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Background The feasibility of using coronary computed tomography angiography (CCTA) for long-term prediction of vital prognosis post-revascularization remains unknown. Objectives To compare the prognostic value of the SYNTAX score II 2020 (SS-2020) derived from invasive coronary angiography (ICA) or CCTA in patients with three-vessel disease and/or left main coronary artery disease undergoing percutaneous or surgical revascularization. Methods In the SYNTAX III REVOLUTION trial, the probability of death at five years was retrospectively assessed by calculating the SS-2020 using ICA and CCTA. High- and low-risk patients for mortality were categorized according to the median percentages of predicted mortality based on both modalities. The discriminative abilities of the SS-2020 were assessed using Harrell's C statistic. Results The vital status at five years of the 215 patients revascularized percutaneously (64 patients, 29.8%) or surgically (151 patients, 70.2%) was established through national registries. In patients undergoing revascularization, the SS-2020 was possibly helpful in discriminating vital prognosis at 5 years, with similar results seen with ICA and CCTA (C-index with ICA = 0.75, intercept = −0.19, slope = 0.92 and C-index with CCTA = 0.75, intercept = −0.22, slope = 0.99). In high- and low-risk patients, Kaplan-Meier estimates showed significant, and almost identical relative differences in observed mortality, irrespective of imaging modality (ICA: 93.8% vs 78.7%, log-lank P < 0.001; CCTA: 93.7% vs 78.5%, log-lank P < 0.001). Conclusions The predictive ability of the SS-2020 for five-year all-cause mortality derived from ICA and CCTA was comparable, and could helpfully discriminate vital prognosis in high- and low-risk patients.
The measurement of exhaled NO has excited considerable interest, as it may provide a simple noninvasive means of measuring airways inflammation. There is now persuasive evidence that levels of NO are increased in association with airway inflammation and are decreased with anti-inflammatory treatment. Correlation of exhaled NO with more direct measurements of inflammation in the airways, such as induced sputum, bronchoalveolar lavage and bronchial biopsies, is needed. The great advantage of exhaled NO is that the measurement is completely noninvasive. It can, therefore, be performed repeatedly, and also in children and patients with severe airflow obstruction, where more invasive techniques are not possible. However, the measurement is not specific, and exhaled NO is increased in inflammation due to asthma, bronchiectasis, and respiratory tract infections. This means that absolute values are less important than serial measurements in individual patients. The value of this approach has been demonstrated in asthmatic patients, where the dose of inhaled steroid is changed, resulting in increased levels when the dose is reduced and lower levels when the dose is increased. Because exhaled NO is reduced by anti-inflammatory treatments, it may be of use in monitoring whether therapy is adequate. The technique may also have application in the monitoring of the anti-inflammatory effects of new antiasthma drugs, such as selective phosphodiesterase inhibitors, leukotriene antagonists and synthesis inhibitors, and immunomodulators. Because the measurement is precise and reasonably reproducible, it may facilitate the measurement of dose-response effects with anti-inflammatory treatments, which is difficult at present. The analysers for exhaled NO that are currently available are expensive, but in the future it is likely that technological advances will make it possible to miniaturize these analysers, so that they are portable and may even be used at home in conjunction with peak flow meters. -his may lead to their application in epidemiological research, which may be a useful screening measurement for community studies. Although we have discussed exhaled nitric oxide, other volatile substances may also be detected in exhaled air. Thus, ethane and pentane, which are volatile products of lipid peroxidation, and hydrogen peroxide, may be used to detect oxidant stress in the respiratory tract and may also be useful as markers of inflammation. There is little doubt that this is a rapidly expanding area of research.
SlUMMARY In 11 patients, 1 mg of i.v.nifedipine was administered over 3 minutes and regional wall motion was studied during atrial pacing.The dominant effect of nifedipine at basal heart rate (HR) was a lowering of peak left ventricular pressure (152 to 128 mm Hg) with an increase in HR from 70 to 86 beats/min.During pacing, nifedipine produced (p < 0.02) a similar reduction in pressure at all rates, which is a mechanism reduc- ing or sparing myocardial oxygen consumption.At the highest paced rate, the maximal velocity (Vmax) of the contractile element was significantly (p < 0.02) increased from 61 to 68 sec-' and the regional shortening frac- tions were increased over the entire pacing range: basal HR, 13.7% to 14.6% (p < 0.025); HR 120 beats/min, 11.6% to 13.5% (p < 0.005); maximal HR, 10.9% to 11.8% (p < 0.05).No evidence of a negative inotropic effect after i.v.administration of nifedipine was observed, myocardial oxygen consumption was probably reduced and there was an increase in regional function.Nifedipine (0.1 mg within 10 seconds) was selectively injected into bypass grafts at a constant paced rate in 10 patients.Seventeen marker pair regions were directly supplied by bypasses selectively injected with nifedipine (group A), and nine were independently perfused (group B).The pressure-derived variables showed a direct negative inotropic effect and a slowed relaxation phase.Thirty seconds after injection, minimal marker separation in group A occurred 78 msec after end-systole (ES), whereas before injection, minimal marker separation occurred 39 msec before ES (p < 0.0001).At the same time, the relation between minimal marker separation and ES in group B was unaffected.In consequence, the regional shortening fraction in group A con- tributing to left ventricular ejection decreased significantly 30 seconds after injection (-32%, p < 0.01), while that calculated simply from minimal and maximal marker separation remained unchanged (-9%, NS).Active regional contraction starting after the beginning of ejection and ending after ES must be considered as asynchrony and can be considered responsible for the slowed isovolumic contraction and relaxation of the whole ventricle.The dominant effect of i.v.nifedipine at clinical dosage levels is a lowering of systemic blood pressure, possibly reducing oxygen demand.When regionally administered, nifedipine exerts a direct negative inotropic effect, but after i.v.injection, this effect is overridden by reflex increases in contractility and in heart rate as a result of lowered systemic arterial pressure.
On the basis of brachytherapy experience, edge stenosis has been raised as a potential limitation for drug-eluting stents. We used serial intravascular ultrasound (IVUS) to prospectively analyze vessel responses in adjacent reference segments after implantation of polymer-controlled paclitaxel-eluting stents.TAXUS II was a randomized, double-blind trial with 2 consecutive patient cohorts that compared slow-release (SR) and moderate-release (MR) paclitaxel-eluting stents with control bare metal stents (BMS). By protocol, all patients had postprocedure and 6-month follow-up IVUS. Quantitative IVUS analysis was performed by an independent core laboratory, blinded to treatment allocation, in 5-mm vessel segments immediately proximal and distal to the stent. Serial IVUS was available for 106 SR, 107 MR, and 214 BMS patients. For all 3 groups, a significant decrease in proximal-edge lumen area was observed at 6 months. The decrease was comparable (by ANOVA, P=0.194) for patients in the SR (-0.54+/-2.1 mm2) and MR (-0.88+/-1.9 mm2) groups compared with the BMS (-1.02+/-1.9 mm2) group. For the distal edge, a significant decrease in lumen area was only observed with BMS (-0.91+/-2.0 mm2, P<0.0001); this decrease was significantly attenuated with SR (0.08+/-2.0 mm2) and MR (-0.19+/-1.7 mm2) stents (P<0.0001 by ANOVA). Negative vessel remodeling was observed at the proximal (-0.48+/-2.2 mm2, P=0.011) but not the distal edges of BMS and at neither edge of SR or MR stents.The marked reduction in in-stent restenosis with SR or MR stents is not associated with increased edge stenosis at 6-month follow-up IVUS. In fact, compared with BMS, there is instead a significant reduction in late lumen loss at the distal edge with TAXUS stents.
Ethane is a product of lipid peroxidation as a result of oxidative stress and can be detected in the exhaled air. Oxidative stress plays a role in the pathogenesis of asthma. We measured exhaled ethane in 26 asthmatic subjects (mean age ± SEM, 38 ± 8 yr; 15 male, FEV1 60 ± 4%) and compared it with exhaled nitric oxide (NO) measured by chemiluminescence, a noninvasive marker of oxidative stress and inflammation. Exhaled ethane was collected during a flow- and pressure-controlled exhalation into a reservoir discarding dead space air contaminated with ambient air. A sample of the expired air was analyzed by chromatography. Exhaled ethane levels were elevated in asthma patients not receiving steroid (n = 12, 2.06 ± 0.30 ppb) compared with steroid-treated patients (n = 14, 0.79 ± 0.10 ppb, p < 0.01) and to 14 nonsmoking control subjects (0.88 ± 0.09 ppb, p < 0.05). In patients not receiving steroid treatment there was a positive correlation between exhaled ethane and NO (r = 0.55, p < 0.05) and air trapping assessed by the ratio of residual volume to total lung capacity (RV/ TLC) (r = 0.60, p < 0.05). In addition, untreated patients with FEV1 < 60% predicted value had higher concentrations of ethane (2.86 ± 0.37 ppb) compared with less obstructed patients (FEV1 > 60%, 1.26 ± 0.12 ppb, p < 0.05). NO concentrations were higher in patients not on steroid treatment (14.7 ± 1.7 ppb) than in steroid-treated patients (8.6 ± 0.5 ppb, p < 0.05). Exhaled ethane is elevated in asthma, reduced in steroid-treated patients, and correlates with NO and airway obstruction. It may be a useful noninvasive marker of oxidative stress.
Bioresorbable vascular scaffolds (BRS) represent a novel approach to provide transient vessel support to drug-delivery capability without the long-term limitations of metallic drug-eluting stents (DES). The technology has the potential to overcome many of the safety concerns associated with metallic DES and possibly even convey further clinical benefit. In particular, the BRS are designed to provide short-term lumen support, and after being completely bioresorbed, eliminate the permanent caging typical of metallic DES. However, this technology has required new imaging modalities and methodologies for its assessment because the design, degradation rate, loss of mechanical property, and drug deliverability may affect its safety and efficacy. We provide an overview of all existing methods for assessing bioresorbable devices, from noninvasive to invasive, from light to sound based, and from morphological to functional parameters.
