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Objectives: The purpose of this study was to assess whether the early discontinuation of eptifibatide infusion in nonemergent percutaneous coronary intervention (PCI) is associated with a higher frequency of periprocedural ischemic myonecrosis.Background: The recommended regimen for eptifibatide is a double bolus followed by an infusion for 18 h. It is not known whether the infusion can be shortened if the PCI is uncomplicated.Methods: We enrolled 624 patients with stable angina, acute coronary syndrome, or recent ST-segment elevation myocardial infarction (>48 h) who underwent successful coronary stenting and received eptifibatide. Patients were randomly assigned to receive either an 18-h infusion or an abbreviated infusion of <2 h. The primary end point was the incidence of periprocedural myonecrosis defined as troponin-I elevation >0.26 microg/l. Secondary end points included death, myocardial infarction, urgent target vessel revascularization at 30 days, and in-hospital major bleeding using the REPLACE-2 (Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events) trial criteria.Results: The incidence of periprocedural myonecrosis was 30.1% in the <2-h group versus 28.3% in the 18-h group (mean difference: 1.8%; upper bound of 95% confidence interval: 7.8%; p < 0.012 for noninferiority). The 30-day incidence of myocardial infarction, death, and target vessel revascularization was similar in both groups (p = NS). Major bleeding was less frequent in the <2-h group (1.0% vs. 4.2%, p = 0.02).Conclusions: After uncomplicated PCI, eptifibatide infusion can be abbreviated safely to <2 h. It is not inferior to the standard 18-h infusion in preventing ischemic outcome, and it may be associated with less major bleeding. (Brief Infusion of Eptifibatide Following Percutaneous Coronary Intervention [BRIEF PCI]; NCT00111566). [ABSTRACT FROM AUTHOR]

We present a case of plaque rupture located inside a restenotic stent. Intravascular ultrasound defined a lesion with a minimal lumen area (MLA) of 3.59 cm², plaque burden of 72%, and reference vessel luminal diameter of 4.0 mm with an external elastic membrane lumen cross-section area of 12.6 mm². There was a clearly identified plaque rupture, with a flap-like dissection within the stented segment. Virtual histology intravascular ultrasound confirmed that the adjacent plaque had necrotic core with a thin overlying fibrous cap. The remaining tissue next to the dissection plane was fibrotic. This case illustrates that neointimal hyperplasia may organize into an unstable plaque, with a thin fibrous cap overlying a lipid-rich necrotic core-a so-called virtual histology thin-capped fibroatheroma. As defined in the PROSPECT trial, the in-stent stenotic lesion in our case conformed to the definition of a high-risk plaque-it had an MLA < 4 mm², plaque burden was ≥ 70%, and there was >10% necrotic core. It became unstable and ruptured. The demonstrated findings of this case may sway physicians against sealing hemodynamically nonsignificant unstable plaques., (Copyright © 2010 Wiley-Liss, Inc.)

Objectives: To construct a calculator to assess the risk of 30-day mortality following PCI., Background: Predictors of 30-day mortality are commonly used to aid management decisions for cardiac surgical patients. There is a need for an equivalent risk-score for 30-day mortality for percutaneous coronary intervention (PCI) as many patients are suitable for both procedures., Methods: The British Columbia Cardiac Registry (BCCR) is a population-based registry that collects information on all PCI procedures performed in British Columbia (BC). We used data from the BCCR to identify risk factors for mortality in PCI patients and construct a calculator that predicts 30-day mortality., Results: Patients (total n = 32,899) were divided into a training set (n = 26,350, PCI between 2000 and 2004) and validation set (n = 6,549, PCI in 2005). Univariate predictors of mortality were identified. Multivariable logistic regression analysis was performed on the training set to develop a statistical model for prediction of 30-day mortality. This model was tested in the validation set. Variables that were objective and available before PCI were included in the final risk score calculator. The 30-day mortality for the overall population was 1.5% (n = 500). Area under the ROC curve was 90.2% for the training set and 91.1% for the validation set indicating that the model also performed well in this group., Conclusions: We describe a large, contemporary cohort of patients undergoing PCI with complete follow-up for 30-day mortality. A robust, validated model of 30-day mortality after PCI was used to construct a risk calculator, the BC-PCI risk score, which can be accessed at www.bcpci.org., (2009 Wiley-Liss, Inc.)

Background: Atherothrombotic embolization during primary percutaneous coronary intervention (PCI) induces microvascular obstruction and reduces myocardial tissue reperfusion. A variety of thrombectomy devices have been evaluated as an adjunct to primary PCI in patients with ST-elevation myocardial infarction (STEMI) to reduce distal embolization. Results have been inconsistent and difficult to predict. The aim of this study was to investigate the safety and efficacy of an innovative thrombectomy device, the Rinspiration System, which simultaneously "rinses" the vessel with turbulent flow and aspirates thrombus., Methods: We prospectively enrolled 109 patients at six academic institutions in three countries referred for primary or rescue PCI for STEMI presenting within 12 hr of symptom onset. The primary endpoint was >or=50% ST-segment elevation resolution (STR) measured 60 min after PCI by continuous electrocardiographic recording, Secondary end points included STR > 70% at 60 min, final TIMI flow, myocardial blush score, and 30-day major adverse cardiac events (MACE)., Results: Mean symptom-to-PCI time was 4.7 +/- 2.7 hr. Rinspiration was successfully delivered in 98% of cases. Final TIMI three flow was achieved in 89% of patients and myocardial blush >or=2 in 78%. Rates of STR >or= 50% and >70% at 60 min were 97 and 80%, respectively. No device-related complications were observed. Thirty-day MACE rate was 4.6%., Conclusions: This international multicenter registry demonstrates that the adjunctive use of Rinspiration during primary PCI is safe and feasible. The excellent STR data compare favorably with results of previous trials using different devices for thrombus management, indicating a potential clinical benefit., ((c) 2008 Wiley-Liss, Inc.)

Background: Intracoronary thrombus is often problematic during percutaneous coronary intervention. Rinspiration is a new thrombectomy catheter system designed to mechanically disrupt and remove intravascular thrombus., Methods: Rinspiration thrombectomy was performed in 15 patients with angiographically visible thrombus in native coronary arteries (10 cases) and in saphenous grafts (5 cases). Indications included acute myocardial infarction in 11 patients and postinfarction ischemia in 4 patients., Results: The Rinspiration system appeared relatively simple to use. There were no device-related complications. Thrombectomy resulted in an improvement in thrombus grade from 3.8 +/- 1.6 to 2.5 +/- 1.7 (p = 0.02), and TIMI flow from 1.5 +/- 1.3 to 2.2 +/- 1.0 (p = 0.047). Stenting further improved thrombus grade to 0.8 +/- 1.6 and TIMI flow to 2.6 +/- 0.8. At 30-day follow up all patients remained free of repeat revascularization and reinfarction; 1 patient died from hemorrhagic stroke., Conclusions: The Rinspiration system appears capable of safely removing intracoronary thrombus and warrants further evaluation.

Angiographic thrombus is associated with poorer procedural and clinical outcomes. We report our experience with the X-Sizer thrombectomy device (EndiCOR Medical) from March 2001 to December 2002. Indications for use in 44 patients (33 male; mean age, 60) included myocardial infarction (27), unstable angina (6), periprocedural thrombosis (2), acute (< 24 hr) stent thrombosis (1), and subacute (> 24 hr) stent thrombosis (8). Three cases involved vein grafts. Deployment was successful in 42/44. Difficulty traversing the stent occurred in 5/9 cases of in-stent thrombosis. Median TIMI flow increased from 1 to 2 (P = 0.01) postthrombectomy. Median final TIMI flow was 3. Complications included dissection (1), perforation, device jam on stent (1), disruption of a covered stent (1), distal macro-embolization (4), and transient no-reflow (5). The X-Sizer thrombectomy device improves TIMI flow but does not always prevent distal embolization. Care is needed when treating in-stent thrombosis., ((c) 2004 Wiley-Liss, Inc.)

Objective: This study was designed to determine whether antisense oligodeoxynucleotides (ODN) directed against the nuclear proto-oncogene c-myc could inhibit restenosis when given by local delivery immediately after coronary stent implantation., Background: Failure of conventional pharmacologic therapies to reduce the incidence of coronary restenosis after percutaneous revascularization techniques has prompted interest in the use of agents that target intracellular central regulatory mechanisms., Methods: Eighty-five patients were randomly assigned to receive either 10 mg of phosphorothioate-modified 15-mer antisense ODN or saline vehicle by intracoronary local delivery after coronary stent implantation. The primary end point was percent neointimal volume obstruction measured by computerized analysis of electrocardiogram-gated intravascular ultrasound (IVUS) at six-month follow-up. Secondary end points included clinical outcome and quantitative coronary angiography analysis., Results: Analysis of follow-up IVUS data was performed on 77 patients. In-stent volume obstruction was similar between groups (44 +/- 16% and 46 +/- 14%, placebo vs. ODN; p = 0.57; 95% confidence interval: -1.13 to 0.85). Minimum luminal diameter increased from 0.84 +/- 0.36 and 0.90 +/- 0.45 (p = 0.55) to 2.70 +/- 0.37 and 2.80 +/- 0.37 (p = 0.28) after stent implantation, which decreased to 1.50 +/- 0.61 and 1.50 +/- 0.53 (p = 0.98) by six months, yielding similar loss indexes (placebo vs. ODN, respectively). There were no differences in angiographic restenosis rates (38.5 and 34.2%; p = 0.81; placebo vs. ODN) or clinical outcome., Conclusions: Treatment with 10 mg of phosphorothioate-modified ODN directed against c-myc does not reduce neointimal volume obstruction or the angiographic restenosis rate in this patient population.

Aims: This study is the contribution by the Thoraxcenter, Rotterdam, to the European(32)P Dose Response Trial, a non-randomized multicentre trial to evaluate the safety and efficacy of the radioactive Isostent in patients with single coronary artery disease., Methods and Results: The radioactivity of the stent at implantation was 6--12 microCi. All patients received aspirin indefinitely and either ticlopidine or clopidogrel for 3 months. Quantitative coronary angiography measurements of both the stent area and the target lesion (stent area and up to 5 mm proximal and distal to the stent edges) were performed pre- and post-procedure and at the 5-month follow-up. Forty-two radioactive stents were implanted in 40 patients. Treated vessels were the left anterior descending coronary artery (n=20), right coronary artery (n=10) or left circumflex artery (n=10). Eight patients received additional non-radioactive stents. Lesion length measured 10+/-3 mm with a reference diameter of 3.07+/-0.69 mm. Minimal lumen diameter increased from 0.98+/-0.53 mm pre-procedure to 2.29+/-0.52 mm (target lesion) and 2.57+/-0.44 mm (stent area) post-procedure. There was one procedural non-Q wave myocardial infarction, due to transient thrombotic closure. Thirty-six patients returned for angiographical follow-up. Two patients had a total occlusion proximal to the radioactive stent. Of the patent vessels, none had in-stent restenosis. Edge restenosis was observed in 44%, occurring predominantly at the proximal edge. Target lesion revascularization was performed in 10 patients and target vessel revascularization in one patient. No additional clinical end-points occurred during follow-up. The minimal lumen diameter at follow-up averaged 1.66+/-0.71 mm (target lesion) and 2.12+/-0.72 (stent area); therefore late loss was 0.63+/-0.69 (target lesion) and 0.46+/-0.76 (stent area), resulting in a late loss index of 0.65+/-1.15 (target lesion) and 0.30+/-0.53 (stent area)., Conclusion: These results indicate that the use of radioactive stents is safe and feasible, however, the high incidence of edge restenosis makes this technique currently clinically non-applicable., (Copyright 2001 The European Society of Cardiology.)

Background: Nonfluoroscopic electromechanical mapping (NEM) has been proposed as a new technique for the evaluation of electrical and mechanical functioning of the myocardium. In this system, linear local shortening (LLS) is the parameter used for assessment of local mechanical properties. To validate this parameter, we compared LLS with regional wall motion (RWM) data derived from contrast left ventriculograms acquired in the same patients., Methods and Results: Angiographic left ventricular RWM was analyzed using the area-length method. The right anterior oblique view was divided in five segments, the left anterior oblique view in two. Through a comparison of enddiastolic and endsystolic areas drawn from a computer-defined central point to the respective wall delineation, RWM was calculated as change in area. In the first approach, we compared area changes to comparable NEM segments. In the second part of the study, LLS values for normokinetic, hypokinetic, akinetic and dyskinetic segments were correlated to the change in angiographic RWM. In the first approach, the overall comparison of segments yielded a correlation coefficient of 0.67 (P<0.0005). In the second part of the study, differences in LLS values between dyskinetic (LLS=-3.68+/-8.86%), akinetic (2.84+/-3.96%), hypokinetic (9.35+/-4.27%) and normokinetic (13.66+/-7.98%) segments were highly significant (overall ANOVA: P<0.0005)., Conclusion: NEM is a powerful tool for invasive electromechanical assessment of myocardial function.

In 40 patients, we compared linear local shortening assessed with nonfluoroscopic electromechanical mapping as a function of regional wall motion with echocardiographic data in a subset of patients with severe coronary artery disease and subsequently decreased left ventricular function. Our study showed that nonfluoroscopic electromechanical mapping can accurately assess regional wall motion. In addition, this study showed a significant decrease in unipolar voltages among segments with declining regional function.

Aims: A randomized trial was performed to assess the safety and efficacy of a laser guidewire, in the treatment of chronic coronary occlusions., Methods and Results: In 18 European centres, 303 patients with a chronic coronary occlusion were randomized to treatment with either the laser guidewire (n=144) or conventional guidewires (mechanical guidewire, n=159). The primary end-point of the study was treatment success, defined as reaching the true lumen distal to the occlusion by the allocated wire within 30 min of fluoroscopic time: laser guidewire vs mechanical guidewire; 52.8% (n=76) vs 47.2% (n=75), P=0.33. Serious adverse events following the initial guidewire attempt were 0% (laser guidewire) and 0.6% (mechanical guidewire), respectively. Angioplasty (performed following successful guidewire crossing) was successful in 179 patients (91%, laser guidewire n=79, mechanical guidewire n=100), followed by stent implantation in 149 (79%). At the 6-month angiographic follow-up, the difference in binary restenosis rate (laser guidewire vs mechanical guidewire; 45.5% vs 38.3 %, P=0.72) or reocclusion rate (25.8% vs 16.1%, P=0.15) did not reach statistical significance. At 1, 6 and 12 months, angina and event-free survival were 69%, 35% and 24% (laser guidewire) vs 74%, 40% and 31% (mechanical guidewire)., Conclusion: Although laser guidewire technology was safe, the increase in crossing success did not reach statistical significance.

Background: Recently, a novel nonfluoroscopic 3-dimensional electromechanical mapping technique was introduced in the clinical arena. Although initial in vitro and in vivo studies suggested the reliability of the system in volumetric and hemodynamic evaluation of the left ventricle, no validation in human beings has been performed., Methods: A nonfluoroscopic electromechanical mapping (NOGA, Biosense-Webster) procedure was performed in 44 patients. All patients received a contrast left ventriculogram during the same session. Volumetric (end-diastolic [EDV] and end-systolic volumes [ESV]) and hemodynamic (left ventricular ejection fraction [LVEF] and stroke volume) parameters of both systems were compared., Results: Two uncomplicated pericardial effusions occurred with the first-generation mapping catheters. No procedural complications were noted with the new-generation mapping catheters. Significant correlations were found between mapping-derived and ventriculography-based measurements for both ESV (r = 0.67, P <.001) and LVEF (r = 0.78, P <.001). Absolute volumes, however, were only comparable for ESV (46.6 +/- 25.3 mL vs 48.8 +/- 37.0 mL, respectively; P =.13) but differed greatly for LVEF (35% +/- 13% vs 65% +/- 19%, respectively; P <.001), EDV (69.1 +/- 28.6 mL vs 125.9 +/- 53.4 mL, respectively; P <.001) and stroke volume (22.4 +/- 9.9 mL vs 77.1 +/- 33.7 respirations; P <.001). Moreover, Bland-Altman analysis showed the clinical noninterchangeability between these techniques for the measurement of hemodynamic parameters., Conclusion: Measurement of hemodynamic parameters with nonfluoroscopic mapping of the left ventricle is feasible and safe. The system provides data that strongly correlate but that are in clinical disagreement with angiographic data. Therefore the interchangeability of these techniques may be questioned.

This study evaluated the intermediate-term follow-up after excimer laser coronary angioplasty (ELCA) and adjunctive percutaneous transluminal coronary angioplasty (PTCA) in patients with diffuse in-stent restenosis (lesion length >10 mm). Clinical and angiographic follow-up were performed at 6 months. Quantitative coronary angiography performed at 3 stages-during stent implantation, before and after ELCA + PTCA, and at follow-up-included measurements of the minimum lumen diameter (MLD) and percent diameter stenosis (DS). Sixteen consecutive patients were included. The (median + range) stent length was 36 mm (range 15 to 105), with a restenotic lesion length of 32 mm (range 10 to 90). After ELCA + PTCA, the MLD increased from 0.60 +/- 0.41 to 2.28 +/- 0.50 mm, whereas the DS decreased from 76 +/- 16% to 22 +/- 8%. Despite adjunctive high-pressure PTCA, the MLD after ELCA + PTCA remained smaller than the MLD after initial stent implantation, (2.28 +/- 0. 50 mm vs 2.67 +/- 0.32 mm, p = 0.014). Adverse events included ELCA-related acute coronary occlusion in 4 patients and a per-procedural intracerebral hematoma in 1. At 6 months, there was recurrence of angina in all patients. Angiographic follow-up was completed in 13 patients (87%), showing a reocclusion in 6 (46%), a >50% DS in 6 (MLD 1.03 +/- 0.87 mm, DS 68 +/- 24%), and a distal de novo lesion in 1. Despite satisfactory acute angiographic results, the recurrence of significant restenosis in all patients suggests that ELCA + PTCA is not a suitable stand-alone therapy for diffuse in-stent restenosis of long stented segments.

Direct myocardial revascularization (DMR) has been proposed to treat patients with severe coronary artery disease who are not amenable for classical revascularization techniques such as percutaneous coronary intervention (PCI) or bypass surgery (CABG). Although recent reports suggest its benefit in alleviating patients' complaints in the long term, there is still a paucity of data on the immediate impact on regional and global myocardial functioning following this treatment. In this overview we discuss our own experience and provide a summary of other data currently available., (Copyright 2000 Harcourt Publishers Ltd.)

BACKGROUND: Although safety and efficacy of the beStent (Medtronic Inc., Santa Rosa, CA, USA) have been described, the long-term angiographic and clinical outcomes have yet to be investigated. The ROSE (Registry for Optimal beStent Evaluation) trial was designed to assess the procedural safety of single 15 mm beStent implantation, and the six-month angiographic and 12-month clinical outcomes of patients treated with this novel coronary stent. METHODS: Patients with angina and a single de novo lesion in a native coronary artery of >/=2.75 mm diameter were included in this multicenter, prospective, observational trial. Clinical follow-up was obtained at one, six and 12 months. Angiography was performed before and after the stent implantation and at six months. The primary end-point included major adverse cardiac events (death, myocardial infarction and target lesion revascularization), major bleeding complications, and thrombotic occlusions at one-month follow-up. Secondary end-points were major cardiac-event-free survival at six- and 12-month follow-up and angiographic restenosis at six months. A total of 120 patients (80% male, mean age 58.6 +/- 10.6 years) with stable (48%) or unstable (44%) angina pectoris were allocated. The target vessel reference diameter pre-procedure was 2.85 +/- 0.52 mm. RESULTS: Minimal lumen diameter pre/post and at follow-up was 0.97 +/- 0.28 mm, 2.53 +/- 0.40 mm and 1.86 +/- 0.63 mm, respectively. Restenosis rate according to the >50% diameter stenosis criterion at six-month follow-up was 21.5%. At 12 months, the event-free survival rate was 75% (no deaths, two Q-wave and seven non-Q-wave infarctions, five bypass surgery interventions and 16 target lesion revascularizations), whilst 87% of the patients were free of angina pectoris. CONCLUSION: Despite the relatively high percentage of small vessels, the outcome of the ROSE trial is comparable to those observed in previous stent trials, indicating that the coronary beStent is safe and effective as a primary device for the treatment of native coronary artery lesions in patients with (un)stable angina pectoris.

BACKGROUND: Coronary stents have been used with increasing frequency and in increasingly complex coronary disease. A new 316 LVM stainless steel coronary stent, the R Stent, has been designed to provide maximum flexibility for tracking and high radial strength post-deployment. PURPOSE: To assess the clinical feasibility of the R Stent in a tertiary referral population of patients with coronary heart disease. Specific objectives are to assess the R Stent's deployment success, angiographic and procedural success (<20% residual stenosis and >TIMI 2 flow), safety (absence of complications), and 30-day clinical success (angiographic/procedural success plus no major adverse coronary events). METHODS: Between April and November 1998, stent deployment was attempted in 27 patients with stable (46%) or unstable (54%) angina pectoris who qualified for percutaneous transluminal coronary angioplasty. Eighty per cent of patients had a pre-existing history of myocardial infarction, coronary bypass surgery or percutaneous transluminal coronary angioplasty, and several of the lesions were anatomically complex (totally occluded, n 32; thrombus present, n 32; heavily calcified, n 33; ostial, n 31; >20 mm long, n 39; angulation >45 degrees, n 37). Lesions in aortocoronary saphenous vein grafts were excluded. Adjunctive medical management included intraprocedural aspirin and heparin and post-procedural aspirin and ticlopidine. After deployment, patients were followed up in the hospital and at 30 days post procedure. RESULTS: Stent deployment was achieved in 32 of 33 attempts (26 of 27 patients). There was one deployment failure in a long, calcified ostial and proximal left coronary lesion. In the 26 successful deployments, TIMI 3 flow was achieved. One other patient experienced a painless increase in creatine kinase to 375 (CK-MB of 59) at 12 h without ECG changes. At 30 days, there were no deaths, no myocardial infarctions, no subacute thromboses, no repeat interventions, no bypass surgeries and no bleeding complications. Only the patient with post-procedural CK-MB elevation experience recurrence of CCS class 2 angina within the 30 days. CONCLUSION: The R Stent is a promising new device for the treatment of complex coronary heart disease. A larger, more broadly-based study is warranted.

Background: Patients with symptomatic myocardial ischemia from a chronic totally occluded coronary (TOC) artery are usually referred for coronary artery bypass surgery. Because guide wire technology has improved considerably in recent years, percutaneous coronary angioplasty has become a useful technique in opening chronic TOC arteries. We evaluated the early functional results of successful percutaneous recanalization by performing dobutamine stress echocardiography (DSE)., Methods: Fifteen patients with a chronic TOC artery who underwent a successful recanalization were prospectively studied. Each patient had a DSE within 24 hours before and 48 hours after the procedure. Wall motion was scored according to a 16-segment/5-point model. A clinical and angiographic follow-up of 6 months was obtained., Results: The wall motion score index at rest improved from 1.26+/-0.23 before to 1.22+/-0.21 after the procedure (P < .05). Of those 10 segments that improved at rest, 7 were collateral recipients and 3 were collateral donors. The number of ischemic segments decreased from 46 before to 4 after the procedure (P < .0001). Wall motion score index at peak stress improved from 1.34+/-0.20 before to 1.15+/-0.12 after the procedure (P < .05). DSE was positive for ischemia in 15 patients before and 2 patients after the procedure (P < .0001). Angina was present in 12 patients before and in 2 patients after recanalization (P < .0001). Two patients (13%) had angiographic reocclusion and 5(33%) restenosis after 6 months of follow-up., Conclusions: Successful percutaneous recanalization of chronic TOC artery results in an early improvement of both clinical status and resting or stress-induced wall motion abnormalities, as detected by DSE.

The occurrence of fresh thrombus during percutaneous coronary interventions, especially in patients with diffusely diseased saphenous vein bypass grafts is associated with an increased incidence of procedural complications and clinical events. The AngioJet Rapid Thrombectomy Catheter was designed to remove thrombus via a Bernoulli effect induced vacuum. Here we report on the technical aspects of the device and the AngioJet thrombectomy procedure. Indications and potential complications, both procedure- and device related are discussed.

The success rates of coronary angioplasty for the treatment of chronic total occlusions are less favorable than for coronary stenosis. Therefore, a new laser guidewire (LW) was designed to facilitate the crossing of chronic total occlusions. We report on the results of a European multicenter surveillance study, evaluating the laser guidewire performance. Between May 1994 and July 1996, 345 patients (age 59 +/- 10 years, 291 men) with chronic total occlusions were enrolled in 28 European centers. The median age of occlusion was 29 weeks (range 2 to 884), the occlusion length 19 +/- 10 mm. LW recanalization was successful in 205 patients (59%/). LW perforation occurred in 73 patients (21%), with hemodynamic consequences in 4 (1%). There were no deaths, emergency coronary artery bypass graft surgery, or Q-wave myocardial infarctions. In a multivariate regression analysis an occlusion age of <40 weeks (p = 0.001, RR = 1.34) and an occlusion length <30 mm (p = 0.01, RR = 1.59) were independent predictors of success. Results indicate that the LW is an effective and safe tool in the treatment of chronic total occlusion refractory to conventional guidewires.

Objectives: This study sought to prospectively evaluate the performance of a laser guide wire in crossing chronic total coronary occlusions in patients with a failed previous mechanical guide wire attempt., Background: Despite continued refinement of mechanical hardware available for coronary angioplasty, restoration and maintenance of blood flow through a chronically occluded coronary artery remains a true challenge., Methods: Fifty patients with a chronic total coronary occlusion and a previous failed attempt at recanalization using mechanical guide wires were included. A mechanical attempt to cross the occlusion was repeated. In case of failure, an additional attempt was made with the laser guide wire., Results: The median age of occlusion was 22 weeks (range 5 to 200), and the occlusion length was 23 +/- 11 mm (mean +/- SD). A repeat mechanical attempt was successful in six cases (12%). Dissection occurred in five other cases, and device crossover was not attempted. Thus, in 39 patients an attempt was made with the laser guide wire, with successful recanalization in 23 (59%). Thereby the overall success rate increased from 12% to 58% (29 of 50 patients). The amount of contrast medium used was 515 +/- 154 ml, fluoroscopy time was 99 +/- 43 min, and total procedure time was 2 h 48 min (+/- 55 min). Procedural success was achieved in 26 cases and clinical success (procedural success without in hospital events) in 24. In-hospital events were two non-Q wave myocardial infarctions related to subacute reocclusion. In one patient, a balloon dilation after laser guide wire perforation resulted in tamponade requiring pericardiocentesis. After a successful procedure, the angina class decreased from 2.9 +/- 0.2 to 1.4 +/- 0.7 at 3 months of clinical follow-up. Six month angiographic follow-up was completed in all 24 eligible patients and showed vessel patency in 20 (80%)., Conclusions: The use of the laser guide wire for recanalization of chronic total coronary occlusions refractory to treatment with mechanical guide wires is feasible and relatively safe and was successful in 59% of cases. This device must thus be considered a valuable addition to the interventional armamentarium and accordingly will be evaluated in a randomized clinical trial.

Excimer laser coronary angioplasty (ELCA) is associated with vascular damage, caused by rapidly expanding water vapour bubbles and accumulation of insoluble gas. The size of the rapidly expanding bubbles and the volume of gas can be reduced by decreasing the laser pulse energy density. However, using current multifibre catheters, penetration through porcine aortic tissue was found to be impossible at energy densities < or = 45 mJ/mm2. By contrast, by employing a 660 microns bare fibre it was observed that efficient tissue crossing was possible at 12 mJ/mm2, with considerable reduction of the rapidly expanding bubble volume and insoluble gas production. We attribute this efficient tissue penetration at low energy densities to the absence of 'dead space' in the homogeneous light distribution (HLD) at the fibre tip. Accordingly we hypothesize the ELCA performed at lower energy densities may result in less mechanical trauma to the vessel wall when compared with ELCA using current multifibre catheters.

Despite continued improvements in mechanical hardware for coronary angioplasty, chronic total occlusions (CTO) remain a true challenge in the field of interventional cardiology. Therefore, new guidewire technology, which made use of the unique forward debulking properties of excimer laser light, was designed and introduced into clinical practice in 1993. After an initial pilot-study phase, a European Multicenter Surveillance Study was initiated to evaluate the performance of the new laser guidewire. A short overview is given of the incidence of CTO. The limitations of the percutaneous treatment with various mechanical guidewires and the clinical and angiographic follow-up of CTO are discussed. Furthermore, the initial experience with the laser guidewire during the pilot-phase and preliminary results of the European Multicenter Surveillance Study are presented. At the introduction of yet another new (and costly) device, the key question is: 'Yes, but does it allow us to expand the battle field of interventional cardiology?'

Water-deprived mice were injected with various concentrations of LiCl or NaCl 15 min before they were allowed to drink either water or 0.1% saccharin. The NaCl injections produced a dose-dependent increase in intake of both fluids: however, the higher dosages of LiCl produced a selective depression of fluid intakes. Saccharin intakes were depressed for less than one hr but water intakes were not affected. LiCl injections also depressed general activity and produced an apparent shift of water from blood into cells. The LiCl-induced depression of saccharin was not significantly influenced by extensive previous experience with the drinking fluid.