Publications

Exhaled nitric oxide (ENO), a marker of inflammation in airway diseases is decreased in cystic fibrosis (CF) patients, perhaps because nitric oxide (NO) is metabolized to oxidative end-products. A stable product, 3-nitrotyrosine, may indicate local formation of reactive nitrogen species. Whether NO metabolites in exhaled breath condensate may be increased in CF patients was investigated. The fractional concentration of ENO ( F eno ), nitrotyrosine and oxides of nitrogen in exhaled breath condensate from 36 stable CF patients were compared to 14 normal subjects using an enzyme immunoassay and fluorescence assay. Nitrotyrosine levels in breath condensate were increased significantly in stable CF patients, compared with normal subjects (25.3±1.5 versus 6.3±0.8 ng·mL −1 , p<0.0001). There was an inverse correlation between the levels of nitrotyrosine and the severity of lung disease. F eno levels were significantly lower in CF patients than in normal subjects (4.4±0.3 versus 5.6±0.4 (parts per billion), p<0.05). No correlation was found between nitrotyrosine and F eno levels in CF. There was no significant difference in the levels of nitrite and nitrate between CF patients and normals. The elevation in nitrotyrosine may reflect increased formation of reactive nitrogen species such as peroxynitrite or direct nitration by granulocyte peroxidases, indicating increased oxidative stress in airways of cystic fibrosis patients.

A recognized limitation of endovascular beta-radiation therapy is the development of new stenosis at the edges of the irradiated area. The combination of injury and low-dose radiation may be the precursor of this phenomenon. We translated the radio-oncological concept of "geographic miss" to define cases in which the radiation source did not fully cover the injured area. The aims of the study were to determine the incidence and causes of geographic miss and evaluate the impact of this inadequate treatment on the outcome of patients treated with intracoronary beta-radiation.We analyzed 50 consecutive patients treated with beta-radiation after percutaneous coronary intervention. The prescribed dose ranged between 12 and 20 Gy at 2 mm from the source axis. By means of quantitative coronary angiography, the irradiated segment (IRS) and both edges were studied before and after intervention and at 6-month follow-up. Edges that were injured during the procedure constituted the geographic miss edges. Twenty-two edges were injured during the intervention, mainly because of procedural complications that extended the treatment beyond the margins of the IRS. Late loss was significantly higher in geographic miss edges than in IRSs and uninjured edges (0.84+/-0.6 versus 0.15+/-0.4 and 0.09+/-0.4 mm, respectively; P<0.0001). Similarly, restenosis rate was significantly higher in the injured edges (10% within IRS, 40.9% in geographic miss edges, and 1.9% in uninjured edges; P<0.001).These data support the hypothesis that the combination of injury and low-dose beta-radiation induces deleterious outcome.

Objectives. This study sought to compare acute lumen changes and late lumen narrowing during and after excimer laser-assisted balloon angioplasty, measured by quantitative coronary angiography, with the immediate and long-term outcome of balloon angioplasty alone. Background. Although excimer laser coronary angioplasty is used as an adjunct or alternative to balloon angioplasty, limited comparative data exist regarding the immediate and long-term efficacy of excimer laser-assisted balloon angioplasty versus balloon angioplasty alone. Methods. A series of 53 lesions in 47 consecutive patients successfully treated with excimer laser-assisted balloon angioplasty were individually matched after completion of 6-month follow-up angiography with 53 successfully treated balloon angioplasty lesions according to vessel location, preprocedural minimal lumen diameter and reference diameter. Immediate and long-term angiographic results were assessed by an automated lumen contour detection algorithm. Results. Before intervention in the laser and balloon angioplasty groups, respectively, minimal lumen diameter (mean ± SD) was 0.73 ± 0.47 and 0.74 ± 0.46 mm, and reference diameter was 2.71 ± 0.42 and 2.72 ± 0.41 mm. Laser angioplasty was followed by adjunctive balloon dilation in 50 lesions. Mean balloon diameter at maximal inflation was similar in both treatment groups (2.61 ± 0.32 and 2.65 ± 0.38 mm, respectively), resulting in similar minimal lumen diameters after intervention of 1.77 ± 0.41 and 1.78 ± 0.34 mm, respectively. At follow-up angiography, minimal lumen diameter after excimer laser-assisted balloon angioplasty was 1.17 ± 0.63 mm, and that after balloon angioplasty alone was 1.46 ± 0.67 mm (p = 0.02). The angiographic restenosis rates at follow-up using the 50% diameter stenosis cutoff criterion were 57% and 34%, respectively (p = 0.02). Conclusions. Quantitative angiographic analysis of a matched group of 106 successfully treated coronary lesions showed a similar immediate outcome but reduced long-term efficacy of excimer laser-assisted balloon angioplasty compared with that after balloon angioplasty alone.

No abstract is provided for this article.

BACKGROUND Acute coronary artery occlusion after percutaneous transluminal coronary angioplasty (PTCA) continues to remain a serious complication despite significant improvement in operator performance and technological advancements. This retrospective study was performed to ascertain the frequency, predictive variables, management, and outcome of acute coronary artery occlusion. METHODS AND RESULTS The study was based on data from 1,423 consecutive patients who underwent an elective coronary angioplasty between January 1986 and December 1988. Acute coronary artery occlusion occurred in 104 patients (7.3%). Acute occlusion developed during the dilatation procedure in 80 patients (5.6%) and within 24 hours after the procedure in 24 patients (1.7%). Four clinical and 14 angiographic variables predictive for acute coronary artery occlusion were analyzed in these 104 patients with a complicated procedure and were compared with those in 104 representative patients with successful attempts. Multivariate analysis found three independent predictive variables: unstable angina, multivessel disease, and complex lesions. The overall clinical outcome after management of acute coronary artery occlusion including immediate repeat dilatation (95 patients), use of intracoronary streptokinase (34 patients), or autoperfusion catheter (12 patients) was successful (reduction of lumen diameter to less than 50%, no death, no myocardial infarction [MI], and no emergency surgery) in 42 patients (40%), was a failure without major complication in four patients (4%), and was a failure with major complication (death, MI, and emergency surgery) in 58 patients (56%). The overall mortality rate was 6% (six patients), the overall MI rate was 36% (37 patients), and emergency bypass surgery was required in 30% of patients (31 patients). At 6 months' follow-up of 42 patients with successful management, recurrent angina pectoris due to restenosis occurred in 10 patients (24%), and a late MI occurred in one patient (3%). At 6 months' follow-up of 56 survivors with unsuccessful management (development of MI or need for emergency bypass surgery), recurrent angina occurred in nine patients (16%), and cardiac death in two patients (4%). However, the majority of patients in both groups were either symptom free or had mild angina pectoris. CONCLUSION Acute coronary artery occlusion during PTCA is often unpredictable, but its frequency is higher in patients with unstable angina, multivessel disease, and complex lesions. Despite immediate redilatation, use of intracoronary streptokinase, and emergency bypass surgery, PTCA is associated with a high mortality and morbidity.

Summary. Intravascular ultrasound is the new gold standard for detection of coronary artery disease. It is an adjunctive diagnostic procedure in cardiac catheterization laboratories. Currently, mechanical single elements or electronic multi-element catheter-based imaging systems are available with significant drawbacks either due to the long catheter drive shaft with an external motor or the multi-element methodological problems of the technology. In order to overcome the limitations of mechanical single element catheters, a micromotor was mounted in the distal part of a scanning compartment in front of a rotating mirror which reflected the ultrasound beam of a 30 MHz transducer. The rotation was between 3000 and 20 000 rev/min, the position accuracy was plusmn;10°, the torque force 1-3μNm, the power dissipation 10-50 mW, the diameter 1 mm, the length 2 mm. Cross-sectional images (360°) are provided. The catheter is connected to a console generating the transmission pulse, amplification of the echo signals and the envelope detection of the ultrasound. The unit is interfaced with a control unit which provides the isolated motor currents with isolated power for the electronics and synchronization signals. For the first time the micromotor tip catheter was used in a 64-year-old patient for imaging the iliac artery in full length. The wall structure, the vessel lumen and even adjacent structures like the iliac vein could be visualized with changes during respiration. Signs of arteriosclerosis were seen by the plaque formation which was located eccentrically. The resolution was as high as with conventional mechanical catheters. Most importantly, no non-uniform rotation artefacts occurred. A micromotor system can be successfully used for replacing the motor drive shaft of catheters which are used for intracoronary and intravascular ultrasound and eliminate non-uniform rotational artefacts due to friction and multiple vessel angulations.

The mechanism of propranolol-induced bronchoconstriction (PIB) remains unclear. Previous uncontrolled studies have suggested that atropine antagonizes PIB in asthma. We conducted a randomized, double-blind, placebo-controlled study of the effect of a new anticholinergic agent, oxitropium bromide, on bronchoconstriction induced by inhaled propranolol in seven subjects with mild asthma 24 to 39 yr of age. Inhaled propranolol induced long-lasting reduction in specific airway conductance (SGaw) in all subjects. This was associated with airway beta-adrenoceptor blockade as demonstrated by a shift in the isoproterenol dose-response curve. Propranolol was less potent than methacholine, with a geometric mean dose causing a 35% fall in SGaw of 4.7 µmol for propranolol compared with 0.48 µmol for methacholine. Pretreatment with oxitropium 200 µg completely inhibited the fall in SGaw in response to inhaled propranolol in all subjects. Oxitropium also reversed PIB. Cholinergic receptor blockade by oxitropium inhibits bronchoconstriction induced by inhaled propranolol, supporting involvement of cholinergic mechanisms in PIB.

In this first multicentre study we assessed the safety and efficacy of percutaneous transendocardial skeletal myoblast injection as a stand alone procedure in congestive heart failure patients.15 patients (14 male), age 63+/-7 (Mean+/-SD), NYHA class 2-4 were injected with 216+/-119 cells (81+/-19% Desmin+) using a NOGA or fluoroscopy guided injection catheter. The cells were injected in the scarred regions 6+/-4 years after myocardial infarction as a stand alone procedure. After treating the first 6 patients, the protocol was amended to require that remaining patients be fitted with an ICD prior to the cellular cardiomyoplasty procedure. Holter monitoring, ECG and ICD readings were obtained at multiple intervals. Stress echocardiography and LV angiography was performed at baseline, 3, 6 and 12 months post procedure.After 1 year follow-up 13 patients were still alive. Patient # 6 died suddenly 9 days post procedure. Patient #15 (ICD patient) survived an electrical storm 12 days post procedure, but died 2 days later due to cardiogenic shock. Two non-ICD patients received an ICD because of observed ventricular arrhythmias. It remains unknown whether these events are directly related to the cell injections.LV ejection fraction (%) changed from 34.4+/-10.3 to 36.6+/-10.4 (baseline versus 12 months FU, p=0.26). Wall motion score index improved both at rest (3.0+/-0.5 to 2.7+/-0.7, p=0.049) and under low-dose dobutamine stress (2.8+/-0.4 to 2.5+/-0.6, p=0.07, baseline versus 12 months FU).Percutaneous autologous skeletal myoblast injection is feasible, resulting in wall motion and functional class improvement, but is potentially associated with an increased risk for ventricular arrhythmias. Randomised studies are needed, however, to further assess overall safety, efficacy and the potential for initial increased risk for arrhythmia following cell injection in these high-risk patients.