Pressure-Controlled Intermittent Coronary Sinus Occlusion: A Novel Approach to Improve Microvascular Flow and Reduce Infarct Size in STEMI

Despite successful primary percutaneous coronary intervention (PCI) for treatment of ST-segment elevation myocardial infarction (STEMI), myocardial salvage is frequently suboptimal resulting in large infarctions with increased rates of heart failure and death. Microvascular dysfunction after the procedure is frequently present and contributes directly to poor outcomes in STEMI. Pressure-controlled intermittent Coronary Sinus Occlusion (PiCSO) is a novel technology designed to mitigate microvascular dysfunction in STEMI. Non-randomized studies have suggested that PiCSO use during primary PCI in STEMI is safe, improves microvascular perfusion and reduces infarct size. Randomized trials are ongoing to investigate the safety and effectiveness of PiCSO in high-risk patients with anterior STEMI undergoing primary PCI.

Angiographic classification of patterns of restenosis following femoropopliteal artery intervention: A proposed scoring system

OBJECTIVES

To propose a classification system for characterizing angiographic femoropopliteal artery restenosis patterns associated with common endovascular modalities.

BACKGROUND

Peripheral artery disease is a worldwide issue affecting millions of people. Despite a myriad of endovascular technologies available to treat peripheral artery disease of the femoropopliteal arteries, restenosis remains a common failure mode. Characterizing common patterns of restenosis is important to discern the potential impact of baseline patient, lesion, and procedural characteristics, as well as treatment modalities on either the primary success or the failure patterns associated with restenosis.

METHODS

Studies included in the analysis were from previous core laboratory-adjudicated femoropopliteal artery disease trials and registries reflecting a wide array of treatment modalities.

RESULTS

From the subjects enrolled and analyzed, there were 403 total angiograms for analysis and adjudication. Target lesion revascularization images of the 32 validation cases were evaluated for index treated length, diameter stenosis, and lesion morphology characteristics. The following lesion types are proposed: Type 1 "Focal" pattern, which may be "Edge Proximal" or "Edge Distal" depending on location; a Type 2 "Multifocal" pattern which may also exhibit edge restenosis, but may also be "Edge Bilateral"; a Type 3 "Moderate" pattern and a Type 4 "Diffuse" pattern; and finally, a Type 5 "Occlusion".

CONCLUSIONS

A classification system that enables healthcare professionals to anticipate and describe failures following the index procedure, thereby impacting the choice of options for retreatment, may facilitate consistency and standardization within the heterogeneous field of endovascular device treatments for the femoropopliteal artery.

A provisional strategy for treating true bifurcation lesions employing a scoring balloon for the side branch: final results of the AGILITY trial

BACKGROUND

The provisional approach for bifurcation stenting with side-branch balloon angioplasty is associated with dissections and suboptimal results requiring kissing balloon techniques or bailout stenting. We hypothesized that using a scoring balloon for the side branch and a drug-eluting stent for the main vessel might improve outcomes of true bifurcation lesions.

METHODS AND RESULTS

A total of 93 patients with complex bifurcations were enrolled in a multicenter, single-arm, prospective clinical trial. A drug-eluting stent was deployed in the main vessel following dilatation of the side-branch stenosis with a scoring balloon. The overall angiographic success rate was 93.5%, and procedural success rate was 91.4%. The final diameter stenosis was 13.9% ± 7.2% for the main vessel and 33.3% ± 22.9% for the side branch. Crossover to stent deployment in the side branch was required in 10.8%. The postscoring balloon dissection rate was 8.2% and 6% (all ≤ class C) for the main vessel and side branch respectively, which was reduced to 1.1 and 2.1% poststenting. At 9-month follow-up, the composite MACE rate [cardiac death, myocardial infarction, or target lesion revascularization (TLR)] was 5.4%, including a TLR rate of 3.3% (1.1% from hospital discharge to 9 months).

CONCLUSION

The 9-month results of the AGILITY trial support a simple provisional strategy for treating complex true bifurcation lesions with deployment of a drug-eluting stent in the main vessel after dilatation of the side-branch vessel with a scoring balloon. This strategy was associated with excellent and safe procedural results, a low rate of crossover to side-branch stenting, and favorable outcomes.

Long-term impact of routinely detected early and late incomplete stent apposition: an integrated intravascular ultrasound analysis of the TAXUS IV, V, and VI and TAXUS ATLAS workhorse, long lesion, and direct stent studies

OBJECTIVES

We sought to determine the 2-year impact of early and late-acquired incomplete stent apposition (ISA) on clinical events.

BACKGROUND

The late clinical impact of early or late-acquired ISA in bare-metal stents (BMS) and TAXUS stents (Boston Scientific, Natick, Massachusetts) is debatable.

METHODS

We evaluated 1,580 patients enrolled in the intravascular ultrasound (IVUS) substudies of TAXUS IV, V, VI and TAXUS-ATLAS WH, LL, and DS trials.

RESULTS

There were 96 cases of early ISA in 26 (7.2%) BMS patients, 35 (9.7%) TAXUS Express patients (p = 0.28 vs. BMS), and 35 (7.3%) TAXUS Liberté patients (p = 0.21 vs. TAXUS Express, and p = 1.00 vs. BMS). Major adverse cardiovascular events were similar at 9 months in patients with early ISA versus control subjects with no ISA for BMS (3.8% vs. 15.2%, p = 0.13) and for TAXUS (11.6% vs. 8.8%, p = 0.45). There was no impact of early ISA on stent thrombosis. At 9-month follow-up, there were 36 cases of late-acquired ISA in 7 (2.7%) BMS patients, 17 (3.1%) patients with TAXUS slow-release (TAXUS Express or TAXUS Liberté), and 12 (15.4%) patients receiving TAXUS moderate-release. Over 2 ensuing years, major adverse cardiovascular events were similar in patients with late-acquired ISA versus control subjects with no ISA for BMS (14.3% vs. 7.9%, p = 0.54), TAXUS (overall, 8.3% vs. 8.1% p = 0.87), or TAXUS slow-release formulation (0% vs. 7.9%, p = 0.28). There was no impact of late-acquired ISA on stent thrombosis.

CONCLUSIONS

Neither routinely detected acute ISA nor routinely detected late-acquired ISA in BMS or TAXUS patients was associated with adverse clinical events over long-term follow-up.

The clinical impact of routine angiographic follow-up in randomized trials of drug-eluting stents: a critical assessment of "oculostenotic" reintervention in patients with intermediate lesions

OBJECTIVES

The aim of this study was to study the long-term clinical effects of routine angiographic follow-up and related reintervention after drug-eluting stenting.

BACKGROUND

Prior stent trials have shown that protocol-mandated angiographic follow-up increases repeat interventions compared with clinical follow-up alone. The long-term clinical impact of this practice is unknown.

METHODS

Long-term outcomes of patients assigned to routine angiographic follow-up in 3 large-scale TAXUS (Boston Scientific, Natick, Massachusetts) trials were compared with patients assigned to clinical follow-up alone, in a propensity score-adjusted patient-level meta-analysis. Outcomes were also compared in patients with treated versus untreated nonischemic intermediate lesions (quantitative angiographic stenosis between >or=40% and <70%) detected at angiographic follow-up.

RESULTS

Target lesion revascularization (TLR) rates at 5 years were significantly higher in the angiographic compared with clinical follow-up cohort (18.3% vs. 11.1%, p < 0.001). This was due to more frequent treatment of intermediate lesions, but there was no associated reduction in rates of cardiac death or myocardial infarction (8.9% vs. 8.8%, p = 0.93). Of patients with nonischemic intermediate lesions, 17% who were not revascularized at the time of angiographic follow-up had a subsequent TLR, whereas 7% of patients who had TLR at this follow-up angiogram required additional revascularization during long-term follow-up.

CONCLUSIONS

A strategy of routine angiographic follow-up increases oculostenotic revascularization of nonischemic intermediate lesions without affecting subsequent rates of cardiac death or myocardial infarction, and TLR was not required in 83% of those lesions. A conservative approach, in which repeat angiography is limited to patients with recurrent ischemia or progressive symptoms, minimizes repeat revascularization of nonischemic intermediate lesions and optimizes long-term event-free survival after drug-eluting stent implantation.

Impact of post-intervention minimal stent area on 9-month follow-up patency of paclitaxel-eluting stents: an integrated intravascular ultrasound analysis from the TAXUS IV, V, and VI and TAXUS ATLAS Workhorse, Long Lesion, and Direct Stent Trials

OBJECTIVES

We investigated the predictive value of the intravascular ultrasound (IVUS) measured post-intervention minimum stent area (MSA) on 9-month follow-up paclitaxel-eluting stent (PES) patency compared with bare-metal stents (BMS).

BACKGROUND

Stent underexpansion is a strong predictor for restenosis after sirolimus-eluting stent implantation, but the implication of underexpansion in PES is still unknown.

METHODS

From the combined TAXUS IV, V, and VI and TAXUS ATLAS Workhorse, Long Lesion, and Direct Stent trials, 1,580 patients (PES 1,098, BMS 482) in IVUS substudies were analyzed. The MSA that best predicted angiographic in-stent restenosis (ISR) (% diameter stenosis > or =50%) was determined.

RESULTS

The post-intervention IVUS MSA was similar in PES and BMS (6.6 +/- 2.5 mm(2) vs. 6.7 +/- 2.3 mm(2), p = 0.92). At 9-month follow-up, ISR was lower in the PES group versus the BMS group (10% vs. 31%, p < 0.0001). Using multivariable logistic regression analysis, post-intervention IVUS MSA was the independent predictor of subsequent ISR in both the PES and BMS groups (p = 0.0002 for PES and p = 0.0002 for BMS). The ability of the post-intervention IVUS MSA to predict ISR was further assessed using receiver operating characteristic analysis. The post-intervention IVUS MSA was found to be a faithful discriminator between patients with and without ISR in both PES (c = 0.6382) and BMS (c = 0.6373). Finally, the optimal thresholds of post-intervention IVUS MSA that best predicted stent patency at 9 months were 5.7 mm(2) for PES and 6.4 mm(2) for BMS.

CONCLUSIONS

Post-intervention MSA measured by IVUS can predict 9-month follow-up stent patency after both PES and BMS implantation. (Randomized Trial Evaluating Slow-Release Formulation TAXUS Paclitaxel-Eluting Coronary Stents to Treat De Novo Coronary Lesions; NCT00301522) (Direct Stenting of TAXUS Liberté-SR Stent for the Treatment of Patients With de Novo Coronary Artery Lesions; NCT00371423) (A Study of the TAXUS Liberté Stent for the Treatment of Long De Novo Coronary Artery Lesions; NCT00371475) (A Study of the TAXUS Liberté Stent for the Treatment of de Novo Coronary Artery Lesions in Small Vessels; NCT00371748).

Defining the length of stay following percutaneous coronary intervention: an expert consensus document from the Society for Cardiovascular Angiography and Interventions. Endorsed by the American College of Cardiology Foundation

Percutaneous coronary intervention (PCI) is the most common method of coronary revascularization. Over time, as operator skills and technical advances have improved procedural outcomes, the length of stay (LOS) has decreased. However, standardization in the definition of LOS following PCI has been challenging due to significant physician, procedural, and patient variables. Given the increased focus on both patient safety as well as the cost of medical care, system process issues are a concern and provide a driving force for standardization while simultaneously maintaining the quality of patient care. This document: (1) provides a summary of the existing published data on same-day patient discharge following PCI, (2) reviews studies that developed methods to predict risk following PCI, and (3) provides clarification of the terms used to define care settings following PCI. In addition, a decision matrix is proposed for the care of patients following PCI. It is intended to provide both the interventional cardiologist as well as the facilities, in which they are associated, a guide to allow for the appropriate LOS for the appropriate patient who could be considered for early discharge or outpatient intervention.

Long-Term Paclitaxel-Eluting Stent Outcomes in Elderly Patients

Background— Although drug-eluting stents have become a mainstay of percutaneous coronary intervention, information about drug-eluting stents outcomes in elderly patients is limited. Data from the paclitaxel-eluting stent (PES) trials and registries were pooled to assess PES benefits relative to advancing patient age, including comparison with bare-metal stents.

Methods and Results— Data from 5 randomized trials (2271 patients with PES, 1397 patients with bare-metal stents) and from 2 postmarket registries (7492 patients with PES) were pooled separately. Each dataset was stratified into age groups: <60, 60 to 70, and >70 years. At baseline, patients aged >70 years in both datasets had significantly more adverse characteristics than younger patients. Through 5 years, trial data showed that patients aged >70 years had higher death rates, but comparable rates of myocardial infarction, stent thrombosis, and target lesion revascularization with younger patients. Compared with patients with bare-metal stents, patients with PES aged >70 years had comparable rates of death, myocardial infarction, and stent thrombosis but a significantly lower target lesion revascularization rate (22.2 versus 10.2, P <0.001). These findings were echoed in the registry data through 2 years that showed that PES patients aged >70 years had significantly higher death rates, but lower myocardial infarction, stent thrombosis, and target lesion revascularization rates, compared with younger patients. Although the mortality rates of patients aged >70 years were higher than those of younger patients, they were comparable with those of age- and gender-matched norms in the general population.

Conclusions— This analysis of almost 10 000 patients demonstrated that percutaneous coronary intervention with PES is a safe and an effective treatment option that should not be withheld based on age.

Design and Rationale of the ARBITER 6 Trial (Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol)-6-HDL and LDL Treatment Strategies in Atherosclerosis (HALTS)

BACKGROUND

Recent evidence on the use of statin therapy indicates the potential for ultra-low levels of LDL-C to provide greater protection from recurrent coronary heart disease events. Guidelines for the treatment of lipid disorders were revised to indicate that an LDL-C treatment goal of 70 mg/dl was optional (NCEP ATPIII). In these same guidelines, low levels of HDL-C are also suggested but not specifically proscribed as a target of therapy. Recently ARBITER 2 (Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol 2) has provided the first evidence of the potential of raising HDL-C with extended release niacin when added to statin monotherapy in secondary prevention. However, whether this approach would be superior to a strategy in which lower concentrations of LDL-C are targeted is unknown.

MATERIALS AND METHODS

ARBITER 6-HALTS ( HDL and LDL Treatment Strategies) will be a randomized, parallel group, open-label study comparing HDL-C and LDL-C focused strategies of lipid treatments for their effects on atherosclerosis. Up to 400 subjects will be assigned to either intensified LDL-C lowering therapy with ezetimibe or HDL-C raising therapy with extended-release niacin. The primary endpoint is the mean change in the intima-media thickness of the common carotid artery after 14 months. Secondary endpoints include the change in lipid values and lipid subfractions, drug discontinuation due to adverse effects, change in quality of life, and a composite endpoint consisting of all major adverse cardiovascular events.

CONCLUSION

ARBITER 6-HALTS will guide clinicians on whether a lipid treatment strategy of raising HDL-C or further LDL-C reduction is superior in the secondary prevention of coronary heart disease.

Polymer-Based, Paclitaxel-Eluting TAXUS Liberté Stent in De Novo Lesions

OBJECTIVES

The goal of this research was to assess non-inferiority of the next-generation TAXUS Liberté stent (Boston Scientific Corp., Natick, Massachusetts) versus the TAXUS Express stent (Boston Scientific Corp.).

BACKGROUND

The introduction of drug-eluting stents (DES) has shifted clinical practice towards more complex lesion subsets, prompting the need for more deliverable DES. TAXUS Liberté was designed to combine the established polymer-based, paclitaxel-elution TAXUS technology with the more advanced Liberté stent platform.

METHODS

The TAXUS ATLAS study is a global, prospective, single-arm trial evaluating outcomes in de novo coronary lesions visually estimated to be 10 to 28 mm in length in vessels 2.5 to 4.0 mm in diameter. The control group is an entry-criteria-matched population of TAXUS Express patients from the TAXUS IV and V trials. The primary end point is non-inferiority of TAXUS Liberté versus TAXUS Express for 9-month target vessel revascularization.

RESULTS

Despite similar inclusion criteria, quantitative coronary angiography-determined baseline lesion characteristics were significantly more complex for TAXUS Liberté than TAXUS Express. The primary non-inferiority end point was met with the 1-sided 95% confidence bound of 2.98% less than the pre-specified non-inferiority margin of 3% (p = 0.0487).

CONCLUSIONS

Despite the treatment of more complex lesions with TAXUS Liberté, the primary end point was met, demonstrating that TAXUS Liberté is non-inferior to TAXUS Express. The successful transfer of the proven TAXUS technology to the more advanced TAXUS Liberté platform was demonstrated. (TAXUS ATLAS: TAXUS Liberté-SR Stent for the Treatment of De Novo Coronary Artery Lesions; http://www.clinicaltrials.gov/ct/show/NCT00371709?order=1; NCT00371709).

Paclitaxel-eluting stents vs vascular brachytherapy for in-stent restenosis within bare-metal stents: the TAXUS V ISR randomized trial

CONTEXT

Restenosis within bare-metal stents is often treated with repeat percutaneous coronary intervention, although subsequent recurrence rates are high, with vascular brachytherapy (VBT) affording the best results. The effectiveness of drug-eluting stents in this setting has not been established.

OBJECTIVE

To investigate the safety and efficacy of the polymer-based, slow-release paclitaxel-eluting stent in patients with restenotic lesions after prior stent implantation in native coronary arteries.

DESIGN, SETTING, AND PATIENTS

Prospective, multicenter, randomized trial conducted between June 6, 2003, and July 16, 2004, at 37 North American academic and community-based institutions in 396 patients with in-stent restenosis of a previously implanted bare-metal coronary stent (vessel diameter, 2.5-3.75 mm; lesion length, < or =46 mm).

INTERVENTIONS

Patients were randomly assigned to undergo angioplasty followed by VBT with a beta source (n = 201) or paclitaxel-eluting stent implantation (n = 195). Clinical and angiographic follow-up at 9 months was scheduled in all patients.

MAIN OUTCOME MEASURE

Ischemia-driven target vessel revascularization at 9 months.

RESULTS

Diabetes mellitus was present in 139 patients (35.1%). Median reference vessel diameter was 2.65 mm and median lesion length was 15.3 mm. In the VBT group, new stents were implanted in 22 patients (10.9%) and in the paclitaxel-eluting stent group, multiple stents were required in 57 patients (29.2%), with median stent length of 24 mm. Follow-up at 9 months was complete in 194 patients in the VBT group and 191 patients in the paclitaxel-eluting stent group (96.5% and 97.9%, respectively). For VBT and paclitaxel-eluting stents, respectively, the number of events and 9-month rates for ischemic target lesion revascularization were 27 (13.9%) vs 12 (6.3%) (relative risk [RR], 0.45; 95% confidence interval [CI], 0.24-0.86; P = .01); for ischemic target vessel revascularization, 34 (17.5%) vs 20 (10.5%) (RR, 0.60; 95% CI, 0.36-1.00; P = .046); and for overall major adverse cardiac events, 39 (20.1%) vs 22 (11.5%) (RR, 0.57; 95% CI, 0.35-0.93; P = .02), with similar rates of cardiac death or myocardial infarction (10 [5.2%] vs 7 [3.7%]; RR, 0.71; 95% CI, 0.28-1.83; P = .48) and target vessel thrombosis (5 [2.6%] vs 3 [1.6%]; RR, 0.61; 95% CI, 0.15-2.50; P = .72). Angiographic restenosis at 9 months was 31.2% (53 of 170 patients) with VBT and 14.5% (25 of 172 patients) with paclitaxel-eluting stents (RR, 0.47; 95% CI, 0.30-0.71; P<.001).

CONCLUSION

Treatment of bare-metal in-stent restenotic lesions with paclitaxel-eluting stents rather than angioplasty followed by VBT reduces clinical and angiographic restenosis at 9 months and improves event-free survival.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00287573.

Pivotal, randomized U.S. study of the Symbiot™ covered stent system in patients with saphenous vein graft disease: Eight-month angiographic and clinical results from the Symbiot III trial

OBJECTIVES

The purpose of this study was to evaluate the clinical and angiographic outcomes of the Symbiot ePTFE covered stent versus bare metal stents (BMS) for the treatment of saphenous vein graft (SVG) disease.

BACKGROUND

The Symbiot stent was developed to reduce periprocedural complications, by potentially preventing distal embolization, and to serve as a possible barrier to cell migration, thus reducing restenosis.

METHODS

Symbiot III is a prospective, randomized trial of 400 patients at 45 US sites, with 201 patients in the Symbiot group and 199 in the BMS group. Randomization was stratified based on the intended use of embolic protection devices and glycoprotein IIb/IIIa inhibitors. The primary endpoint was percent diameter stenosis (%DS) as measured by quantitative coronary angiography at 8 months. Secondary endpoints included MACE (cardiac death, MI, TVR).

RESULTS

The groups were well matched for all baseline clinical and lesion characteristics. At 8 months, %DS was comparable between groups (30.9% Symbiot, 31.9% BMS, P = 0.80). Although the rates of binary restenosis in the stented segment were similar (29.1% Symbiot, 21.9% BMS, P = 0.17), more patients in the Symbiot group had binary restenosis at the proximal edge (9.0% Symbiot, 1.8% BMS, P = 0.0211). There was no difference in the incidence of MACE between groups (30.6% Symbiot, 26.6% BMS, P = 0.43).

CONCLUSIONS

This study failed to show an advantage for the Symbiot stent in the treatment of degenerated SVGs. This PTFE covered stent does not appear to act as a barrier to prevent restenosis.

Primary Angioplasty in Acute Myocardial Infarction at Hospitals With No Surgery On-Site (the PAMI-No SOS study) versus transfer to surgical centers for primary angioplasty

OBJECTIVES

To investigate primary angioplasty (PA) for high-risk acute myocardial infarction (AMI) at hospitals with no cardiac surgery on-site (No SOS), we hypothesized that a nonrandomized registry of such patients treated with PA would show clinical outcomes similar to those of a group randomized to transfer for PA, and that reperfusion would occur faster.

BACKGROUND

Primary angioplasty provides outcomes superior to fibrinolytic therapy in AMI, but its use in community hospitals with No SOS has been limited.

METHODS

Fibrinolytic-eligible patients with high-risk AMI prospectively consented if they had one or more high-risk characteristic. Nineteen hospitals with No SOS prospectively enrolled 500 patients for PA on-site. Seventy-one similar Air Primary Angioplasty in Myocardial Infarction trial patients were randomized to transfer for PA.

RESULTS

Primary angioplasty was performed in 88% of patients. Patients transferred for PA had a longer mean time to treatment (187 vs. 120 min; p < 0.0001). Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 was achieved in 96% for on-site PA, 86% in the transfer group (p = 0.004). The combined primary end point of 30-day mortality, re-infarction, and disabling stroke occurred in 27 (5%) on-site PA patients and 6 (8.5%) transfer patients (p = 0.27). Unadjusted one-year mortality was improved in on-site PA patients compared with those transferred (6% vs. 13%, p = 0.043), but after adjustment for differences in baseline variables, this difference was not significant.

CONCLUSIONS

On-site PA and transfer groups had similar 30-day outcomes and more rapid reperfusion for on-site PA. Primary angioplasty in high-risk AMI patients at hospitals with No SOS is safe, effective, and faster than PA after transfer to a surgical facility.

The anticoagulant therapy with bivalirudin to assist in the performance of percutaneous coronary intervention in patients with heparin-induced thrombocytopenia (ATBAT) study: main results

Up to 5% of patients given heparin develop heparin-induced thrombocytopenia (HIT). These patients may need anticoagulation for acute coronary syndromes (ACS) or percutaneous coronary intervention (PCI), a clinical challenge given the limited alternatives. In a prospective, open-label study, we evaluated the safety and efficacy of bivalirudin in patients with HIT or HIT with thrombotic syndrome (HITTS) undergoing PCI. Patients aged 18 years were enrolled in 24 centers in 2 countries. Bivalirudin was given 5 minutes before PCI (1 mg/kg bolus; 2.5 mg/kg/hour infusion for 4 hours [high-dose group] or 0.75 mg/kg bolus; 1.75 mg/kg/hour infusion [low-dose group]). Clinical and hematological measures were assessed within 24 hours after starting bivalirudin, just before PCI, just before sheath removal, and 48 hours after treatment or at discharge, whichever occurred first. The primary endpoint was major bleeding 48 hours after discontinuation or until discharge, whichever occurred first. From July 1999 to February 2003, 52 patients were recruited. Procedural success (TIMI grade 3 flow and < 50% stenosis) was achieved in 98% of patients, and clinical success (absence of death, emergency bypass surgery, or Q-wave infarction) was achieved in 96%. One high-dose patient who underwent elective bypass surgery had major bleeding (1.9%; 95% CI: 0.05 10.65%), and 7 patients had minor bleeding. No patient had significant thrombocytopenia (platelet count < 50 109/L) after treatment. One patient in the low-dose group died from cardiac arrest ~46 hours after uncomplicated PCI. Bivalirudin appeared safe and provided effective anticoagulation during PCI. These data, and extensive experience with bivalirudin in PCI, support its use in high-risk patients with HIT requiring PCI.

Morphometric changes in normal arteries and those undergoing transluminal angioplasty

To understand the morphometric effects of balloon catheter angioplasty in autopsy specimens, we studied the effect of histologic preparation on the size of control arterial specimens (N) and those having angioplasty at room temperature (CD) or body temperature (WD). Diameters of external and internal iliac arteries were measured with calipers, photography, and X-rays without any distention, after 200 mm Hg in a balloon catheter, after angioplasty to 4 atmospheres, and after fixation with a balloon catheter in place was inflated to 200 mm Hg. Arterial diameters were also taken from the tissue blocks and histologic slides. Images taken from the photos, X-rays, tissue blocks, and slides were digitized, and the diameter was calculated from circumference measurements. Diameters increased approximately 30% (P less than .001) when distended from the resting state to 200 mm Hg. There was a 7.4-8.2% decrease in diameter of arteries in blocks (P less than .01) and a further decrease of 9.8-11.9% from block to slide (P less than .005). Thus, significant size changes occur during arterial preparation. The postmortem artery shrinks without any distending pressure. Paraffin embedding and slide preparation are also associated with significant decreases in arterial size. These changes may influence the understanding of the pathophysiology of angioplasty and the estimation of stenoses by histopathology.