Intravascular ultrasound-guided optimized stent deployment: Immediate and 6 months clinical and angiographic results from the Multicenter Ultrasound Stenting in Coronaries Study (MUSIC Study)

Objectives A study was set up to validate the safety and feasibilityof intravascular ultrasound-guided stenting without subsequentanticoagulation, and its impact on the 6 months restenosis rate. Methods The study was designed to be multicentred, prospective,and observational. Results One hundred and sixty-one patients with stable anginaand a de novo coronary artery lesion were enrolled. In fourpatients, the implantation of a Palmaz–Schatz (with spiralbridge) stent had failed. One of these four patients died 3days following bypass surgery. In two other patients, intravascularultrasound assessment was not performed. One hundred and twenty-fiveof the remaining 155 patients (81%) were treated with aspirin(100mg.day^–1), because all three criteria for optimizedstent expansion were met. Twenty-two of the remaining 38 patients(25%), in whom at least one criterion was not met were treatedwith aspirin and acenocoumarol (3 months, INR 2·5–3·5),while 16 patients only received aspirin. Stent thrombosis wasdocumented in two patients (1·3%) for which repeat angioplastywas performed. During the hospital stay, there were no deathsor Q-wave myocardial infarctions. Five patients (3·2%)sustained a non-Q-wave myocardial infarction. During the follow-upperiod (198±38 days, complete for all patients, exceptone), one patient (0·6%) sustained a Q-wave myocardialinfarction, one (0·6%) underwent bypass surgery, andrepeat angioplasty was performed in nine patients (5·7%).In two of the nine patients, repeat angioplasty involved anotherlesion. Therefore, the target lesion revascularization rateduring follow-up was 4·5% (seven patients).At quantitativecoronary angiography, the minimal lumen diameter (mean±SD)increased from 1·12± 0·34mm before to 2·89±0·35mmafter stenting. Repeat angiography at 6 months was performedin 144 patients (92%). The minimal lumen diameter at follow-upwas 2·12±0·67mm. Restenosis (diameter stenosisof 50% or more) was documented in 12 patients or 8·3%.When the two patients with documented stent thrombosis are included,the restenosis rate amounts to 9·7%. Conclusions These data confirm that, in selected patients, stentscan safely be implanted without the use of systemic anticoagulation,provided optimal stent expansion is achieved. The exact roleof intravascular ultrasound in the achievement of these resultsneeds to be established by appropriately designed studies. Inthe meantime, intra-vascular ultrasound coupled with the Palmaz–Schatzstent incorporating a spiral bridge, may have contributed considerablyto the immediate angiographic outcome, which in turn may explainthe favourable clinical and angiographic outcome at 6 months.     

Evidence-based paediatrics

Evidence-based medicine is practised widely in some specialties and is now part of many undergraduate and graduate medical curricula. However, the extent to which it is used in clinical paediatric practice is not known and its expansion remains a major challenge. Access to technology which facilitates literature searching, and development of journals addressing specific paediatric problems, will encourage the use of evidence-based medicine by the busy paediatrician. Informed practice of evidence-based medicine will ensure that clinical expertise is complemented by a thorough search, evaluation and judicious application of relevant information from the medical literature.     

Hypoxaemia in infants with respiratory tract infections

Nineteen infants who were graduates from special care baby units underwent two overnight tape recordings of oxygen saturation (SaO2) and breathing movements; one during an upper (n = 12) or lower (n = 7) respiratory tract infection and the other when free of infection. Baseline SaO2 was lower during infection (median 99.6 vs 100%, p less than 0.01), with four patients having values (84.3-95.5%) below the normal lower limit for full-term infants (97%). The median number of apnoeic pauses was also lower during respiratory tract infection (4.7 vs 15.7/h, p less than 0.02). The median number of episodic desaturations (SaO2 less than or equal to 80%) did not change significantly (1.3 vs 1.9/h, p greater than 0.05), with the exception of one patient who had extremely increased values during infection for both apnoeic pauses (63/h) and desaturations (112/h). No infant, however, was considered clinically hypoxaemic. Clinically unsuspected hypoxaemia may thus occur during respiratory tract infection in a proportion of infants graduating from special care baby units. Such hypoxaemia may have potentially deleterious effects.     

Relative coronary flow velocity reserve improves correlation with stress myocardial perfusion imaging in assessment of coronary artery stenoses

STUDY OBJECTIVE: To evaluate the angiographic and coronary flow velocity parameters that best correlate with the results of stress myocardial perfusion imaging. DESIGN: Criterion standard. SETTING: Tertiary care center. PATIENTS: Forty-eight patients undergoing diagnostic coronary angiography for angina or silent ischemia. INTERVENTIONS: We performed angiographic and coronary flow velocity measurements at rest and during hyperemia at the post-stenotic segment and in the adjacent angiographically normal branch of the left coronary artery. Relative coronary flow velocity reserve (RCFVR) was calculated as the ratio of post-stenotic to reference vessel coronary flow velocity reserve (CFVR). The best cutoff points for reversible perfusion defects were calculated using receiver operating characteristic curves. MEASUREMENTS AND RESULTS: Post-stenotic CFVR showed fairly good correlations with minimal lumen diameter and percentage of diameter stenosis (r = 0.57 and r = 0.55, respectively; p < 0.001). RCFVR showed stronger correlations with these angiographic indexes of stenosis severity (r = 0.66 and r = 0.68, respectively; p < 0.0001). Based on receiver operating characteristic cutoff values (1.67 for post-stenotic CFVR and 0.64 for RCFVR), RCFVR had better agreement with myocardial perfusion imaging results, compared to post-stenotic CFVR (92% vs 75%, respectively). This agreement was more meaningful in patients with moderate coronary artery stenoses (50 to 75%). The area under the curve was 0.65 (not significant) for post-stenotic CFVR and 0.88 (p < 0.01) for RCFVR. CONCLUSIONS: RCFVR describes better than post-stenotic CFVR the functional significance of coronary artery stenoses.     

Endoscopic management of postoperative bile leak

Significant bile leak is an uncommon but serious complication of biliary tract surgery. Of twenty-five patients presenting with postoperative bile leak, 11 had complete tie-off of common bile duct and required surgery, while the remaining 14 had injury without complete obstruction and could be managed by endoscopic methods. Of these 14 cases, bile leak occurred from the cystic duct in 11 patients and from the common hepatic duct, right hepatic duct and left hepatic duct in one patient each. Endoscopic procedures performed included sphincterotomy alone (four patients), sphincterotomy and stent placement (seven patients) and sphincterotomy followed by nasobiliary catheter drainage (three patients). There was no technical failure and bile leak was stopped in all patients. One patient died of haemobilia 5 days after stent placement. When technically feasible, postoperative bile leak can be managed safely and effectively by endoscopic methods, obviating the need for surgical reexploration.     

Results of percutaneous valvuloplasty for calcific aortic stenosis with different balloon catheters

Percutaneous aortic valvuloplasty is a palliative treatment for patients with calcific aortic stenosis who would be poor candidates for surgical treatment. The results and associated complications of this procedure were analysed in a series of 47 patients in which different types of dilating catheters were used. In 25 patients a single balloon (19 mm) was used (group A), in 13 patients a bifoil balloon (2 x 15mm) (group B), and in the remaining nine patients (group C) a trefoil balloon (3 x 10mm) was used. An increase in aortic valve area was achieved in all patients. The results obtained with the bifoil balloon were better than with the other types of balloon catheter, with an increase in aortic area of + 118% vs. + 74% (monofoil) and + 76% (trefoil) (P less than 0.05). The tolerance of the inflation procedure was also better with this type of balloon, as it allowed for shorter inflation and deflation times. These results show that balloon aortic valvuloplasty, when indicated, is best performed with a bifoil balloon dilating catheter, and undue complications usually do not occur.     

Reproducibility of myocardial ischemia induced by atrial stimulation

Reproducibility of myocardial ischemia induced by atrial pacing (P) was investigated in 25 patients (pts) without previous anterior myocardial infarction and showing a positive exercise stress test. The second period of atrial pacing (P2) was exerted 20 minutes after the first (P1). During P2, a reduction in the parameters reflecting myocardial oxygen requirements (maximal left ventricular pressure, dp/dt max, TTI*HR values) was noted, while the signs of ischemia were less pronounced (ST depression decreasing from 2.3 +/- 1 mm to 1.6 +/- 1.0 mm; % of lactate extraction (%L) decreasing from - 6.4 +/- 25.5 to + 8.5 +/- 19.2; p less than 0.5). The 25 pts were divided into 2 groups according to the ejection fraction (EF greater than .55 16 pts Gr.F+; EF less than .55 9 pts Gr.F-). The distribution of coronary lesions was the same for the 2 groups. During P1 GR.F+ registered a negative % L as opposed to Gr.F-. During P2, the difference in the % L between the 2 groups was also significant (2.6 +/- 19.9% F+ vs 18.9 +/- 14.3% F-; p less than .05). Collateral circulation had no effect upon the results, neither for P1 or P2. This study shows that a second period of atrial pacing, 20 minutes after the first, induced lesser ischemia than the first period of atrial pacing. This phenomenon could explain the paradoxical improvement observed in certain patients after a first episode of angina. These results have implications as regards the necessity of double blind studies compared to placebo when using this technique in the evaluation of the effects of anti-ischemic drugs.     

Resuscitation from Prolonged Ventricular Fibrillation by Epinephrine Combined with Sodium-Hydrogen Exchanger Isoform-1 Inhibitor Cariporide

Formorethan４０years，epinephrinehasbeenthevasopressoragentofchoiceforcardiopulmonaryresus－citation（CPR）andcurrentlyisstillbesuggestedbyAmericanHeartAssociationandwidelyuseinclinicCPR．However，recentstudiesquestionthevalueofepinephrineadministrationdu