Elective Coronary Stenting as an Adjunct to Balloon Angioplasty in Stable Coronary Artery Disease: No Association with Incidence of Acute Complications. Results of the PTCA Registry of the German Community Hospitals

Background: Elective coronary stenting has hem shown to reduce the rate of recurrent stenoses after angioplasty but no firm data are available on its possible association with in-hospital ischemic complications . Methods: We analyzed the data of the registry of the German community hospitals covering approximately one quarter of all interventions in Germany. We included all angioplasty procedures performed in patients with stable coronary artery disease in 1996. Interventions with elective coronary stenting were compared to those with conventional balloon angioplasty. Interventions with bailout stenting were excluded . Results: Of 19,170 angioplasty procedures, 32.2% included elective coronary stenting. The immediate angiographic success rate (residual stenosis < 50%) was 90.6% of the procedures with stents versus 86.3% of those without stents (P < 0.001). The overall incidence of complications (death, myocardial infarction, bypass surgery, vessel closure, reintervention) was 3.9% and 3.8% (NS). Major events (death, myocardial infarction, bypass surgery) were more common in the stent-treated group (1.8% vs 1.4%, P = 0.027). In multivariate analysis, the following factors were significantly associated with complications: residual stenosis ≥ 50%, female gender, angioplasty of proximal left anterior descending coronary artery, morphological fype of lesion B2 or C, and multivessel disease. Angioplasty of restenoses after previous angioplasty was associated with significantly less risk than of de novo lesions. Stents were neutral with respect to the overall incidence of complications . Conclusions: Complications after elective coronary angioplasty remain largely unpredictable in individual patients despite the identification of several clinical and procedural risk factors. Elective coronary stenting is not associated with the immediate therapeutic risk of angioplasty in stable coronary artery disease .     

Angiographic and Histologic Course after Implantation of Balloon Expandable Intravascular Stents in Miniswine Coronary Arteries: Short- and Mid-Term Observations

Sixteen balloon expandable Medtronic Wiktor tantalum stents were implanted in the major coronary arteries of six minipigs, which were maintained on a normal diet and given 500 mg aspirin per day. Angiographic and histologic examinations were performed 6 and 26 weeks after implantation. Angiographically reviewed, stenting increased the inner diameter of the coronary arteries from 2.61 ± 0.44 to 3.02 ± 0.34 mm (n = 16, P ≤ 0.001). Six weeks later, this value was reduced from 2.98 ± 0.35 to 2.33 ± 0.46 mm (n = 9, P ≤ 0.05), and between 6 and 26 weeks, an increase from 2.17 ± 0.44 to 2.93 ± 0.40 mm occurred (n = 6, P ≤ 0.05). Histologic evaluation at 26 weeks after stent implantation revealed an increase of the cross-sectional area of the total vessel from 4.30 ± 1.09 to 5.50 ± 1.67 mm² (n = 9; P ≤ 0.01). This was due to widening of the total vessel and intimal proliferation, which amounted to 1.19 ± 0.46 mm² within the stented segment, as compared to 0.03 ± 0.03 mm² in control sections (P ≤ 0.01). The areas of free vessel lumen, media muscularis, and adventitia remained unchanged. In 15 of the 16 hislologically examined coronary arteries, the internal elastica was fractured at the site of stent implantation. Twelve stents had also penetrated through the external elastica without evidence of wall hemorrhage. Thirteen out of 16 stents were angiographically followed, of which 12 were patent at the final reangiography. In one animal, acute thrombosis of the stented vessel after guidewire induced coronary artery spasm caused chronic right heart failure due to right ventricular myocardial infarction. Sudden death occurred in another pig 2 hours after successful implantation of three grossly oversized stents (inner vessel diameter: 2.4 ± 0.2 mm, stent diameter 3.2 ± 0.5 mm). Autopsy revealed extensive dissections of the media with subsequent vessel occlusion. It is concluded that Medtronic Wiktor stents can be placed easily, even in more distal or curved coronary arteries. Despite antiaggregational medication, intimal proliferation is observed early after implantation, reaches a maximum at about 6 weeks, and is followed by a regression 26 weeks poststenting. At 26 weeks follow-up, the free vessel lumen at the stent site was not significantly reduced as compared to control segments. Proper adjustment of internal vessel diameter and stent diameter is necessary to prevent major dissections and thrombotic occlusions.     

Ear involvement in Wegener's granulomatosis*

In 16 of 19 patients with biopsy-proved Wegener's granulomatosis the early manifestations were limited to the ear and nose. the audiological data of 13 patients revealed middle ear involvement in 16 of 26 ears. Twenty-one of 26 ears presented with a low to moderate sensorineural hearing loss. One ear remained deaf after a sudden hearing loss in the early stage ofthe disease. Serologically, 4 of 6 tested patients with sensorieneural hearing loss demonstrated antibodies against sarcolemma. One patient showed antinuclear antibodies. It is remarkable that these antibodies can often be detected in classic inner ear disorders. The course of inner ear function, serum findings and the success of immunosuppressive therapy in Wegener's granulomatosis are comparable with immunologically mediated vasculitis in the inner ear.     

Murine Th1 clone defines a 60 kD tachyzoite antigen of Toxoplasma gondii

Toxoplasma gondii -specific murine CD4⁺ T cell clone 3Tx9 belongs to the Th1 subtype by virtue of secreting high levels of interleukin(IL)-2, interferon-γ and tumor necrosis factor without producing IL4 and IL10. To characterize the clonal antigen, Toxoplasma lysate was separated by SDS-PAGE and probed in T cell blot analysis with 3Tx9 T cells, revealing a fraction of about 60 kD molecular weight. This fraction proved highly stimulatory also for CD4⁺ splenocytes isolated from infected mice. The expression pattern of the relevant 60 kD antigen was determined by challenge of clone 3Tx9 with T. gondii strains from all three intraspecies subgroups and tachyzoites versus bradyzoites isolated from two strains as a source of antigen. While the T cell clone reacted with tachyzoites of all strains tested, bradyzoites lacked antigenic activity. Parallel T cell blot and ELISA confirmed co-migration of the T cell-stimulatory antigen p60 and rhoptry proteins ROP1, ROP2,3,4, and ROP5 among which ROP1 is a molecule of similar size and has only been shown on tachyzoites. However, a ROP1 knock-out Toxoplasma mutant still had antigen activity for 3Tx9 T cells. Since the two known tachyzoite-specific proteins, surface antigens SAG1/p30 and SAG2/p22, have a much lower molecular weight, we suggest that p60 represents a new T. gondii tachyzoite marker which is defined by clone 3Tx9.