ACCF/ACG/AHA 2008 expert consensus document on reducing the gastrointestinal risks of antiplatelet therapy and NSAID use: a report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents

Influences of different proton pump inhibitors on the anti-platelet function of clopidogrel in relation to CYP2C19 genotypes

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Active metabolism of clopidogrel is mainly mediated by CYP2C19. There are genetic differences in the activity of CYP2C19. Therefore, active metabolism of clopidogrel is affected by CYP2C19 genotypes. The main metabolizing enzyme of proton pump inhibitors (PPIs) is CYP2C19. Therefore, the anti-platelet function of clopidogrel is attenuated by concomitant use of PPIs. There are differences in the metabolic disposition among different PPIs. Affinity to CYP2C19 differs among different PPIs.

WHAT THIS STUDY ADDS

Whether a PPI attenuates the efficacy of clopidogrel depends on CYP2C19. Individuals who are decreased metabolizers, i.e. carriers the allele of CYP2C19*2 and/or *3, are more likely to convert from 'responder' to 'non-responder' to clopidogrel when placed on a concomitant PPI. We found that rabeprazole, whose affinity to CYP2C19 has been considered lower, attenuated the efficacy of clopidogrel. * We tested whether the separate dosing of a PPI and clopidogrel decreased the risk of attenuation of clopidogrel efficacy. We unfortunately found that separate dosing did not avoid the problematic interaction between clopidogrel and a PPI in subject's with CYP2C19*2 and/or CYP2C19*3.

AIMS

The efficacy of clopidogrel is influenced by CYP2C19 genotypes and substrates of CYP2C19, such as proton pump inhibitors (PPIs). We assessed the influence of three different PPIs on the anti-platelet function of clopidogrel in relation to CYP2C19 genotype status.

METHODS

Thirty-nine healthy volunteers with different CYP2C19 genotypes took clopidogrel 75 mg with or without omeprazole 20 mg, lansoprazole 30 mg or rabeprazole 20 mg in the morning for 7 days. The influence of the three PPIs on the anti-platelet function of clopidogrel was determined. A less than 30% inhibition of platelet aggregation (IPA) during clopidogrel dosing was defined as a 'low responder'. We also examined whether evening dosing of omeprazole could prevent the interaction with clopidogrel dosed in the morning.

RESULTS

In rapid metabolizers (RMs, *1/*1, n=15) of CYP2C19, omeprazole and rabeprazole significantly attenuated the anti-platelet function of clopidogrel. In decreased metabolizers (DMs, carriers of *2 and/or *3, n=24), there was a large variation in IPA and there was a trend but no significant decrease in IPA when placed on a concomitant PPI. Some DMs became 'low-responders' when placed on a concomitant PPI. Evening omeprazole dose in RMs did not seem to cause a significant decrease in IPA in contrast to morning dosing, but did so in DMs.

CONCLUSIONS

The three PPIs affected the efficacy of clopidogrel to different degrees. Both omeprazole and rabeprazole significantly decreased IPA in RMs but not DMs, although there was a trend towards lower IPA in DMs. Morning and evening dosing of omeprazole were both associated with lower IPA in DMs.

Clinical events as a function of proton pump inhibitor use, clopidogrel use, and cytochrome P450 2C19 genotype in a large nationwide cohort of acute myocardial infarction: results from the French Registry of Acute ST-Elevation and Non-ST-Elevation Myocardial Infarction (FAST-MI) registry

BACKGROUND

Clopidogrel requires metabolic activation by cytochrome P450 2C19 (CYP2C19). Proton pump inhibitors (PPIs) that inhibit CYP2C19 are commonly coadministered with clopidogrel to reduce the risk of gastrointestinal bleeding. This analysis compares treatment outcomes for patients in the French Registry of Acute ST-Elevation and Non-ST-Elevation Myocardial Infarction (FAST-MI) who did or did not receive clopidogrel and/or PPIs.

METHODS AND RESULTS

The FAST-MI registry included 3670 patients (2744 clopidogrel- and PPI-naïve patients) presenting with definite MI. Patients were categorized according to use of clopidogrel and/or PPI within 48 hours after hospital admission. PPI use was not associated with an increased risk for any of the main in-hospital events (in-hospital survival, reinfarction, stroke, bleeding, and transfusion). Likewise, PPI treatment was not an independent predictor of 1-year survival (hazard ratio, 0.97; 95% confidence interval [CI], 0.87 to 1.08; P=0.57) or 1-year MI, stroke, or death (hazard ratio, 0.98; 95% CI, 0.90 to 1.08; P=0.72). No differences were seen when the type of PPI or CYP2C19 genotype was taken into account. In the propensity-matched cohorts, the odds ratios for major in-hospital events in PPI versus no PPI were 0.29 (95% CI, 0.06 to 1.44) and 1.70 (95% CI, 0.10 to 30.3) for patients with 1 and 2 variant alleles, respectively. Similarly, the hazard ratio for 1-year events in hospital survivors was 0.68 (95% CI, 0.26 to 1.79) and 0.55 (95% CI, 0.06 to 5.30), respectively.

CONCLUSION

PPI use was not associated with an increased risk of cardiovascular events or mortality in patients administered clopidogrel for recent MI, whatever the CYP2C19 genotype, although harm could not be formally excluded in patients with 2 loss-of-function alleles.

How Should Patients Requiring Dual Antiplatelet Therapy be Managed When Undergoing Elective Endoscopic Gastrointestinal Procedures?

OPINION STATEMENT

The following are general guidelines for the management of patients on dual antiplatelet therapy as they undergo gastrointestinal procedures with potential for bleeding complications: Avoid cessation of all antiplatelet therapies after percutaneous coronary intervention (PCI) with stent placement when possible. Avoid cessation of clopidogrel (even when aspirin is continued) within the first 30 days after PCI and either drug-eluting stent (DES) or bare metal stent placement. Defer elective endoscopic procedures, possibly up to 12 months, if clinically acceptable from the time of PCI and DES placement. Perform endoscopic procedures, particularly those associated with bleeding risk, 5 to 7 days after thienopyridine drug cessation. Aspirin should be continued when possible. Resume thienopyridine and aspirin drug therapy after the procedure once hemostasis is achieved. A loading dose of the former should be considered among patients at risk for thrombosis. Continue platelet-directed therapy in patients undergoing elective endoscopy procedures associated with a low risk for bleeding.

Drug-drug interactions that reduce the formation of pharmacologically active metabolites: a poorly understood problem in clinical practice

Drug-drug interactions can lead to reduced efficacy of medical treatment. Therapeutic failure may for instance result from combined treatment with an inhibitor of the specific pathway that is responsible for the generation of pharmacologically active drug metabolites. This problem may be overlooked in clinical practice. Several examples of drugs will be discussed -clopidogrel, losartan, tamoxifen and codeine - to illustrate differences in the potential impact on drug treatment in clinical practice. We conclude that the combined use of cytochrome P450-blocking serotonin reuptake inhibitors and tamoxifen or codeine should be avoided, whereas the situation is much more complex regarding the use of proton pump inhibitors together with clopidogrel, and the evidence regarding cytochrome P450 inhibitor-dependent activation of losartan is inconclusive.

Effect of proton pump inhibitors on clinical outcome in patients treated with clopidogrel: a systematic review and meta-analysis

To investigate whether proton pump inhibitors (PPIs) negatively affect clinical outcome in patients treated with clopidogrel. Systematic review and meta-analysis. Outcomes evaluated were combined major adverse cardiac events (MACE), myocardial infarction (MI), stent thrombosis, death and gastrointestinal bleeding. Studies included were randomized trials or post-hoc analyzes of randomized trials and observational studies reporting adjusted effect estimates. Twenty five studies met the selection criteria and included 159 138 patients. Administration of PPIs together with clopidogrel corresponded to a 29% increased risk of combined major cardiovascular events [risk ratio (RR) = 1.29, 95% confidence intervals (CI) = 1.15-1.45] and a 31% increased risk of MI (RR = 1.31, 95%CI = 1.12-1.53). In contrast, PPI use did not negatively influence the mortality (RR = 1.04, 95%CI = 0.93-1.16), whereas the risk of developing a gastrointestinal bleed under PPI treatment decreased by 50% (RR = 0.50, 95% CI = 0.37-0.69). The presence of significant heterogeneity might indicate that the evidence is biased, confounded or inconsistent. The sensitivity analysis, however, yielded that the direction of the effect remained unchanged irrespective of the publication type, study quality, study size or risk of developing an event. Two studies indicate that PPIs have a negative effect irrespective of clopidogrel exposure. In conclusion, concomitant PPI use might be associated with an increased risk of cardiovascular events but does not influence the risk of death. Prospective randomized trials are required to investigate whether a cause-and-effect relationship truly exists and to explore whether different PPIs worsen clinical outcome in clopidogrel treated patients as the PPI-clopidogrel drug-drug interaction does not seem to be a class effect.

Interaction between clopidogrel and proton-pump inhibitors and management strategies in patients with cardiovascular diseases

Dual antiplatelet therapy (DAPT) with clopidogrel and aspirin has been successful in reducing ischemic events in a wide range of patients with cardiovascular diseases. However, the anti-ischemic effects of DAPT may also be associated with gastrointestinal (GI) complications including ulceration and bleeding particularly in ‘high risk’ and elderly patients. Current guidelines recommend the use of proton-pump inhibitors (PPIs) to reduce the risk of GI bleeding in patients treated with DAPT. However, pharmacodynamic studies suggest an effect of PPIs on clopidogrel metabolism with a resultant reduction in platelet inhibitory effects. Similarly, several observational studies have demonstrated reduced clopidogrel benefit in patients who coadministered PPIs. Although recent US Food and Drug Administration and European Medicines Agency statements discourage PPI (particularly omeprazole) and clopidogrel coadministration, the 2009 AHA/ACC/SCAI PCI guidelines do not support a change in current practice in the absence of adequately powered prospective randomized clinical trial data. The data regarding pharmacologic and clinical interactions between PPI and clopidogrel therapies are herein examined and treatment strategies are provided.

Pantoprazole does not influence the antiplatelet effect of clopidogrel-a whole blood aggregometry study after coronary stenting

Recent attention has been drawn to a potential drug-drug interaction observed between clopidogrel and proton pump inhibitors (PPIs). However, this potential interaction may not be a class effect of PPIs. We investigated if pantoprazole, which has a different metabolism than omeprazole, diminishes the effectiveness of clopidogrel. Our study included 336 patients (mean age 64.6 years; 106 women) 48 hours after percutaneous coronary stent implantation with a loading dose of 600 mg clopidogrel hydrogensulfate and 500 mg aspirin, followed by 75 mg clopidogrel and 100 mg aspirin daily. Whereas 188 patients (59 women) were not given any PPI comedication, 122 patients received pantoprazole and 26 either omeprazole or esomeprazole. The platelet aggregation followed by impedance aggregometry (in Ohm) was induced by 5 mmol/L adenosine diphosphate. The percentage of clopidogrel low-response (CLR) was similar between the non-PPI group [2.75 Ohm (confidence interval, CI: 2.25-3.26); 21.9% CLR] and the pantoprazole group [2.33 Ohm (CI: 1.79-2.87); 16.4% CLR] but higher in patients treated with omeprazole/esomeprazole (3.00 Ohm (CI: 1.49-4.51); 30.8% CLR). Multivariate regression analysis reveals that the risk of CLR in the pantoprazole comedication group was not increased compared with the group without any PPI [odds ratio 0.59 (CI: 0.31-1.13) 0.11]. Our data suggest that pantoprazole does not diminish the antiplatelet effectiveness of clopidogrel early after coronary stenting. Therefore, the use of pantoprazole seems preferable in patients treated with clopidogrel when a concomitant medication with a PPI is indicated.

Personalized approaches to clopidogrel therapy: are we there yet?

Clopidogrel is one of the most commonly prescribed medications worldwide. Recent advisories from the US Food and Drug Administration have drawn attention to the possibility of personalized decision-making for people who are candidates for clopidogrel. As is the case with antihypertensives, statins, and warfarin, common genetic sequence variants can influence clopidogrel metabolism and its effect on platelet activity. These genetic variants have, in multiple studies, been associated with adverse clinical outcomes. Concurrent medication use also influences how the body handles clopidogrel. Proton pump inhibitors, widely prescribed in conjunction with clopidogrel, may blunt its effectiveness. We address implications for bedside decision-making in light of accumulated data and current Food and Drug Administration advisories and conclude that genetic testing for CYP2C19 genotype and limitation of proton pump inhibitor interactions do not yet appear to offer an opportunity to optimize treatment given the current state of knowledge.

Review Article: Combination of Clopidogrel and Proton Pump Inhibitors: Implications for Clinicians

Objectives: To evaluate the existing literature on a proposed interaction between clopidogrel and proton pump inhibitors (PPIs) and discuss its implications for clinicians treating patients with this combination therapy. Background: Each year millions of patients receive antiplatelet therapy. A number of these patients are prescribed PPIs concomitantly to reduce the risk of gastrointestinal side effects associated with antiplatelet therapy. Several studies have been published recently addressing a potential adverse drug-drug interaction between clopidogrel and PPIs. Methods: Literature was evaluated through Pubmed using the terms clopidogrel, PPI, prasugrel, cytochrome P450, genetic polymorphisms, H 2 blockers, famotidine, genetic cytochrome P450 polymorphisms, and drug interaction. Articles with these terms were considered for evaluation. In addition, reference citations from publications identified in the searches were further reviewed and analyzed. Results: None of the currently published studies were specifically designed to evaluate this drug-drug interaction or address the clinical relevance of this interaction prospectively. Conflicting evidence raised concerns but the information did not conclude with certainty a cause-and-effect relationship between concomitant use of the drugs and emerging safety issues. However, the Food and Drug Administration issued a public-health warning on the possible interaction between clopidogrel and PPIs, predominantly with omeprazole, in November 2009. Conclusions: Controversies exist on a potential drug-drug interaction between clopidogrel and PPIs. Although further studies are warranted, several studies indicated that there was a drug-drug interaction through this combination therapy with detrimental clinical outcomes and increased costs. Studies suggested that the use of a PPI may make clopidogrel less effective resulting in a higher risk of myocardial infarction, stroke, or death. Until additional information becomes available clinicians should consider discontinuing PPI use if no clear indication is documented. Alternative options like H2-receptor antagonists should be considered. Upon availability, genetic testing may provide additional valuable information.

Histamine2-receptor antagonists are an alternative to proton pump inhibitor in patients receiving clopidogrel

BACKGROUND & AIMS

Previous observational studies reported that concomitant use of clopidogrel and proton pump inhibitors (PPIs) in patients with prior acute coronary syndrome (ACS) was associated with adverse cardiovascular outcomes. We investigated whether H(2)-receptor antagonist (H(2)RA) is an alternative to PPI in patients with ACS.

METHODS

We conducted a population-based retrospective cohort study of 6552 patients in Taiwan discharged for ACS between 2002 and 2005. Patients were divided into 5 cohorts: clopidogrel plus H(2)RA (n = 252), clopidogrel plus PPI (n = 311), clopidogrel alone (n = 5551), H(2)RA alone (n = 235), and PPI alone (n = 203). The primary outcome was rehospitalization for ACS or all-cause mortality within 3 month of rehospitalization.

RESULTS

The 1-year cumulative incidence of the primary outcome was 26.8% (95% CI: 21.5%-33.0%) in the clopidogrel plus H(2)RA cohort and 33.2% (95% CI: 27.8%-39.4%) in the clopidogrel plus PPI cohort, compared with 11.6% (95% CI: 10.8%-12.5%) in the clopidogrel alone cohort (P < .0001). No significant difference was observed between the PPI alone cohort (11.0%; 95% CI: 7.1%-16.8%), the H(2)RA alone cohort (11.8%; 95% CI: 8.2%-16.8%), and the clopidogrel alone cohort in terms of the primary outcome. The number needed to harm was 7 with concomitant H(2)RA and 5 with concomitant PPI. On multivariate analysis, concomitant H(2)RA and PPI were independent risk factors predicting adverse outcomes (adjusted hazard ratios, 2.48 and 3.20, respectively; P < .0001).

CONCLUSIONS

Concomitant use of clopidogrel and H(2)RA or PPI after hospital discharge for ACS is associated with increased risk of adverse outcomes.

An evaluation of the CHADS₂ stroke risk score in patients with atrial fibrillation who undergo percutaneous coronary revascularization

BACKGROUND

There are various schemas designed to stratify the risk of thromboembolism (TE) in patients with atrial fibrillation (AF), of which the CHADS(2) (congestive heart failure, hypertension, age ≥ 75 y, diabetes, stroke [doubled]) score is the most widely studied. We evaluated whether the CHADS(2) score was adequate for TE risk stratification while assessing cardiac risk in patients with AF revascularized with coronary artery stents.

METHODS

We reviewed 604 consecutive patients with AF treated with at least one stent between 2001 and 2008 in relation to TE risk using CHADS(2) score. We stratified our patients with a CHADS(2) score ≤ 1 as low-moderate thromboembolic risk (group 1: n = 193, 32%) and > 1 as high risk (and, hence, requiring anticoagulation; group 2: n = 411, 68%). We determined the benefits and/or risks of oral anticoagulation (OAC) therapy in both cohorts.

RESULTS

Completed follow-up was achieved in 90.4% (mean 642.2 days). Group 1 event-free survival was better than group 2 (major adverse cardiovascular events [MACEs], log-rank test P = .03; and death, log-rank test P = .03). In group 1, event-free survival was better on OAC vs non-OAC use (death 5% vs 15%, P = .04; MACE 10% vs 26%, P < .01) with a trend for more major hemorrhages (12% vs 4%, P = .08). Stroke rate was 4.1% per 100 patient-years in patients without OAC therapy and 1.38% in patients on OAC therapy. Group 2 had a lower incidence of death (20% vs 34%, P < .01) and MACE (26% vs 43%, P < .01) among those on OAC therapy on discharge, with a higher incidence of major hemorrhages (18% vs 8%, P < .01).

CONCLUSION

In a population of patients with AF revascularized with stents, even those with CHADS(2) ≤ 1 should be regarded as being at high risk. OAC should be considered as thromboprophylaxis in patients with AF revascularized with coronary stents.

The efficacy and safety of clopidogrel in vascular surgery patients with immediate postoperative asymptomatic troponin T release for the prevention of late cardiac events: Rationale and design of the Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echo-VII (DECREASE-VII) trial

BACKGROUND

Major vascular surgery patients are at high risk for developing asymptomatic perioperative myocardial ischemia reflected by a postoperative troponin release without the presence of chest pain or electrocardiographic abnormalities. Long-term prognosis is severely compromised and characterized by an increased risk of long-term mortality and cardiovascular events. Current guidelines on perioperative care recommend single antiplatelet therapy with aspirin as prophylaxis for cardiovascular events. However, as perioperative surgical stress results in a prolonged hypercoagulable state, the postoperative addition of clopidogrel to aspirin within 7 days after perioperative asymptomatic cardiac ischemia could provide improved effective prevention for cardiovascular events.

STUDY DESIGN

DECREASE-VII is a phase III, randomized, double-blind, placebo-controlled, multicenter clinical trial designed to evaluate the efficacy and safety of early postoperative dual antiplatelet therapy (aspirin and clopidogrel) for the prevention of cardiovascular events after major vascular surgery. Eligible patients undergoing a major vascular surgery (abdominal aorta or lower extremity vascular surgery) who developed perioperative asymptomatic troponin release are randomized 1:1 to clopidogrel or placebo (300-mg loading dose, followed by 75 mg daily) in addition to standard medical treatment with aspirin. The primary efficacy end point is the composite of cardiovascular death, stroke, or severe ischemia of the coronary or peripheral arterial circulation leading to an intervention. The evaluation of long-term safety includes bleeding defined by TIMI criteria. Recruitment began early 2010. The trial will continue until 750 patients are included and followed for at least 12 months.

SUMMARY

DECREASE-VII is evaluating whether early postoperative dual antiplatelet therapy for patients developing asymptomatic cardiac ischemia after vascular surgery reduces cardiovascular events with a favorable safety profile.

Clopidogrel and proton pump inhibitor (PPI) interaction: separate intake and a non-omeprazole PPI the solution?

Background

Dual therapy with aspirin and clopidogrel increases the risk of gastrointestinal bleeding. Therefore, co-therapy with a proton pump inhibitor (PPI) is recommended by most guidelines. However, there are warnings against combining PPIs with clopidogrel because of their interactions with cytochrome P450 isoenzyme 2C19 (CYP2C19).

Methods

The effects of the combined or separate intake of 20 mg of omeprazole and 75 mg of clopidogrel on the clopidogrel-induced inhibition of platelet aggregation were measured in four healthy subjects whose CYP2C19 exon sequences were determined. The effects of co-therapy with 10 mg of rabeprazole were also examined.

Results

Two subjects showed the wild-type CYP2C19 sequence. The concurrent intake of omeprazole had no effect on clopidogrel-induced platelet inhibition in these subjects. Two subjects were heterozygous for the *2 allele, with predicted reduced CYP2C19 activity. One of them was a clopidogrel non-responder. In the second heterozygous subject, omeprazole co-therapy reduced the clopidogrel anti-platelet effect when taken simultaneously or separately. However, the simultaneous intake of rabeprazole did not reduce the clopidogrel effect.

Conclusion

The clopidogrel-PPI interaction does not seem to be a PPI class effect. Rabeprazole did not affect the clopidogrel effect in a subject with a clear omeprazole-clopidogrel interaction. The separate intake of PPI and clopidogrel may not be sufficient to prevent their interaction.

Proton pump inhibitor and clopidogrel interaction: the case for watchful waiting

Clopidogrel is an integral part of the management of several important vascular diseases. However the medium to long term clinical outcomes are poorer for these patients if they experience gastro-intestinal bleeding, hence patients with risk factors for gastro-intestinal bleeding are frequently prescribed proton pump inhibitors. Conflicting evidence exists as to the existence of an adverse interaction between clopidogrel and proton pump. This review examines the original studies, which suggested the adverse interaction, the subsequent and most recent studies, the pharmaco-dynamics of the two drugs and suggests an algorithm for the use of clopidogrel with proton pump inhibitors.

Gastrointestinal bleeding associated with low-dose aspirin use: relevance and management in clinical practice

IMPORTANCE OF THE FIELD

Aspirin reduces the risk of cardiovascular events, but it is well documented that it can also damage the gastrointestinal (GI) tract. However, the reasons why some people develop serious lesions, whereas most only have minor, clinically irrelevant lesions are poorly understood.

AREAS COVERED IN THIS REVIEW

A number of risk factors can be used to determine which patients are more likely to develop aspirin-associated GI bleeding, mainly in the upper GI tract; these include a previous GI ulcer, ulcer complications, dyspepsia, and concomitant drug therapy with non-steroidal anti-inflammatory drugs (NSAIDs) or clopidogrel. The possible role of Helicobacter pylori infection is also considered.

WHAT THE READER WILL GAIN

Aspirin-induced GI damage can be reduced, and a number of strategies can be implemented to shift the risk-benefit ratio in favour of aspirin. Proton pump inhibitors are more effective than H(2)-receptor antagonists in preventing dyspeptic symptoms, peptic ulcers and bleeding ulcers in aspirin users. Although H. pylori infection may be a risk factor of aspirin-induced ulcer bleeding, the role of its eradication in the prevention of this outcome requires further investigation.

TAKE HOME MESSAGE

The individual assessment of the benefits and risks with aspirin, based on the underlying GI and cardiovascular risk factors, is the key to successful therapy. Understanding the effect of aspirin on colorectal cancer can also alter the risk-benefit ratio in at-risk aspirin users.

Nonsteroidal Anti-Inflammatory Drug-Induced Gastroduodenal Bleeding: Risk Factors and Prevention Strategies

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely prescribed medications in the World. A frequent complication of NSAID use is gastroduodenal bleeding. Risk factors for gastroduodenal bleeding while on NSAID therapy are age, prior peptic ulcer and co-medication with anti-platelet agents, anticoagulants, glucocorticosteroids and selective serotonin-reuptake inhibitors (SSRI). Prevention strategies for at-risk patients include the use of the lowest effective dose of NSAIDs, co-therapy with proton-pump inhibitors and/or the use of a COX-2 selective agent. Treatment of Helicobacter pylori infection is beneficial for primary prophylaxis of NSAID-induced gastroduodenal bleeding in NSAID-naive patients. For patients with cardiovascular risk factors requiring NSAIDs, naproxen should be selected. In very high risk patients for both gastrointestinal and cardiovascular complications NSAID therapy should be avoided altogether.

Blood Pressure Levels and Bleeding Events During Antithrombotic Therapy

Background and Purpose— A prospective, multicenter, observational cohort study was conducted to clarify the association between major bleeding events and blood pressure (BP) levels during follow-up before development of bleeding events in antithrombotic users.

Methods— A total of 4009 patients taking oral antithrombotic agents for cardiovascular or cerebrovascular diseases (2728 men, 69±10 years old) were followed. Changes in systolic and diastolic BPs between entry and the last clinic visit before intracranial hemorrhage (ICH) or extracranial hemorrhage were assessed.

Results— Over a median follow-up of 19 months, ICH developed in 31 patients and extracranial hemorrhage developed in 77. Entry BP levels were similar among patients with ICH, those with extracranial hemorrhage, and those without hemorrhagic events. Both systolic BP and diastolic BP were relatively high during follow-up as compared with the levels at entry in patients with ICH, whereas they showed plateaus in patients with extracranial hemorrhage and patients without hemorrhagic events. Average systolic BP levels between 1 and 6 months (hazard ratio, 1.45; 95% CI, 1.08 to 1.92 per 10-mm Hg increase) and between 7 and 12 months (hazard ratio, 1.47; 95% CI, 1.05 to 2.01) as well as average diastolic BP levels between 7 and 12 months (hazard ratio, 2.05; 95% CI, 1.15 to 3.62) were independently associated with development of ICH after adjustment for established ICH predictors. The optimal cutoff BP level to predict impending risk of ICH was ≥130/81 mm Hg using receiver operating characteristic curve analysis.

Conclusions— An increase in BP levels during antithrombotic medication was positively associated with development of ICH, suggesting the importance of adequate BP control for avoiding ICH. BP levels did not appear to be associated with extracranial hemorrhage.

Antiplatelet agents and proton pump inhibitors - personalizing treatment

Introduction:

Antiplatelet therapy remains one of the cornerstones in the management of non-cardioembolic ischemic stroke. However, a significant percentage of patients have concomitant gastroesophageal reflux or peptic ulcer disease that requires acid-reducing medications, the most powerful and effective being the proton pump inhibitors (PPIs). Antiplatelet efficacy, at least in vivo, and particularly for clopidogrel, has been shown to be reduced with concomitant proton pump inhibitor use. Whether this is clinically relevant is not clear from the limited studies available.

Methods:

We conducted an extensive review of studies available on Medline related to pharmacodynamic interactions between the antiplatelet medications and proton pump inhibitors as well as clinical studies that addressed this potential interaction.

Results:

Based on the present pharmacodynamic and clinical studies we did not find a significant interaction that would reduce the efficacy of antiplatelet agents with concomitant user of proton pump inhibitors.

Conclusions:

Patients on antiplatelet agents after a transient ischemic attack or ischemic stroke can safely use aspirin, and extended release dipyridamole/aspirin with proton pump inhibitors. Patients on clopidogrel may use other acid-reducing drugs besides proton pump inhibitors. In rare cases where proton pump inhibitors and clopidogrel have to be used concurrently, careful close monitoring for recurrent vascular events is required.

Antithrombotic management of atrial fibrillation patients presenting with acute coronary syndrome and/or undergoing coronary stenting: executive summary--a Consensus Document of the European Society of Cardiology Working Group on Thrombosis, endorsed by the European Heart Rhythm Association (EHRA) and the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

There remains uncertainty over optimal antithrombotic management strategy for patients with atrial fibrillation (AF) presenting with an acute coronary syndrome and/or undergoing percutaneous coronary intervention/stenting. Clinicians need to balance the risk of stroke and thromboembolism against the risk of recurrent cardiac ischaemia and/or stent thrombosis and the risk of bleeding. The full consensus document comprehensively reviews the published evidence and presents a consensus statement on a 'best practice' antithrombotic therapy guideline for the management of antithrombotic therapy in such AF patients. This executive summary highlights the main recommendations from the consensus document.

Incidence, Predictors, and Prognostic Implications of Hospitalization for Late Bleeding After Percutaneous Coronary Intervention for Patients Older Than 65 Years

Background— Previous data on bleeding after percutaneous coronary intervention (PCI) have been obtained primarily from randomized trials that focused on in-hospital bleeding. The incidence of late bleeding after PCI, its independent predictors, and its prognostic importance in clinical practice has not been fully addressed.

Methods and Results— We evaluated 22 798 patients aged >65 years who underwent PCI from December 1, 2003, to March 31, 2007, in Ontario, Canada. Cox proportional hazard models were used to determine factors associated with late bleeding, which was defined as hospitalization for bleeding after discharge from the index PCI, and to estimate risk of death or myocardial infarction associated with late bleeding. We found that 2.5% of patients were hospitalized for bleeding in the year after PCI, with 56% of bleeding episodes due to gastrointestinal bleed. The most significant predictor of late bleeding was warfarin use after PCI (hazard ratio [HR], 3.12). Other significant predictors included age (HR, 1.41 per 10 years), male sex (HR, 1.24), cancer (HR, 1.80), previous bleeding (HR, 2.42), chronic kidney disease (HR, 1.93), and nonsteroidal antiinflammatory drug use (HR, 1.73). After adjusting for baseline covariates, hospitalization for a bleeding episode was associated with a significantly increased 1-year hazard of death or myocardial infarction (HR, 2.39; 95% CI, 1.93 to 2.97) and death (HR, 3.38; 95% CI, 2.60 to 4.40).

Conclusions— Hospitalization for late bleeding after PCI is associated with substantially increased risk of death and myocardial infarction. The use of triple therapy (ie, aspirin, thienopyridine, and warfarin) is associated with the highest risk of late bleeding.

Gastrointestinal and liver side effects of drugs in elderly patients

It is expected that the percentage of people >60 years of age will be 22% worldwide by the year 2050. Multi-morbidity and poly-pharmacy are common in individuals during old age, while adverse drug reactions are at least twice as common in the elderly compared to younger adults. Publications related to drug side effects are rather rare in this age group since most clinical trials exclude patients >75-80 years of age. Gastrointestinal adverse drug reactions studied in the elderly include non-steroidal anti-inflammatory drugs (NSAIDs) and anticoagulant-induced gastrointestinal tract mucosal injuries. Malabsorption, diarrhoea and constipation are common side effects of laxatives, antibiotics, anticholinergics and calcium channel blockers. Drug (amoxycilin/clavulanic acid, isoniazide, nitrofurantoin, diclifenac and methotrexate)-induced hepatotoxicity in the elderly is four times more common than in younger adults and may simulate almost all known liver disorders. Further clinical studies are needed to investigate gastrointestinal and hepatic side effects of drugs in elderly patients.

Clopidogrel suppresses the proliferation of human gastric epithelial GES-1 cells

AIM: To investigate the effects of clopidogrel on the proliferation of human gastric epithelial GES-1 cells.

METHODS: GES-1 cells were cultured in vitro. After GES-1 cells were incubated with clopidogrel at concentrations of 0.01, 0.1, 0.5 and 1 mmol/L for 24, 48 and 72 h, the reduced proliferation rates of GES-1 cells were examined using methyl thiazolyl tetrazolium (MTT) assay. A dose-response curve was established by plotting the reduced cell proliferation rates against the concentrations of clopidogrel. The half maximal inhibitory concentration (IC₅₀₎ and safe concentration (IC₉₀, concentration that achieves 90% inhibition) of clopidogrel were calculated using the Bliss method. The morphology changes of GES-1 cells treated with clopidogrel were observed under an inverted phase contrast microscope. Flow cytometry was used to detect cell apoptosis after GES-1 cells were incubated with clopidogrel for 24 h.

RESULTS: Clopidogrel induced GES-1 cell injury in a concentration-dependent manner (F = 11.546, P = 0.002), but not in an obvious time-dependent manner (F = 13.455, P = 0.003). The IC50 and IC90 of clopidogrel at 24, 48 and 72 h were 0.36 and 0.51, 0.35 and 0.08, and 0.16 and 0.08 mmol/L, respectively. After clopidogrel treatment, the number of adherent cells was reduced, cells became round and suspended, and some cells showed nuclear condensation. Flow cytometry analysis indicated that the apoptosis rates of cells treated with clopidogrel at concentrations of 0, 0.01, 0.1, 0.5 and 1 mmol/L were 4.7%, 5.3%, 14.7%, 51.0% and 60.5%, respectively. The apoptosis rate of GES-1 cells rose with the increase in drug concentration.

CONCLUSION: Clopidogrel can inhibit the proliferation and induce the apoptosis of GES-1 cells in a concentration-dependent manner.

Advances in clinical research on the interaction between proton pump inhibitors and clopidogrel

As a new antiplatelet drug, clopidogrel is the cornerstone of drug treatment for coronary artery disease. However, clinical use of clopidogrel frequently leads to gastrointestinal injury or increases the risk of gastrointestinal bleeding. To prevent clopidogrel-associated gastrointestinal injury, concomitant proton pump inhibitors (PPIs) have been used widely in clinical practice. However, recent studies show that treatment with clopidogrel plus PPIs can increase the incidence of adverse cardiovascular events. Despite being controversial, this finding has attracted wide attention from clinicians. This article will review the recent advances in clinical research on the interaction between proton pump inhibitors and clopidogrel.

Management of platelet-directed pharmacotherapy in patients with atherosclerotic coronary artery disease undergoing elective endoscopic gastrointestinal procedures

The periprocedural management of patients with atherosclerotic coronary heart disease, including those who have heart disease and those who are undergoing percutaneous coronary intervention and stent placement who might require temporary interruption of platelet-directed pharmacotherapy for the purpose of an elective endoscopic gastrointestinal procedure, is a common clinical scenario in daily practice. Herein, we summarize the available information that can be employed for making management decisions and provide general guidance for risk assessment.

The Clinical Significance of the Interaction between Proton Pump Inhibitors and Clopidogrel

Objective:

To determine whether the interaction between omeprazole and clopidogrel is a proton pump inhibitor (PPI) class effect or a drug-specific effect.

Data Sources:

A MEDLINE search for primary literature was completed (through August 2009) using the search terms proton pump inhibitors and clopidogrel. Additional data obtained from references and abstracts presented at clinical meetings were included when appropriate.

Study Selection:

Nine primary literature articles were identified and reviewed. This included only one prospective, double-blind, placebo-controlled, randomized trial. The remainder were prospective and retrospective cohort studies and a population-based nested case-control study.

Data Extraction:

Omeprazole, a CYP2C19 inhibitor, has been shown to increase the platelet reactivity index (PRI) when combined with clopidogrel (52.4% vs 39.8%; p < 0.0001), leading to an increased risk of thrombosis. This combination was also shown to cause a 25% increase in the risk of mortality or rehospitalization for acute coronary syndrome (ACS), with a significantly higher risk for each 10% increase in time on this combination therapy (odds ratio [OR] 1.07; CI 1.05 to 1.09). Conversely, combination therapy with pantoprazole or esomeprazole and clopidogrel caused a nonsignificant increase in PRI (p = 0.382) and adenosine diphosphate-induced platelet aggregation (p = 0.69 and 0.88, respectively). Similarly, the combination of pantoprazole and clopidogrel was not associated with an increased risk of myocardial infarction (OR 1.02 [0.70–1.47]) when patients were followed for 90 days following hospital discharge for ACS. One study has shown a class effect when PPIs are combined with clopidogrel, leading to an increased risk of a major adverse cardiovascular event (hazard ratio 1.51; 1.39 to 1.64). Histamine2(H2)-receptor antagonists have not been associated with a significant interaction with clopidogrel in any study.

Conclusions:

The use of PPIs with clopidogrel may be warranted, based on comorbid disease states for many patients, but H2-receptor antagonists should be considered when appropriate, due to their lack of interaction with clopidogrel.

Interaction between clopidogrel and proton-pump inhibitors

The American Heart Association/American College of Cardiology guidelines recommend initiating a proton-pump inhibitor (PPI) to prevent gastrointestinal bleeding if patients are receiving concomitant therapy with clopidogrel and aspirin. Recently, concern has been raised regarding the ability of PPIs to decrease the antiplatelet activity of clopidogrel. To date, there are 16 studies that evaluated the outcomes of using clopidogrel with a PPI. One of the studies has shown that adding lansoprazole to clopidogrel has no effect on the concentration of clopidogrel's inactive metabolite. The eight clinical trials that studied the effect of using PPIs and clopidogrel together on platelet function testing have shown differing effects between PPIs. Concurrent omeprazole and clopidogrel use was shown to decrease the antiplatelet effects of clopidogrel in three studies; whereas pantoprazole, lansoprazole and esomeprazole have been shown to have no significant effect on the antiplatelet response to clopidogrel. Six other studies showed that using PPIs and clopidogrel together led to adverse clinical outcomes; however, one study that did a separate analysis on pantoprazole, showed that using pantoprazole with clopidogrel had no significant impact on clinical outcomes. Post hoc analysis from a large randomized trial comparing prasugrel with clopidogrel indicated no clinically significant effects of PPIs in patients treated with either prasugrel or clopidogrel. Preliminary results from a prospective, randomized trial comparing cardiovascular clinical outcomes between omeprazole and placebo in clopidogrel-treated patients have been reported and suggest no interaction. However, the study was stopped prematurely secondary to loss of funding and follow-up limited to a median of 133 days so no firm conclusions were drawn. The data currently available regarding concurrent clopidogrel and PPI use are limited, so further studies are needed to provide a definite conclusion. Until additional prospective studies are available, the use of clopidogrel with a PPI should be avoided, if possible, and a H(2)-receptor antagonist be selected instead. Prasugrel may be administered safely with a PPI as there is currently no evidence of a pharmacokinetic, pharmacodynamic or adverse clinical effects.

Management of platelet-directed pharmacotherapy in patients with atherosclerotic coronary artery disease undergoing elective endoscopic gastrointestinal procedures

The periprocedural management of patients with atherosclerotic coronary heart disease, including those who have heart disease and those who are undergoing percutaneous coronary intervention and stent placement who might require temporary interruption of platelet-directed pharmacotherapy for the purpose of an elective endoscopic gastrointestinal procedure, is a common clinical scenario in daily practice. Herein, we summarize the available information that can be employed for making management decisions and provide general guidance for risk assessment.

Drug-related damage of the ageing gastrointestinal tract

Drug use increases with age and the elderly is at increased risk of adverse drug reactions. Gastrointestinal adverse effects are one of the most often reported. Serious event are mostly caused by NSAIDs and/or aspirin which are the most widely prescribed medications in the world. NSAIDs and/or aspirin use are associated with complications from both the upper and the lower gastrointestinal tract. The risk of these complications depends on presence of risk factors, and age is the most frequent and relevant one. At-risk patients should be on prevention strategies including the use of the lowest effective dose, co-therapy with a gastroprotective agents or use of a COX-2 selective agent. Treatment of Helicobacter pylori infection is beneficial in patients starting therapy with these agents, especially in the presence of ulcer history. The best strategy to prevent lower GI complications has yet to be defined.

Peptic ulcer disease

Peptic ulcer disease had a tremendous effect on morbidity and mortality until the last decades of the 20th century, when epidemiological trends started to point to an impressive fall in its incidence. Two important developments are associated with the decrease in rates of peptic ulcer disease: the discovery of effective and potent acid suppressants, and of Helicobacter pylori. With the discovery of H pylori infection, the causes, pathogenesis, and treatment of peptic ulcer disease have been rewritten. We focus on this revolution of understanding and management of peptic ulcer disease over the past 25 years. Despite substantial advances, this disease remains an important clinical problem, largely because of the increasingly widespread use of non-steroidal anti-inflammatory drugs (NSAIDs) and low-dose aspirin. We discuss the role of these agents in the causes of ulcer disease and therapeutic and preventive strategies for drug-induced ulcers. The rare but increasingly problematic H pylori-negative NSAID-negative ulcer is also examined.

Second Asia-Pacific Consensus Guidelines for Helicobacter pylori infection

The Asia-Pacific Consensus Conference was convened to review and synthesize the most current information on Helicobacter pylori management so as to update the previously published regional guidelines. The group recognized that in addition to long-established indications, such as peptic ulcer disease, early mucosa-associated lymphoid tissue (MALT) type lymphoma and family history of gastric cancer, H. pylori eradication was also indicated for H. pylori infected patients with functional dyspepsia, in those receiving long-term maintenance proton pump inhibitor (PPI) for gastroesophageal reflux disease, and in cases of unexplained iron deficiency anemia or idiopathic thrombocytopenic purpura. In addition, a population 'test and treat' strategy for H. pylori infection in communities with high incidence of gastric cancer was considered to be an effective strategy for gastric cancer prevention. It was recommended that H. pylori infection should be tested for and eradicated prior to long-term aspirin or non-steroidal anti-inflammatory drug therapy in patients at high risk for ulcers and ulcer-related complications. In Asia, the currently recommended first-line therapy for H. pylori infection is PPI-based triple therapy with amoxicillin/metronidazole and clarithromycin for 7 days, while bismuth-based quadruple therapy is an effective alternative. There appears to be an increasing rate of resistance to clarithromycin and metronidazole in parts of Asia, leading to reduced efficacy of PPI-based triple therapy. There are insufficient data to recommend sequential therapy as an alternative first-line therapy in Asia. Salvage therapies that can be used include: (i) standard triple therapy that has not been previously used; (ii) bismuth-based quadruple therapy; (iii) levofloxacin-based triple therapy; and (iv) rifabutin-based triple therapy. Both CYP2C19 genetic polymorphisms and cigarette smoking can influence future H. pylori eradication rates.

Antithrombotics in acute coronary syndromes

Antithrombotic agents are an integral component of the medical regimens and interventional strategies currently recommended to reduce thrombotic complications in patients with acute coronary syndromes (ACS). Despite great advances with these therapies, associated high risks for thrombosis and hemorrhage remain as the result of complex interactions involving patient comorbidities, drug combinations, multifaceted dosing adjustments, and the intricacies of the care environment. As such, the optimal combinations of antithrombotic therapies, their timing, and appropriate targeted subgroups remain the focus of intense research. During the last several years a number of new antithrombotic treatments have been introduced, and new data regarding established therapies have come to light. Although treatment guidelines include the most current available data, subsequent findings can be challenging to integrate. This challenge is compounded by the complexity associated with different efficacy and safety measures and the variability in study populations, presenting syndromes, physician, and patient preferences. In this work we review recent data regarding clinically available antiplatelet and anticoagulation agents used in the treatment of patients with ACS. We address issues including relative efficacy, safety, and timing of therapies with respect to conservative and invasive treatment strategies. In specific cases we will highlight remaining questions and controversies and ongoing trials, which will hopefully shed light in these areas. In addition to reviewing existing agents, we take a look forward at the most promising new antithrombotics currently in late-stage clinical development and their potential role in the context of ACS management.