Drug Insight: bleeding after percutaneous coronary intervention-risks, measures and impact of anticoagulant treatment options

Patients undergoing PCI from the femoral route by default radial operators are at high risk of vascular access-site complications

AIMS

Radial artery (RA) access for PCI has a lower incidence of vascular access-site (VAS) complications than the femoral artery (FA) approach. However, even for default radial operators certain patients are intervened upon from the FA. We examined the demographics and incidence of VAS complications when default radial operators resort to the FA for PCI.

METHODS AND RESULTS

The demographics and VAS complications were compared by access site retrospectively for all PCI cases performed by default radial operators (n=1,392). A modified ACUITY trial definition of major VAS complication was used. FA puncture occurred in 25.2% (351/1,392) of cases. Patients were more likely to be female, older and weigh less than patients undergoing PCI from the RA. The FA procedure was likely to be more complex with larger sheaths, more left main stem, graft and multivessel intervention, and there was a greater proportion of emergency cases. Despite increased case complexity, glycoprotein inhibitors were used less frequently in femoral cases (26.5% vs. 36.8%, p<0.001). A VAS complication occurred in 12.5% (44/351) of cases.

CONCLUSIONS

The risk factors for access-site bleeding are disproportionately high in the population requiring FA puncture by default radial operators, and as a result such patients have a high rate of vascular access-site complications.

Anemia, bleeding, and blood transfusion in the intensive care unit: causes, risks, costs, and new strategies

The definition of anemia is controversial and varies with the sex, age, and ethnicity of the patient. Anemia afflicts half of hospitalized patients and most elderly hospitalized patients. Acute anemia in the operating room or intensive care unit is associated with increased morbidity as well as other adverse outcomes, including death. The risks of anemia are compounded by the added risks associated with transfusion of red blood cells, the most common treatment for severe anemia. The causes of anemia in hospitalized patients include iron deficiency, suppression of erythropoietin and iron transport, trauma, phlebotomy, coagulopathies, adverse effects of and reactions to medications, and stress-induced gastrointestinal bleeding. The types and causes of anemia and the increased health care utilization and costs associated with anemia and undetected internal bleeding are described. The potential benefits and risks associated with transfusion of red blood cells also are explored. Last, the strategies and new tools to help prevent anemia, allow earlier detection of internal bleeding, and avoid unnecessary blood transfusions are discussed.

Prognostic impact of major bleeding in patients with acute coronary syndromes.A systematic review and meta-analysis

AIMS

The causative relationship between major bleeding in acute coronary syndromes (ACS) and the increase in mortality and morbidity has frequently been suggested in recent pharmaco-invasive trials and registries. However, the magnitude of this increased risk is the subject of debate. In order to determine the prognostic significance of major bleeding in ACS, we have conducted a systematic review and meta-analysis.

METHODS AND RESULTS

Databases were searched for articles published up to March 2007. Any study, either retrospective or prospective, assessing the impact of major bleeding in patients with ACS was included if all-cause mortality was reported as an outcome measure.Data from 10 studies involving a total of 133,597 patients with ACS at baseline, of whom 3,644 had major bleeding (2.7%) were included in a meta-analysis using a random-effects model. An overall pooled relative risk (RR) mortality increase of 7.6 (95% CI; 5.5-10.4) was found in patients with major bleeding. Although most of the 95% confidence intervals (CIs) for the primary studies overlapped, some heterogeneity was observed (Chi2 for heterogeneity, P <0.0001), hence the need for the random-effects meta-analysis. However, the overall effect was highly significant (Z=12.65; P <0.00001). Major bleeding in ACS was also associated with a statistically significant increase in the secondary endpoints assessed including acute myocardial infarction (AMI), and stroke.

CONCLUSIONS

This meta-analysis indicates that major bleeding in patients with ACS is a strong predictor of in-hospital or 30-day death and AMI. The pooled estimates presented should alert clinicians and interventionalists to the importance of prevention of major bleeding in patients hospitalised with ACS.

Hematomas of at least 5 cm and outcomes in patients undergoing elective percutaneous coronary intervention: insights from the SafeTy and Efficacy of Enoxaparin in PCI patients, an internationaL randomized Evaluation (STEEPLE) trial

BACKGROUND

Major bleeding significantly impacts outcomes in patients undergoing percutaneous coronary intervention (PCI). No uniform definitions exist for major and minor bleeding. Hematomas > or =5 cm at the femoral puncture site are considered major bleeding events in some trials and minor in others. Limited information is available on the incidence and clinical relevance of hematomas > or =5 cm in PCI patients.

METHODS

Data from the STEEPLE trial in patients undergoing elective PCI were used to assess the impact of hematomas > or =5 cm on ischemic outcomes (mortality, nonfatal myocardial infarction, or urgent target vessel revascularization) up to day 30 and all-cause 1-year mortality. Hematoma data were available for 3,342 of 3,528 patients in STEEPLE. Patients with (n = 103) and without (n = 3,239) hematomas > or =5 cm were evenly distributed across treatment groups.

RESULTS

No differences were observed in 30-day ischemic outcomes between patients with and without hematomas (5.8% vs 5.9%, respectively; P = .96). No transfusions were observed in patients with hematomas as compared with patients without hematomas (0% and 0.4%, respectively; P = .52). A greater reduction in hemoglobin was observed (pre- vs post-PCI) in patients with hematomas as compared with patients without hematomas (-0.84 vs -0.35 g/L, P < or = .001). No significant difference in all-cause 1-year mortality was observed between patients with and without hematomas (0.0% vs 1.7%, P = .98).

CONCLUSIONS

After PCI, hematomas > or =5 cm had no effect on 30-day ischemic events or 1-year mortality. Although there is no agreed classification for large hematomas, the lack of a relationship between hematomas > or =5 cm and clinical outcome after PCI justifies the classification of these hematomas as minor bleeds in STEEPLE.

Transradial intervention for minimizing bleeding complications in percutaneous coronary intervention

Femoral arterial access site complications are responsible for a substantial proportion of the bleeding complications that occur in patients undergoing percutaneous coronary intervention (PCI). Because bleeding is associated with an increase in morbidity and mortality, pharmacologic and nonpharmacologic strategies associated with lower bleeding risk may improve outcomes. From this perspective, radial artery access, which is associated with a similar rate of success as femoral artery access with lower rates of bleeding, might become the "gold standard" for PCI. Although transradial technique requires a specific skill set and significant learning curve, success rates comparable to those of the femoral approach may be achieved. The benefits of radial access may be further enhanced by using antithrombotic strategies that maintain efficacy but limit bleeding risk. Indeed, a substantial proportion of bleeding complications unrelated to the access site occur, a finding that supports the use of safer antithrombotic regimens to optimize patient outcomes.

Comparison of access-related bleeding complications in women versus men undergoing percutaneous coronary catheterization using the radial versus femoral artery

Women constitute a high-risk population for bleeding, which is a major prognostic predictor after percutaneous coronary catheterization procedures. We prospectively followed 3,261 consecutive percutaneous coronary procedures performed by radial artery catheterization (RAC) or femoral artery catheterization (FAC). The primary study objective was to determine the relative incidences of in-hospital major and minor puncture-related hemorrhages. Secondary objectives were to (1) identify predictors of major bleeds and (2) estimate how often a second, alternative access site is required for catheterization. In women, no major bleeding occurred after 299 RAC procedures performed, whereas 25 major bleeding episodes occurred after 601 FAC procedures (p = 0.0008). Women who underwent RAC also had a significantly lower incidence of minor hemorrhages than women who underwent FAC (19 of 299, 6.4%, vs 237 of 601, 39.4%, respectively, p = 0.00001). On multivariate analysis, independent predictors of major bleeding were FAC (odds ratio [OR] 27.4, 95% confidence interval [CI] 3.8 to 199.9), use of glycoprotein IIb/IIIa inhibitors (OR 5.6, 95% CI 2.7 to 11.9), female gender (OR 4.5, 95% CI 2.2 to 9.0), age >70 years (OR 2.4, 95% CI 1.2 to 4.8), and an acute coronary syndrome setting (OR 2.4, 95% CI 1.1 to 5.0). Women who underwent RAC were more likely to require a second access site than men (14% vs 1.7%), but operators less selective in RAC use successfully completed the procedure by radial approach in >90% of patients. In conclusion, extensive RAC was more effective at preventing access-related bleeding complications in women than FAC.

Bivalirudin in patients with acute coronary syndromes undergoing percutaneous coronary intervention: a subgroup analysis from the Acute Catheterization and Urgent Intervention Triage strategy (ACUITY) trial

BACKGROUND

The aim of this study was to assess anticoagulation with the direct thrombin inhibitor bivalirudin during percutaneous coronary intervention in individuals with moderate and high-risk acute coronary syndromes.

METHODS

13,819 individuals in the Acute Catheterization and Urgent Intervention Triage strategy (ACUITY) trial were prospectively randomly assigned to receive heparin (unfractionated or enoxaparin) plus glycoprotein IIb/IIIa inhibitors, bivalirudin plus glycoprotein IIb/IIIa inhibitors, or bivalirudin alone. Of these individuals, 7789 underwent percutaneous coronary intervention after angiography. The effect of the three regimens on the primary 30-day endpoints of composite ischaemia (death, myocardial infarction, or unplanned revascularisation for ischaemia), major bleeding, and net clinical outcomes (composite ischaemia or major bleeding) was assessed in this subgroup. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, with the number NCT00093158.

FINDINGS

Of the individuals who underwent percutaneous coronary intervention, 2561 received heparin plus glycoprotein IIb/IIIa inhibitors, 2609 received bivalirudin plus glycoprotein IIb/IIIa inhibitors, and 2619 received bivalirudin alone. 26 (0.3%) individuals dropped out or were lost to follow-up. There was no significant difference in the proportion of individuals with composite ischaemia, major bleeding, or net clinical outcomes at 30 days between those who received bivalirudin plus glycoprotein IIb/IIIa inhibitors and those who received heparin plus glycoprotein IIb/IIIa inhibitors (composite ischaemia: 243 [9%] patients vs 210 [8%] patients, p=0.16; major bleeding: 196 [8%] patients vs 174 [7%] patients, p=0.32; net clinical outcomes: 389 [15%] patients vs 341 [13%] patients, p=0.1). Rates of composite ischaemia were much the same in those who received bivalirudin alone and those who received heparin plus glycoprotein IIb/IIIa inhibitors (230 [9%] patients vs 210 [8%] patients, p=0.45); however, there were significantly fewer individuals who experienced major bleeding among those who received bivalirudin alone than among those who received heparin plus glycoprotein IIb/IIIa inhibitors (92 [4%] patients vs 174 [7%] patients, p<0.0001, relative risk 0.52, 95% CI 0.40-0.66), resulting in a trend towards better 30-day net clinical outcomes (303 [12%] patients vs 341 [13%] patients, p=0.057; 0.87, 0.75-1.00).

INTERPRETATION

Substitution of unfractionated heparin or enoxaparin with bivalirudin results in comparable clinical outcomes in patients with moderate and high-risk acute coronary syndromes treated with glycoprotein IIb/IIIa inhibitors in whom percutaneous coronary intervention is done. Anticoagulation with bivalirudin alone suppresses adverse ischaemic events to a similar extent as does heparin plus glycoprotein IIb/IIIa inhibitors, while significantly lowering the risk of major haemorrhagic complications.

Drug Insight: antithrombotic therapy after percutaneous coronary intervention in patients with an indication for anticoagulation

Antiplatelet therapy with aspirin and clopidogrel is standard care following revascularization by percutaneous coronary intervention with stent insertion. This so-called dual therapy is recommended for up to 4 weeks after intervention for bare-metal stents and for 6-12 months after intervention for drug-eluting stents. Although it is estimated that 5% of patients undergoing percutaneous coronary intervention require long-term anticoagulation because of an underlying chronic medical condition, continuing treatment with triple therapy (warfarin, aspirin and clopidogrel) increases the risk of bleeding. In most patients triple antithrombotic therapy seems justified for a short period of time. In some patients, however, a more considered judgment based on absolute need for triple therapy, risk of bleeding and risk of stent thrombosis is required, but the optimum antithrombotic treatment for these patients who require long-term anticoagulation has not been defined. This Review summarizes the existing literature concerning antithrombotic therapy and makes recommendations for initiation and duration of triple therapy in the small proportion of patients already receiving anticoagulant therapy who require percutaneous coronary intervention.

Selective cleavage of heparin using aqueous 2-hydroxypyridine: Production of an aldose-terminating fragment with high anticoagulant activity

Unfractionated heparin (UFH) was partially depolymerized by heating at 115 degrees C with aqueous 2-hydroxypyridine. Compared to starting UFH, no significant loss of anticoagulant (anti-Xa) activity was observed. Products consisted of polysaccharide fragments and small quantities of ammonia, sulfate, and hexuronic acid. Fragments with aldose termini that reacted with [3H]NaBH4 (fragment A) were of relatively uniform size (6000 D) and increased as depolymerization time increased. Fragment A contained the anticoagulant activity, with 90-94% and 24-31% binding to Sepharose-thrombin and Sepharose-antithrombin, respectively. In contrast, a non-reducing fragment B that did not react with [3H]NaBH4 was more heterogeneous (6000-10,000 D) and did not have anticoagulant activity or Sepharose-antithrombin affinity. Given the polysaccharide 3H-incorporation, small release of monosaccharide products, and fragment A end-group analysis, thermolysis of UFH is likely limited to one site per molecule when protected by 2-hydroxypyridine. Thus, an anticoagulant fragment A is hydrolytically released from UFH leaving a variable-length fragment B complete with linkage region.