and similar in both groups (1.4% vs 0.6%; P = .21), with no abrupt vessel closure, distal embolization, or thrombotic events during any procedure.

CONCLUSIONS

The use of IVL to treat calcified PAD in this observational registry demonstrated favorable acute safety and effectiveness in both women and men.

Women are Not at Higher Risk for Reintervention or Major Amputation after Lower Extremity Atherectomy for Peripheral Artery Disease

BACKGROUND

Our objective was to compare short-term and long-term differences in reintervention-free and major amputation-free survival between female and male patients undergoing lower extremity atherectomy for peripheral artery disease.

METHODS

We analyzed lower extremity atherectomy procedures performed on 294 patients between January 2014 and September 2019. Reintervention was defined as either open bypass or endovascular procedure to the same region following the index operation. Kaplan-Meier (KM) survival analysis was performed to compare reintervention-free and major amputation-free survival between sexes. Multivariate logistic regression analyses were performed to determine the adjusted odds of reintervention and major amputation based on sex. We conducted subgroup analyses by anatomic region (femoropopliteal vs. tibial), indication (claudication vs. chronic limb-threatening ischemia (CLTI)), and balloon type (drug-coated balloon (DCB) versus plain balloon angioplasty (POBA)) across sexes.

RESULTS

Of the 294 patients, 125 (42.5%) were female. Compared to men, women receiving atherectomy were more likely to be Black (28.0% vs. 16.6%; P = 0.018), a nonsmoker (44.8% vs. 21.3%; P < 0.001), and present with CLTI (55.2% vs. 43.2%; P = 0.042). There were no differences in atherectomy region, lesion type, or balloon type between sexes. KM analysis showed similar 4-year reintervention-free survival (68.8% vs. 75.1%; P = 0.88) and major amputation-free survival (97.6% vs. 97.6%; P = 0.41) between sexes. Women and men had similar reintervention-free survival when grouped by femoropopliteal (67.9% vs. 70.8%; P = 0.69) or tibial (76.2% vs. 83.9%; P = 0.68) atherectomy region. Indication (claudication versus CLTI) did not affect reintervention-free survival in either women (64.5% vs. 69.6%; P = 0.28) or men (68.5% vs. 76.7%; P = 0.84). KM curves for DCB versus POBA were also similar between sexes and showed an early benefit in reintervention rate favoring DCB, which dissipated in both women (65.4% vs. 72.7%; P = 0.61) and men (75.5% vs. 78.4%; P = 0.18) by 3 years.

CONCLUSIONS

Compared to men, women demonstrate commensurate benefit from atherectomy for lower extremity revascularization. There were no differences seen in long-term reintervention or major amputation between sexes.

Intravascular Lithotripsy for Peripheral Artery Calcification: Mid-term Outcomes From the Randomized Disrupt PAD III Trial

Background

Endovascular treatment of calcified peripheral artery lesions may be associated with suboptimal vessel expansion, increased complication risk, and reduced long-term patency. The primary endpoint from the Disrupt PAD III randomized controlled trial (RCT) demonstrated superior procedural success in patients treated with intravascular lithotripsy (IVL) vs percutaneous transluminal angioplasty (PTA). The present study evaluates primary patency after 1 and 2 years in this randomized population.

Methods

The Disrupt PAD III RCT enrolled 306 patients with moderately-to-severely calcified femoropopliteal arteries treated with IVL (n = 153) or PTA (n = 153) prior to DCB treatment or stenting. The powered secondary effectiveness endpoint was primary patency at 1 year, defined as freedom from clinically driven target lesion revascularization plus freedom from restenosis determined by duplex ultrasound. Acute PTA failure requiring stent placement during the index procedure was prespecified as a loss of primary patency.

Results

Primary patency at 1 year was significantly greater in the IVL arm (80.5% vs 68.0%, P = .017). The requirement for provisional stenting was significantly lower in the IVL group (4.6% vs 18.3%, P < .0001). Freedom from clinically driven target lesion revascularization (IVL: 95.7% vs PTA: 98.3%, P = .94) and restenosis rates (IVL: 90.0% vs PTA: 88.8%, P = .48) were similar between the 2 groups at 1 year. At 2 years, primary patency remained significantly greater in the IVL arm (70.3% vs 51.3%, P = .003).

Conclusions

The Disrupt PAD III RCT secondary endpoint of superior 1-year primary patency was achieved, confirming the consistent safety and effectiveness of IVL followed by DCB treatment to facilitate a durable approach for patients with heavily calcified femoropopliteal arteries largely without stent requirement.

Intravascular Lithotripsy for Peripheral Artery Calcification: 30-Day Outcomes From the Randomized Disrupt PAD III Trial

OBJECTIVES

The study sought to compare short-term outcomes in patients with femoropopliteal artery calcification receiving vessel preparation with intravascular lithotripsy (IVL) or percutaneous transluminal angioplasty (PTA) prior to drug-coated balloon (DCB) for symptomatic peripheral artery disease.

BACKGROUND

Endovascular treatment of calcified peripheral artery lesions is associated with suboptimal vessel expansion and increased complication risk. Although initial results from single-arm studies with IVL have been reported, comparative evidence from randomized trials is lacking for most devices in the presence of heavy calcification.

METHODS

The Disrupt PAD III (Shockwave Medical Peripheral Lithoplasty System Study for PAD) randomized trial enrolled patients with moderate or severe calcification in a femoropopliteal artery who underwent vessel preparation with IVL or PTA prior to DCB or stenting. The primary endpoint was core lab-adjudicated procedural success (residual stenosis ≤30% without flow-limiting dissection) prior to DCB or stenting.

RESULTS

In patients receiving IVL (n = 153) or PTA (n = 153), procedural success was greater in the IVL group (65.8% vs. 50.4%; p = 0.01) and the percentage of lesions with residual stenosis ≤30% (66.4% vs. 51.9%; p = 0.02) was greater in the IVL group, while flow-limiting dissections occurred more frequently in the PTA group (1.4% vs. 6.8%; p = 0.03). Post-dilatation (5.2% vs. 17.0%; p = 0.001) and stent placement (4.6% vs. 18.3%; p < 0.001) were also greater in the PTA group. The rates of major adverse events (IVL: 0% vs. PTA: 1.3%; p = 0.16) and clinically driven target lesion revascularization (IVL: 0.7% vs. PTA: 0.7%; p = 1.0) at 30 days were comparable between groups.

CONCLUSIONS

IVL is an effective vessel preparation strategy that facilitates definitive endovascular treatment in calcified femoropopliteal arteries in patients with peripheral artery disease. (Shockwave Medical Peripheral Lithoplasty System Study for PAD [Disrupt PAD III]; NCT02923193).

Principles of Intravascular Lithotripsy for Calcific Plaque Modification

A significant proportion of lesions treated with transcatheter interventions in the coronary and peripheral vascular beds exhibit moderate to severe calcific plaques known to portend lower procedural success rates, increased peri-procedural adverse events, and unfavorable clinical outcomes compared with noncalcific plaques. Adapted from lithotripsy technology used for treatment of ureterorenal calculi, intravascular lithotripsy (IVL) is a novel technique for the treatment of severely calcific plaque lesions that uses acoustic shockwaves in a balloon-based delivery system. Shockwaves induce calcium fractures, which facilitate stent expansion and luminal gain. In this review, the authors summarize the physics, preclinical and clinical data on IVL use in the coronary and peripheral vasculature, and future directions of IVL in transcatheter cardiovascular therapies.

Three-Year Outcomes of Orbital Atherectomy for the Endovascular Treatment of Infrainguinal Claudication or Chronic Limb-Threatening Ischemia

Purpose: To investigate the outcomes of orbital atherectomy (OA) for the treatment of patients with peripheral artery disease (PAD) manifesting as claudication or chronic limb-threatening ischemia (CLTI). Materials and Methods: The database from the LIBERTY study (ClinicalTrials.gov identifier NCT01855412) was interrogated to identify 503 PAD patients treated with any commercially available endovascular devices and adjunctive OA for 617 femoropopliteal and/or infrapopliteal lesions. Cox regression analyses were employed to examine the association between baseline Rutherford category (RC) stratified as RC 2-3 (n=214), RC 4-5 (n=233), or RC 6 (n=56) and all-cause mortality, target vessel revascularization (TVR), major amputation, major adverse event (MAE), and major amputation/death at up to 3 years of follow-up. The mean lesion lengths were 78.7±73.7, 131.4±119.0, and 95.2±83.9 mm, respectively, for the 3 groups. Results: After OA, balloon angioplasty was used in >98% of cases, with bailout stenting necessary in 2.0%, 2.8%, and 0% of the RC groups, respectively. A small proportion (10.8%) of patients developed angiographic complications, without differences based on presentation. During the 3-year follow-up, claudicants were at lower risk for MAE, death, and major amputation/death than patients with CLTI. The 3-year Kaplan-Meier survival estimates were 84.6% for the RC 2-3 group, 76.2% for the RC 4-5 group, and 63.7% for the RC 6 group. The 3-year freedom from major amputation was estimated as 100%, 95.3%, and 88.6%, respectively. Among CLTI patients only, the RC at baseline was correlated with the combined outcome of major amputation/death, whereas RC classification did not affect TVR, MAE, major amputation, or death rates. Conclusion: Peripheral artery angioplasty with adjunctive OA in patients with CLTI or claudication is safe and associated with low major amputation rates after 3 years of follow-up. These results demonstrate the utility of OA for patients across the spectrum of PAD.

Intravascular Lithotripsy for Treatment of Calcified Lower Extremity Arterial Stenosis: Initial Analysis of the Disrupt PAD III Study

Purpose: To evaluate the performance of peripheral intravascular lithotripsy (IVL) in a real-world setting during endovascular treatment of multilevel calcified peripheral artery disease (PAD). Materials and Methods: The Disrupt PAD III Observational Study (ClinicalTrials.gov identifier NCT02923193) is a prospective, nonrandomized, multicenter, single-arm observational study assessing the acute safety and effectiveness of the Shockwave Peripheral IVL System for the treatment of calcified, stenotic lower limb arteries. Patients were eligible if they had claudication or chronic limb-threatening ischemia and moderate or severe arterial calcification. Between November 2017 and August 2018, 200 patients (mean age 72.5±8.7 years; 148 men) were enrolled across 18 sites and followed through hospital discharge. Results: In the 220 target lesions, IVL was more commonly used in combination with other balloon-based technologies (53.8%) and less often with concomitant atherectomy or stenting (19.8% and 29.9%, respectively). There was a 3.4-mm average acute gain at the end of procedure; the final mean residual stenosis was 23.6%. Angiographic complications were rare, with only 2 type D dissections and a single perforation following drug-coated balloon inflation (unrelated to the IVL procedure). There was no abrupt closure, distal embolization, no reflow, or thrombotic event. Conclusion: Use of peripheral IVL to treat severely calcified, stenotic PAD in a real-world study demonstrated low residual stenosis, high acute gain, and a low rate of complications despite the complexity of disease.

Primary outcomes and mechanism of action of intravascular lithotripsy in calcified, femoropopliteal lesions: Results of Disrupt PAD II

OBJECTIVE

DISRUPT PAD II was designed to evaluate the safety and performance of intravascular lithotripsy (IVL), a novel approach using pulsatile sonic pressure waves, to modify intimal and medial calcium in stenotic peripheral arteries.

BACKGROUND

Vascular calcification restricts vessel expansion, increases the risk of vascular complications, and may impair the effect of anti-proliferative therapy.

METHODS

Disrupt PAD II was a non-randomized, multi-center study that enrolled 60 subjects with complex, calcified peripheral arterial stenosis at eight sites. Patients were treated with IVL and followed to 12-months. The primary safety endpoint was major adverse events (MAE) through 30 days. The primary effectiveness endpoint was patency at 12 months as adjudicated by duplex ultrasonography (DUS). Key secondary endpoints included acute procedure success, freedom from re-intervention, and functional outcomes.

RESULTS

Between June 2015 and December 2015, subjects with moderate or severe calcified arterial lesions were enrolled. The final residual stenosis was 24.2%, with an average acute gain of 3.0 mm. The 30-day MAE rate was 1.7% with one grade D dissection that resolved following stent placement. Primary patency at 12 months was 54.5%, and clinically driven TLR at 12 months was 20.7%. Optimal IVL technique defined by correct balloon sizing and avoiding therapeutic miss, improved 12-month primary patency and TLR outcomes to 62.9% and 8.6%, respectively.

CONCLUSIONS

IVL demonstrated compelling safety with minimal vessel injury, and minimal use of adjunctive stents in a complex, difficult to treat population.

Atherectomy-Associated Complications in the Southern California Vascular Outcomes Improvement Collaborative

BACKGROUND

Atherectomy has become an increasingly utilized modality for the endovascular treatment of peripheral arterial occlusive disease. The objective of this study was to determine the incidence and risk factors for atherectomy-associated complications.

METHODS

A retrospective review was performed for all atherectomy procedures performed between January 2011 and December 2015 in the Southern California Vascular Outcomes Improvement Collaborative. Atherectomy was defined as laser, orbital, or excisional atherectomy. Complications were dissection, perforation, and distal embolization.

RESULTS

Seven hundred twenty-nine atherectomy procedures were performed at 7 institutions by 27 practitioners. The mean age was 73 years with 415 (57%) males. Four hundred nineteen (57%) were diabetic, 673 (92%) hypertensive, 457 (63%) smokers, and 244 (34%) had coronary artery disease. Dissection occurred in 51 (7%) procedures, embolization in 23 (3.1%), and perforation in 12 (1.6%). The mean number of lesions treated per artery was the same at 1.6 in patients with any complication and no complication (P = 0.77). The total occluded length was 7.4 cm for complications versus 7.2 cm for no complication (P = 0.73). The total treated length was 12.9 cm for complications versus 11.3 cm for no complication (P = 0.03). The incidence of complications for Trans-Atlantic Inter-Society Consensus (TASC) C/D lesions were 13% compared to 10% for TASC A/B lesions (P = 0.05). The incidence of complications in superficial femoral/popliteal lesions was 12.9% vs. 10.4% in tibial lesions (P = 0.13). In multivariable analysis, treatment length was associated with a small increased risk of complication (odds ratio = 1.02, 95% confidence interval = 1.0-1.04).

CONCLUSIONS

Increased treatment length is associated with an increased risk of atherectomy-associated complications. Demographic factors and comorbidities were not predictors of complications.

Emerging and Future Therapeutic Options for Femoropopliteal and Infrapopliteal Endovascular Intervention

Despite recent advances in endovascular therapy for peripheral artery disease, current technologies remain limited by rates of long-term restenosis and application to complex lesion subsets. This article presents data on upcoming therapies, including novel drug-coated balloons, drug-eluting stents, bioresorbable scaffolds, novel drug delivery therapies to target arteries, techniques to limit postangioplasty dissection, and treatment of severely calcified lesions.