Clinical and angiographical follow-up after implantation of a 6--12 microCi radioactive stent in patients with coronary artery disease.

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.

Validation of the local shortening function as assessed by nonfluoroscopic electromechanical mapping: a comparison with computerized left ventricular angiography.

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.

Total occlusion trial with angioplasty by using laser guidewire. The TOTAL trial.

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.

Comparison of mechanical properties of the left ventricle in patients with severe coronary artery disease by nonfluoroscopic mapping versus two-dimensional echocardiograms.

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.

Evaluation of left ventricular volumes and ejection fraction with a nonfluoroscopic endoventricular three-dimensional mapping technique.

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.

Six-month outcome after excimer laser coronary angioplasty for diffuse in-stent restenosis in native coronary arteries.

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.

Acute changes of global and regional left ventricular function immediately after direct myocardial revascularization.

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.

Early recovery of wall motion abnormalities after recanalization of chronic totally occluded coronary arteries: a dobutamine echocardiographic, prospective, single-center experience.

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.

Recanalization of total coronary occlusions using a laser guidewire (the European TOTAL Surveillance Study).

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.

Recanalization of chronic total coronary occlusions using a laser guide wire: a pilot study.

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.

Treatment of thrombus containing lesions in diseased native coronary arteries and saphenous vein bypass grafts using the AngioJet Rapid Thrombectomy System.

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.

Homogeneous light distribution to reduce vessel trauma during excimer laser angioplasty.

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.

The laser guidewire experience: 'crossing the Rubicon'.

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?'

LiCl-induced selective depression of saccharin drinking in the mouse.

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.