Subacute thrombosis with antiplatelet treatment in a non-selected population of intracoronary stents: incidence and predictors

INTRODUCTION: After coronary stenting, the incidence of subacute stent thrombosis have been reduced to 0% using aspirin and ticlopidine, in studies with selected populations and intracoronary ultrasounds. OBJECTIVE: To evaluate the incidence and predictors of subacute stent thrombosis in a nonselected population, using antithrombotic therapy. METHODS: We studied 285 stents, consecutively and successfully implanted in 268 lesions of 226 patients. We used high pressure balloon inflation without intracoronary ultrasound. Post-stenting protocol included aspirin and ticlopidine during four weeks with no anticoagulation. We defined subacute stent thrombosis as death, acute myocardial infarction myocardial infarction or angiographic occlusion of stent, with TIMI flow 0-1, after the first 24 hours and during the first month. RESULTS: Four patients presented events (1.7%): Three nonfatal myocardial infarction after discharge, with documented angiographic thrombosis of stent, and one death due to in-hospital myocardial infarction. All three non-fatal AMI, occurred in vessels less than 3 mm (p = 0.07) and in patients taking aspirin without ticlopidine (p < 0.001). After discharge, three (17%) of 18 patients with inadvertent discontinuation of ticlopidine presented subacute stent thrombosis, in contrast to none of 25 patients taking ticlopidine without aspirin. Excluded patients with discontinuation of ticlopidine, the incidence of subacute stent thrombosis was 0.5%. CONCLUSION: After intracoronary stenting in a nonselected population, using antithrombotic treatment with aspirin and ticlopidine, we may expect a rate of subacute stent thrombosis about 1%. Ticlopidine seems to have the main role in preventing subacute stent thrombosis, above all in predisposing circumstances as small vessels.     

Timing of coronary stent thrombosis in patients treated with ticlopidine and aspirin

In patients receiving coronary stents treated with aspirin and coumadin, the peak incidence of stent thrombosis occurs on the fifth and sixth days following the implantation procedure. Little is known about the timing of stent thrombosis in patients treated with aspirin and ticlopidine. We compared the timing of coronary stent thrombosis in patients treated with ticlopidine and aspirin with the timing in those receiving coumadin and aspirin. A retrospective databank analysis was performed and 39 patients were identified who experienced stent thrombosis after successful coronary stent implantation. Of these, 21 had been treated with ticlopidine and aspirin and 18 with coumadin and aspirin therapy. The median time from stent implantation to stent thrombosis in the ticlopidine and aspirin group was 12 hours (interquartile range 6 to 72 hours) compared with 4 days in the coumadin and aspirin group (interquartile range 21 to 68 hours) (p <0.0001). There was no significant difference between the timing of stent thrombosis in patients treated with abciximab in addition to ticlopidine and aspirin (median 17 hours, interquartile range 6 to 29) versus ticlopidine and aspirin patients who did not receive abciximab (median 11 hours, interquartile range 9 to 12, p = 0.57). Thus, in patients who receive coronary stents, stent thrombosis occurs much earlier after the procedure in patients treated with ticlopidine and aspirin than in patients treated with anticoagulation therapy.     

Combination therapy with clopidogrel and aspirin after coronary stenting.

Combination antiplatelet therapy using aspirin and ticlopidine has been the standard of care for prevention of subacute thrombosis following coronary stent implantation. However, the use of ticlopidine is associated with a significant risk of adverse hematologic side effects. Clopidogrel is an inhibitor of ADP-induced platelet aggregation that has a better safety profile than ticlopidine. We examined the 30-day clinical outcome following coronary stent implantation in 253 consecutive patients treated with clopidogrel and aspirin. Follow-up was achieved in 99% of patients and four adverse events were documented. Two patients had angiographically confirmed subacute stent thrombosis (0.8%), and both of these patients underwent successful repeat angioplasty at the stent site. There were two patient deaths during follow-up (0. 8%). One was sudden within 1 week of stent placement and the other occurred in a patient with multisystem organ failure after an extensive myocardial infarction that antedated the stent procedure, with no clinical evidence for stent thrombosis. The combined frequency of subacute stent thrombosis and death was 1.6%. This is comparable to prior studies using the combination of ticlopidine and aspirin following stenting. Therefore, clopidogrel in combination with aspirin appears to be a safe and effective therapy in the prevention of subacute thrombosis following coronary stent implantation.     

Timing of coronary stent thrombosis in patients treated with prophylactic tirofiban

BACKGROUND: Acute and subacute stent thromboses (ASST) are the major thrombotic complications of coronary stenting. The time course of ASST seems to be related to the type of antithrombotic therapy (four days in patients treated with aspirin and coumadin compared to 12 hours with the use of aspirin and ticlopidine). In this report, we compared the timing of ASST in patients treated with aspirin, ticlopidine/clopidogrel, heparin and tirofiban with that in patients treated with the same drugs but without tirofiban. METHODS: Retrospective analysis of the Hermann intervention database between January 1997 and October 1999 was performed. We identified 13 patients who required reintervention in the first week after a successful coronary stenting ( 1 stent). Four patients were treated with tirofiban (Group 1) and 9 were not (Group 2). RESULTS: The median time from stent deployment to ASST was 7 hours (interquartile range, 2.5Eth 33 hours) in group 2 compared to 84.5 hours (interquartile range, 56Eth 124.5 hours) in group 1. The mean time from stent deployment to ASST was 90.3 +/- 43.1 hours in group 1 versus 12.8 +/- 15.3 hours in group 2 (p = 0.0005). All episodes of ASST occurred 3 days in patients treated with tirofiban, whereas they occurred in the first 2 days in all patients not treated with tirofiban. CONCLUSION: Prophylactic tirofiban treatment delays the time to stent thrombosis after successful coronary artery stent implantation for more than two days. Patients at high risk for stent thrombosis treated with short-acting glycoprotein IIb/IIIa platelet receptor inhibitors may warrant close follow-up during the first week after stenting.     

Young woman with repeated late stent thrombosis: a case report

A 34-year-old woman with hypertension, obesity, and history of smoking presented with unstable angina and severe stenosis of the proximal left anterior descending artery. Percutaneous coronary intervention was performed with stent implantation resulting in adequate expansion. She was treated with aspirin and ticlopidine for 1 month, then only aspirin for 1 month. One year after stenting, she presented with acute myocardial infarction and total occlusion at the stent. Balloon angioplasty was performed. She took ticlopidine and aspirin for 9 months. Two months later, she presented with acute myocardial infarction with reocclusion at the stent. Blood examination showed no manifest collagen disease or thrombophilia. This case of repeated late stent thrombosis occurred in a young woman not treated by brachytherapy.     

Frequency of and risk factors for stent thrombosis after drug-eluting stent implantation during long-term follow-up

Despite concerns regarding the long-term safety of drug-eluting stent (DES) implantation because of late-onset stent thrombosis, the actual incidence of stent thrombosis after 1 year is unknown. We investigated the incidence, risk factors, and association of antiplatelet therapy interruption for the development of stent thrombosis after DES implantation during long-term follow-up. A total of 1,911 consecutive patients with DES implantation were enrolled (sirolimus-eluting stents in 1,545 patients, 2,045 lesions; paclitaxel-eluting stents in 366 patients, 563 lesions). During long-term follow-up (median 19.4 months, interquartile range 15.3 to 24.3), 15 patients (0.8%, 95% confidence interval 0.5% to 1.3%) developed stent thrombosis within 6 hours to 20.4 months. Eleven patients (0.6%, 95% confidence interval 0.3% to 1.0%) had late thrombosis (median 6.1 months). The incidence of stent thrombosis was 3.3% (4 of 121 patients) in patients with complete interruption of antiplatelet therapy (vs 0.6% in those without, p = 0.004) and 7.8% (5 of 64 patients) with premature interruption of aspirin or clopidogrel, or both (vs 0.5% in those without, p < 0.001). Independent predictors of stent thrombosis were premature antiplatelet therapy interruption, primary stenting in acute myocardial infarction, and total stent length. Stent thrombosis also developed while patients were on dual antiplatelet therapy (all patients with acute/subacute stent thrombosis and 36% of those with late stent thrombosis; 47% of total with stent thrombosis). In conclusion, stent thrombosis occurred in 0.8% after DES implantation during long-term follow-up. The incidence of late stent thrombosis was 0.6%, similar to that for bare metal stents. The predictors of stent thrombosis were premature antiplatelet therapy interruption, primary stenting in acute myocardial infarction, and total stent length.     

Comparison of cilostazol versus ticlopidine therapy after stent implantation.

The aim of this study was to evaluate the efficacy of cilostazol for prevention of stent thrombosis compared with ticlopidine. Cilostazol is a potent antiplatelet agent with less serious side effects. However, few data are available about the effect of cilostazol in preventing stent thrombosis after coronary stent implantation. Four hundred ninety patients selected for elective stent placement were randomized to receive aspirin plus ticlopidine (n = 243) or aspirin plus cilostazol (n = 247) for 1 month. Clinical and laboratory evaluations were performed at regular interval. There were no differences in baseline characteristics between the 2 groups. During the first 30 days after stent implantation, major cardiac events or adverse drug effects were similar between the 2 groups: ticlopidine (2.9%) vs cilostazol (1.6%) group, p = NS; stent thrombosis (0.4% vs 0.8%, p = NS, respectively), myocardial infarction (0.4% vs 0.8%, p = NS), severe leukopenia (1.2% vs 0%, p = NS), severe thrombocytopenia (0.4% vs 0%, p = NS), and cerebral hemorrhage (0.4% vs 0%, p = NS). Adverse effects led to drug withdrawal in 7 patients in the ticlopidine group (2.9%) and in 5 in the cilostazol group (2.0%). There was no death during the follow-up period. Thus, aspirin plus cilostazol may be an effective antithrombotic regimen with comparable results to aspirin plus ticlopidine after elective coronary stenting.     

Palmaz-Schatz Coronary Stent Implantation Without Intravascular Ultrasound and Without Subsequent Anticoagulation: Clinical Outcome

OBJECTIVES: To determine the safety and efficacy of antiplatelet therapy alone in a selected group of patients following coronary stenting. BACKGROUND: Coronary stent implantation is an effective treatment for abrupt closure, and can also reduce the restenosis rate following percutaneous transluminal coronary angioplasty. However, anticoagulation therapy following stent implantation is associated with a significant incidence of vascular complications and subacute stent thrombosis. METHODS: Between February and November 1994 we implanted 62 Palmaz-Schatz stents in 50 patients with an optimal angiographic result following stent deployment. In these patients, intravascular ultrasound was not used, and a regimen of aspirin 100 mg daily indefinitely and ticlopidine 250 mg twice daily for 3 months was started without anticoagulation. RESULTS: Of these 50 patients (10 females : 40 males, mean age 63 +/- 12 years, LVEF 64 +/- 10%), 39 (78%) were stented for a suboptimal angiographic result post angioplasty, 2 (4%) received stents as a bailout procedure, and 9 (18%) were stented electively. Average hospital stay following stent implantation was 3.7 +/- 3.0 days. After a mean follow-up period of 140 +/- 70 days, there were no instances of stent occlusion, death, stroke, need for coronary bypass surgery, Q-wave myocardial infarction or femoral artery pseudoaneurysm. There was 1 case (2%) of significant puncture site hemorrhage. CONCLUSIONS: Immediate angiographic appearance after stent implantation can be used to define patients at low risk of stent thrombosis who do not require anticoagulation and can safely be discharged early from the hospital.     

A safe and effective regimen without heparin therapy after successful primary coronary stenting in patients with acute myocardial infarction

Short-term heparin therapy has been administered routinely after primary coronary stenting. However. heparin therapy results in a significantly higher incidence of bleeding and vascular complications. A new therapeutic regimen of ticlopidine and aspirin without further heparin after coronary stenting in patients without AMI has been shown to be safe and reduce the incidence of stent thrombosis. The aim of this study was to evaluate whether a new therapeutic regimen of aspirin and ticlopidine without heparin is safe and effective in patients with acute myocardial infarction (AMI) who have undergone primary coronary stenting and have Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in the infarct-related artery. Between January 1997 and September 1999, one hundred and fifty two consecutive patients with AMI on Killip score 1 or 2 who underwent primary coronary stenting resulting in TIMI grade 3 flow were enrolled and divided into two groups: Group 1 (n = 95 patients) received aspirin, ticlopidine and further intravenous heparin infusion for 48 hours following primary coronary stenting; Group 2 (n = 57 patients) received only aspirin and ticlopidine without further heparin therapy following primary coronary stenting. No in-hospital major cardiac events were observed in either group. However, the combined incidence of bleeding and vascular complications (27.4% vs 12.3%, p = 0.029) and the need for blood transfusions (9.5% vs 0%, p = 0.013) were significantly higher in Group I patients. Furthermore, hospital stay was also longer in Group I patients (5.8+/-2.4 vs 4.7+/-1.7 days, p = 0.0003). At the 30-day follow-up, there were no differences (1.05% vs 0%, p = 0.63) in the combined incidence of vascular complications and the major cardiac events were similar (1.05% vs 1.75%, p = 0.71) between the groups. The results suggest that further heparin therapy following primary coronary stenting increases the combined incidence of bleeding and vascular complications as well as the need for blood transfusions and prolongs the length of hospital stay without further benefit to those patients with coronary flow restored to TIMI 3 grade flow.     

Thrombotic and hemorrhagic complications of stenting coronary arteries: Incidence,management and prevention

Stents are intravascular prostheses which provide endoluminal scaffolding, effectively reducing elastic recoil and sealing local dissections. Stents have become the treatment of choice for acute vessel closure following percutaneous coronary intervention. In addition, by providing a large, smooth lumen, stenting increases procedural success and decreases late restenosis compared with conventional balloon angioplasty. All stents evaluated clinically are constructed of non-corrosive metallic alloys which are inherently thrombogenic.The incidence of stent thrombosis ranges from 0.4-18%. While acute thrombosis is uncommon, subacute thrombosis may occur from 5 to 21 days (mean 7 days) after placement. Predictors of stent thrombosis include stenting for bailout indication, angiographically visible thrombus after implantation, stenting of smaller vessels, presence of residual dissection after stenting, poor distal runoff, incomplete stent expansion and stenting in the setting of acute myocardial infarction. Stent thrombosis is associated with high incidence of Q-wave myocardial infarction (70–90%) and mortality (7–20%), and is best treated with emergency catheterization and balloon angioplasty.To prevent stent thrombosis, aggressive procedural and postprocedural pharmacological regimens employing antiplatelet agents (aspirin, dipyridamole and dextran) and anticoagulation (heparin followed by warfarin) have been used. While these regimens have reduced the incidence of stent thrombosis to <5%, they are associated with a high incidence of vascular and hemorrhagic complications, increased length of hospitalization and total cost. To decrease the incidence of stent thrombosis and obviate the need for anticoagulation, strategies such as intravascular ultrasound guided optimal stenting and addition of the antiplatelet agent ticlopidine, are being evaluated. In the future coating of stents with agents such as heparin, may further reduce the risk of thrombosis and the requirement for long-term anticoagulation.     

Documented subacute stent thrombosis within thirty days after stenting with sirolimus-eluting stent (Cypher) for acute myocardial infarction: a Japanese single center retrospective non-randomized study.

BACKGROUND: The incidence of subacute stent thrombosis (SAT) within 30 days after stenting with a sirolimus-eluting stent (Cypher) for acute myocardial infarction (AMI) was retrospectively compared to that with bare-metal stents (BMS). METHODS AND RESULTS: Among 559 lesions in 558 consecutive AMI from April 2003 to February 2006, the incidence of documented SAT after Cypher implantation (2/276 lesions, 0.72%) was almost the same as for BMS (2 cases, 0.71%). Aspirin (81-100 mg/day) plus ticlopidine (200 mg/day) were administered continuously after admission in all 4 cases. CONCLUSION: Documented SAT did not increase after stenting with Cypher for AMI under aspirin plus ticlopidine.     

Increased long term rates of stent thrombosis and mortality in patients given clopidogrel as compared to ticlopidine following coronary stent implantation

BACKGROUND: Clopidogrel has largely replaced ticlopidine following coronary stent implantation. Recently, concern has been raised regarding the possibility of excess long term mortality in patients given clopidogrel rather than ticlopidine following coronary stenting. METHODS: We studied 1519 consecutive patients who underwent 2020 stent implantations and were discharged on dual antiplatelet regimens of either aspirin and ticlopidine or aspirin and clopidogrel given for up to 4 weeks. Thrombotic stent occlusion (TSO) was defined as ST elevation myocardial infarction in the stented artery territory associated with angiographic demonstration of complete stent occlusion. Mortality follow up was obtained for all patients by linkage to the Population Register. Follow up duration was 12 months. RESULTS: TSO occurred in 37 stents at a median of 29 days post procedure. Of these cases, six occurred in the ticlopidine group (0.7%) and 31 in the clopidogrel group (2.8%) (p<0.01). The median time to TSO was 34 days and 28 days in ticlopidine and clopidogrel treated patients, respectively (p<0.01). After controlling for multiple demographic, clinical and angiographic variables clopidogrel (vs. ticlopidine) treatment remained the sole predictor of TSO (OR: 5.4, 95% CI=1.2-24.1, p=0.028). Of even more concern, clopidogrel treatment was associated with an increased risk of 1 year mortality (OR: 1.8, 95% CI=1.2-2.8). CONCLUSIONS: Long term follow up after stent implantation in patients receiving the traditional 2-4 weeks course of dual antiplatelet therapy reveals increased rates of TSO and mortality in patients given clopidogrel as opposed to ticlopidine. Whether longer treatment with clopidogrel will change these observations deserves further study.     

A randomized comparison of clopidogrel and aspirin versus ticlopidine and aspirin after the placement of coronary artery stents

OBJECTIVES: The aim of the present study was to compare clopidogrel and ticlopidine after coronary stenting with regard to cardiovascular death during long-term follow-up. BACKGROUND: Randomized trials comparing clopidogrel and ticlopidine with a restricted use of intravenous glycoprotein IIb/IIIa inhibition have reported a trend toward a higher incidence of thrombotic stent occlusion with clopidogrel at 30 days. METHODS: After successful coronary stent implantation, 700 patients with 899 lesions were randomly assigned to receive a four-week course of either 500 mg ticlopidine (n = 345) or 75 mg clopidogrel (n = 355) in addition to 100 mg aspirin. Cardiovascular death was the primary end point and was recorded during a median follow-up period of 28 months. RESULTS: Cardiovascular death occurred in eight patients with ticlopidine versus 26 patients with clopidogrel (hazard ratio with ticlopidine compared with clopidogrel, 0.30; 95% confidence interval [CI], 0.14 to 0.66; p = 0.003). After adjustment for co-variables, ticlopidine reduced the risk of cardiovascular death by 63% compared with clopidogrel. The combined end point of cardiovascular death or nonfatal myocardial infarction was present in 19 patients assigned ticlopidine, compared with 40 patients assigned clopidogrel (hazard ratio, 0.45; p = 0.005). The hazard ratio for all-cause mortality with ticlopidine as compared with clopidogrel was 0.30 (95% CI, 0.14 to 0.64; p = 0.002). CONCLUSIONS: After the placement of coronary artery stents in unselected patients, ticlopidine was associated with a significantly lower mortality than clopidogrel. This raises concern about the current practice of substituting clopidogrel for ticlopidine after stenting and highlights the need for further long-term studies.     

Elective implantation of intracoronary stents without intravascular ultrasound guidance or subsequent warfarin

Two hundred forty-three stents (203 Palmaz-Schatz, 40 Glanturco-Roubin) were electively implanted in 188 lesions in 168 patients (mean age 58 ± 10 years, 77% males) using angiographic but not ultrasound guidance. Patients were treated subsequently with aspirin and observed in hospital for up to 7 days. Those with acute myocardial infarction, radiolucent defects in coronary arteries suggestive of thrombus, and results that were not optimal after stent implantation were anticoagulated with warfarin and not included in the study. Two had subacute stent thrombosis and two patients non-Q-wave myocardial infarction in-hospital. At follow-up (median 149 days) none had had subacute stent thrombosis, one suffered non-Q-wave myocardial infarction, none had died, and none had developed major complications at the vascular access site. Fourteen (8%) had undergone further revascularisation procedures. This initial experience suggests that aspirin is sufficient to prevent subacute stent thrombosis after elective high pressure assisted coronary stent implantation without intravascular ultrasound guidance if the angiographic appearance after stent deployment is optimal. © 1996 Wiley-Liss, Inc.     

Comparative inhibitory effects of cilostazol and ticlopidine on subacute stent thrombosis and platelet function in acute myocardial infarction patients with percutaneous coronary intervention

We compared the effects of ticlopidine and cilostazol on the prevention of subacute stent thrombosis (SAT) in acute myocardial infarction (AMI) patients with stenting. We also analyzed the cause of the difference by measuring platelet aggregation activity. Consecutive patients who underwent successful stenting for AMI between March 2001 and March 2004 were analyzed. In addition to aspirin (100 mg/day), cilostazol (200 mg/day) was administered to 99 cases between March 2001 and May 2002 and ticlopidine (200 mg/day) was administered to 85 cases between June 2002 and February 2004. The incidence of SAT within four weeks after stenting was analyzed. Thirty-eight AMI patients were randomized and their platelet aggregation activity was measured using a laser-scattered aggregometer (18 cases in the cilostazol group and 20 cases in the ticlopidine group). SAT did not occur in the ticlopidine group while 5 cases (5.1%) of SAT occurred in the cilostazol group (P < 0.05). The inhibitory activity of cilostazol for ADP-induced platelet aggregation was lower than that of ticlopidine (P < 0.05). Cilostazol with aspirin after stenting in AMI patients showed more frequent SAT than ticlopidine with aspirin. One of the causes for this difference was speculated to be the weaker inhibitory activity of cilostazol for ADP-induced platelet aggregation.     

Focused clinical review: periprocedural management of antiplatelet therapy in patients with coronary stents

Coronary stent implantation, particularly drug eluting stents, is now the major method of coronary revascularisation. Following drug-eluting stent implantation dual antiplatelet therapy with aspirin and thienopyridine is recommended for at least 12 months. Premature discontinuation, often at the time of noncardiac surgery, has been associated with stent thrombosis which has a significant risk of death and myocardial infarction. Late (>30 days) and very late (>365 days) stent thrombosis appears to more common with DES and poses the questions of when is it safe to stop antiplatelet therapy post coronary stenting and how to manage patients who need non-cardiac surgery. This article reviews the evidence for stent thrombosis and the peri-operative management of patients with coronary stents and provides an algorithm for patient management based on multidisciplinary assessment of bleeding risk, perioperative cardiac event and stent thrombosis risk.     

A case report of very late thrombosis of coronary bare-metal stent 10 years after stenting

Although late stent thrombosis is not uncommon with the use of drug-eluting stents, it is unusual with the use of bare-metal stents (BMS) because stent endothelialization is considered to be completed 4 weeks after the intervention.(1) A 64 year-old male had undergone percutaneous coronary intervention (PCI) for a proximal left anterior descending (LAD) artery lesion with a BMS and excellent angiographic results were obtained. Two hundred mg of ticlopidine was prescribed for one month and 100 mg of aspirin daily was continued. One year after stent implantation, coronary angiography (CAG) showed no restenosis. Ten years and 7 months after stent implantation, he suffered an acute myocardial infarction due to stent thrombosis. Intra-coronary aspiration thrombectomy was successful. To the best of our knowledge, the longest delayed case of BMS thrombosis is 5 years after stent implantation.(2) Our report demonstrated evidence of the latest reported case of stent thrombosis with the use of a BMS.     

Triple versus dual antiplatelet therapy after coronary stenting: impact on stent thrombosis.

OBJECTIVES: We evaluated safety and efficacy of triple antiplatelet therapy with aspirin, clopidogrel, or ticlopidine and cilostazol after coronary stenting. BACKGROUND: Triple antiplatelet therapy might have beneficial effect to prevent thrombotic complications in patients undergoing coronary stenting. METHODS: Patients undergoing successful coronary stenting were divided into dual antiplatelet therapy (aspirin plus clopidogrel or ticlopidine, group I, n = 1,597) and triple antiplatelet therapy (aspirin plus clopidogrel or ticlopidine plus cilostazol, group II, n = 1,415) groups. The primary end point included death, myocardial infarction, target lesion revascularization, or stent thrombosis within 30 days. The secondary end point was side effects of study drugs, including major bleeding, vascular complication, hepatic dysfunction, and hematological complications. RESULTS: Multi-vessel stenting and the use of long stents were more prevalent in group II than in group I. The primary end point was 0.8% in group I and 0.3% in group II (p = 0.085). Stent thrombosis within 30 days was significantly lower in group II (n = 1, 0.1%) than in group I (n = 9, 0.5%; p = 0.024). The independent predictors of stent thrombosis were primary stenting (odds ratio [OR] 7.9, 95% confidence interval [CI] 2.0 to 30.8, p = 0.003) and triple therapy (OR 0.12, 95% CI 0.015 to 0.98, p = 0.048). The overall adverse drug effects, including major bleeding, neutropenia, and thrombocytopenia, were no different between two groups (1.8% vs. 2.6%, p = 0.104). CONCLUSIONS: Compared with the dual antiplatelet regimen, triple antiplatelet therapy seemed to be more effective in preventing thrombotic complications after stenting without an increased risk of side effects. Triple antiplatelet therapy might be safely applied in patients or lesions with a high risk of stent thrombosis.     

Subacute thrombosis after coronary stenting occurring with resistance to ticlopidine

A 79-year-old man underwent stent implantation from the proximal site to the left main trunk with one bare metal stent after rotation atherectomy. He received 200 mg/day ticlopidine and 200 mg/day aspirin from 2 days pre-stenting. Subacute thrombosis occurred 5 days after coronary stenting. We performed a test of platelet aggregation one month after the commencement of dual antiplatelet therapy and the test showed no response to ticlopidine in this case. An increased dose of ticlopidine was not effective for suppressing platelet aggregation. We report a case of subacute stent thrombosis which is related to ticlopidine resistance.     

Coronary implantation of silicone-carbide-coated Palmaz-Schatz stents in patients with high risk of stent thrombosis without oral anticoagulation

Coronary stenting in bail-out situations is effective but associated with increased stent thrombosis and bleeding rates. Silicone-carbide coating reduces fibrinogen activation on alloplastic surfaces and thus may also reduce stent thromboses. A total of 44 patients received 58 silicone-carbide-coated stents for threatened (80%) or abrupt (20%) closure. In addition to heparin, patients were treated with aspirin and ticlopidine (75%) or aspirin (25%) only. Two patients (4.5%) died in the hospital. The combined in-hospital complication rate including death, emergency revascularization, stent-related myocardial infarction, and stent thrombosis was 9% (4 of 44 patients). Major bleeding occurred in 4 patients (9%). Six-month follow-up angiography was obtained in all eligible patients (42 of 44), revealing a restenosis rate of 21% (9 of 42). Thus, coronary implantation of silicone-carbide-coated stents is feasible in bail-out situations without oral anticoagulation and with a low complication rate. Further studies are required to optimize the anticoagulation regimen with this type of coating. Cathet. Cardiovasc. Diagn. 41:71–78, 1997. © 1997 Wiley-Liss, Inc.