Prolonged heparin after uncomplicated coronary interventions: a prospective, randomized trial

Prognostic value of post-procedural aPTT in patients with ST-elevation myocardial infarction treated with primary PCI

Unfractionated heparin is the most commonly used anticoagulant in ST-elevation myocardial infarction (STEMI) and its effect can be monitored with activated partial thromboplastin time (aPTT). However, the optimal aPTT range during heparin therapy after primary percutaneous coronary intervention (PCI) is yet to be defined. A mean aPTT was calculated of all aPTT measurements in the first 24 hours after pPCI in a total of 1,876 STEMI patients. Mean aPTT measurements were stratified into four categories; < 1.5 times the upper limit of normal (ULN), 1.5 – 2.0 times ULN (the therapeutic group), 2.01 – 3.99 times ULN, and ≥ 4 times ULN. Compared to patients with a therapeutic aPTT, patients with aPTTs < 1.5 times ULN had no increase in recurrent ischaemic events and had similar rates of bleeding complications. Patients with a mean aPTT ≥ 4 times ULN had higher rates recurrent ischaemic and haemorrhagic complications. After multivariable analyses, aPTT ratios ≥ 4 times ULN were no longer associated with recurrent ischaemic events, but remained a strong predictor of severe and moderate bleeding (hazard ratio [HR] 4.64, p = 0.016 and HR 2.27, p = 0.052). In conclusion, in 1,876 STEMI patients treated with pPCI, low aPTTs in the first 24 hours after PCI were not associated with an increase in ischaemic events, whereas high aPTT values were associated with more frequent bleeding complications. These results indicate no clear benefit as well as a safety concern with heparin treatment after primary PCI.

Thrombocytopenia following percutaneous coronary intervention

BACKGROUND

Thrombocytopenia following percutaneous coronary intervention (PCI) is an underappreciated condition that is often clinically challenging. There are no guidelines on the management of patients with this condition.

OBJECTIVE

To review recent data in etiologies, risk factors, prevention, management, and prognostic implications of thrombocytopenia following PCI.

EVIDENCE ACQUISITION

Search of MEDLINE, EMBASE, the Cochrane Database, and Google Scholar using the term thrombocytopenia + PCI and other relevant keywords to identify systematic reviews, clinical trials, cohort studies, case series, and case reports. The review was limited to English-language articles published between January 1980 and June 2009. Articles on patients with baseline thrombocytopenia prior to PCI were excluded.

EVIDENCE SYNTHESIS

Thrombocytopenia is not infrequent following PCI. The typical patient with post-PCI thrombocytopenia is on multiple therapies that can potentially cause a decrease in the platelet count. Identification of the cause is critical because management of the condition varies significantly based on the etiology. The severity of the thrombocytopenia also determines the clinical management of the patient. Several observational studies have demonstrated the adverse prognostic impact of the complication on clinical outcomes and have identified risk factors.

CONCLUSIONS

Judicious use of therapies that can cause thrombocytopenia, efficient detection of the cause of the decrease in platelet count, and appropriate management of the condition can potentially improve the quality of care and outcomes following PCI. Further research into risk factors that predispose post-PCI patients to developing thrombocytopenia is warranted.

Rapid adoption of drug-eluting stents: clinical practices and outcomes from the early drug-eluting stent era

OBJECTIVES

We sought to evaluate the early drug-eluting stent (DES) era, characterized by widespread device use.

BACKGROUND

Contemporary clinical practice incorporating more selective DES use can only be assessed by understanding the early DES era.

METHODS

All patients receiving DES during the first 3 waves of the Evaluation of Drug Eluting Stents and Ischemic Events (EVENT) Registry (2004-2006) were evaluated. The primary end point was a composite of death, myocardial infarction (MI), and urgent revascularization at discharge and death, MI, or target lesion revascularization (TLR) at 1 year. The composite end point at each time point was compared across waves. Multivariable logistic regression was used for in-hospital outcomes and multivariable Cox regression was used for 1-year end points.

RESULTS

Ninety-two percent of EVENT patients received at least one DES. One third of patients were treated for Acute Coronary Syndromes (ACS) (33.8%), and later waves included lower lesion complexity. Across waves there was more frequent clopidogrel loading, a decrease in heparin and an increase in bivalirudin use (all P < .01). The primary composite end point of in-hospital death, MI or urgent revascularization occurred in 7.2% of patients, and did not differ across waves. Despite remarkably high levels of routine DES usage, the composite end point of death, MI, or TLR at 1 year averaged 13.5% and did not differ across waves. After adjustment, no statistically significant effect of wave on composite bleeding (P = .068) as well as in-hospital TLR (P = .053) was noted. At 1 year, wave was associated with a lower likelihood of TLR in the adjusted model (HR 0.81, P = .03).

CONCLUSIONS

The high-adoption DES era was associated with favorable outcomes, decreasing bleeding rates and changes in antithrombotic approach.

Unfractionated Heparin Use After Percutaneous Coronary Intervention: Results of a Trial with a Vascular Ultrasound Endpoint

BACKGROUND

Previous studies in the pre-stent era have evaluated the postprocedural use of unfractionated heparin (UFH) on clinically defined vascular complications and ischaemic cardiac complications. We prospectively evaluated the benefits and risks of this practice, using vascular ultrasound determined endpoints in the current stent era.

METHODS

Patients undergoing percutaneous coronary intervention (PCI) and enrolled in two of our previous routine and prospective vascular ultrasound studies were included in the analysis. Generally the decision to use UFH after sheath removal was at the discretion of the operator, however a subset of patients was randomised to receive UFH or not. Femoral vascular ultrasound was performed prior to hospital discharge and interpreted by an experienced vascular ultrasonographer blinded to whether UFH was used or not. The primary endpoint was a composite of significant vascular ultrasound determined complications including major haematoma, pseudoaneurysm, arterio-venous fistula, femoral venous or arterial thrombosis and retroperitoneal haemorrhage. Secondary endpoints included in hospital ischaemic events, length of stay and outcome at 30 days.

RESULTS

A total of 530 patients (43% receiving UFH) were included in the analysis. The incidence of the primary endpoint for the entire population was 4.0% in both the UFH and no UFH groups (p=1.00). In the 226 (43%), randomised patient subset, the primary endpoint occurred in 5.2% in the UFH group and 4.5% in the no UFH group (p=0.80). Time to ambulation and discharge was similar in both groups. At 30 days, the incidence of major adverse cardiac events (4.7% for entire cohort) was similar in all groups whether randomised or not.

CONCLUSIONS

When vascular ultrasound is used to determine major vascular complications the use of UFH after PCI in the stent era was not associated with increased major vascular complications. We also failed to provide evidence of a meaningful clinical benefit with the routine use of postprocedural heparin in this selected patient cohort.

Angiographic predictors of femoral access site complications: Implication for planned percutaneous coronary intervention

This study examined the relationship between the femoral arteriotomy location and the risk of femoral access site complications after diagnostic and interventional cardiac catheterization procedures. One of the most common complication of cardiac catheterization and percutaneous coronary intervention (PCI) involves the vascular access site. The femoral approach is the most frequent site of vascular access during invasive cardiac procedures. This approach is associated with vascular complications, such as retroperitoneal bleeding, which can be life-threatening. If angiographic predictors of retroperitoneal bleeding can be identified, this complication could be avoided. A prospective cohort of 33 patients with femoral access site complications was subgrouped based on the angiographic arteriotomy site. Concurrent patients without complications were randomly selected to form a control group. Study and control patients were compared on presenting risk factors and outcomes. Logistic regression analysis was used to identify independent predictors for femoral access site complications. Arteriotomy location above the most inferior border of the inferior epigastric artery in patients undergoing PCI was associated with 100% of all retroperitoneal bleeds (P < 0.001). Low, high middle, and high femoral arteriotomy sites were associated with 71% of all vascular access complications. The combination of these locations for the femoral arteriotomy was an independent predictor of adverse vascular access site complications beyond traditional risk factors (odds ratio = 28.7; CI = 6.73-122.40; P < 0.0001). Vascular complications occurred more frequently in patients who were of older age (72 vs. 66 years; P < 0.001). The location of the femoral arteriotomy site assessed by a femoral angiogram is predictive of life-threatening complications. Patients undergoing PCI with an arteriotomy above the most inferior border of the inferior epigastric artery are at an increased risk for retroperitoneal bleeding. This complication may be avoided by risk-stratifying patients prior to intervention with a femoral angiogram.

Characteristics of cerebrovascular accidents after percutaneous coronary interventions

OBJECTIVES

We sought to identify the incidence, predictors, and clinical implications of cerebrovascular accidents (CVAs) after percutaneous coronary interventions (PCIs).

BACKGROUND

Cerebrovascular accidents after PCI, although rare, can be devastating. Limited information exists regarding the characterization of this complication.

METHODS

The study population comprised 20,679 patients who underwent PCI between September 1993 and April 2002. A CVA was defined as a composite of transient ischemic attack (TIA) and stroke. The characteristics of those who had a periprocedural CVA were compared with those who did not.

RESULTS

A CVA occurred in 92 patients (0.30% of procedures). Of these, TIA occurred in 13 patients (0.04%) and stroke in 79 patients (0.25%). On multivariate analysis, patients with this complication more frequently had diabetes mellitus (adjusted odds ratio [OR] 1.8, 95% confidence interval [CI] 1.1 to 3.0; p = 0.013), hypertension (OR 1.9, 95% CI 1.1 to 3.3; p = 0.033), previous CVA (OR 2.3, 95% CI 1.3 to 4.0; p = 0.0059), and creatinine clearance < or =40 ml/min (OR 3.1, 95% CI 1.8 to 5.2; p < 0.0001). They underwent urgent or emergent procedures (OR 2.7, 95% CI 1.3 to 5.5; p = 0.0092) with more thrombolytic (OR 4.7, 95% CI 2.3 to 9.7; p < 0.0001) and intravenous heparin (OR 1.9, 95% CI 1.1 to 3.4; p = 0.030) use before PCI, and they more often required emergent intra-aortic balloon pump placement (OR 2.2, 95% CI 1.1 to 4.3; p = 0.028). On multivariate analysis, CVA was independently associated with in-hospital death (OR 7.8, 95% CI 4.2 to 14.7; p < 0.0001), acute renal failure (OR 2.8, 95% CI 1.4 to 5.7; p = 0.0042), and new dialysis (OR 3.73, 95% CI 1.01 to 13.8; p = 0.049) after PCI.

CONCLUSIONS

Cerebrovascular accidents after PCI, although rare, are associated with high rates of in-hospital death and acute renal failure, often requiring dialysis.

Safety and efficacy of combined use of low molecular weight heparin (enoxaparin, lovenox) and glycoprotein IIb/IIIa receptor antagonist (eptifibatide, integrelin) during nonemergent coronary and peripheral vascular intervention

Coronary and peripheral intervention requires intraprocedural anticoagulation to prevent intraluminal thrombosis. Traditionally, unfractionated heparin (UFH) is administered during the procedure to achieve activated clotting time (ACT) of 300 to 400 seconds. When the intravenous IIb/IIIa antagonists are also used, the recommended ACT is 250 to 300 seconds because higher anticoagulation (ACT, 300-400 seconds) is accompanied by an unacceptable bleeding complication rate without added benefits. Because low molecular weight heparin has a more predictable anticoagulant effect and a higher anti-factor Xa/anti-factor IIa ratio, allows better bioavailability, is resistant to inhibition by activated platelets, and does not require routine monitoring using ACT, its use for intraprocedural anticoagulation (instead of UFH) has been an area of increasing interest. The safety and efficacy of coadministration of low molecular weight heparin with IIb/IIIa antagonists have not been adequately evaluated. We report a study of prospective evaluation of the safety and efficacy of combined use of intravenous enoxaparin and intravenous eptifibatide during nonemergent coronary and peripheral vascular intervention in 93 consecutive procedures performed on 56 patients. The procedural success rate was 99% (92/93 procedures), the acute clinical success rate was 98% (54/55 patients), the major bleeding complication rate was 2% (1/56 patients), and the vascular complication rate was 0.0%. In conclusion, the use of intravenous enoxaparin in conjunction with intravenous eptifibatide during nonemergent coronary and peripheral vascular intervention is safe and effective and eliminates the need for routine measurement of ACT during the procedure.

Immediate protamine administration and sheath removal following percutaneous coronary intervention: a prospective study of 429 patients

We tested the approach of reversing anticoagulation following PCI and immediate sheath removal in 429 consecutive patients. On completion of the PCI, protamine was administered, and the vascular sheath was immediately removed. Stents were used in 364 patients (85%) and GP IIb/IIIa inhibitors were used in 52 patients (12%). Time to achieve hemostasis was 30 +/- 17 min. Minor groin bleeding occurred in six patients. One patient required repair of femoral pseudoaneurysm. Mean creatine kinase at 8 and 16 hr post-PCI were 129 +/- 35 and 145 +/- 32 units, respectively. Creatine kinase rose to > 3 times normal in 12 out of 350 patients (3.4%). Prior to 48 hr, eight patients (1.9%) required emergency PCI or coronary bypass surgery. Follow-up at 30 days observed no deaths and only three target vessel revascularizations (0.7%). In conclusion, immediate reversal of anticoagulation and sheath removal after PCI is safe and feasible.

Predictors of length of stay after coronary stenting

BACKGROUND

Postprocedure length of stay (LOS) remains an important determinant of medical costs after coronary stenting. Variables that predict LOS in this setting have not been well characterized.

METHODS

We evaluated 359 consecutive patients who underwent coronary stenting with antiplatelet therapy. Sequential multiple linear regression (MLR) models were constructed with use of 4 types of variables to predict log-transformed LOS: preprocedure, intraprocedure, and postprocedure factors and adverse outcomes.

RESULTS

Preprocedure factors alone explained more than one third of the variability in postprocedure LOS (adjusted R(2) = 0.37). The addition of procedural variables added little to the model (adjusted R(2) = 0.39). Entering nonoutcome postprocedure variables significantly enhanced the predictive capacity of the model, explaining more than half the variability in postprocedure LOS (adjusted R(2) = 0.54). In the final model, addition of outcome variables increased its predictive capacity only slightly (adjusted R(2) = 0.61). In this model, significant preprocedure factors included: myocardial infarction (MI) within 24 hours, MI within 1 to 30 days, women with peripheral vascular disease, intravenous heparin, and chronic atrial fibrillation. High-risk intervention was the only significant intraprocedure variable. Significant postprocedure factors included periprocedure ischemia; cerebrovascular accident or transient ischemic attack; treatment with intravenous heparin or nitroglycerin or intra-aortic balloon pump; and need for blood transfusion. Significant adverse outcomes included contrast nephropathy, gastrointestinal bleeding, arrhythmia, vascular complication, and repeat angiography.

CONCLUSION

This prediction model identifies a number of potentially reversible factors responsible for prolonging LOS and may enable the development of more accurate risk-adjusted methods with which to improve or compare care.

Antithrombotic Therapy during and after Intracoronary Stenting

Objective:

To evaluate the impact on patient outcomes of antithrombotic therapy during and after intracoronary stenting.

Data Sources:

A MEDLINE search (1966-July 2000) for English-language clinical trials and review articles using the search terms stent and coronary with one or more of the following search terms: abciximab, tirofiban, orofiban, xemilofiban, eptifibatide, aspirin, heparin, enoxaparin, tinzaparin, dalteparin, hirudin, danaparoid, dipyridamole, cilostazol, dextran, warfarin, anticoagulant, ticlopidine, and Clopidogrel. References from these articles were reviewed for additional articles. Pharmaceutical companies were contacted to identify unpublished studies. A total of 177 sources were initially identified.

Study Selection:

Studies were selected through an unblinded individual review for prospective, randomized clinical trials evaluating patient outcomes related to antithrombotic therapy during or after intracoronary stent placement. Additional human and animal studies were included for background and introductory information.

Data Extraction:

Patient characteristics in each study were compared with those of the overall stent population. The primary end point measurements were defined. The completeness of follow-up and power analysis was assessed.

Data Synthesis:

Intracoronary stenting is now a common modality for maintaining patency of occluded arteries. Antithrombotic therapy during coronary artery stent placement is changing as knowledge about the pathophysiology of thrombus formation expands and new medications become available. Development of new stent placement techniques, new stent designs, and methods of restenosis irradiation or prevention have coincided with evolving antithrombotic regimens.

Conclusions:

The current antithrombotic regimen used in coronary artery stenting is complex, but has a lower incidence of hemorrhagic complications and thrombosis compared with previous anticoagulant regimens. Antithrombotic therapy may need to be tailored to individual patient contraindications.

Early mobilization after protamine reversal of heparin following implantation of phosphorylcholine-coated stents in totally occluded coronary arteries

Immediate removal of the femoral artery sheath after coronary angioplasty may allow rapid mobilization and reduces the number of in-hospital days. We studied the early and 1-month clinical and angiographic follow-up of patients having heparin reversed with protamine after implantation of phosphorylcholine-coated metal (Divysio) stents, followed by removal of the femoral artery sheath. Fifty patients (37 men, mean age 59 +/- 10 years) with stable angina pectoris and a single totally occluded artery (1 unprotected left main stem, 15 left anterior descending, 11 left circumflex, 23 right) underwent coronary angioplasty. Antithrombotic medication was salicylic acid 75 to 160 mg before, heparin bolus 7,500 IU during, and protamine sulfate 25 mg and oral ticlopidine 250 mg after the procedure. Angiography was performed after 30 minutes and at 1 month. The mean number of stents was 1.4 +/- 0.6/lesion, with a mean final diameter of 2.69 +/- 0.40 mm. One stent thrombus was detected after 30 minutes and was treated with balloon dilatation. One patient underwent emergency bypass surgery for non-stent-related problems. Forty-six patients were mobile after 5 hours, and 2 after >5 hours. At 1 month there had been no major coronary end points, rehospitalizations, groin bleeding, or more thrombi. One episode of transient pulmonary edema occurred after protamine injection. Thirty-eight patients (79%) had no angina at 1 month, maximal bicycle exercise capacity increased from 128 +/- 42 to 160 +/- 45 W (p <0.05), and left ventricular ejection fraction increased from 63% to 68% (p <0.05). Thus, reversal of heparin with protamine sulfate after implantation of a phosphorylcholine-coated stent enables early mobilization. This approach seems safe in patients with 1 -vessel total occlusions and angioplasty could be performed as an outpatient procedure.