Efficacy of various percutaneous interventions for in-stent restenosis: comprehensive network meta-analysis of randomized controlled trials

BACKGROUND

In-stent restenosis (ISR) remains a difficult problem in interventional cardiology. The relative efficacy and safety of available interventions is not clear. We aimed to perform a network meta-analysis using both direct evidence and indirect evidence to compare all available interventions.

METHODS AND RESULTS

We systematically searched electronic databases for randomized trials comparing ≥2 treatments for ISR. A network meta-analysis was performed using a Bayesian approach. Eleven treatments were compared in 31 studies with 8157 patient-years follow-up. Compared with balloon angioplasty, everolimus-eluting stent (hazard ratio [95% credibility interval], 0.13 [0.048-0.35]), paclitaxel-eluting balloon (0.32 [0.20-0.49]), paclitaxel-eluting cutting balloon (0.054 [0.0017-0.5]), paclitaxel-eluting stent (0.39 [0.24-0.62]), and sirolimus-eluting stent (0.32 [0.18-0.50]) are associated with lower target vessel revascularization. Balloon angioplasty is not different from cutting balloon (0.73 [0.31-1.5]), excimer laser (0.89 [0.29-2.7]), rotational atherectomy (0.96 [0.53-1.7]), and vascular brachytherapy (0.60 [0.35-1.0]). In drug-eluting stent ISR, balloon angioplasty was inferior to everolimus-eluting stent (0.19 [0.049-0.76]), paclitaxel-eluting balloon (0.43 [0.18-0.80]), paclitaxel-eluting stent (0.35 [0.13-0.76]), and sirolimus-eluting stent (0.36 [0.11-0.86]) for target vessel revascularization. There was no difference between treatments in probable or definitive stent thrombosis. The results of binary restenosis and target lesion revascularization were similar. Paclitaxel-eluting cutting balloon, everolimus-eluting stent, and paclitaxel-eluting balloon have the highest probability of being in the top 3 treatments based on low target lesion revascularization, but there was no statistical significant difference between them.

CONCLUSIONS

Balloon angioplasty is inferior to all drug-eluting treatments for ISR, including drug-eluting stent ISR. Drug-eluting stent, particularly everolimus-eluting stent, or paclitaxel-eluting cutting balloon and paclitaxel-eluting balloon should be preferred for treating ISR.

Maximizing Lumen Gain With Directional Atherectomy

PURPOSE

To describe the use of a low-pressure balloon inflation (LPBI) technique to delineate intraluminal plaque and guide directional atherectomy in order to maximize lumen gain and achieve procedure success.

TECHNIQUE

The technique is illustrated in a 77-year-old man with claudication who underwent superficial femoral artery revascularization using a HawkOne directional atherectomy catheter. A standard angioplasty balloon was inflated to 1 to 2 atm during live fluoroscopy to create a 3-dimensional "lumenogram" of the target lesion. Directional atherectomy was performed only where plaque impinged on the balloon at a specific fluoroscopic orientation. The results of the LPBI technique were corroborated with multimodality diagnostic imaging, including digital subtraction angiography, intravascular ultrasound, and intra-arterial pressure measurements.

CONCLUSION

With the LPBI technique, directional atherectomy can routinely achieve <10% residual stenosis, as illustrated in this case, thereby broadly supporting a no-stent approach to lower extremity endovascular revascularization.

Lower extremity revascularization using directional atherectomy: 12-month prospective results of the DEFINITIVE LE study

OBJECTIVES

The aim of this study was to assess the safety and effectiveness of directional atherectomy (DA) for endovascular treatment of peripheral arterial disease (PAD) in infrainguinal arteries in patients with claudication or critical limb ischemia.

BACKGROUND

To date, no prospective, multicenter, independently-adjudicated study has evaluated the effectiveness and durability of DA in the treatment of PAD. Previous DA studies have not been prospectively powered to evaluate any differences in outcomes in patients with and without diabetes.

METHODS

DEFINITIVE LE (Determination of EFfectiveness of the SilverHawk(®) PerIpheral Plaque ExcisioN System (SIlverHawk Device) for the Treatment of Infrainguinal VEssels / Lower Extremities) prospectively enrolled subjects at 47 multinational centers with an infrainguinal lesion length up to 20 cm. Primary endpoints were defined as primary patency at 12 months for claudicants and freedom from major unplanned amputation for critical limb ischemia (CLI) subjects. A pre-specified statistical hypothesis evaluated noninferiority of primary patency in diabetic versus nondiabetic claudicants. Independent angiographic and sonographic core laboratories assessed outcomes, and events were adjudicated by a clinical events committee.

RESULTS

A total of 800 subjects were enrolled. The 12-month primary patency was 78% (95% confidence interval: 74.0% to 80.6%) in claudicants, with a 77% rate in the diabetic subgroup versus 78% in the nondiabetic subgroup (noninferior, p < 0.001). The rate of freedom from major unplanned amputation of the target limb at 12 months in CLI subjects was 95% (95% confidence interval: 90.7% to 97.4%). Periprocedural adverse events included embolization (3.8%), perforation (5.3%), and abrupt closure (2.0%). The bail-out stent rate was 3.2%.

CONCLUSIONS

The DEFINITIVE LE study demonstrated that DA is a safe and effective treatment modality at 12 months for a diverse patient population with either claudication or CLI. Furthermore, DA was shown to be noninferior for treating PAD in patients with diabetes compared with those without diabetes. (Study of SilverHawk/TurboHawk in Lower Extremity Vessels [DEFINITIVE LE]; NCT00883246).

The potential cost-effectiveness of the Diamondback 360® Coronary Orbital Atherectomy System for treating de novo, severely calcified coronary lesions: an economic modeling approach

Background:

Patients who undergo percutaneous coronary intervention (PCI) for severely calcified coronary lesions have long been known to have worse clinical and economic outcomes than patients with no or mildly calcified lesions. We sought to assess the likely cost-effectiveness of using the Diamondback 360^® Orbital Atherectomy System (OAS) in the treatment of de novo, severely calcified lesions from a health-system perspective.

Methods and results:

In the absence of a head-to-head trial and long-term follow up, cost-effectiveness was based on a modeled synthesis of clinical and economic data. A cost-effectiveness model was used to project the likely economic impact. To estimate the net cost impact, the cost of using the OAS technology in elderly (⩾ 65 years) Medicare patients with de novo severely calcified lesions was compared with cost offsets. Elderly OAS patients from the ORBIT II trial (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) [ClinicalTrials.gov identifier: NCT01092426] were indirectly compared with similar patients using observational data. For the index procedure, the comparison was with Medicare data, and for both revascularization and cardiac death in the following year, the comparison was with a pooled analysis of the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI)/Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trials. After adjusting for differences in age, gender, and comorbidities, the ORBIT II mean index procedure costs were 17% (p < 0.001) lower, approximately US$2700. Estimated mean revascularization costs were lower by US$1240 in the base case. These cost offsets in the first year, on average, fully cover the cost of the device with an additional 1.2% cost savings. Even in the low-value scenario, the use of the OAS is cost-effective with a cost per life-year gained of US$11,895.

Conclusions:

Based on economic modeling, the recently approved coronary OAS device is projected to be highly cost-effective for patients who undergo PCI for severely calcified lesions.

Successful retrieval of a firmly stuck rotablator burr by using a modified STAR technique

Rotablator burr entrapment occurring during rotational atherectomy is a rare but serious complication that can lead to coronary occlusion and require emergency cardiac surgery. Although several bailout techniques for stuck burrs have been proposed, no definitive methods for removal have been established. We report here a difficult case of a stuck rotablator burr, in which various techniques failed to retrieve the burr. It was ultimately removed using the subintimal tracking and reentry (STAR) technique with a 3-g tapered tip hydrophilic wire. This modified STAR technique, which was originally developed for percutaneous coronary intervention for chronic total occlusion, may be useful as a bailout technique in patients with a firmly stuck rotablator burr that cannot be removed by using standard procedures.

One-Year Outcomes Following Directional Atherectomy of Infrapopliteal Artery Lesions: Subgroup Results of the Prospective, Multicenter DEFINITIVE LE Trial

PURPOSE

To report a subgroup analysis of the prospective, multicenter, single-arm DEFINITIVE LE trial to assess the effectiveness of directional atherectomy for the treatment of infrapopliteal artery lesions at 1 year.

METHODS

In the DEFINITIVE LE trial, follow-up assessments occurred up to 1 year postprocedure. Of the 800 patients enrolled, 145 subjects with 189 infrapopliteal lesions met the criteria for this analysis. Seventy (48.3%) and 75 (51.7%) patients were suffering critical limb ischemia (CLI) and intermittent claudication, respectively; 68.3% (99/145) had diabetes. The mean lesion length was 58±44 mm (all lesions); 20.2% were occluded. The primary endpoint for patients with claudication was duplex ultrasound-derived primary patency, while for subjects with CLI it was freedom from major amputation of the target limb at 1 year. Endpoints and adverse events were independently assessed.

RESULTS

Procedure success (≤30% residual stenosis) was achieved in 84% of treated lesions. The 1-year primary patency rate was 84% (claudicants 89.6% and CLI patients 78%, p=0.11), and the freedom from major amputation rate was 97.1% (claudicants 100% and CLI 93.8%, p=0.03). In both claudication and CLI patients, significant improvements in Rutherford category and objective measures of walking distance and quality of life were seen at 1 year in comparison to baseline.

CONCLUSION

This study demonstrates that directional atherectomy in infrapopliteal arteries results in promising technical and clinical results at 1 year for claudicant as well as CLI patients.

A Comparison of Clinical Outcomes for Diabetic and Nondiabetic Patients Following Directional Atherectomy in the DEFINITIVE LE Claudicant Cohort

PURPOSE

To report a subset analysis that evaluated the hypothesis that directional atherectomy for peripheral artery disease in diabetic claudicants has noninferior primary patency at 12 months compared with nondiabetic claudicants.

METHODS

DEFINITIVE LE, a US/European multicenter study, assessed the effectiveness of directional atherectomy using SilverHawk/TurboHawk systems for treatment of peripheral artery disease in the superficial femoral, popliteal, and infrapopliteal arteries. Of the 800 patients enrolled in the study, only the 598 claudicant patients (mean age 69.5±10.4 years; 336 men) who were classified at baseline as Rutherford category 1-3 were eligible for this subset analysis. Of these, 46.8% (280/598) had diabetes. Follow-up to 12 months included duplex ultrasound examination, functional assessments, and adverse event evaluations. Independent angiographic and duplex ultrasound core laboratories assessed primary patency and secondary endpoints; a clinical events committee adjudicated adverse events.

RESULTS

Although diabetics had significantly more baseline comorbidities, 12-month primary patency (77.0%) was no different than for nondiabetics (77.9%; superiority p=0.98; noninferiority p<0.001) across all anatomic territories treated. Freedom from clinically driven target lesion revascularization was no different between diabetics (83.8%) and nondiabetics (87.5%) overall (p=0.19) or by lesion locations. Secondary clinical outcomes (Rutherford category, ankle-brachial index, and walking impairment) improved at 12 months for both diabetics and nondiabetics.

CONCLUSION

Noninferior 12-month patency rates demonstrate that directional atherectomy is an effective treatment in diabetic as well as nondiabetic claudicants. Directional atherectomy remains an attractive treatment option, improving luminal diameters without stents, which preserves future treatment options for both diabetic and nondiabetic patients with progressive, diffuse vascular disease.

Optical coherence tomography assessment of the mechanistic effects of rotational and orbital atherectomy in severely calcified coronary lesions

OBJECTIVES

This study sought to assess the mechanistic effect of rotational atherectomy (RA) and orbital atherectomy (OA) on heavily calcified coronary lesions and subsequent stent placement using optical coherence tomography (OCT).

BACKGROUND

RA and OA are two main approaches to ablate coronary calcium. While small case reports have described the mechanistic effect of RA in calcified coronary lesions, there has been no imaging study to assess the effect of OA on coronary artery architecture and/or compare the effects of two atherectomy devices.

METHODS

This study analyzed 20 consecutive patients with OCT imaging performed after atherectomy and after stent implantation, RA (n = 10) and OA (n = 10).

RESULTS

Postatherectomy OCT analysis identified tissue modification with deep dissections in around a third of lesions after RA and OA; however, post OA dissections ("lacunae") were significantly deeper (1.14 vs. 0.82 mm, P = 0.048). Post OA/RA lesions with dissections had significantly higher percentage of lipid rich plaques and smaller calcification arcs as compared to plaques without dissections. Stents after OA were associated with a significantly lower percent of stent strut malapposition than post RA stents (4.36 vs. 8.02%, P = 0.038).

CONCLUSIONS

Although the incidence of dissections was comparable between RA and OA cases, OA resulted in deeper tissue modifications (lacunae) as shown by OCT imaging. The finding might provide an explanation for a better stent apposition after OA as compared to RA. Their impact on long-term outcome needs to be determined.

Short-term outcomes of excisional atherectomy in lower limb arterial disease

BACKGROUND

Endovascular interventions are increasingly utilized in managing occlusive peripheral vascular disease. Angioplasty and stenting remain the mainstay of endovascular management; however, newer treatment modalities such as excisional atherectomy provide the clinician with additional treatment options. While demonstrating promising results in available trials, a paucity of data exist regarding peripheral atherectomy. The purpose of this retrospective clinical study was to assess the efficacy and safety of excisional atherectomy with the TurboHawk atherectomy device (Covidien/ev3, Plymouth, MN, USA) in the treatment of lower limb peripheral vascular disease and to evaluate the learning curve involved in the institution of a new treatment modality.

METHODS

A retrospective analysis was performed on all patients undergoing atherectomy for symptomatic lower limb peripheral vascular disease by a single clinician between November 2011 and June 2013. Forty-seven vessels on 28 legs in 24 patients were treated during the period.

RESULTS

Atherectomy was possible in 98% of cases. The 6- and 12-month primary patency was 72.6 and 58.9%, respectively. The primary-assisted patency was 93.2% at 6 months and 74.6% at 12 months. There were significantly greater patency rates in the TransAtlantic Inter-Society Consensus A + B lesions and a non-significant trend towards improved patency rates in claudicants versus critical limb ischaemia. There were four instances of embolization and four cases of dissection.

CONCLUSION

Excisional atherectomy provides a further option for the minimally invasive management of peripheral vascular disease. It has similar patency rates to established endovascular therapies and should be considered among the treatment options in patients with favourable pathology.

Optimal use of atherectomy in critical limb ischemia

Critical limb ischemia (CLI) is the most severe and debilitating form of peripheral arterial disease and is associated with high rates of limb loss and cardiovascular mortality. The unique physical environment of tibial occlusive disease underlying most CLI cases limits treatment options and long-term durability, with resulting frequent rates of persistent obstruction, restenosis, and reintervention. Atherectomy represents a potential strategy to improve acute and late results when treating patients with CLI. Available atherectomy devices each have specific performance characteristics, evidentiary rationale, and limitations that mandate a clear understanding of the optimal albeit evolving use of this category of interventional tools.

Unjailing of the septal perforator using a rotational atherectomy device prior to alcohol septal ablation in a patient with symptomatic hypertrophic obstructive cardiomyopathy

We report a novel approach in which successful unjailing of the septal perforator was performed through the side branch of a coronary stent using a rotational atherectomy device for the purpose of alcohol septal ablation in a patient with symptomatic hypertrophic obstructive cardiomyopathy.

Late presenting, contained rupture of the superficial femoral artery following atherectomy and stenting: case report and literature review

Excisional atherectomy alone or followed by stenting is considered an appropriate treatment strategy for patients with lifestyle-limiting claudication due to obstructive infra-inguinal peripheral arterial disease (Ramaiah et al., J Endovasc Ther 2006;13:592-6021). We present a case of a 69-year-old man with eccentric severely calcified disease of the superficial femoral artery (SFA) treated with excisional atherectomy followed by stenting with an interwoven nitinol stent. The procedure was complicated by extravascular stent migration associated with a contained rupture presenting 30 days after the intervention. The complication was successfully treated with a stent graft. Although rare, pseudoaneurysms have been reported at the site of prior atherectomy; however, this case is the first description of a contained rupture post atherectomy associated with erosion of a nitinol stent into an extra-luminal position. The mechanism and management of this complication are discussed.

An overview of optimal endovascular strategy in treating the femoropopliteal artery: mechanical, biological, and procedural factors

Treatment of the femoropopliteal (FP) artery remains a challenge to the endovascular specialist. Long-term patency is low with a high rate of target lesion revascularization. The true patency rate varies considerably between studies partly because there is a lack of uniform performance criteria and reporting standards in peripheral arterial interventions. Literature review supports three principles that emerge as important components of an optimal strategy in treating the FP artery: (1) improving vessel compliance and subsequently less dissections and bailout stenting, (2) reducing smooth muscle cell proliferation, and (3) protecting outflow vessels from distal embolization. In this overview, we examine current data that support the validity of this strategy.

SCAI expert consensus statement for femoral-popliteal arterial intervention appropriate use

Successful endovascular intervention for femoral-popliteal (FP) arterial disease provides relief of claudication and offers limb-salvage in cases of critical limb ischemia. Technologies and operator technique have evolved to the point where we may now provide effective endovascular therapy for a spectrum of lesions, patients, and clinical scenarios. Endovascular treatment of this segment offers a significant alternative to surgical revascularization, and may confer improved safety for a wide range of patients, not solely those deemed high surgical risk. Although endovascular therapy of the FP segment has historically been hampered by high rates of restenosis, emerging technologies including drug-eluting stents, drug-coated balloons, and perhaps bio-absorbable stent platforms, provide future hope for more durable patency in complex disease. By combining lessons learned from clinical trials, international trends in clinical practice, and insights regarding emerging technologies, we may appropriately tailor our application of endovascular therapy to provide optimal care to our patients. This document was developed to guide physicians in the clinical decision-making related to the contemporary application of endovascular intervention among patients with FP arterial disease.

Rotational Atherectomy in a Patient with Acute ST-Elevation Myocardial Infarction and Cardiogenic Shock

Rotational atherectomy (rotablation) of coronary artery is relatively contraindicated in high thrombotic state such as acute ST-elevation myocardial infarction (STEMI) because of the risk of platelet activation by the rotablator. We present a case where rotablation was necessary to recanalize the right coronary artery in a patient presenting with acute STEMI complicated by cardiogenic shock, after unsuccessful attempts with balloon catheters. He improved remarkably after the procedure and was discharged after 4 days.

Transpopliteal balloon-assisted excimer-laser atherectomy for the treatment of chronic femoropopliteal occlusions: feasibility and initial results

PURPOSE

Recanalization of chronic total occlusions (CTOs) of the femoropopliteal arteries depends on a successful lesion crossing with the guide wire. The aim of this retrospective study was to evaluate the safety, feasibility, and the primary results of retrograde recanalization of CTOs with balloon-assisted excimer–laser atherectomy (ELA) via a transpopliteal approach after failed antegrade attempts.

METHODS

A total number of 15 patients (10 male, 5 female) with a mean age of 68.5 years (range: 43–91 years) treated with retrograde transpopliteal ELA in the years 2009–2012 were included retrospectively. After unsuccessful antegrade recanalization attempts with conventional guide wires and catheters, patients were treated with a retrograde recanalization attempt via a transpopliteal access using an excimer laser, followed by pressure-only balloon angioplasty (POBA). The mean length of the CTOs in the femoropopliteal arteries was 17.8 ± 5.4 cm (range: 9–29 cm).

RESULTS

Technically successful recanalization was achieved in 14 of 15 patients. Provisional stenting was done in two cases. There were no major adverse events regarding the laser atherectomy or popliteal access site. One acute reocclusion was observed in the first 48 hours after intervention. The ankle-brachial Index increased from preinterventional 0.45 ± 0.07 to 0.77 ± 0.29 (P < 0.05) in the follow-up period (1.5 months), resulting in a primary patency of 80%.

CONCLUSION

The retrograde ELA for recanalization of chronic femoropopliteal occlusions via a popliteal access turned out to be a safe and effective procedure with promising primary results. Thus it may be an endovascular treatment option for long chronic occlusions after failed antegrade recanalization or in patients who are not suitable for surgery.

Predictors of provisional stenting in patients undergoing lower extremity arterial interventions

Predictors of provisional stenting in patients undergoing lower extremity arterial interventions remain unclear. We performed an ad hoc analysis on the predictors of provisional stenting during infrainguinal arterial percutaneous interventions using data from the Percutaneous Lower Extremity Arterial Interventions Using Primary Balloon Angioplasty versus Silverhawk Atherectomy (SA) and Adjunctive Balloon Angioplasty trial. In the above trial, SA of infrainguinal de novo arterial lesions was shown to reduce significantly provisional stenting compared with primary percutaneous transluminal angioplasty (PTA). In this ad hoc analysis, patients were divided into two groups based on whether provisional stenting has occurred. Univariate analysis was conducted between the stent versus the no-stent group. Logistic regression (LR) analysis was performed to model for the predictors of provisional stenting. Variables included were diabetes, presence of moderate calcification (versus none to little), age, gender, hypercholesterolemia, Transatlantic Intersociety Consensus (TASC) D lesion (vs. TASC A to C), and treatment method (primary PTA vs. SA with adjunctive PTA). By LR analysis, predictors of stenting were as follows: moderate calcification (odds ratio [OR] 6.56, 95% confidence interval [CI] 1.21 to 35.56, p = 0.029), primary PTA (vs. SA) (OR 0.19, 95% CI 0.04 to 0.93, p = 0.04), and TASC D lesions (vs. A to C) (OR 0.10, 95% CI 0.01 to 0.87, p = 0.037). Provisional stenting in infrainguinal interventions is predicted by the use of primary PTA, presence of moderate calcification, and TASC D lesions after controlling for gender, age, hypercholesterolemia, and diabetes.

Endovascular revascularization of symptomatic infrapopliteal arteriosclerotic occlusive disease: comparison of atherectomy and angioplasty

The preferred method for revascularization of symptomatic infrapopliteal arterial occlusive disease (IPAD) has traditionally been open vascular bypass. Endovascular techniques have been increasingly applied to treat tibial disease with mixed results. We evaluated the short-term outcome of percutaneous infrapopliteal intervention and compared the different techniques used. A retrospective analysis of consecutive patients undergoing endovascular treatment for infrapopliteal arterial occlusive lesions between 2003 and 2007 in a tertiary teaching hospital was performed. Patient demographic data, indication for intervention, and periprocedural complications were recorded. Periprocedural and short-term outcomes were measured and compared. Forty-nine infrapopliteal arteries in 35 patients were treated. Twenty vessels (15 patients) underwent angioplasty and 29 vessels (20 patients) were treated with atherectomy. Demographic and angiographic characteristics were similar between the groups. Twenty-six patients had concurrent femoral and/or popliteal artery interventions. Overall, technical success was 90% and similar between angioplasty and atherectomy groups (85% versus 93%, p = NS). The vessel-specific complication rate was 10% and was similar between both groups (angioplasty 5% versus atherectomy 14%, p = NS). One dissection occurred in the angioplasty group; one perforation and three thromboembolic events occurred in the atherectomy group. Limb salvage and freedom from reintervention at 6 months were 81% and 68%, respectively, and were not significantly different between the angioplasty and atherectomy groups. Endovascular intervention for IPAD had acceptable periprocedural and short-term success rates in our high-risk patient population. Both atherectomy and angioplasty can be used successfully to treat symptomatic IPAD.

Long-term outcome of infrapopliteal catheter-based intervention for critical limb ischemia

CONTEXT

Percutaneous treatment of tibioperoneal occlusive disease is associated with decreased morbidity compared with bypass surgery. The long-term patency and limb salvage rates are not well documented.

AIMS

To evaluate the long-term outcome of endoluminal interventions for tibioperoneal lesions.

METHODS

A retrospective study was performed to determine the outcomes of patients undergoing infrapopliteal catheter-based intervention for critical limb ischemia. Collected data included demographics, comorbidities, clinical presentation, pre- and postintervention noninvasive vascular measurements (segmental pressure and waveforms, and ankle-brachial index [ABI]), type of intervention, limb loss rate, patient follow-up and need for surgical revascularization. Statistical analysis was performed with the two-tailed t test. P<0.05 was considered significant; results were reported as mean ± SD. Cox regression analysis and Kaplan-Meier limb survival analysis were performed to demonstrate freedom from amputation over time.

RESULTS

Thirty-five patients underwent intervention from 2003 to 2008; technical success was achieved in 26 patients (75%). Arterial segmental pressure studies revealed a significant increase in ABI - preprocedure ABI was 0.62±0.24 versus a postintervention ABI of 0.81±0.29 (P=0.02). The limb salvage rate was 63% during the follow-up period. Limb salvage was better for patients who underwent isolated infrapopliteal intervention versus combined above and below the knee intervention.

CONCLUSION

Percutaneous interventions for tibioperoneal occlusive disease offer an acceptable limb salvage rate and may be the preferred initial treatment for critical limb ischemia.

Comparison of the histopathology of culprit lesions in chronic stable angina, unstable angina, and myocardial infarction

BACKGROUND

The etiology of unstable angina (UA) and myocardial infarction (MI) both involve rupture of an atherosclerotic plaque in a coronary artery. It has been suggested that the two syndromes differ because MI results if a red occlusive permanent thrombus occurs and UA occurs only if a nonocclusive platelet (white) thrombus occurs.

HYPOTHESIS

The purpose of this study was to determine the differences between coronary lesion pathology in MI and UA and compare them with lesions of chronic stable angina (CSA).

METHODS

We reviewed the pathologic specimens of culprit lesions obtained by directional coronary atherectomy in 27 patients with MI, 29 patients with UA, and 16 patients with CSA.

RESULTS

The incidence of ruptured plaque was high and identical in patients with MI (77.8%), and UA (75.8%), and significantly lower in patients with CSA (25.0%) (p < 0.001). Similarly, the incidence of red thrombus was the same in MI (92.6%) and UA (82.7%), and significantly less in CSA (p < 0.001).

CONCLUSIONS

The underlying pathophysiology of both UA and MI appears to be the same, with red thrombus playing an important role in both syndromes. The only difference is in the degree of occlusiveness of the red thrombus on the ruptured plaque and whether the occlusion is transient (UA) or persistent (MI). The balance between thrombosis and endogenous clot lysis determines which syndrome occurs. Lytic therapy is not effective in UA, probably because the clot is not occlusive or because endogenous lysis has already achieved the degree of coronary opening that eventuates from tissue plasminogen activator or streptokinase administration. Prompt catheterization and revascularization may be as indicated in patients with MI if there remains viable myocardium as in patients with UA.