Percutaneous coronary excimer laser-assisted angioplasty: initial multicenter experience in 141 patients.

Initial multicenter clinical experience with percutaneous coronary excimer laser-assisted angioplasty is described for 158 lesions in 141 patients. Using a xenon chloride (308 nm) excimer laser generator and 1.5 to 1.75 mm catheters, excimer laser angioplasty was attempted at 135 ns pulse width, 25 to 40 Hz repetition rate, 2 to 5 s laser delivery time and 30 to 60 mJ/mm2 energy fluence. Laser success (greater than 20% improvement in luminal diameter) was achieved in 138 (87%) of 158 lesions, with a reduction to less than 50% stenosis noted in 77 lesions (49%). Overall, laser-assisted balloon angioplasty success (less than 50% residual stenosis without major complication) was observed in 129 (91%) of 141 patients. Procedural complications (abrupt closure 1.3%, side branch occlusion 1.9%, intimal dissection 6.3%, embolization 1.3%, filling defect 1.3%, perforation 1.9% and spasm 1.3% and major complications (non-Q wave myocardial infarction 4.8%, emergency coronary bypass surgery 3.5% and death 0%) were infrequent and predominantly related to subsequent balloon angioplasty. In the early follow-up period (range 1 to 10 months, mean 7), 111 (79%) of the 141 patients remain asymptomatic, whereas symptoms have recurred in 27 (19%) and 3 patients (2.1%) have died. Thus, percutaneous coronary excimer laser angioplasty appears to be a feasible and safe procedure. Assessment of the impact of this technology on the acute complications of and restenosis rates after angioplasty awaits further follow-up analysis.

Percutaneous coronary excimer laser-assisted balloon angioplasty: initial clinical and quantitative angiographic results in 50 patients.

The initial clinical experience and quantitative angiographic results of percutaneous coronary excimer laser-assisted balloon angioplasty are described for 55 lesions in 50 patients. With use of a xenon chloride (308 nm) excimer laser generator and 1.5 to 1.75 mm catheters, excimer laser angioplasty was attempted at 135 ns pulse width, 25 to 40 Hz repetition rate, 2 to 5 s laser delivery time and 30 to 60 mJ/mm2 energy fluence. Laser success (greater than 20% reduction in absolute percent diameter stenosis) was achieved in 41 (75%) of 55 lesions, with 100% subsequent balloon angioplasty success (less than 50% residual stenosis). By quantitative digital caliper technique, the percent diameter stenosis (mean +/- SE) was reduced from 81 +/- 1% to 50 +/- 3% after excimer laser angioplasty (p less than 0.001) and to 20 +/- 1% after balloon angioplasty (p less than 0.001); minimal luminal diameter increased from 0.56 +/- 0.04 to 1.46 +/- 0.08 mm (p less than 0.001) and 2.03 +/- 0.07 mm (p less than 0.001), respectively. By videodensitometric techniques, the percent area stenosis decreased from 86 +/- 2% to 54 +/- 3% after excimer angioplasty (p less than 0.001) and to 26 +/- 3% after balloon angioplasty (p less than 0.001). There were no perforations, need for emergency bypass surgery or deaths. The overall incidence of abrupt closure (3.6%), dissection (1.8%), embolization (1.8%), filling defect (6%), myocardial infarction (5.5%), side branch occlusion (3.6%) or spasm (3.6%) was infrequent and more related to subsequent balloon angioplasty than to the laser procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Balloon valvuloplasty in adult aortic stenosis: determinants of clinical outcome.

STUDY OBJECTIVE: To determine the clinical variables affecting outcome after balloon aortic valvuloplasty. DESIGN: Longitudinal follow-up of consecutive case series. PATIENTS: Consecutive sample of 36 patients with severe calcific aortic stenosis, and without active infection or left ventricular mural thrombus. INTERVENTIONS: Percutaneous transluminal dilatation of the aortic valve until the peak gradient was reduced by 50% or a maximal balloon size was used. Hemodynamic measurements taken before and after dilatation. MEASUREMENTS AND MAIN RESULTS: Thirty-three patients had a successful dilatation. Eighty-nine percent (95% confidence interval [CI]. 74% to 97%) improved symptomatically at 2 weeks, but by 26 weeks only 56% (CI, 35% to 76%) remained improved (P = 0.0078). Mortality rates were high at 8 (9%) and 26 (28%) weeks. Predictors of adverse events included left ventricular ejection fraction (P = 0.04, r = 0.46), pulmonary artery systolic pressure (P = 0.048, r = 0.65), pulmonary vascular resistance (P = 0.008, r = 0.69), and right ventricular end-diastolic pressure (P = 0.009, r = 0.43) at 8 weeks and all these factors except left ventricular ejection fraction at 26 weeks. These clinical outcomes were unrelated to other cardiac or pulmonary diseases. CONCLUSIONS: Symptomatic improvement is only temporary in many patients undergoing balloon aortic valvuloplasty, and the mortality rate in the mid-term follow-up period is high. Valve surgery remains the treatment of choice for aortic stenosis in the adult.

Reversal of chronic ischemic myocardial dysfunction after transluminal coronary angioplasty.

From a cohort of patients referred for elective transluminal coronary angioplasty, a subset of patients was evaluated to determine whether revascularization using coronary angioplasty could salvage chronically ischemic myocardium. Reversible chronic ischemic left ventricular dysfunction was identified by a severe wall motion abnormality at rest and at least one of the following: 1) persistent angina pectoris; 2) postextrasystolic ventricular contraction potentiation of motion in the asynergic zone on baseline ventriculogram; and 3) thallium-201 uptake in the asynergic zone. Twelve patients were identified as having reversible chronic ischemia and underwent coronary angioplasty. Their mean age was 63 +/- 11 years and duration of symptoms 8.3 +/- 9.7 weeks. Immediate pre- and postangioplasty left ventriculograms were obtained. Regional wall motion was analyzed using a radial axis model, and global ejection fraction was calculated. After angioplasty, tension development (heart rate-systolic pressure product) increased in the absence of an increase in left ventricular end-diastolic pressure. Global ejection fraction increased from 46 +/- 20 to 62 +/- 19% (p less than 0.005). The percent of left ventricular diastolic perimeter showing asynergy decreased from 29 +/- 11 to 10 +/- 13% (p less than 0.005). During follow-up ranging from 6 to 51 months, sudden death occurred in one patient who had had no improvement in wall motion after angioplasty, repeat angioplasty was performed in three patients and eight patients remained asymptomatic. Application of easily obtainable clinical data identifies a subset of patients with chronically ischemic myocardium. Coronary angioplasty in such patients is useful in salvaging hibernating myocardium.

N-nitroso compounds: evidence for their presence in airborne particles.

Chemical, infrared, and thermal energy analyses have provided evidence for the presence of the N-nitroso functional group in extracts of airborne particles. The total molar N-nitroso concentrations in New York City air are equivalent to the total concentrations of polycyclic aromatic hydrocarbons. Since 90 percent of the N-nitroso compounds that have been tested are carcinogens, the newly discovered but untested materials may represent a significant environmental hazard.