Background Whether focal vasospasticity plays a pathogenic role in the progression or regression of coronary atherosclerosis is unknown. To determine whether evidence for such a role exists, we studied long-term changes in coronary luminal measurements in patients with vasospastic angina. Methods and Results Quantitative coronary angiography and repeated ergonovine provocation tests were performed 45±16 months apart in 30 patients. All patients had vasospastic anginal symptoms and coronary spasm on the initial provocation test. Of the 30 patients, 16 had persistent symptoms of vasospastic angina and showed coronary spasm at the same site on the follow-up angiogram (group 1), while the remaining 14 whose vasospastic anginal symptoms disappeared at follow-up demonstrated a negative response to ergonovine on the follow-up tests (group 2). There was no significant difference in patients’ baseline characteristics between the two groups. Long-term changes in minimal (MLD) and mean (MEAN) luminal diameter were measured (in millimeters) after administration of isosorbide dinitrate in 19 spastic and 93 nonspastic segments in group 1 and in 17 previously spastic and 81 nonspastic segments in group 2. Both MLD and MEAN were measured in 210 coronary segments of the 30 patients at baseline and after administration of ergonovine and isosorbide dinitrate by use of a computer-based quantitative coronary angiography system. Stenosis progression and regression of individual lesions were defined as a change in MLD of ≥0.40 mm. In group 1, both the MLD and MEAN of 19 spastic segments were significantly smaller (progression) at follow-up compared with the initial angiogram (MLD, 2.21±0.54 initially versus 1.95±0.65 at follow-up, P <.01; MEAN, 2.80±0.56 initially versus 2.56±0.58 at follow-up, P <.01), whereas the MLD and MEAN of 93 nonspastic segments in group 1 were not significantly different between the initial and follow-up angiograms (MLD, 2.47±0.67 initially versus 2.44±0.69 at follow-up, P =NS; MEAN, 2.96±0.69 initially versus 2.91±0.68 at follow-up, P =NS). In group 2, the MLD of the 17 previously spastic segments significantly improved (regression) at follow-up (MLD, 1.99±0.68 initially versus 2.24±0.54 at follow-up, P <.05); the MLD and MEAN of the 81 nonspastic segments were not significantly different (MLD, 2.36±0.59 initially versus 2.39±0.60 at follow-up, P =NS; MEAN, 2.81±0.58 initially versus 2.81±0.61 at follow-up, P =NS). In group 1, significant stenosis progression of individual lesions was observed more frequently at spastic than nonspastic segments (6 of 19 versus 10 of 93, P <.05), whereas stenosis regression was observed in no spastic and 3 nonspastic segments ( P =NS). In group 2, stenosis progression was observed at 1 previously spastic segment and 4 nonspastic segments ( P =NS), while significant stenosis regression of individual lesions was seen more commonly in previously spastic than nonspastic segments (6 of 17 versus 7 of 81, P <.01). Conclusions These results have demonstrated in patients an association between persistent vasospastic activity and progression of atherosclerosis and an association between cessation of vasospastic activity and regression of atherosclerosis.
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.
To the Editor: We read with interest the paper by Zetterquist et al. 1 in which the levels of exhaled nitric oxide (NO) and carbon monoxide (CO) were measured in a group of asthmatic and cystic fibrosis (CF) patients using two different methods. A new fast-response nondisperse infrared (NDIR) CO analyser was used alongside the old electrochemical method and the results obtained with the two methods were compared. Surprisingly, contrary to what has previously been shown by our own and other groups 2–6, as shown by both methods, the levels of exhaled CO were found to be similar in a group of asthmatic patients and patients with CF compared with normal subjects. The authors conclude that exhaled CO …
Abstract Current stainless steel design standards are based on elastic, perfectly plastic material behaviour providing consistency with carbon steel design expressions, but often leading to overly conservative results, particularly in the case of stocky elements. More economic design rules in accordance with the actual material response of stainless steel, which shows a rounded stress–strain curve with significant strain hardening, are required. Hence, the continuous strength method (CSM) was developed. The CSM replaces the concept of cross-section classification with a cross-section deformation capacity and replaces the assumed elastic, perfectly plastic material model with one that allows for strain hardening. This paper summarises the evolution of the method and describes its recent simplified form, which is now suitable for code inclusion. Comparison of the predicted capacities with over 140 collected test results shows that the CSM offers improved accuracy and reduced scatter relative to the current design methods. The reliability of the approach has been demonstrated by statistical analyses and the CSM is currently under consideration for inclusion in European and North American design standards for stainless steel structures.
Abstract We studied the mechanisms of IL-22 production by NK cells in human Mycobacterium tuberculosis (M. tb) infection. CD3-CD56+ NK cells from 17 healthy donors produced IL-22 upon culturing with autologous monocytes and irradiated M. tb (417 ± 99 vs 52 ± 22 pg/ml, p &lt; 0.001). In 14 healthy donors anti-IL-15 and anti-IL-23 reduced IL-22 production by NK cells from 494 ± 110 pg/ml to 193 ± 50 pg/ml (p = 0.01) and 256.1 ± 64.7 pg/ml (p = 0.03) respectively. In contrast, anti-IL-12 and anti-IL-18 had no effect. Recombinant IL-15 induced IL-23 receptor expression (18.7 ± 5.1% vs 6.7 ± 1.9%, p =0.03). Recombinant IL-15 induced IL-22 production by NK cells (4294 ± 1627 vs 43.50 ± 29 pg/ml, p=0.04), but recombinant IL-12 and 1L-18 had no effect. To identify signaling pathways involved in IL-15 mediated IL-22 production, we cultured NK cells from healthy donors with recombinant IL-15 for 48 hrs. In 5 healthy donors IL-15-stimulated NK cells expressed 12 times more DAP10 mRNA compared to control NK cells. In 8 healthy donors DAP10 siRNA inhibited IL-15-mediated IL-22 production by NK cells, compared to control siRNA-transfected NK cells (346 ± 121 vs 1248 ± 465 pg/ml, p =0.05). Studies are underway to determine the effect of IL-22 on intracellular survival of M. tuberculosis in macrophages. We conclude that IL-15 and DAP-10 are involved in IL-22 production by NK cells in human M. tb infection.