Enhancement of platelet inhibition of ticlopidine plus aspirin vs aspirin alone given prior to elective PTCA

Use of antiplatelet agents for prevention of ischemic stroke

Overall management to lower risk for ischemic stroke is multifaceted. Management includes measures to treat risk factors for accelerated atherosclerosis and stroke, antithrombotic therapies to lower the risk for thromboembolism, and surgery to treat a defined arterial or cardiac lesion. Treatment decisions are made on a case-by-case basis, with most patients receiving some combination of medication and recommendations for lifestyle modification. Some patients will also undergo surgical or endovascular interventions. This article discusses antithrombotic treatment for ischemic stroke prevention, placing major emphasis on the indications for and administration of antiplatelet therapy.

Incremental effect of clopidogrel on important outcomes in patients with cardiovascular disease: a meta-analysis of randomized trials

OBJECTIVES

To quantify the impact of clopidogrel plus aspirin on the individual outcomes of death, myocardial infarction, or stroke in patients with established cardiovascular disease, or in patients with multiple risk factors for vascular disease.

BACKGROUND

Randomized trials have demonstrated a reduction in composite outcomes when clopidogrel is added to aspirin therapy in patients with coronary artery disease; however, the magnitude of benefit on individual outcomes is unknown.

METHODS

We conducted a meta-analysis on randomized, controlled trials that compared aspirin plus clopidogrel with aspirin plus placebo for the treatment of coronary artery disease.

RESULTS

This analysis included five randomized trials (CURE, CREDO, CLARITY, COMMIT, and CHARISMA) in 79 624 patients. The incidence of all-cause mortality was 6.3% in the aspirin plus clopidogrel group versus 6.7% in the aspirin group (odds ratio [OR] 0.94; 95% CI 0.89, 0.99; p = 0.026). The incidence of myocardial infarction was 2.7% and 3.3% (OR 0.82; 95% CI 0.75, 0.89; p < 0.0001), and stroke was 1.2% and 1.4% (OR 0.82; 95% CI 0.73, 0.93; p = 0.002). Similarly, the incidence of major bleeding was 1.6% and 1.3% (OR 1.26; 95% CI 1.11, 1.41; p < 0.0001), and fatal bleeding was 0.28% and 0.27% (OR 1.04; 95% CI 0.76, 1.43; p = 0.79).

CONCLUSION

The addition of clopidogrel to aspirin results in a small reduction in all-cause mortality in patients with ST-elevation myocardial infarction and a modest reduction in myocardial infarction and stroke in patients with cardiovascular disease. The overall incidence of major bleeding however is increased, although there is no excess of fatal bleeds or hemorrhagic strokes.

Oral antiplatelet therapy and percutaneous coronary intervention

The benefit of oral antiplatelet therapy following percutaneous coronary intervention (PCI) with intracoronary stent implantation is well established. Combined aspirin with clopidogrel or ticlopidine therapy is superior to aspirin alone in reducing thrombotic events after stent placement. Clopidogrel is the drug of choice, given that its efficacy is comparable to ticlopidine and it has a superior safety profile. Despite dual antiplatelet therapy, patients remain at risk of recurrent vascular events. Optimal timing, duration and dosage of antiplatelet therapy remain controversial. Recent evidence suggests additional benefit with clopidogrel pretreatment, high clopidogrel loading dose and long-term dual antiplatelet therapy post-PCI in high-risk patients.

Bisphosphonates as anti-inflammatory agents in ankylosing spondylitis and spondylarthropathies

NSAIDs remain the cornerstone of the treatment of ankylosing spondylitis (AS) and spondylarthropathies (SpA), and have been successfully used for a long time in these diseases. However, some patients remain refractory or intolerant to NSAIDs and new effective treatments have recently emerged, namely TNF-alpha-blocker agents. Other therapeutic options targeting the bone, such as bisphosphonates, have also been tried in refractory AS or SpA patients. The anti-inflammatory properties of bisphosphonates give the rationale for the use of these compounds in AS and SpA, and include the inhibition of antigen presenting cells, the modulation of pro-inflammatory cytokine generation, and also a decreased bone mass in AS. Open trials using pamidronate gave favourable results, and one controlled study comparing the efficacy of pamidronate 10 versus 60mg showed that the 60mg dose was effective in AS. Further studies are required to confirm these preliminary data and to better determine the optimal regimen (dosage and rhythm) of administration.

A randomized comparison of elective high-pressure stenting with balloon angioplasty: six-month angiographic and two-year clinical follow-up. On behalf of AS (Angioplasty or Stent) trial investigators

BACKGROUND

Previous randomized trials have shown beneficial effects of coronary stenting on restenosis and event-free survival rates. However, it has not yet been fully established if routine high-pressure stenting with an antiplatelet regimen can show similar results.

METHODS

We compared the 6-month angiographic restenosis rate and 2-year event-free survival rate in 400 patients randomly assigned to stent or angioplasty. Aspirin and ticlopidine were prescribed in both groups.

RESULTS

The procedural success rate did not significantly differ between the stent and angioplasty groups (97.92% vs 97.45%, P = not significant). No stent thrombosis was found. The 6-month restenosis rate was lower in the stent group (18. 18% vs 24.87%, P =.055). At 2 years target lesion revascularization rate was 17.19% in the stent group and 25.51% in the angioplasty group (P =.02, 33% reduction). No significant differences with regard to death and myocardial infarction were observed. Event-free survival rate at 6, 12, and 24 months was 86.77% vs 78.84%, 84.13% vs 76.70%, and 83.07% vs 73.54% for stent and angioplasty groups, respectively (P =.0172).

CONCLUSIONS

The 6-month angiographic and 2-year clinical outcomes were better in patients who received stent than in those after balloon angioplasty. The difference in 2-year event-free survival rate was explained by a reduction in target lesion revascularization rate in the stent group.

Clopidogrel as adjunctive antiplatelet therapy during coronary stenting

OBJECTIVES

We examined the procedural and 30-day clinical outcomes among patients receiving aspirin and either ticlopidine or clopidogrel during coronary stenting.

BACKGROUND

Ticlopidine-plus-aspirin has become standard antiplatelet therapy for the prevention of thrombotic complications after coronary stenting. Clopidogrel has a similar mechanism of action as ticlopidine, but both its efficacy and its safety as a pharmacologic adjunct to coronary stenting have not been well described.

METHODS

This single-center, prospective analysis examined the in-hospital procedural and 30-day clinical outcomes among 875 consecutive patients undergoing coronary stenting who received adjunctive aspirin and either clopidogrel (n = 514; 58.7%) or ticlopidine (n = 361; 41.3%) therapy.

RESULTS

Procedural success rates were similar among the clopidogrel- (99.6%) and ticlopidine-treated patients (99.4%). Subacute stent thrombosis (i.e., >24 h < or =30 days) occurred in one clopidogrel-treated (0.2%) and in one ticlopidine-treated (0.3%) patient (p = 0.99). By 30 days following the index procedure, the combined rates of death, nonfatal myocardial infarction and need for target vessel revascularization were similar among patients who received either clopidogrel (2.1%) or ticlopidine (1.4%; p = 0.57) therapy.

CONCLUSIONS

In this analysis the antiplatelet combination therapy of aspirin-plus-clopidogrel was an effective regimen for preventing thrombotic complications and major adverse cardiovascular events among a broad spectrum of patients undergoing coronary artery stenting.

Ticlopidine and clopidogrel

The thienopyridines ticlopidine and clopidogrel are inhibitors of platelet function in vivo. Their mode of action has not been defined, but it appears that they require conversion to as yet unidentified metabolites that are noncompetitive antagonists of the platelet ADP receptor. Inhibition of platelet aggregation with these compounds is delayed until 24 to 48 hours after administration. Maximum inhibition occurs after 3 to 5 days, and recovery is slow after drug withdrawal. Ticlopidine is effective in preventing cardiovascular events in cerebrovascular, cardiovascular, and peripheral vascular disease, with an efficacy that is similar to aspirin. However, its use is associated with significant and sometimes fatal adverse reactions, specifically neutropenia and bone marrow aplasia. Gastrointestinal side effects and skin rashes are common and result in discontinuation of therapy in up to 10% of patients. Clopidogrel is at least as effective as aspirin in preventing cardiovascular events in patients with a history of vascular disease. It appears to be safer than ticlopidine, although its efficacy in acute coronary syndromes or post-coronary-stent insertion has not been reported. Important outstanding issues are whether clopidogrel adds to the benefit of aspirin and whether the combination of these agents is safe. If so, this combination may become the standard for antithrombotic therapy in cardiovascular disease.

The duration of pretreatment with ticlopidine prior to stenting is associated with the risk of procedure-related non-Q-wave myocardial infarctions

OBJECTIVES

This study sought to determine whether the duration of pretreatment with the adenosine diphosphate receptor antagonist ticlopidine prior to intracoronary stenting is associated with the incidence of procedure-related non-Q-wave myocardial infarctions (MIs).

BACKGROUND

Dual antiplatelet therapy with ticlopidine and aspirin is routinely used with stenting, although ticlopidine is commonly not begun until the day of the procedure. Periprocedural MIs are at least partially platelet-dependent events. As the maximal platelet inhibitory effects of this drug take 2 to 3 days to be realized, we hypothesized that longer treatment prior to stenting would be associated with lower rates of procedure-related MIs.

METHODS

We reviewed outcomes in 175 consecutive patients treated with ticlopidine prior to stenting at the Cleveland Clinic Foundation. Those patients with an elevation in creatine kinase above our laboratory normal (>210 IU/L) with > or =4% MB fraction on routine evaluation were defined as having a non-Q-wave MI. RESULTS. There were 28 patients (16%) who had a non-Q-wave MI. Longer duration of ticlopidine pretreatment was strongly associated with a lower incidence of procedure-related non-Q-wave MIs (duration of pretreatment <1 day, 29% had MI; 1 to 2 days, 14%; > or =3 days, 5%; chi-square for trend=9.6; p=0.002). Ticlopidine pretreatment of > or =3 days was associated with a significant reduction in the risk of non-Q-wave MI (unadjusted odds ratio 0.18, 95% confidence interval=0.04 to 0.78, p=0.01) compared with pretreatment of <3 days.

CONCLUSIONS

Among patients undergoing intracoronary stenting, beginning ticlopidine therapy several days prior to the procedure is associated with a reduced risk of procedural non-Q-wave MIs.