经皮冠状动脉介入治疗中静脉注射不同剂量那屈肝素的抗血栓疗效比较

目的比较冠状动脉介入治疗术(PCI)中静脉注射2种不同剂量那屈肝素的抗血栓疗效,明确取得理想抗血栓疗效的最佳剂量.方法采用前瞻性、随机、双盲的设计,共入选42例因患冠心病需行PCI术的患者,随机分为小剂量那屈肝素组(0.075 ml/10 kg)及大剂量组(0.1 ml/10 kg).PCI术前静脉注射那屈肝素,分别在注射前、注射后8 min、1 h、2 h和4 h,用发色底物法测定血浆抗Ⅹa因子活性.同时还观察了出血指数(定义为PCI治疗术后24 h内血红蛋白的下降值)及30 d内出血事件.结果 (1)小剂量组注射那屈肝素前、注射后8 min及1 h血浆抗Ⅹa因子活性分别为(0.10±0.00) IU/ml、(1.89±0.24) IU/ml、(0.96±0.24) IU/ml,均与大剂量组相应时间点的血浆抗Ⅹa因子活性[分别为(0.10±0.00) IU/ml,(1.89±0.30) IU/ml,(0.93±0.14) IU/ml]相似(P值分别为0.162、0.962和0.702).那屈肝素注射后2 h及4 h,小剂量组抗Ⅹa因子活性[分别为(0.47±0.13) IU/ml和(0.30±0.12) IU/ml]低于大剂量组[分别为(0.75±0.14) IU/ml和(0.45±0.08) IU/ml,P值均小于0.001]. (2)小剂量组的出血指数(3.3±3.8)g/L与大剂量组(0.2±6.4)g/L相似(P=0.061).(3)二组30 d内均未发现根据TIMI试验标准确定的大出血或轻度出血,均未发生死亡、心绞痛复发、心肌梗死及需行血管再通术等临床事件.结论 PCI术前注射二种剂量的那屈肝素均能达到理想的抗血栓效果,其中小剂量组能维持其有效的抗血栓疗效1 h,大剂量组能维持长达2 h的抗血栓效果.     

择期PCI术前应用那屈肝素和达肝素钠安全性有效性的对比研究

目的:评价经皮冠状动脉介入(PCI)术前皮下注射那屈肝素和达肝素钠抗凝的安全性和有效时间。探讨2种药物抗Ⅹa因子活性与活化部分凝血活酶时间(APTT)及活化凝血时间(ACT)的关系。方法:选择行PCI术的患者101例,随机分为那屈肝素组(50例,0.01mL/kg)和达肝素钠组(51例,120IU/kg)均皮下注射,2次/d,应用至少48h后行PCI。测定血浆抗Ⅹa因子活性、ACT及APTT。观察术后1个月内出血并发症、死亡、急性心肌梗死情况。结果:1.4h后2组抗Ⅹa因子活性>0.5IU/mL均为92.0%以上;8h、12h后,那屈肝素组比例为74.0%、36.0%;达肝素钠组比例为54.9%、23.5%,2者间差异无统计学意义;24h、48h后,2组均为96.0%以上。2.2组抗Ⅹa因子活性与APTT在给药后4h、24h和48h呈正相关(P<0.05);与ACT差异无统计学意义。3.2组30d内均未发生不良临床事件,出血事件发生率相同。结论:择期PCI术前应用那屈肝素和达肝素钠抗凝安全、有效,强度至少可以维持8h。APTT能反应2种药物的有效抗凝强度,ACT则不能。     

急性冠状动脉综合征高危患者围介入期应用依诺肝素和那屈肝素有效性和安全性的比较

目的比较急性冠状动脉综合征(ACS)高危患者在接受冠状动脉介入术(PCI)治疗的围手术期使用依诺肝素和那屈肝素的有效性和安全性。方法84例ACS高危患者随机分为依诺肝素组(44例)和那屈肝素组(40例),负荷剂量阿司匹林(300mg)和氯吡格雷(300mg)口服后继以口服维持量(阿司匹林300mg/d,氯吡格雷75mg/d),皮下注射依诺肝素1mg/kg或那屈肝素0.01ml/kg,q12h,共7d,每日及术前术后测定抗Xa因子活性。使用低分子肝素(LMWH)后48h行PCI,最后一次注射LMWH后8h内进入导管室,术中不追加LMWH或普通肝素。结果第3次给药后4h,两组87.5%患者抗Χa因子活性>0.5IU/ml,48h后95.5%患者抗Χa因子活性>0.5IU/ml,基本达到较稳定水平。30d内随访中,依诺肝素组和那屈肝素组临床主要心脏事件差异无统计学意义(P>0.05),两组之间出血发生率的差异也无统计学意义(P>0.05);两组每日测定的抗Χa因子活性差异亦无统计学意义(P>0.05)。结论两种LMWH在高危ACS患者围手术期使用均安全有效。     

使用依诺肝素48 h行冠脉造影的安全性和有效性

目的 低分子量肝素(LMWH)可以有效取代普通肝素(UH)应用于急性冠脉综合征(ACS)的治疗.然而,这些患者行冠脉造影(CAG)的最佳抗凝策略尚不明了.国外有关LMWH在冠脉造影中的应用研究表明,皮下应用低分子肝素至少48h(≥4次)冠脉造影,术中不追加抗凝剂是安全有效的,但此方案不一定适合我国.我科室曾沿用此法人选176例ACS患者,结果显示CAG前肝素抗-X a因子活性(0.808±0.265)IU/ml,93.2%的患者抗-X a活性＞0.5 IU/ml.本研究扩大样本量,试图进一步评价LMWH在心导管室应用的安全性和有效性,探索适合国人的心导管检查抗凝策略.方法 与结果人选278例ACS患者.所有患者按照1 mg(100 IU)/kg每隔12 h(7 am～7 pm)皮下注射依诺肝素(克赛),在接受至少48 h(≥4次)的LMWH后进行导管检查.末次注射(7 am)距离冠脉造影不超过8 h(3 pm之前).穿刺前(≈末次注射的3～5 h内)取血测定抗-X a活性.如病情需要,可行经皮冠脉介入术(PCI),术中追加普通肝素5000 IU.结果 显示冠脉造影前肝素抗-X a活性为(0.745±0.304)IU/ml,79.7%的患者抗-X a活性＞0.5 IU/ml,5.4%抗-X a活性＞1.2 IU/ml.1例在造影过程中,另3例在PCI中出现血栓,无严重出血事件.结论 皮下注射依诺肝素至少48h行冠脉造影抗凝强度偏低,可能需要寻找新的抗凝方案.     

急性冠状动脉综合征介入治疗中应用那屈肝素的临床研究

目的 研究急性冠状动脉综合征患者在经皮冠状动脉介入治疗前应用那屈肝素的合适剂量并评估其安全性.方法 236例急性冠状动脉综合征高危患者随机分为Ⅰ组(那屈肝素0.075ml/10 kg,120例)和Ⅱ组(那屈肝素0.1 ml/10 kg,116例).两组给予相应剂量那屈肝素,每12 h皮下注射1次,至少48 h,最后一次注射1 h后行经皮冠状动脉介入治疗,术中不再追加那屈肝素.分别在末次注射前、注射后1 h、2 h、4 h、6 h、8 h测定血浆抗Xa因子活性.观察记录患者30 d内的主要心脏不良事件(死亡、再梗死、血运重建)及出血事件.结果 两组的一般临床资料、30 d内随访主要心脏事件及出血发生率差异均无统计学意义(P>0.05).各时间点血浆抗Xa因子活性Ⅱ组高于Ⅰ组,差异有统计学意义(P<0.01).结论 在急性冠状动脉综合征介入治疗前应用两种剂量那屈肝素均能达到有效的抗凝效果.     

达肝素与普通肝素对血浆抗凝血因子Ⅹa活性及活化凝血时间影响的对比研究

目的探讨冠心病患者择期PCI及冠状动脉造影术中应用达肝素替代普通肝素的可行性和有效性。方法共入选拟行择期PCI的患者87例,分为普通肝素组（10 000 IU）、小剂量（5 000 IU）达肝素组和大剂量（10 000 IU）达肝素组,分别于用药前及全部剂量的药物注射后10 min、20 min、1 h、2 h及4 h采血,测定活化凝血时间（ACT）及血浆抗凝血因子Ⅹa活性。结果（1）普通肝素组、小剂量达肝素组和大剂量达肝素组ACT均在全部剂量的药物注射后10 min升高至峰值,分别为524.68±278.32 s、191.26±39.35 s、304.20±42.71 s（P〈0.05）;其后各组ACT开始逐渐回落,在4 h后降至最低。（2）三组抗凝血因子Ⅹa活性均在药物全部注射后20 min达到峰值,分别为0.80±0.11 IU/mL、0.72±0.10 IU/mL及0.72±0.09 IU/mL,但各组间差异无统计学意义（P〉0.05）。结论与普通肝素相比,达肝素用于PCI中可达到手术所需抗凝效果。     

抗Xa因子活性测定评价依诺肝素在心导管室中应用的安全性和有效性

目的　低分子量肝素可以有效的取代普通肝素应用于急性冠状动脉综合征 (ACS)的治疗。然而 ,ACS患者在行心导管检查时最佳的抗凝策略尚不明了。本研究旨在用抗Xa因子活性检测评价低分子量肝素在心导管室中应用的安全性和有效性 ,探索适合国人的心导管检查及经皮冠状动脉介入治疗 (PCI)的抗凝策略。方法　共入选ACS患者 1 76例。在每 1 2h(7:0 0 1 9:0 0 )皮下注射依诺肝素 1mg kg至少 48h后 ,不追加普通肝素或低分子量肝素于心导管室行冠状动脉造影 ,不进行凝血系统监测。 60例 (34 1 % )患者继之行PCI。结果　在心导管检查前的肝素抗Xa因子活性是 (0 81±0 2 7)IU ml,93 2 %的患者抗Xa因子活性 >0 50IU ml,且抗Xa因子活性与从注射到开始导管检查的时间无关 (P =0 0 97)。PCI组术后 30d无死亡、急性冠状动脉再闭塞或急诊血管重建事件。 3例(5 0 % )PCI患者术中出现血栓和 (或 )栓塞事件。单纯冠状动脉造影组有 1例因三支血管病变在术后1 7d等待冠状动脉旁路移植术时发生急性心肌梗死而行急诊PCI;另 1例患者在冠状动脉造影后 2 1d死于十二指肠穿孔。 1 76例入选患者无一例出现严重出血事件 ;PCI组有 3例 (5 0 % )患者出现轻度穿刺部位出血 ,单纯冠状动脉造影组为 5例 (4 3 % )。结论　本研究初步表明     

冠状动脉介入诊断治疗时那屈肝素与普通肝素联合应用的安全性研究

目的评价在无ST段抬高的急性冠脉综合征(ACS)患者行冠状动脉(冠脉)介入治疗(PCI)前后接受那屈肝素皮下注射与PCI术中普通肝素联合应用的安全性。方法190例ACS患者接受抗血小板治疗和2—4天那屈肝素治疗后分成3组：A组未行介入诊断和治疗,继续那屈肝素治疗;B组行冠状动脉造影(CAG)而未行PCI治疗;C组CAG后立即接受PCI治疗。B组和C组分别在停用最后1次那屈肝素注射后8—12小时内行CAG及CAG和PCI,介入操作时给予普通肝素,术后继续那屈肝素治疗。那屈肝素总的治疗时间不超过7天,观察10天期间出血发生情况。结果3组总的出血发生率分别为8．33％、12．7％和14．5％,差异无显著性。结论对接受抗血小板治疗的ACS患者,行PCI术前、术后那屈肝素皮下注射和术中普通肝素联合应用是安全的。     

达肝素与普通肝素对血浆抗凝血因子Xa活性及活化凝血时间影响的对比研究

目的 探讨冠心病患者择期PCI及冠状动脉造影术中应用达肝素替代普通肝素的可行性和有效性.方法 共人选拟行择期PCI的患者87例,分为普通肝素组(10 000 IU)、小剂量(5 000 IU)达肝素组和大剂量(10000 IU)达肝素组,分别于用药前及全部剂量的药物注射后10 min、20 min、1 h、2 h及4 h采血,测定活化凝血时间(ACT)及血浆抗凝血因子Xa活性.结果 (1)普通肝素组、小剂量达肝素组和大剂量达肝素组ACT均在全部剂量的药物注射后10 min升高至峰值,分别为524.68±278.32 s、191.26±39.35 s、304.20±42.71 s(P＜0.05);其后各组ACT开始逐渐回落,在4 h后降至最低.(2)三组抗凝血因子Xa活性均在药物全部注射后20 min达到峰值,分别为0.80±0.11 IU/mL、0.72±0.10 IU/mL及0.72±0.09 IU/mL,但各组问差异无统计学意义(P＞0.05).结论 与普通肝素相比,达肝素用于PCI中可达到手术所需抗凝效果.     

急性冠脉综合征患者抗Ⅹa因子、抗Ⅱa因子的变化及低分子质量肝素的干预作用

目的观察急性冠脉综合征(ACS)患者抗Ⅹa因子、抗Ⅱa因子的变化及低分子肝素(LMWH)的干预作用。方法将上海交通大学附属第一医院2003-01~2003-09收治的24例ACS患者和10例正常人(作对照)纳入研究对象。采用发色底物法测定血浆中的抗Ⅹa因子、抗Ⅱa因子。ACS患者用LMWH抗凝治疗并分别于入院即刻,LMWH注射后4h、注射后24h、注射7d后观察抗Ⅹa因子和抗Ⅱa因子的变化。结果(1)ACS患者血浆抗Ⅹa因子和抗Ⅱa因子明显高于正常者(P<0·01)。(2)抗Ⅹa因子在LMWH注射后4h、24h、7d较注射前明显增加(P<0·01),注射后4h达高峰,以后逐渐下降;抗Ⅱa因子在LMWH注射后4h、24h、7d较注射前明显增加(P<0·01),在注射后24h达高峰。结论ACS患者血浆抗Ⅹa因子升高与ACS的发病机制及LMWH的干预作用有关。LMWH对Ⅹa因子的作用较Ⅱa因子强,且达峰时间短。     

Safety of coronary stenting with eptifibatide and ultra-low-dose heparin

With the advent of multiple potent antiplatelet and anticoagulation agents in percutaneous coronary intervention (PCI), the risk of bleeding complications has increased. The optimal dose of unfractionated heparin in this setting is unclear. This study was designed to determine the feasibility and safety of PCI with an ultra-low-dose weight-adjusted unfractionated heparin regimen (30 IU/kg bolus, maximum 3,000 IU) in combination with aspirin, clopidogrel, and eptifibatide. We enrolled 83 patients who underwent nonemergency PCI of native coronary arteries. At 30 days, all patients were free of the primary clinical outcomes defined as a composite of death, myocardial infarction, or repeat target vessel revascularization, and there were no major bleeding complications.     

Safety of concomitant therapy with eptifibatide and enoxaparin in patients undergoing percutaneous coronary intervention: results of the Coronary Revascularization Using Integrilin and Single bolus Enoxaparin Study

OBJECTIVES: This study was designed to assess whether use of enoxaparin during percutaneous coronary intervention (PCI) increased bleeding compared with unfractionated heparin, in addition to background therapy with eptifibatide. BACKGROUND: Data supporting the benefits of enoxaparin and the glycoprotein IIb/IIIa inhibitor eptifibatide evolved in parallel. Information on combining these two classes of medications is limited. METHODS: A total of 261 patients undergoing elective or urgent PCI were randomized to either eptifibatide plus enoxaparin or eptifibatide plus unfractionated heparin. RESULTS: The primary end point of the study, the bleeding index (change in hemoglobin corrected for blood transfusions), was 0.8 in the patients randomized to enoxaparin and 1.1 in patients randomized to unfractionated heparin (p = 0.15). The rate of vascular access site complications was 9.3% in the enoxaparin arm versus 9.8% in the unfractionated heparin arm (p = NS). The rate of bleeding complications was not significantly different between the two arms of the study, including in those patients who received vascular closure devices. The rate of angiographic complications was 6.3% in the enoxaparin group and 6.2% in the unfractionated heparin group (p = NS). Similarly, there were no significant differences in the composite of death, myocardial infarction, or urgent target vessel revascularization at 48 h or 30 days. CONCLUSIONS: Compared with unfractionated heparin plus eptifibatide, the combination of enoxaparin plus eptifibatide is not associated with an excess of bleeding or vascular complications, including in those receiving closure devices. Despite no monitoring of anticoagulation activity with enoxaparin, there was no apparent increase in angiographic or clinical complications.     

Combination therapy with tirofiban and enoxaparin in acute coronary syndromes

BACKGROUND: Tirofiban, an intravenous glycoprotein IIb/IIIa antagonist, and enoxaparin, a low molecular weight heparin, have each been shown to be effective at reducing cardiac ischemic events compared to unfractionated heparin alone in separate trials of patients with unstable angina and non-Q-wave myocardial infarction. The combination of these agents may offer further therapeutic benefit. MATERIALS AND METHODS: Fifty-five patients with non-Q-wave myocardial infarction were randomized to receive double-blind treatment with tirofiban (0.1 microgram/kg/min i.v.) for 48-108 h coadministered with either enoxaparin (1 mg/kg sc q 12 h) (n=26) or unfractionated heparin (i.v. adjusted to activated partial-thromboplastin time) (n=27) to evaluate pharmacokinetics, pharmacodynamics, and safety. The primary objective of the study was to investigate the effect of unfractionated heparin versus enoxaparin on the plasma clearance of tirofiban. RESULTS: Coadministration of tirofiban and enoxaparin was generally well tolerated. Plasma clearance of tirofiban was 176.7+/-59.8 and 187.5+/-81.8 ml/min, respectively, for enoxaparin and unfractionated heparin-treated patients (P=NS). The mean difference was well within the prespecified criterion for comparability. Administration of tirofiban with enoxaparin vs. unfractionated heparin resulted in lesser variability and a trend towards greater inhibition of platelet aggregation using 5 microM adenosine phosphate agonist. More patients achieved target inhibition of platelet aggregation >70% in the tirofiban and enoxaparin group (84% vs. 65%, P=0.19). Median bleeding time was 21 min for tirofiban and enoxaparin vs. > or =30 min for tirofiban and unfractionated heparin (P=NS). For a given level of inhibition of platelet aggregation, bleeding time was less prolonged with tirofiban and enoxaparin than tirofiban and unfractionated heparin (adjusted mean bleeding time 19.6 vs. 24.9 min, P=0.02). Tirofiban plasma concentration and clearance were comparable whether coadministered with enoxaparin or unfractionated heparin. There were no major or minor bleeding events in either group by the TIMI criteria. INTERPRETATION: The more consistent inhibition of platelet aggregation and lower adjusted bleeding time of tirofiban and enoxaparin vs. tirofiban and unfractionated heparin support the therapeutic potential of combining these two agents. These data from the first clinical report of coadministration of a glycoprotein IIb/IIIa receptor antagonist and a low molecular weight heparin are consistent with prior data which show differential pharmacodynamic effects of enoxaparin and unfractionated heparin on platelet aggregation.     

Comparison of the radial and femoral approaches in left main PCI: a retrospective study

Transradial percutaneous coronary intervention (PCI) is a safe and effective method of percutaneous revascularization. However, there are no data on the efficacy of the transradial approach in left main (LM) PCI. We studied 80 patients (pts) who underwent LM PCI between February 1994 and January 2002, and compared the radial (27 pts) and femoral (53 pts) approaches. Patients were considered free of restenosis if they were free of angina and had a negative treadmill or nuclear imaging study 6 months post-PCI. Mean follow-up time was 27.4+/-23.0 months. Reason for PCI (stable angina, unstable angina, acute myocardial infarction) and lesion location (ostial, mid, distal) were similar in both groups (p>0.05), whereas mean ejection fraction was higher in the radial group (56.5+/-11.1% versus 49.2+/-14.7%, respectively; p<0.05). Sheath size (7 or 8 French; 44.4% radial versus 77.3% femoral) and amount of heparin used (9,192+/-3,645 IU versus 11,468+/-5,083 IU) were significantly larger in the femoral group (p<0.05), and the use of intra-aortic balloon pump was significantly more frequent (3.7% versus 22.6%). Mean fluoroscopy time (21.3+/-12.8 minutes versus 16.7+/-8.5 minutes), amount of contrast used (227+/-92 ml versus 225+/-85 ml), mean procedural time (67.0+/-27.6 minutes versus 73.4+/-32.7 minutes), procedure success (96.3% versus 98.1%), in-hospital major adverse cardiac events (MACE; 7.4% versus 5.6%) and 6-month MACE (14.8% versus 25.5%) were similar in the 2 groups (p>0.05). However, major vascular complications occurred only in the femoral group (5.7%). Radial LM PCI is as fast and successful as the femoral approach and results in fewer vascular complications.     

What anti‐thrombotic therapy is best with primary PCI for acute ST elevation myocardial infarction: How should the HORIZONS trial change current practice?

The current standard of care for anti‐thrombotic therapy with primary PCI for acute ST elevation myocardial infarction (STEMI) is aspirin, clopidogrel, unfractionated heparin and platelet glycoprotein IIb/IIIa inhibitors. However, heparin and glycoprotein IIb/IIIa inhibitors are associated with a high incidence of bleeding, and many of the trials documenting benefit with this therapy were performed before the widespread use of stents and clopidogrel. Bivalirudin is a direct thrombin inhibitor which has been found to have similar efficacy with less bleeding compared with heparin plus glycoprotein IIb/IIIa inhibitors when used with elective PCI and with PCI for unstable angina and non‐ST elevation myocardial infarction. The HORIZONS trial evaluated bivalirudin compared with unfractionated heparin and IIb/IIIa inhibitors in patients with STEMI treated with primary PCI and found similar MACE (major adverse cardiac events) with less bleeding and a lower incidence of net adverse clinical events (MACE or major bleeding) at 30 days. Mortality at 30 days was also significantly less with bivalirudin. These results make a strong case for the use of bivalirudin with primary PCI in the great majority of patients with STEMI, with the possible exception of patients with cardiogenic shock or stent thrombosis, and patients with a large thrombus burden or no re‐flow following PCI. In the latter case, platelet glycoprotein IIb/IIIa inhibitors would be used as a bail‐out strategy. © 2008 Wiley‐Liss, Inc.     

Comparison of bivalirudin versus heparin plus glycoprotein IIb/IIIa inhibitors in patients undergoing an invasive strategy: A meta-analysis of randomized clinical trials

Objective

This meta-analysis was performed to assess the efficacy and safety of bivalirudin compared with unfractionated heparin or enoxaparin plus glycoprotein (GP) IIb/IIIa inhibitors in patients undergoing percutaneous coronary intervention (PCI).

Background

Pharmacotherapy for patients undergoing PCI includes bivalirudin, heparin, and GP IIb/IIIa inhibitors. We sought to compare ischemic and bleeding outcomes with bivalirudin versus heparin plus GP IIb/IIIa inhibitors in patients undergoing PCI.

Methods

A literature search was conducted to identify fully published randomized trials that compared bivalirudin with heparin plus GP IIb/IIIa inhibitors in patients undergoing PCI.

Results

A total of 19,772 patients in 5 clinical trials were included in the analysis (9785 patients received bivalirudin and 9987 patients received heparin plus GP IIb/IIIa inhibitors during PCI). Anticoagulation with bivalirudin, as compared with heparin plus glycoprotein IIb/IIIa inhibitors, results in no difference in major adverse cardiovascular events (odds ratio [OR] 1.07, 95% confidence interval [CI] 0.96 to 1.19), death (OR 0.93, 95% CI 0.72 to 1.21), or urgent revascularization (OR 1.06, 95% CI 0.86 to 1.30). There is a trend towards a higher risk of myocardial infarction (OR 1.12, 95% CI 0.99 to 1.28) but a significantly lower risk of TIMI major bleeding with bivalirudin (OR 0.55, 95% CI 0.44 to 0.69).

Conclusion

In patients who undergo PCI, anticoagulation with bivalirudin as compared with unfractionated heparin or enoxaparin plus GP IIb/IIIa inhibitors results in similar ischemic adverse events but a reduction in major bleeding.     

New heparin dosing recommendations for patients with acute coronary syndromes

Despite major innovations in antithrombotic and antiplatelet therapy, unfractionated intravenous heparin is widely used to treat acute coronary syndromes. Recommendations for unfractionated heparin dosing in acute myocardial infarction and unstable angina have been issued in two recent American College of Cardiology/American Heart Association guidelines. An initial heparin bolus of 60 U/kg (maximum, 4000 U) followed by a 12-U/kg/h infusion (maximum 1000 U/h) is recommended with alteplase for ST-elevation myocardial infarction. When intravenous heparin is administered for myocardial infarction with non-ST elevation and unstable angina, an initial bolus of 60 to 70 U/kg (maximum, 5000 U) followed by a 12- to 15-U/kg/h infusion is recommended. The goal is to achieve an activated partial thromboplastin time of 50 to 70 seconds. Here, we review these new dosing regimens and explain the rationale for their use. We also review the risk of bleeding with heparin, especially when administered concurrently with aspirin, thrombolytic agents, and glycoprotein IIb/IIIa antagonists, and the relationship between activated partial thromboplastin time and cardiac events.     

Elective percutaneous coronary intervention using broad-spectrum antiplatelet therapy (eptifibatide, clopidogrel, and aspirin) alone, without scheduled unfractionated heparin or other antithrombin therapy

Background

Adjunctive pharmacotherapy during percutaneous coronary intervention (PCI) has historically consisted of a regimen of antiplatelet agents accompanied by an antithrombin agent, typically unfractionated heparin. Paradoxically, unfractionated heparin may activate platelets, induce other pro-thrombotic activities, increase bleeding complications, and cause thrombocytopenia. To optimize patient care and avoid the potential risks of unfractionated heparin in patients undergoing elective PCI, one of the authors began to use adjunctive pharmacotherapy consisting of broad-spectrum antiplatelet therapy alone, without scheduled unfractionated heparin or other antithrombin therapy.

Methods

Five hundred consecutive patients undergoing scheduled, elective PCI (stent deployment, cutting balloon atherotomy, conventional balloon angioplasty, or high-speed rotational atherectomy) received adjunctive pharmacotherapy consisting of eptifibatide, clopidogrel, and aspirin.

Results

The technical success rate was 100%. During the first 24 hours, there were no major adverse clinical events. Non-Q-wave myocardial infarction occurred in 1.6% of patients, major and minor bleeding complications in 0.2% and 0.6%, respectively, and thrombocytopenia in 0.6%. During the first 30 days, there was 1 (0.2%) major adverse clinical event.

Conclusions

For elective PCI, adjunctive pharmacotherapy consisting of broad-spectrum antiplatelet therapy alone, without scheduled unfractionated heparin or other antithrombin therapy, appears to be safe and may prove to be efficacious.     

Low‐Dose Heparin for Elective Percutaneous Coronary Intervention

Objectives

We evaluated the safety and efficacy of low‐dose heparin (40 IU/kg) for elective percutaneous coronary intervention (PCI).

Background

Current guidelines recommend a 70–100 IU/kg bolus of heparin for elective PCI, but this dose may be associated with increased bleeding risk. Low‐dose heparin may have an advantage in this regard, but has not been well studied.

Methods

From January 2008 to October 2012, 300 patients underwent elective transfemoral PCI and were treated with an initial bolus of 40 IU/kg of heparin at the UCLA Medical Center. Dual antiplatelet therapy with clopidogrel and aspirin was administered prior to or just after diagnostic coronary angiography. The primary end‐point was the composite of cardiac death, myocardial infarction, urgent target vessel revascularization for ischemia, or major bleeding within 30 days after PCI.

Results

The mean activating clotting time was 233 ± 28 seconds. The primary end‐point occurred in 2.3%. The cardiac death rate was 0.3% but was not related to the PCI. The myocardial infarction rate was 1.3%. Urgent target vessel revascularization occurred in 1 patient (0.3%). The major bleeding rate was 0.3%. No stent thrombosis occurred.

Conclusion

Using a lower dose of heparin with dual antiplatelet therapy is safe and is associated with a low bleeding risk after transfemoral PCI while providing suppression of ischemic events. This may also represent a cost savings compared with other antithrombotic strategies. A randomized clinical trial comparing low‐dose heparin with bivalirudin in patients is required to determine the optimal anticoagulation strategy. (J Interven Cardiol 2014;27:58–62)