Activated clotting times in acute coronary syndromes and percutaneous transluminal coronary angioplasty

A discrete fall in the ACT (activated coagulation time) has been observed in patients with known activation of the coagulation cascade. Injury to the coronary artery resulting in thrombin activation, whether spontaneous as in the case of acute myocardial infarction or planned as with percutaneous transluminal coronary angioplasty (PTCA), may there-fore be reflected in a change in ACT values. We reviewed the records of patients under-going PTCA at St. Luke's Episcopal Hospital/Texas Heart Institute from January 1990 through December 1992 for information regarding ACT values and clinical events. A total of 469 patients, whose record contained adequate information for study inclusion, were divided into four separate groups: acute myocardial infarction (group I, n = 62), unstable angina with heparin therapy that was withdrawn at least 4 hr prior to PTCA (group II, n = 102), unstable angina with heparin therapy continued until the time of PTCA (group III, n = 154), and stable angina undergoing elective PTCA (group IV, n = 151). Heparin was discontinued 12–15 hr after the procedure in all but group I where anticoagulation was often maintained up to 72 hr. ACT values were measured prior to the PTCA procedure (baseline), after the initial heparin bolus of 10,000 U (postheparin) and ～ 12–18 hr after the procedure (heparin withdrawal). The “baseline” ACT was significantly lower in patients with unstable angina (93 ± 13 sec) or acute myocardial infarction (78 ± 9 sec) who had their baseline value obtained off of heparin therapy than in patients with stable angina (136 ± 21 sec) or those receiving heparin at the time of baseline measurement (135 ± 14 sec, P < 0.001). All patients with unstable coronary syndromes had a blunted response to heparin (group 1–189 sec, group II-221 sec, group III-248 sec). Although groups I-III were not significantly different compared to one another, each was significantly lower than group IV whose past heparin ACT was 279 sec. Heparin withdrawal ACT values fell within the ranges seen in patients with unstable coronary syndromes untreated with heparin in all but group I (whose heparin therapy was continued through the time of the 12–18-hr postprocedure measurement time). Recurrent ischemic events were seen with increased frequency (16.6%) only in patients with unstable angina whose heparin therapy was interrupted prior to PTCA. In conclusion, low baseline ACT values and a blunted ACT response to heparin are associated with clinical syndromes known to result from thrombus formation. The possibility that the ACT may be of value in reflecting thrombus activity requires prospective evaluation.     

Percutaneous transluminal coronary angioplasty of coronary artery embolism

A 35-yr-old woman with known valvular heart disease presented with acute myocardial infarction. Angiography demonstrated a totally occluded distal left anterior descending coronary artery. Though initially successful, angioplasty ultimately failed to maintain arterial patency, leaving a more distal total occlusion after several balloon inflations. In spite of this, PTCA possibly provided a more localized infarction via a peripheral mobilization of the embolus.     

Comparison of activated clotting times to heparin management test for adequacy of heparin anticoagulation in percutaneous transluminal coronary angioplasty

The aim of this study was to compare the activated clotting time (ACT) obtained with the Hemochron device and the Heparin Management Test (HMT) on a new automated whole-blood coagulometer, the Thrombolytic Assessment System, in patients undergoing angioplasty. Fifty patients undergoing balloon angioplasty were prospectively enrolled. The mean ACT after a 10,000 unit bolus of heparin was 283 ± 39 sec at the end of the procedure. The mean HMT after 10,000 units of heparin was 286 ± 31 sec at the end of the procedure in the same patients. The correlation between the two methods was significant (r = 0.6; P < 0.01). The HMT appears to correlate well with standard values obtained with the Hemochron ACT monitor in patients undergoing percutaneous transluminal coronary angioplasty. Cathet. Cardiovasc. Diagn. 45:329–331, 1998. © 1998 Wiley-Liss, Inc.     

Percutaneous transluminal coronary angioplasty through 4 french diagnostic catheters

The use of 4 French (4F) diagnostic catheters as guiding catheters for coronary angio-plasty using fixed-wire balloons in 2 patients with a stenosis of the right and left anterior descending coronary artery, respectively, is reported.     

Relationship between arterial and venous activated partial thromboplastin time values in patients after percutaneous transluminal coronary angioplasty

This quasi-experimental study was conducted to determine whether reliable activated partial thromboplastin time (APTT) values could be obtained from samples taken from indwelling arterial catheter lines. The 30 subjects, who were receiving heparin infusions after a percutaneous transluminal coronary angioplasty (PTCA), had femoral intraarterial lines. With use of a counterbalanced design, APTT values determined in two serial samples of venous and arterial blood were compared for the 30 subjects. The venous blood samples were drawn at the same time as the comparable arterial blood samples. The arterial blood samples were withdrawn after discarding arterial blood equal to four or six times the indwelling catheter volume. A significance level of 0.01 was established to increase statistical control. A histogram was developed from the differences between the arterial and venous blood samples for each of the two groups (four times and six times the discard volume). The histogram indicated that three of the 30 subjects had arterial-venous APTT differences that exceeded 19 seconds when four times the discard volume was used. In the samples where six times the discard volume were used, only one person had an APTT reading greater than 8 seconds. Paired t tests revealed statistically significant differences between the arterial and venous APTT values (t = 2.95, df = 29, p less than 0.01) for discards of four times the catheter dead space volume, whereas no statistically significant difference was found between the arterial and venous APTT values (t = 2.62, df = 28, p greater than 0.01) for discards of six times the dead space volume.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous transluminal coronary angioplasty in multivessel coronary disease patients: short- and long-term follow-up in single and multiple dilatations

Transluminal coronary angioplasty was successfully performed in 658 of 752 patients with multivessel disease. An angiographic success was achieved in 1198 of 1358 lesions (88%). One lesion was attempted in 338 patients (45%); 2 in 273 (37%); 3, in 101 (13%); and, 4 or more in 40 cases (5.3%). Significant complications occurred in 39 patients (5.2%): 19 (2.5%) had a transmural infarction; 26 (3.5%) required urgent myocardial revascularization; and 14 (1.9%) died. An apparent lesion recurrence occurred in 233 of 658 (35%) patients with 162 of 171 (95%) having a successful second coronary angioplasty. A second apparent lesion recurrence occurred in 37 of 162 patients (23%) with 24 of 28 (86%) having a successful third coronary angioplasty. Clinical improvement (mean follow-up: 31 +/- 17 months) persisted in 81% of successful patients. The cumulative probability of survival was 91.5% at 72 months. Survival was adversely affected, at 63 months, by the presence of prior bypass surgery (no prior bypass surgery, 94% vs. prior bypass surgery, 86%; p less than 0.05): at 24 months by a low left ventricular ejection fraction (less than or equal to 35%, 82% vs. left ventricular ejection fraction greater than 35%, 95%; p less than 0.01) and, at 57 months, in the multiple dilatation group with prior bypass surgery (no bypass surgery 96% vs. prior bypass surgery 84%; p less than 0.05). Multiple dilatation had a beneficial effect upon survival, at 27 months, in patients with a left ventricular ejection fraction less than or equal to 35% [single dilatation, 74% vs. multiple dilatation, 93%; p less than 0.001], and in patients greater than or equal to 70 years, at 39 months (79% vs. multiple dilatation, 92%; p less than 0.01). These data suggest that coronary angioplasty can be an effective treatment in patients with multivessel coronary disease without the need to dilate all diseased vessels, with good success, acceptable complication rates, and a reasonable expectation of satisfactory long-term clinical improvement.     

Percutaneous transluminal coronary angioplasty in a patient with paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired chronic hemolytic anemia associated with an unusual susceptibility to hemolytic crisis, infection, and venous thrombosis which would be aggravated by a number of factors including surgery. We report a case of PNH undergoing percutaneous transluminal coronary angioplasty and discuss the corresponding perioperative management.     

应用小C臂X光机行经皮冠状动脉腔内成形术(附134例报告)

目的探讨应用小Ｃ臂Ｘ光机（ＯＥＣ）行经皮冠状动脉腔内成形术（ＰＴＣＡ）和冠状动脉内支架植入术的可行性。方法１３４例冠心病患者造影显示冠状动脉狭窄程度均≥７５％,采用美国ＯＥＣ９６００型小Ｃ臂Ｘ光机行ＰＴＣＡ和冠状动脉内支架置入术。结果１３４例冠心病患者共２０４处病变成功地完成了ＰＴＣＡ,其中９２例置入了１０６枚冠脉内支架,６例因多支冠脉病变分别置入２～３枚支架,术后冠脉造影显示管腔扩张满意,无残余狭窄。全部病例术后心绞痛症状较术前明显减轻或消失。除１例在支架置入术后发生急性血栓形成和３例出现术后穿刺部血肿外,无其它并发症发生。结论对冠心病患者应用小Ｃ臂Ｘ光机行ＰＴＣＡ和冠脉内支架置入术可能是一种安全有效的治疗方法。     

Use of angioplasty in the management of complicated perioperative infarction following bypass surgery

The optimal level of heparin anticoagulation for elective PTCA is unknown. To determine if PTCA complications are related to the level of anticoagulation, serial ACT values were prospectively measured in 189 patients undergoing 201 elective PTCA procedures. The mean heparin dose before balloon inflation (pre-inflation) was 10,100 units, and the mean dose per procedure was 13,200 units. The mean pre-inflation ACT was 295 sec, but was <300 sec in more than 50% of patients. Acute complications were not related to any ACT parameter and the development of new intracoronary thrombus was not observed. In elective PTCA procedures, the routine monitoring of ACT values is unnecessary when standard heparin doses are used. © 1993 Wiley-Liss, Inc.     

Monitoring the effect of heparin by measurement of activated clotting time during and after percutaneous transluminal coronary angioplasty.

The anticoagulant effect of heparin during percutaneous transluminal coronary angioplasty was monitored by measurements of the activated clotting time in two studies that compared the effects of a single bolus of heparin with those of a bolus of heparin combined with a continuous infusion of the drug. In a preliminary study 40 patients received a single heparin bolus of 10,000 units (protocol I) and a further 40 patients received both a heparin bolus of 10,000 and a continuous infusion of heparin at a rate of 2000 units per hour (protocol II). During the first 45 minutes, nine patients (23%) in protocol I but only two patients (5%) in protocol II were found to be inadequately anticoagulated. For 24 hours after angioplasty both groups received an infusion of heparin at the rate of 2000 units per hour which led to consistent anticoagulation in 73 (91%) of patients. In a subsequent randomised study, 40 patients received heparin according to either protocol I or II. Protocol II was again found to lead to a higher rate of adequate anticoagulation. During the first 60 minutes 11 patients (55%) in protocol I but only three patients (15%) in protocol II were inadequately anticoagulated. In addition, the activated clotting time of arterial blood in the first 30 minutes was significantly higher than that of venous blood in 70% of the patients. A bolus of heparin (10,000 units) together with an infusion of 2000 units per hour should be routinely given during coronary angioplasty. The effects of heparin, which can vary considerably from patient to patient, should be monitored by the measurement of the activated clotting time of arterial blood.     

Myocardial protection during percutaneous transluminal coronary angioplasty: effects of trimetazidine.

Trimetazidine (TMZ) has recently been shown to improve anginal symptoms without altering haemodynamic variables. A randomized, double-blind, placebo-controlled study was conducted in 20 patients to study the effects of TMZ on the severity of myocardial ischaemia during PTCA of the left anterior descending coronary artery. Five minutes after a first successful dilatation (D0), a control balloon inflation (D1) was performed until onset of ischaemic signs on both the intracoronary (i.c.) and precordial ECG. Two minutes later, patients received either TMZ 6 mg or placebo i.c. Another inflation (D2) was performed 5 min after D1. No differences were found between the two groups regarding responses in heart rate, systemic and i.c. pressures during the study. TMZ decreased the maximum ST-segment shift at D2 compared with D1 (0.8 +/- 0.1 vs 1.4 +/- 0.3 mV, P = 0.023) and delayed its onset (46 +/- 4 vs 36 +/- 5 s, P = 0.024). TMZ also decreased maximum T-wave changes (1.06 +/- 0.24 vs 2.19 +/- 0.3 mV, P = 0.001), and significantly reduced the area under the curve (mv s-1) of the i.c. ST-segment and T-wave changes during balloon inflation (P = 0.042 and P = 0.009 respectively). The placebo had no effect on these parameters. These results support the hypothesis that trimetazidine has a direct anti-ischaemic effect on human myocardial cells.     

Heparin dosing for percutaneous coronary angioplasty: Use of body surface area to improve initial activated clotting time values

Background: Activated clotting time (ACT) values during percutaneous transluminal coronary angioplasty (PTCA) after the initial 10,000 U heparin bolus are often below target values of 350 or 400 s (Hemochron) and have to be supplemented with additional heparin. This study evaluated the initial 10 min post-heparin bolus clotting time value using a body surface area (BSA)-adjusted heparin bolus versus the traditional 10,000 U heparin bolus. Hypothesis: Body surface area adjustment of initial heparin dosing prior to PTCA will be more effective in reaching target ACT values compared with the 10,000 U heparin bolus method. Methods: Twenty-seven patients receiving the BSA-adjusted heparin bolus were compared with 27 age- and gender-matched controls who had received the traditional heparin bolus. The adjusted heparin bolus formula used was [BSA(m²)/1.3m²] X 10,000 U of heparin. Results: The success rate at reaching the target value of 400 s was 13 of 27 (48.1%) and 2 of 27 (7.4%) for the BSA-guided and 10,000 U heparin-guided groups, respectively (p < 0.01). The success rate at reaching the 350 s target value was 25 of 27 (92.6%) and 6 of 27 (22.2%) for the BSA-guided and 10,000 U heparin-guided groups, respectively (p < 0.01). The 95% confidence intervals for the difference in success between the BSA-guided and 10,000 U heparin-guided groups were 0.19–0.62 and 0.52–0.89 for the 400 s and 350 s ACT targets, respectively. Conclusion: Body surface area adjustment of initial heparin dosing is a more effective method of reaching the initial ACT target values of 350 and 400 s compared with the traditional method prior to PTCA. This conclusion applies to the Hemochron ACT device and arterial samples, and adjustments may need to be made for other devices and/or venous samples.     

经皮冠状动脉腔内成形术的临床应用──附161例报告

经皮冠状动脉腔内成形术（PTCA）已广泛应用于冠心病的治疗［’］。我们自1991年一1996年对161例病人进行了IqC．ra治疗，现对其临床疗效进行初步评价。对象和方法l、临床资料19911510月一1996年12月共完成IqCA161例。男性140例，女性ZI例。平均年龄57．IL14．2（36－84）岁。其中稳定性心绞痛86例，不稳定型心绞痛75例。证实至少有1支血管直径＞扣％狭窄ZlyTwx方法按照Gnientrig等操作方法进行。部分全闭血管病人采用双侧冠状动脉顺序造影以显示闭塞血管长度［’］．成功标准：所扩张血管残留狭窄小于50％且无严重并发症。3疗效评价…     

Percutaneous transluminal coronary angioplasty of coronary artery embolism.

A 35-yr-old woman with known valvular heart disease presented with acute myocardial infarction. Angiography demonstrated a totally occluded distal left anterior descending coronary artery. Though initially successful, angioplasty ultimately failed to maintain arterial patency, leaving a more distal total occlusion after several balloon inflations. In spite of this, PTCA possibly provided a more localized infarction via a peripheral mobilization of the embolus.     

Percutaneous transluminal coronary angioplasty in acute myocardial infarction

Percutaneous transluminal coronary angioplasty (PTCA) has, in general, been restricted to therapy for patients with angina pectoris. Thrombolytic therapy and guide wire recanalization have been used to recanalize coronary arteries in patients with evolving myocardial infarction. Recently we and others have examined the use of PTCA to recanalize the acutely occluded artery associated with the early evolving phase of myocardial infarction. PTCA was performed as definitive therapy in eight patients with acute myocardial infarction. Seven of these had totally occluded arteries to the region of infarct. The infarct-related artery was open within 20 minutes in each of these cases. PTCA recanalization resulted in evidence for reperfusion in each case. Residual stenoses either were not present or were minimal. The procedure was well tolerated. These preliminary results suggest that PTCA may be a reasonable alternative to intracoronary thrombolytic therapy in certain patients with acute evolving myocardial infarction.     

Percutaneous transluminal coronary angioplasty: Application for acute myocardial infarction

Seventy-eight of 1,000 consecutive PTCA procedures were performed in the setting of acute MI. Twenty-four of 26 patients with subtotal coronary occlusions underwent successful PTCA, including 9 patients with and 15 patients without previous intracoronary streptokinase infusions. Of 52 patients with total occlusions, PTCA was performed after reperfusion by streptokinase in 24 patients, after unsuccessful intracoronary streptokinase infusion in 6 patients and without previous thrombolytic therapy in 14 patients (27%). Six patients (7.7%) died. The immediate post-PTCA course was stable in 59 of 63 successfully dilated patients and 4 had coronary reocclusion. Late catheterization (mean 10 days) in 41 patients showed improved left ventricular function in most. At 6.5 months of follow-up, there were 9 restenoses that required PTCA, 1 reocclusion, 1 elective CABG and no deaths.     

Percutaneous transluminal coronary angioplasty: six years' experience

It can be foreseen that with properly selected cases, percutaneous transluminal coronary angioplasty will have the same primary and long-term results as bypass surgery in this subset of patients. The socioeconomic and psychologic advantages of the procedure, compared to the advantages of heart surgery, are obvious. The classic indication for the procedure is single-vessel disease. At the present level of experience and case selection, approximately 10% of the surgical candidates could undergo dilatation. If patients with discrete proximal stenosis in double-vessel disease are included, the number will be slightly higher. Future developments in technique, as well as an increase in experience, will broaden the spectrum of this promising treatment.     

Monitoring the effect of heparin by measurement of activated clotting time during and after percutaneous transluminal coronary angioplasty

The anticoagulant effect of heparin during percutaneous transluminal coronary angioplasty was monitored by measurements of the activated clotting time in two studies that compared the effects of a single bolus of heparin with those of a bolus of heparin combined with a continuous infusion of the drug. In a preliminary study 40 patients received a single heparin bolus of 10,000 units (protocol I) and a further 40 patients received both a heparin bolus of 10,000 and a continuous infusion of heparin at a rate of 2000 units per hour (protocol II). During the first 45 minutes, nine patients (23%) in protocol I but only two patients (5%) in protocol II were found to be inadequately anticoagulated. For 24 hours after angioplasty both groups received an infusion of heparin at the rate of 2000 units per hour which led to consistent anticoagulation in 73 (91%) of patients. In a subsequent randomised study, 40 patients received heparin according to either protocol I or II. Protocol II was again found to lead to a higher rate of adequate anticoagulation. During the first 60 minutes 11 patients (55%) in protocol I but only three patients (15%) in protocol II were inadequately anticoagulated. In addition, the activated clotting time of arterial blood in the first 30 minutes was significantly higher than that of venous blood in 70% of the patients. A bolus of heparin (10,000 units) together with an infusion of 2000 units per hour should be routinely given during coronary angioplasty. The effects of heparin, which can vary considerably from patient to patient, should be monitored by the measurement of the activated clotting time of arterial blood.     

Diffuse embolization following percutaneous transluminal coronary angioplasty of occluded vein grafts: the blush phenomenon.

Percutaneous transluminal coronary angioplasty (PTCA) was performed on 146 saphenous vein grafts in 116 patients. In 29 patients, 31 grafts were totally occluded. Myocardial staining lasting over 5 minutes--"the blush phenomenon"--followed the opening of the occluded grafts in 9 of these patients. In 5 of these 9, enzyme release suggested infarction. A sixth patient died within a few hours of PTCA, with suspected infarction. Autopsy demonstrated diffuse and extensive distal coronary arterial embolization of grumous material, including cholesterol crystals, platelets, and fibrin. The blush phenomenon was not seen following PTCA in the remaining 20 patients with total occlusions, nor in any of the 87 patients with stenosed grafts. We have not observed the blush phenomenon following PTCA of more than 3300 coronary arteries. Of the 9 patients demonstrating the blush phenomenon, 6 had a recent history of myocardial infarction or unstable angina pectoris, compared with 4 of the remaining 20 patients with occluded grafts. We now approach occluded grafts with injection of intragraft thrombolytic agents or with atherectomy prior to PTCA. Future approaches may include atherectomy or laser angioplasty.