No abstract is provided for this article.
Background —Coronary stenting improves outcomes compared with balloon angioplasty, but it is costly and may have other disadvantages. Limiting stent use to patients with a suboptimal result after angioplasty (provisional angioplasty) may be as effective and less expensive. Methods and Results —To analyze the cost-effectiveness of provisional angioplasty, patients scheduled for single-vessel angioplasty were first randomized to receive primary stenting (97 patients) or balloon angioplasty guided by Doppler flow velocity and angiography (523 patients). Patients in the latter group were further randomized after optimization to either additional stenting or termination of the procedure to further investigate what is “optimal.” An optimal result was defined as a flow reserve >2.5 and a diameter stenosis <36%. Bailout stenting was needed in 129 patients (25%) who were randomized to balloon angioplasty, and an optimal result was obtained in 184 of the 523 patients (35%). There was no significant difference in event-free survival at 1 year between primary stenting (86.6%) and provisional angioplasty (85.6%). Costs after 1 year were significantly higher for provisional angioplasty (EUR 6573 versus EUR 5885; P =0.014). Results after the second randomization showed that stenting was also more effective after optimal balloon angioplasty (1-year event free survival, 93.5% versus 84.1%; P =0.066). Conclusions —After 1 year of follow-up, provisional angioplasty was more expensive and without clinical benefit. The beneficial value of stenting is not limited to patients with a suboptimal result after balloon angioplasty.
No abstract is provided for this article.
No abstract is provided for this article.
New therapeutic approaches to asthma involve either improvements in existing classes of drug, or the development of novel drugs. Over the last 20 years there have been no new types of drug introduced, although several new classes of compound are now under development. Improvements in existing bronchodilators include long-acting inhaled beta 2-agonists, methyl xanthines with a reduced side effect profile and M3-selective anticholinergics. New bronchodilators include K+ channel activators and selective phosphodiesterase inhibitors. Corticosteroids are the most effective anti-inflammatory drugs and there are attempts to develop inhaled steroids with greater topical potency or increased systemic metabolism, or to develop drugs which retain the anti-inflammatory effects of steroids without side effects. Steroids are probably effective in asthma by inhibiting the synthesis of cytokines and drugs which inhibit cytokine synthesis or receptors are now being sought. Inhibitors of mediator synthesis and receptors currently under development and leukotriene D4-antagonists are promising. Immunomodulatory drugs such as methotrexate, cyclosporin A and gold may be useful in more severe asthma, but drugs which modulate the immune abberation of asthma more specifically may be of more widespread use in the future. There is no immediate prospect of a cure for asthma and a drug which may be taken orally once daily and has no side effects would be ideal.
Nonadrenergic, noncholinergic nerves are the predominant inhibitory nervous pathway in human airway smooth muscle, and there is evidence in animals that the major neurotransmitter of this system is vasoactive intestinal peptide (VIP). We have investigated the effect of VIP on bronchomotor tone and bronchial responsiveness to inhaled histamine in 6 atopic asthmatic subjects. The VIP was given by inhalation to avoid any indirect effects on the airways that might arise from the potent cardiovascular actions of this peptide when given systemically. The VIP (100 μg) was compared with control solution (diluent: 1% human serum albumin in 2 ml 0.9% saline) and with β2-agonist (salbutamol, 200 μg) given double blind in random order on separate days. Specific airway conductance (SGaw) did not change after control or VIP inhalations, but it significantly increased after salbutamol inhalation. The provocation concentration of histamine causing a 35% fall in SGaw (PC35) did not change after control inhalation, but significantly increased after VIP (from 2.18 ± 1.04 to 5.00 ± 2.31 mg/ml histamine, mean ± SE; p < 0.05), and after salbutamol (from 1.71 ± 0.83 to 15.6 ± 4.2 mg/ml, p < 0.01), the increase after salbutamol being significantly greater than after VIP. No changes in heart rate or blood pressure were found after any inhalation. We conclude that VIP protects against histamine-induced bronchoconstriction in human airways in vivo, and therefore has the capacity to be the neurotransmitter of nonadrenergic, noncholinergic inhibitory nerves in human airway smooth muscle.