冠心病经皮冠状动脉介入治疗术后支架内再狭窄与尿微量白蛋白的关系

目的探讨冠心病PCI术后支架内再狭窄（ISR）与尿微量白蛋白（MAU）的关系。方法选取2008年12月至2009年12月160例行PCI治疗并于1年[平均随访（10．2±2．5）个月]内再次行冠状动脉造影术（CAG）检查的冠心病患者。通过术前MAU的测定及术后1年内的冠状动脉造影检查支架内再狭窄与否的结果,分为无再狭窄组（NISR）（作为对照组）及再狭窄组（ISR）。依据再狭窄组中植入支架的血管支数,分为单支组、双支组、三支组。结果ISR组MAU水平（60±19）mg／L,较NISR组（41±17）mg／L明显增高（t=5．109,P〈0．05）;ISR组三支组MAU水平（83±12）mg／L较双支组（58-4-7）mg／L明显增高（P〈0．05）,双支组MAU水平较单支组（38．9±2．0）mg／L明显增高（P〈0．05）。结论尿微量白蛋白可能是预测PCI术后支架内再狭窄的一个指标。     

冠状动脉介入术后胸痛再发和冠状动脉再狭窄因素分析

目的探讨冠状动脉介入（PCI）术后胸痛再发的原因和冠状动脉再狭窄的危险因素。方法78例PCI术后2年内胸痛再发患者,按冠状动脉是否再狭窄分为再狭窄组21例和无再狭窄组57例,对两组临床资料、危险因素等进行对比分析。结果 PCI术后胸痛原因：心绞痛复发7例（9．0％）,多支架或长支架刺激引起牵张痛9例（11．5％）,焦虑或失眠等精神因素所致35例（44．9％）,其他系统相关的非心源性胸痛27例（34．6％）。再狭窄组心绞痛复发5例（23．8％）,无再狭窄组心绞痛复发2例（3．5％）,再狭窄组心绞痛复发率高于无再狭窄组（P＜0．01）。再狭窄组吸烟、高血压、糖尿病及小血管病变的发生率均明显高于无再狭窄组（P＜0．05）;再狭窄组患者血总胆固醇、低密度脂蛋白胆固醇及使用的支架数量均高于无再狭窄组（P＜0．05）。结论 PCI术后胸痛再发原因多为非心脏器质性因素,少数为心绞痛复发;心血管危险因素增多、小血管病变、支架数量增加是PCI术后心绞痛复发和影响再狭窄的危险因素。     

冠状动脉支架内再狭窄的危险因素分析

目的探讨冠状动脉支架内再狭窄的危险因素。方法选择成功施行冠状动脉支架置入并进行冠状动脉造影随访的164例冠心病患者。根据冠状动脉造影结果将其分为再狭窄组与无再狭窄组。应用单因素和Logistic多因素回归分析临床特征、冠状动脉造影特征与再狭窄的相关性。结果164例中,有172支靶血管置入支架,59例患者的63支靶血管发生再狭窄,靶血管再狭窄率为36.6%。单因素分析显示:与无再狭窄组比较,再狭窄组的冠状动脉造影随访时间短、脂蛋白(Lp)(a)浓度高、术前狭窄程度和术后残余狭窄程度重、参照血管直径和支架直径小、靶血管病变长度长(P值均<0.05)。参照血管直径<3mm的靶血管再狭窄率显著高于参照血管直径≥3mm的靶血管(P<0.05)。Logistic回归分析显示:参照血管直径、支架直径与再狭窄呈负相关(OR值分别=0.70、0.26);而术后残余狭窄、病变血管长度与再狭窄呈正相关(OR值分别=1.19、1.47)。结论冠状动脉支架术后患者发生再狭窄多在术后6个月内。支架置入术后残余狭窄重、小血管病变、长病变是支架置入术后再狭窄的独立预测因素。尽量减少支架置入术患者的术后残余狭窄是减少再狭窄的重要环节。     

冠状动脉内支架再狭窄相关因素的研究

目的：探讨冠状动脉内支架再狭窄的相关因素,方法：收集行冠状动脉支架术和随访冠脉造影的病例1012例,按随访结果分为支架再狭窄线338例,无再狭窄组674例,并分别进行单因素和多因素分析,比较两组病人临床,病变特征及手术操作相关参数。结果：再狭窄危险性增高的因素包括糖尿病,高血压,复杂病变（B2／C）,慢性阻塞性病变,再狭窄病变,长病变,小血管病变,重度狭窄病变和长段支架置入,其相对应的比数比（Odds Ratio)分别为1．42,1．21,1.39,1.84,1.35,1.76,1.92,1.22,1.82,置入Multilink支架相对于Palmaz-Schatz,Wiktor,NIR,S670,Bestent支架再狭窄的危险性减少（OR为0．85）,结论：应结合患者的临床特点,病变特征选择冠脉内支架置入的适应征和适当类型的支架。     

纤维蛋白原与支架内再狭窄的相关性研究

目的：探讨纤维蛋白原（ FIB）与支架内再狭窄的相关性。方法：选取我院收治的冠心病行经皮冠状动脉介入术（ PCI）治疗的患者64例,本组患者均于术后3～12个月内完成冠状动脉造影术（ CAG）复查,根据有无支架内狭窄分为再狭窄组和无再狭窄组,术前检测血清FIB、低密度脂蛋白酯（LDL－C）、高密度脂蛋白酯（HDL－C）、总胆固醇（TC）、甘油三酯（TG）、载脂蛋白B（ApoB）、载脂蛋白A1（ ApoA1）,比较FIB在两组间有无差异,并且对FIB 与再狭窄进行偏相关分析及多元逐步回归分析。结果：FIB在术后支架内再狭窄组明显高于无狭窄组（ P＜0．001）;多元线性回归分析发现,FIB与再狭窄的相关性是除TC外的第二个最强指标（ P＜0．001）。结论：FIB水平异常升高与PCI术后支架内再狭窄关系密切相关。     

紫杉醇药物涂层支架治疗左前降支病变临床研究

目的：探讨紫杉醇药物涂层支架（PES）治疗冠状动脉左前降支（LAD）病变的即刻疗效及预后。方法：2003年2月～2005年3月在本院造影证实连续LAD单支病变患者94例,共107处病变,按常规行经皮冠状动脉成形术加支架置入术,分析患者临床、X线影像学特征及手术成功率,并行随访。结果：94例患者中,29例置入PES,65例置入金属裸支架（BMS）,手术成功率100％。病变弥漫性30例（31．9％）,位于近段52例（55．3％）,中段12例（12．8％）。全部患者均完成术后6个月的随访并行造影复查。PES组术后6个月时造影复查2例（6,9％）发生再狭窄;BMS组1例1个月内因急性前壁心梗死亡,6个月时造影复查21例（32．3％）发生再狭窄。结论：PES置入治疗冠状动脉LAD病变安全有效,术后心源性猝死及非Q波性心肌梗死发生率与置入BMS者相似,支架内再狭窄发生率明显降低,因再狭窄需冠脉搭桥率也显著降低,术后6个月再狭窄率与文献报道冠脉搭桥术相近。     

冠心病介入治疗前后C-反应蛋白的变化及临床意义

目的：观察冠心病患者经皮冠状动脉介入术（PCI）前后血清C-反应蛋白（CRP）的变化及其临床意义。方法：选择66例住院行PCI术的冠心病患者，于术前，术后24h、48h，术后14d测定血清CRP水平，根据术后CRP水平分为A组fCRP水平〈3．0mg／L）21例和B组（CRP水平≥3．0mg／L）45例，分析术后6个月内的心血管事件及支架内再狭窄的发生率。结果：B组术后6个月内的心血管事件及支架内再狭窄的发生率显著高于A组（P〈0．01）。结论：PCI术后CRP水平的增高与随访期内心血管再发事件及支架内再狭窄发生率相关，提示PCI术后血管壁的炎症反应增强是心血管再发事件及支架内再狭窄的发病机制之一。     

冠心病合并2型糖尿病患者冠状动脉造影特点及PCI预后分析

目的分析冠心病合并2型糖尿病的冠脉造影结果,观察经皮冠状动脉介入治疗（PCI）的临床疗效。方法比较40例冠心病合并2型糖尿病患者与82例无糖尿病患者的冠脉造影结果,并比较两组患者冠脉介入治疗的疗效。结果①DM组冠状动脉病变Gens㈨积分明显高于NDM组,多支病变比例显著高于NDM组（P〈0.05）。弥漫及复杂病变比例显著高于NDM组（P〈0.01）.②随访6～56个月,DM组支架内再狭窄和再次血运重建比例均显著高于后者（P〈0.05）,主要临床心血管事件、总病死率差异无统计学意义。结论2型糖尿病加重冠状动脉病变程度．冠状动脉病变以多支、弥漫性病变多见。冠状动脉介入术后冠心病合并2型糖尿病患者远期预后相对理想,但是支架内再狭窄率和再次血运重建率高。     

血清脂蛋白（a）与冠状动脉支架置入术后心血管事件和再狭窄的关系研究

目的 探讨血清脂蛋白（a）[LP（a）]水平对冠状动脉支架置入术后6个月心血管事件和再狭窄的预测价值。方法 术前测定88例冠状动脉支架置入术患者基础的LP（a）水平，随机分为LP（a）〈300mg／L和LP（a）≥300mg／L两组，随访术后6个月内心血管事件（心肌梗死和死亡）发生率和支架内再狭窄等情况。结果 （1）基础血清LP（a）不稳定型心绞痛组与稳定型心绞痛组相比明显升高（P〈0．01）；（2）在LP（a）升高组和正常组，在冠状动脉病变的特点、PTCA和支架所用的球囊、支架长短、大小、最大扩张压力及扩张时间等方面差异均无显著性（P〉0．05）；（3）术后6个月主要心血管不良事件LP（a）≥300mg／L组和LP（a）〈300mg／L相比有增加趋势，但差异无显著性（P〉0．05）；（4）术后6个月内支架内再狭窄发生率在LP（a）≥300mg／L、不稳定型心绞痛组与LP（a）〈300mg／L、稳定型心绞痛组相比明显升高。结论 基础血清LP（a）水平是冠状动脉支架置入术后6个月心血管主要不良事件和支架再狭窄发生率的一个重要预测指标。     

1-磷酸鞘氨醇及脂联素在支架内再狭窄患者中的预测价值

目的：探讨1‐磷酸鞘氨醇（S1P）及脂联素在冠状动脉支架植入术后的预测价值。方法选择经复查冠脉造影后证实为支架内再狭窄患者50例为再狭窄组,选取同时期支架内无再狭窄者50例为对照组,收集研究对象的临床相关资料,分别检测其血清1‐磷酸鞘氨醇（S1P）、HDL‐S1P、脂联素及IL‐18水平,分析其与支架内再狭窄的相关性。结果与对照组比较,再狭窄组血清总S1P水平更低[（96．10±26．33）ng／mLvs．（113．40±32．72）ng／mL,P＜0．01],HDL‐S1P水平明显降低[（32．81±10．02）ng／mLvs．（42．72±11．75）ng／mL,P＜0．01],脂联素水平也明显降低[（7．38±2．11）mg／Lvs．（9．25±3．29）mg／L,P＜0．01],而两组间IL‐18水平则差异无统计学意义[（258．15±82．19）ng／Lvs．（224．98±84．15）ng／L,P＞0．05];脂联素与S1P（r＝0．712,P＜0．05）及HDL‐S1P（r＝0．821,P＜0．01）之间均呈正相关。结论S1P及脂联素是冠脉支架内再狭窄的独立预测因素,相对较高的S1P及脂联素浓度能降低经皮冠状动脉介入治疗（PCI）术后患者支架内再狭窄的风险。     

Treatment of in-stent coronary restenosis with excimer laser angioplasty

Objective To evaluate the efficacy and safety of excimer laser coronary angioplasty (ELCA) with adjunctive balloon angioplasty in patient with in-stent restenosis.Methods ELCA was performed in 20 patients of in-stent restenosis.All patients were symptomatic and had class Ⅲ-Ⅳ angina. ELCA was performed with the Spectranetics CVX-300 System. The laser catheter of Vittesse C (concentric) and E (eccentric) with diameter of 1.4-2.0 mm was used.Results Laser catheter crossed all stenotic stents without difficulty. The lesion length was 4.6-51.2 mm,mean 20.7±13.7 mm, including 14 lesions &gt;10 mm. Laser treatment alone increased minimal lumen diameter (MLD) from 0.3±0.3 mm to 1.4±0.3 mm (P&lt;0.0001) and improved the diameter stenosis from 88.8%±10.0% to 46.0%±8.0% (P&lt;0.0001). Adjunctive balloon angioplasty further increased minimal lumen diameter to 2.3±0.7 mm and reduced diameter stenosis to 14.2%±8.2% (P&lt;0.0001). At follow-up (1-17 months, mean 8.9±5.7 months), 17 (85%) patients had remained asymptomatic, 3 (15%) patients had mild to moderate exertional angina, 1 (5%) patient received CABG. Conclusion ELCA with adjunctive percutaneous transluminal coronary angioplasty (PTCA) is an efficient and safe technique to debulk tissue in the patient with in-stent restenosis. The incidence of procedural related complication was low and ELCA may be used as a good method for in-stent restenosis treatment.     

A single center investigation of bare-metal or drug-eluting stent restenosis from 1633 consecutive Chinese Han ethnic patients

Background Stents are widely used in China but the clinical impression is somehow that restenosis is less common because of the lower prevalence of coronary artery disease (CAD) and associated risk factors in Chinese populations. However, no large-sample published studies are available on angiographic stent restenosis including those of bare-metal stent (BMS) or drug-eluting stent (DES) in Chinese Han ethnic population.Mothods A total of 1633 consecutive patients with CAD who had undergone coronary stenting, quantitative coronary angiography (QCA) were retrospectively studied. At the time of stent implantation and at 7 months post-stenting 675 patients had a follow-up angiography. Statistical analysis was made with the chi-square test for categorical variables, unpaired t test for continuous variables, univariate or multivariate regression for baseline and angiographic characteristics and the Kaplan-Meier method for rate of target lesion revascularization (TLR).Results Stent restenosis was defined as ≥50% diameter stenosis in the dilated segment. A total of 675 patients with 1074 lesions were subjected to angiographic follow-up for 7 months on average. Of these lesions, 448 were implanted with BMS whereas 626 lesions with DES. At 7 months, bare-metal in-stent restenosis occured in 148 lesions (33.0%), and bare metal in-segment restenosis in 155 lesions (34.6%) in contrast to drug-eluting in-stent restenosis in 48 lesions (7.7%) and drug-eluting in-segment restenosis in 73 lesions (11.7%) (P&lt;0.001 compared with BMS respectively). Late loss in both in-stent and in segment was higher in BMS than in DES groups [(1.00±0.69) vs (0.28±0.52); (0.78±0.71) vs (0.21±0.52), P&lt;0.001 respectively]. Angulated lesion, lesion length, pre-procedural minimal luminal diameter (MLD), and BMS were independent predictors for TLR, (P&lt;0.01 respectively), whereas current smoker, ostial lesion, and stent overlapping, post-procedure in-stent MLD, lesion length, and stent types were independent predictors for in-segment restenosis (P&lt;0.01 respectively). Standard coronary risk factors such as hypertension, hyperlipidemia, diabetes, and history of CAD were not associated with a higher rate of restenosis caused by BMS or DES implantation in our Chinese Han ethnic population.Conclusions Coronary stenting including BMS or DES implantation in Chinese Han ethnic patients is associated with a restenosis rate comparable to that demonstrated in previous studies from the western countries, and predictors of stent restenosis are somehow different from those in the western population.     

Stenting of partial and total coronary occlusions in Trinidad and Tobago

In order to evaluate the efficacy and safety of coronary stenting, we reviewed the first 32 consecutive patients (34 vessels) who underwent elective coronary stenting during the period August 1999 to August 2000 inclusive at the Digital Lab installed at the Eric Williams Medical Sciences Complex, Trinidad and Tobago. Aspirin, heparin and ticlopidine were used routinely. Abciximab was used in selected cases (38%). The mean age of patients was 55 +/- 10 years. Eighty-one per cent were male, 52% were hypertensive and 21% were diabetic. Sixty-five per cent had severe angina. Prior Coronary Artery Bypass Grafting (CABG) was performed in 3% and previous Percutaneous Transluminal Coronary Angioplasty (PTCA) in 3%. Multivessel disease was present in 43%. The mean left ventricular ejection fraction was 53 +/- 12%. The culprit lesion was located in either the native left anterior descending (LAD) coronary artery (53%), right coronary artery (RCA) (31%), circumflex artery 13% and saphenous vein graft (3%). The mean baseline diameter stenosis was 91 +/- 9% and this was reduced to 13 +/- 33% after stenting. Procedural success was 100% for 26 partially occluded vs 50% for 8 totally occluded vessels. For the total occlusions, procedural success was inversely related to the duration of the occlusion. There were no cases of death, acute vessel closure, Q-wave myocardial infarction, repeat PTCA or emergent Coronary Artery Bypass Graft (CABG) during and following the procedure. Distal embolization occurred in one patient. The mean duration of hospital stay was one day (for 30 outpatient cases). One patient had recurrence of symptoms with a negative stress test. No patient underwent repeat angiography during the first year of follow-up. Coronary stents were successfully implanted at a tertiary care facility in the Caribbean with low in-hospital morbidity and mortality. Stents markedly reduced the diameter stenosis of the coronary lesion during PTCA. The incidence of clinical restenosis was low. Coronary revascularisation can be successfully achieved by coronary stenting in the Caribbean.     

冠脉内多普勒血流速度描记评价介入治疗效果

目的 应用冠状动脉内多普勒血流速度描记技术,评价经皮冠状动脉球囊扩张术（ＰＴＣＡ）及支架植入术对冠脉血流储备的影响。方法 对２１支（１８例）有狭窄病变的冠状动脉进行ＰＴＣＡ术,其中１６支冠脉ＰＴＣＡ术后植入支架。在ＰＴ－ＣＡ前后和支架植入术后,采用Ｃａｒｄｉｏｍｅｔｒｉｃ ＦｌｏＭａｐⅡ血管腔内多普勒血流速度描记仪和多普勒导丝,测量狭窄近端和远端的平均峰值流速（ＡＰＶ）、舒张期与收缩期流速比（ＤＳ     

冠心病患者血浆尾加压素Ⅱ的临床研究

OBJECTIVE: To investigate the changes in plasma urotensin II(U II) expression levels in patients with coronary heart disease (CHD). METHODS: Plasma U II levels in 50 CHD patients with coronary stenosis indicated by coronary angiography and 20 healthy subjects were determined by radio immunoassay. RESULTS: Venous plasma U II levels were significantly lowered in CHD patients in comparison with the healthy subjects (1.61+/-1.02 pg/ml vs 3.70+/-1.30 pg/ml, P=0.000). In the CHD patient group, significantly differences were noted in the U II levels between patients with stable angina (2.62+/-1.20 pg/ml), unstable angina (1.39+/-0.80 pg/ml) and acute myocardial infarction (AMI, 1.04+/-0.45 pg/ml, P=0.004). CHD patients with coronary artery occlusion and those with only coronary stenosis had comparable venous plasma U II levels (1.29+/-1.02 pg/ml vs 1.76+/-1.00 pg/ml, P=0.131), whereas the patients with restenosis after percutaneous transluminal coronary angioplasty (PTCA) had higher U II levels than the other subjects in the CHD patient group (2.28+/-0.94 pg/ml vs 1.40+/-0.96 pg/ml, P=0.008), and the femoral plasma U II levels were significantly elevated after PTCT, increasing from 1.18+/-1.14 pg/ml to a postoperative level of 2.22+/-1.77 pg/ml (P=0.001). CONCLUSION: U II might play a role in the pathophysiological process of CHD and can be involved in the restenosis after angioplasty.     

经皮冠状动脉腔内成形术对急性心肌梗塞行早期血运重建

１２例急性心肌梗塞患者应用经皮冠状动脉腔内成形术进行早期血运重建，１１例梗塞相关血管再灌注血流为ＴＩＭＩ３级，残留狭窄１５．５±８．８％，１例并发血管内膜夹层形成行紧急冠状动脉旁路移植术，术后死亡。结果认为急性心肌梗塞早期直接进行经皮冠状动脉腔内成形术可实现稳定有效的血运重建，有利于减少心肌梗塞面积及心脏泵功能损害、降低再梗塞率和病死率。     

经皮腔内冠状动脉成形术30例报告

对３０例严重冠心病患者进行经皮腔内冠状动脉成形术（ＰＴＣＡ），４８支冠状动脉狭窄病变中的４２支进行了有效扩张，平均扩张次数３．６＋／－２．７次／处，扩张时间６８＋／－２３秒／次，扩张压力７．４＋／－２．３ａｔｍ／次，平均狭窄程度由术前９２％减轻至１６％，狭窄完全消失的病变有３６支血管，３例发生急性冠状动脉闭塞，经植入冠状劝脉支架或采用灌注球囊低压扩张而及时获得再通。术后心绞痛、心电图缺血性ＳＴ－Ｔ     

Clinical outcome of patients with left anterior descending artery ostial lesions treated with percutaneous coronary intervention: case-matched comparison with bypass surgery

Objective To assess the immediate and late clinical outcome of left anterior descending artery ostial lesions treated with percutaneous coronary intervention.Methods Seventeen patients (6 females and 11 males) treated with percutaneous coronary intervention for ostial left anterior descending artery stenoses have had clinical follow-ups over 12 months. Clinical events were defined as an occurrence of death, myocardial infarction, recurrent angina, and reguiring repeat revascularization (either by angioplasty or by surgery). A matched population treated with coronary bypass surgery was selected based on the similarities in age, left ventricular ejection fraction and the number of diseased vessels. Kaplan-Meier event-free survival curves were generated and the matched comparison was done using the Chi-square test (Mc Neimar method).Results In the catheter-based angioplasty group, the patients’ mean age was 63±8 years. One patient was treated with directional atherectomy plus balloon, 6 with rotational atherectomy plus balloon, 7 with stent and 3 with rotational atherectomy plus stent. Glycoprotein Ⅱb/Ⅲa antagonist was used in 4 cases. Initial procedural success without major complications was achieved in all cases. The mean reference diameter was 2.90±0.48 mm. The minimum lumen diameter increased from 1.05±0.30 mm to 2.40±0.45 mm, and the diameter stenosis decreased from 64%±7% to 8%±13%. During the follow-up period, adverse events reguiring repeat revascularization occurred in 8 patients. The event-free probability was 0.42±0.14 in a two-year period. In a matched population treated with bypass surgery (single mammary graft), only one event occurred, and the difference in event-free survival in two-year period between the two patient groups was significant.Conclusions Percutaneous coronary intervention for left coronary descending artery ostial lesion is technically feasible and safe, leading to an optimal early success rate, but has a higher risk of late restenosis and greater need for repeat revascularization than coronary bypass surgery.     

冠状动脉内支架植入术的临床研究

目的探讨冠状动脉内支架植入术在临床上的应用价值。方法８例冠心病患者，经冠状动脉造影证实４例为前降支（ＬＡＤ）近端狭窄，４例为右冠状动脉（ＲＣＡ）中段或近端狭窄。先对狭窄部进行经皮冠状动脉成形术（ＰＴＣＡ），３例因内膜撕裂，１例因动脉夹层形成，２例因血管弹性回缩及２例为预防再狭窄而在扩张处植入了冠状动脉内支架（其中Ｇｉａｎｔｕｒｃｏ－Ｒｏｂｉｎ支架２个，ＮＩＲ支架６个）。结果８例患者冠状动脉内支架植入均获得成功，无并发症。１例患者仍有较轻的心绞痛发作，药物能够控制，其余患者心绞痛症状均完全消失。结论冠状动脉内支架可以安全地应用于临床，以治疗ＰＴＣＡ时因血管损伤引起的急性并发症及降低ＰＴＣＡ术后再狭窄率。     

Use of cutting balloons in coronary interventions

Objective To study the efficacy and safety of cutting balloons in coronary interventions.Methods Twenty-two patients with 23 narrowed coronary arteries and 25 lesions enrolled the study, 17 of whom had 18 diseased coronary arteries and 18 lesions were in- stent restenosis. The average time from previous stenting was 7.60±3.53 mont hs. The lesions were dilated with cutting balloons.Results All of the lesions were dilated successfully by 5.16±2.30 inflations of a cutting balloon. The mean total duration of balloon inflation was 233.96±94. 83 seconds at pressures up to 9.40±1.96 bars. The severity of vascular ste nosis was lessened substantially (89.64±8.65% vs 17.60±17.15%, P=0 .000) without severe complications. Three restenotic lesions were further di lated with conventional balloons, another one was stented again because of a dis section distal to the previous stent. Three primary lesions were stented for di ssection or residual stenosis. Angina pectoris reoccurred in two patients in a mean follow-up period of 7.42±6.87 (range 0.5-20) months. Conclusion Cutting balloon dilation is an effective and safe choice in interventions for co ronary disease especially for in-stent restenosis.