Post-dilatation improves stent apposition in patients with ST-segment elevation myocardial infarction receiving primary percutaneous intervention: A multicenter, randomized controlled trial using optical coherence tomography

Stent failure is more likely in the lipid rich and thrombus laden culprit lesions underlying ST-segment elevation myocardial infarction (STEMI). This study assessed the effectiveness of post-dilatation in primary percutaneous coronary intervention (pPCI) for acute STEMI. METHODS: The multi-center POST-STEMI trial enrolled 41 consecutive STEMI patients with symptom onset <12 hours undergoing manual thrombus aspiration and Promus Element stent implantation. Patients were randomly assigned to control group (n=20) or post-dilatation group (n=21) in which a non-compliant balloon was inflated to >16 atm pressure. Strut apposition and coverage were evaluated by optical coherence tomography (OCT) after intracoronary verapamil administration via thrombus aspiration catheter, post pPCI and at 7-month follow-up. The primary endpoint was rate of incomplete strut apposition (ISA) at 7 months after pPCI. RESULTS: There were similar baseline characteristics except for stent length (21.9 [SD 6.5] mm vs. 26.0 [SD 5.8] mm, respectively, P=0.03). In post-dilatation vs. control group, ISA rate was lower (2.5% vs. 4.5%, P=0.04) immediately after pPCI without affecting nal TIMI ow 3 rate (95.2% vs. 95.0%, P>0.05) or corrected TIMI frame counts (22.6±9.4 vs .22.0±9.7, P>0.05);and at 7-month follow-up (0.7% vs .1.8%, P<0.0001), the primary study endpoint, with similar strut coverage (98.5% vs. 98.4%, P=0.63) and 1-year rate of major adverse cardiovascular events (MACE). CONCLUSION: In STEMI patients, post-dilatation after stent implantation and thrombus aspiration improved strut apposition up to 7 months without affecting coronary blood ow or 1-year MACE rate. Larger and longer term studies are warranted to further assess safety.

A more than 2-year follow-up of incomplete apposition after drug-eluting stent implantation

Background Incomplete stent apposition （ISA） has been demonstrated to be more common after drug-eluting stent （DES） implantation than after bare metal stent （BMS） implantation, Clinical outcomes of ISA remain controversial and the predictive accuracy of previous studies was limited by the short follow-up period of only 12-18 months. In the present study, we present the outcomes of a more than 2-year follow-up in patients with ISA after DES implantation, Methods From the clinical and core intravascular ultrasound （IVUS） database of the hospital, we identified 76 patients who had undergone DES implantation in de novo lesions between January 2004 and June 2005 and had received IVUS examination at a scheduled 6-month follow-up. A total of 13 （17.1%） patients had documented I SA at the follow-up by IVUS. Clinical follow-up was available up to 41 months after DES implantation and up to 33 months after identification of ISA, Results Over a mean follow-up of （34：~5） months （range 24-41 months）, 3 of the 13 patients （23.1%） suffered from ST elevated myocardial infarction with one death. Angiography confirmed the very late stent thrombosis （ST） in the area with ISA, All the 3 patients were implanted with sirolimus elulJng stents in left anterior descending artery （LAD） and the very late ST occurred at 29, 31 and 32 months after DES implantation, and separately at 20, 23 and 23 months after the identification of ISA, All of the 3 patients had antiplatelet therapy continued before suffering from ST, and had been apparentJy stable on antiplatelet monotherapy with aspirin for a long peried following dual antiplatelet therapy with aspirin and clopidogrel for more than 12 months. Conclusion ISA of DES may be associated with a high incidence of very late stent thrombosis, even in clinically stable patients with dual antiplatelet therapy of at least 12 months after the procedure.

Acute coronary syndrome is an independent risk factor for late incomplete stent apposition after sirolimus-eluting stent implantation

Background Late incomplete stent apposition （ISA） may occur after drug-eluting stent implantation, affecting long-term clinical outcomes. This study aimed to evaluate the impact of clinical presentations of coronary artery disease on late ISA after percutaneous coronary intervention （PCI） with sirolimus-eluting stents （SES） by means of three-dimensional volumetric intravascular ultrasound （IVUS） analyses. Methods One hundred and thirty-seven patients with coronary artery disease received SES implantation during PCI and had repeat angiography with IVUS examination. All patients were followed up one year after the procedure. Results In overall 219 treated lesions （137 patients）, late ISA was identified in 25 lesions （16 patients）. Clinical diagnosis of acute coronary syndrome （ACS） and use of long stents were more common in patients with than in those without late ISA. Patients with late ISA had greater external elastic membrane （EEM） area in stented segment （（15.34±5.44） vs （13.83±4.51） mm^2, P=0.026）, stented-to-reference segment EEM area ratio （1.13±0.22 vs 1.02±0.18, P 〈0.001）, and plaque and media area （（8.43±3.93） vs （7.01±2.93） mm^2, P =0.002） than in those without late ISA. Multivariate Logistic regression analysis showed that clinical diagnosis of ACS and use of long stents were independent risk factors for late ISA （OR 6.477, 95%CI 2.297-18.263, P 〈0.001; OR 3.680, 95%Cl 1.181-11.469, P =0.025; respectively）. During one-year follow-up after IVUS examination, the rate of very late stent thrombosis tended to be higher in patients with than in those without late ISA （18.7% vs 3.3%, P =0.051）. Conclusions The occurrence of late ISA after SES implantation may be related to clinical status, use of long stents, and marked positive vessel remodeling. Late ISA tended to increase the rate of very late stent thrombosis during follow-up, highlighting the importance of long-term dual antiplatelet therapy for these patients.

Fine structural description of the compound eye of the Madagascar ＇hissing cockroach＇ Gromphadorhinaportentosa （Dictyoptera： Blaberidae）

The compound eyes of the wingless adults of the Madagascar ＇hissing cockroach＇ Gromphadorhinaportentosa Sachum, 1853 were examined by light and electron microscopy. Each eye contains 2 400-2 500 mostly hexagonal facets. However, irregularities affecting both shape and size of the ommatidia are relatively common, especially towards the margins of the eye. An individual ommatidium of this eucone type of apposition eye contains eight retinula cells, which give rise to a centrally-fused, tiered rhabdom. The distal end of the latter is funnel-shaped and accommodates the proximal end of the cone in its midst, Further below, the rhabdom （then formed by the rhabdomeres of four retinula cells） assumes a squarish profile with microvilli aligned in two directions at right-angle to each other. Cross sections through the proximal regions of the rhabdom display triangular rhabdom outlines and microvilli （belonging to 3-4 retinula cells different from those involved in the squarish more distal rhabdom） that run in three directions inclined to one another by 120°. Overall the organization of the eye conforms to the orthopteroid pattern and particularly closely resembles that of the American cockroach Periplaneta americana. However, since G. portentosa possesses fewer ommatidia, this could be a consequence of its inability to fly. On the other hand, the large size of the facets and the voluminous rhabdoms suggest considerable absolute sensitivity and an ability to detect the plane of linearly polarized light. Based on the pattern of microvillus orientations in combination with the crepuscular lifestyle G. portentosa leads and the habitat it occurs in, the prediction is made that this insect uses its green receptors for e-vector discrimination in the environment of down-welling light that reaches the forest floor.

Milestone of the meridian science──970th anniversary of the Chinese Bronze Statue of Meridian

For more than a thousand years, Chinese people were aware of the transmitted sensations by the application of needles on the body surface. This practice is called acupuncture. Acupuncture had been recorded and transcribed in writings and in drawings, until finally the acupoints were inscribed onto a bronze statue. The bronze statue was called the Meridian Figure. Deeply embodied in the bronze statue is a tripartite confrontation-prism representation of the humans body. This concept was a great scientific achievement in ancient China. The author traces the history of Meridian science described in traditional Chinese medical terms. Then he explores a clear analogy of the meridian pathway (MP) phenomenon. In a model system, by using a simple segmental in vertebrate, certain parallels can be demonstrated with the meridian concept. For example, the author demonstrated a clear correlation rule among the central mechano-sensory channels, and characteristics of positional discrimination in individual nerve cells from different receptive field inputs. The evidence suggests that the MP phenomenon is an objective neurobiological response. To clarify the research objective in this paper, the author suggests that the MP is a bi-directional pathway along which a positional message signal is transmitted. This phenomenon is evoked by physical stimulation, transmitted linearly across the human body segments, and is perceived by the brain. The MP consists of low resistance paths, is connected by the liquid media contained in the apposite membranous structure. At the cellular level, the regulation functions of MP must pass through along this low resistance path. Two aspects of the modern Meridian research are the functional regulation and the mechanism of intercellular liquid modulation at the nanometer level.