He Guoxiang

CURATIVE EFFECT OF ENDOVASCULAR THERAPY ON TAKAYASU ARTERITIS

Objective To observe the curative effect of endovascular therapy including percutaneous transluminal angioplasty (PTA) and PTA plus stenting on Takayasu arteritis (TA). Methods Forty-eight inpatients with TA (17 males and 31 females) at the age of 19–53 years (mean 27.6±18.1 years), who underwent endovascular therapy (PTA only or PTA plus stenting)in Department of Cardiology, Southwest Hospital, Third Military Medical University (Chongqing, China) from January 2002 to May 2009, were enrolled in this study. Treatment outcome and data including erythrocyte sedimentation rate, C-reactive protein, CTA, MRA, Doppler vascular ultrasound findings obtained during a follow-up period of 42.8 months were analysed. Results A total of 180 lesions were detected in the 48 patients by angiography. Of the 101 lesions that underwent endovascular therapy, 29 were found in subclavian artery and arteria innominata, 28 in carotid, 34 in renal artery, two pulmonary, and eight coronary artery, respectively. Good revascularisation was achieved in all these lesions. No residual stenosis occurred in 76 lesions (75.2%) with only minimal residual stenosis observed in 25 patients (24.8%). Restenosis was observed in three lesions (12.0%) after treatment with PTA only and in five lesions (6.5%) after treatment with PTA plus stenting during the follow-up period of 3–6 months. No significant complication occurred in all recurrent stenoses after endovascular therapy. Conclusions Endovascular therapy including simple PTA or PTA plus stenting is a safe and effective treatment modality for chronic inactive TA.

e0498 Case report: percutaneous multiple overlapped, overlength self-expanding stent placement treatment Superficial femoral artery chronic subtotal occlusions

PAD is a significant cause of both morbidity and death. In spite of TASC II recommendation that surgery is the preferred treatment for femoro-popliteal Type C&D lesions, promising clinical results of percutaneous revascularization had been obtained with a low risk of morbidity and mortality. We present a case of multiple overlapped, overlength self-expanding stent (extend as long as 450mm) placement to treat superficial femoral artery (SFA) chronic subtotal occlusions. No stent fractures or restenoses were observed at 1-year follow-up and with a favourable clinical results. Clinical and research medicine.

e0704 The study of effect of angiotensin II on the biological behaviour of rat vascular smooth muscle cells in vitro

Objective To study the effect of Angiotensin II on the roliferation, migration and apoptosis of vascular smooth muscle cell (VSMC) in rats. Methods The recombinant adenoviral vector, AdCMV-AT2R, containing rat AT2 receptor gene was constructed by homologous recombination, and then it was used to transfer AT2 receptor gene to rat VSMC in vitro. The expression of AT2R mRNA was detected by RT-PCR and the rate of expression in VSMC was determined by flow cytometer. Cell proliferation was determined by incorporation of bromodeoxyuridine (BrdU). The modified Boydens chamber method was used to test the migration of VSMC. Apoptosis was quantified by flow cytometer. Results RT-PCR showed that the expression of AT2R mRNA increased obviously in transferred VSMC, and the peak value of expression rate was about 89.51% at 48 h. When the expression of AT2R was at peak value, the OD value of BrdU incorporation were reduced by 51.6% (p<0.01), and the number of VSMC migration was also decreased by 62.2% (p<0.05). The ratio of apoptosis in VSMC was increased from 7.6±1.6% in control group to 32.1±5.5% in treated group. Conclusion The results indicated that the expression of AT2R can inhibit the proliferation and migration of rat VSMC and induce its apoptosis.

e0474 Effect of plaque distribution to biomechanical

Introduction we presume that the plaque vulnerability of mildly lesions will be related to its intrinsic structural features and biomechanical characteristics. However, very little is known about their relationship between structural features and plaque vulnerability and about effect of biomechanical characteristics and plaque behaviour on vulnerable plaque. It is well known that coronary angiography (CAG) cannot accurately determine lesion morphology because it only shows the silhouette of the contrast materiel passing through the stenotic lesions. In recent years, intravascular ultrasound (IVUS) has evolved as a valuable adjunct to angiography. IVUS allows precise tomographic measurement of lumen area and plaque size, distribution and, to some extent, composition. Therefore, IVUS provide us likelihood for study on structural features and biomechanics characteristics in angiographic mildly stenosis in vivo. Materials and methods In 42 patients of angiographic intermediate coronary stenosis (diameter stenosis 40%-60%), IVUS imaging was performed and intracoronary pressure was recorded. The patients were classified as either unstable plaques group (n=30) or stable plaques group (n=12) by IVUS image. The biomechanical properties (distensibility index and stiffness) of coronary artery were calculated and the plaque behaviour during cardiac cycle was determined. Results There was no significant difference in percent area stenosis between eccentric plaque group and concentric plaque group (53.9±8.9% vs 58.4±9.8%, p>0.05). The coronary distensibility index in unstable plaques was significantly greater than it was in stable plaques (2.1±0.3 vs 1.2±0.2 mm Hg-1, p<0.01), but stiffness β for stable plaques was significantly greater than it was for unstable plaques (8.1±1.3 vs 29.4±7.2, p<0.01). The change of plaque area during cardiac cycle (plaque distensibility) in unstable plaque group was greater than it was in stable plaque group (0.52±0.22 mm2 vs 0.24±0.19 mm2, p<0.01). Positive remodelling occurred more frequently with unstable plaques than with stable plaques (63% vs 8%, p<0.01). Conclusion High coronary artery distensibility and high plaque distensibility during the cardiac cycle in eccentric lesions will likely increase plaque vulnerability.

e0373 Intravascular ultrasound study on angiographic contrast materiel drain-lagged coronary segments

Introduction To investigate the structural characteristics and its clinical significant of angiographic contrast materiel drain-lagged coronary segments. Materials and methods 23 segments coronary arteries in 20 patients with angiographic contrast materiel drain-lagged were performed by intravascular ultrasound (IVUS) imaging. The characteristics of the plaques and reference segments were analysed. Percent area stenosis and remodelling index were calculated. Results External elastic membrane cross-sectional area in angiographic contrast materiel drain-lagged segments greater than reference segments (17.04±3.86 mm2 vs 14.35±3.62 mm2, p<0.01). Lesions had greater lumen area compared with reference (13.72±2.38 mm2 vs 11.86±2.57 mm2, p<0.01). Lesions had a soft plaque and minor stenosis (percent area stenosis 19.48%±5.23%) and positive remodelling was more frequent (20/23, 87%) in lesions. Conclusion Posimentive remodelling and minor atherosclerosis plaque in coronary segments are the causes of angiographic contrast materiel drain-lagged. This lesion has structural characteristics of unstable plaque.

e0372 Post-operative observation of the safety and angiogenesis effect of direct current stimulation in a myocardial infarction rabbit model

Introduction The purpose of the current study was to evaluate the safety of low voltage direct current (DC) electric stimulation and its angiogenesis effect in a rabbit myocardial infarction (MI) model with electrodes directly fixed on the epicardium. Materials and methods 28 Japanese white rabbits were randomly divided into control and treatment groups with 14 rabbits in each group. MI was induced by left anterior descending (LAD) artery ligation. A pair of platinum electrodes was directly placed on the ambilateral epicardium next to the LAD artery. Low voltage DC electric stimulation (4.0 V/cm, 60 min/day) was given to the treatment group immediately following the surgery until the 4th week post-operation. Parameters including blood routine, biochemistry, cardio and respiratory, pathology and immunohistochemisty from both groups were monitored throughout the experiment. Capillary density was counted at the end of the experiment. Results The overall mortality rate was 7.1%, pneumothorax rate was 3.6%, and the intraoperative arrhythmia rate was 7.1%. Transient hypotension, anaemia, leucocytosis, hypoxaemia and slight increase of the myocardium enzyme were observed in both control and treatment groups. Except minor inflammatory cell infiltration and mild hyperaemia, there was no other adverse response observed on the myocardium caused by electric thermal effect. The capillary density in the treatment group (140.7±21.5) was significantly higher than that of the control group (60.3±21.7) (p<0.001) at the end of the experiment. Conclusion It is safe to apply low voltage DC electric stimulation to the MI rabbits in addition to promote the myocardium angiogenesis.

e0688 Intravascular Ultrasound Criteria for the Assessment of the Functional Significance of Intermediate Coronary Artery Stenosis

Introduction In recent years, intravascular ultrasound (IVUS) has evolved as a valuable adjunct to angiography. IVUS allows precise tomographic measurement of lumen area and plaque size, distribution and, to some extent, composition. It is essential in clinic decision making. Myocardial fractional flow reserve (FFRmyo) is a special index of the functional severity of coronary stenosis. Although the application of FFRmyo to assess intermediate coronary lesion is widely performed in some centers in developed countries, its use in China was lagged. Because it is relatively expensive to measure FFRmyo, it will be beneficial to save the expenses and to short operation time if CAG and IVUS criteria could be clinically used as tools to discriminate functional significant of intermediate stenosis. Materials and methods In 46 lesions of intermediate severity (eg, 40% to 60% diameter stenosis) we assessed 1. by pressure wire: myocardial fractional flow reserve (FFRmyo, index of functional significance), and 2. by IVUS: minimal lumen cross-sectional area (MLA) and percent area stenosis at the lesion site. Receiver operating characteristic curve analysis was performed to establish the best cut-off values of IVUS indexes (ie, MLA and percent area stenosis) that were most predictive of FFRmyo<0.75. Results FFRmyo in 46 lesions of angiographic intermediate stenosis (49±11%) was significantly lower than it was in angiographic normal artery (0.83±0.15 vs 0.97±0.02, p<0.01). 14 lesions (30%) were functionally critical (eg, FFRmyo<0.75). By regression analysis, percent area stenosis had a significant inverse correlation with FFRmyo (r=−0.68, p<0.01). MLA showed a significant positive relation with FFRmyo (r=0.63, p<0.01). By receiver operating characteristic analysis, we identified a IVUS area stenosis ≥65% (sensitivity 100%, specificity 72%), a minimal lumen cross-sectional area ≤4 mm2 (sensitivity 93%, specificity 77%) to be the best cut-off values to fit with FFRmyo<0.75. Conclusion IVUS area stenosis ≥65% and minimal lumen cross-sectional area ≤4 mm2 reliably identified functionally critical intermediate coronary stenosis.