Clinical Experience with Wiktor Stent Implantation: A Report from the French Multicentric Registry

Our objective was to evaluate, in a French multicenter study, the results of implantation of Wiktor tantalum wire coronary stents in stenosed or occluded coronary vessels or in saphenous vein bypass grafts. The study was a retrospective analysis of clinical and angiographic data from patients treated with tantalum wire stent implanted at five centers. Stenting of native coronary arteries or saphenous vein bypass grafts was attempted in 272 patients after acute or threatened closure of the target vessel, or because the lesions concerned were considered to be at particularly high risk of becoming restenosed, or because the result of primary angioplasty was inadequate. Successful stent deployment was achieved in 261 95.9%) of 272 patients. The incidence of major complications such as death, myocardial infarction (MI), or a condition requiring urgent bypass surgery was 8.1%. Major vascular complications occurred in 2.6% and actually decreased with a new anticoagulant regimen. Angiographic follow-up at a mean of 6 months after stenting showed restenosis in 23.6% with a more frequent restenosis in the group with stent size equal to 3 mm than in the group with stent size superior to 3 mm (46.1% vs 13.7%, P < 0.01). Stenting with the Wiktor tantalum wire stent is an effective means of treating acute complications and suboptimal results after angioplasty. This stent seems to offer hope of a significant reduction in the rate of late restenosis in native coronary vessels, but a prospective comparison of balloon angioplasty and stenting is needed .     

SYNTHESIS OF ANALOGS OF THE SERUM THYMIC NONAPEPTIDE, “FACTEUR THYMIQUE SERIQUE” (FTS) Part II

New analogs of FTS (Facteur Thymique Sérique), <Glu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn · OH, a circulating thymic factor, were prepared by replacing the amino acid residues in positions 1, 3, 4, 5, 6 and 3 and 6 together. Five other analogs of C-terminal heptapeptide were prepared by replacing the amino acid residues in position 3 or 6. These peptides were synthesized using conventional synthesis in solution.     

Synthesis of tritiated tuftsin and macrophage inhibitory tripeptide via acetylenic intermediates

Acetylenic analogues of tuftsin (Thr-Dah-Pro-Arg) and of a macrophage inhibitory tripeptide (Thr-Dah-Pro) have been synthesized by conventional procedures in solution (Dah = 2,6-diamino-4-hexynoic acid). These acetylenic derivatives are intermediates for the preparation of structurally unmodified, tritiated peptides. Catalytic tritiation of Thr-Dah-Pro-Arg and of Thr-Dah-Pro has afforded the radioactive tetra- and tripeptides with specific activities of 11.4 Ci/mmol and 37 Ci/mmol, respectively.     

Catheter Ablation Induced Reversal of Chronic Left Ventricular Dysfunction in Permanent Junctional Tachycardia

Three patients with the permanent form of junctional tachycardia are reported. All had a normal cardiac function when the rhythm disorder was discovered. The basis for tachycardia in the three cases was atrioventricular junctional reentry whose retrograde limb was a concealed posteroseptal accessory pathway. Because of the development of heart failure over the years, one patient had His bundle ablation combined with pacemaker insertion, and the others underwent catheter ablation of the accessory pathway. Reversal of left ventricular involvement, as ossessed by chest X ray and echocardiography was noted in every patient. Ejection fraction in one patient, measured by radionuclide angiography, returned to normal 3 months later. Thus catheter ablation of permanent junctional tachycardia can effectively suppress rhythmic cardiomyopathy.     

Asystolic Cardiac Arrest During Head-Up Tilt Test: Incidence and Therapeutic Implications

Occasionally, the cardioinhibitory response may be profond during tilt induced syncope. Whether this response is associated with more severe symptoms or predicts a poor response to pharmacotherapy remains controversial. The aim of this study was to characterize patients with vasovagally mediated asystole occurring during head-up tilt test and to evaluate the respective interests of sequential pacing and β-blockers to treat them. We performed 60° tilt testing in 179 consecutive patients with unexplained syncope (91 women and 88 men, age 36.6 ± 20.1 years). Asystole was defined as a ventricular pause > 5 seconds. All patients with tilt induced asystole received therapy with either β-blockers or sequential pacing, the efficacy of which was evaluated with serial tilt tests. Of 77 patients with positive tilt test, 10 developed syncope related to asystole (mean duration 11.9 ± 4.9 s), 2 with spontaneous recovery, and 8 with seizures needing a brief cardiopulmonary resuscitation. When compared with patients without asystole, asystolic patients had more severe symptoms (seizures: 6/10 vs 9/67, P = 0.05, injury: 9/10 vs 27/67, P = 0.0048). In the first six patients in whom cardiac pacing was considered, syncope or presyncope still occurred despite atrioventricular pacing at 45 beats/min. Five of these 6 patients, as well as the remaining 4 asystolic patients, were tilted with β-biockers: 3 patients became tilt-negative; 3 were significantly improved; and 3 did not respond. During follow-up (mean 22.7 ± 11.7 months) with every patient taking β-blockers and seven having a permanent pacemaker, no syncopal recurrence was observed. Tilt-induced asystole that may require resuscitative maneuvers occurs especially in patients with a history of seizures or injury. Therapy with β-blockers is often effective to prevent induction of syncope as well as recurrences.     

Renal and haemodynamic responses to a novel kappa opioid receptor agonist, niravoline (RU 51,599), in rats with cirrhosis

Because renal water retention is a complication of cirrhosis, niravoline (RU 51,599), a novel kappa (κ) opioid receptor agonist which is known to cause a water diuresis under normal conditions, may be useful in the therapy of chronic liver diseases. Thus, the present study examined the effects of niravoline on renal function in rats with cirrhosis. Urine was collected during the 2 h period following the administration of vehicle (saline) in one group of animals or niravoline (3 mg/kg, i.v.) in auother group. Urinary and plasma osmolality were measured prior to and 2 h after niravoline in a third group of animals. Urine flow and natraemia were significantly higher after niravoline (147±12 μL/min and 153±2 mmol/L, respectively) than after vehicle (27 ± 7 μL/min and 146 ± 1 mmol/L, respectively). Niravoline significantly decreased urinary osmolality and significantly increased plasma osmolality and free water clearance. This substance did not significantly change urinary sodium excretion. In conclusion, this study shows that niravoline, a κ opioid receptor agonist, induced a water diuresis in rats with cirrhosis.     

Angiographic morphology and intraluminal coronary artery thrombus in patients with angina pectoris: clinical correlations

A prospective study was conducted in 104 consecutive patientswho underwent coronary angiography for the evaluation of anginapectoris. 50 patients experienced unstable symptoms, while therest of them were stable. Coronary lesions reducing the luminaldiameter by at least 50% were compared between both groups accordingto localization, grade, length, type and collateralization.Eccentric irregular lesions (EIL) appeared more frequently inthe unstable group of patients (27% vs 3%, P<0.01), whilethe incidence of concentric lesions was higher in stable group(45% vs26%, P <0.02). There was no significant differencein localization, grade, length, or collateralization. EIL weremost frequently identified as spontaneous AP producing lesions(55%, P <0.001) in 29 patients in the unstable group. Spontaneousangina was associated in 86% with EIL, occlusions, or fillingdefects— all of these lesions might contain occlusiveor nonocclusive thrombi. EIL with a narrow neck appeared onangiograms earlier than EIL with a wall irregularity. We concludethat EIL is a sensitive and very specific angiographic markerof unstable AP. The morphologic details of EIL may help oneto choose appropriate therapy.     

SEDATION AND RESPIRATORY MECHANICS IN MAN

The effects of sedation with halo thane, enflurane or midazolamon respiratory mechanics and lung volumes were studied in younghealthy volunteers, in the supine position. Functional residualcapacity increased with halothane sedation, but was unchangedwith sedation produced by enflurane or midazolam. Sedation withhalothane and enflurane, but not midazolam, tended to increaselung static recoil pressure. Total lung capacity was decreasedduring sedation with midazolam. No evidence was found that sedationwith these three agents increased airway resistance. These findingsimply that changes in respiratory mechanics induced by the residualeffects of anaesthetic agents are unlikely to contribute significantlyto the impairment in pulmonary gas exchange which may occurin the period immediately after operation.