A clinical risk score for prediction of stent thrombosis.

The aim was to develop a clinically useful patient risk score predictive for stent thrombosis (ST). Using readily available baseline clinical and angiographic characteristics, a Cox proportional hazards multivariate model was used to identify significant (p <0.10) predictors of ST through 1 year in 2,487 patients receiving a TAXUS Express (Boston Scientific Corp., Natick, Massachusetts) drug-eluting stent (DES) in the ARRIVE 1 registry. Hazard ratios of significant predictors were rounded to an integer value ranging from 2 to 5. These values were summed for a maximum possible score of 24. The model was validated using 1-year data from a similar DES data set (ARRIVE 2, n = 4,820 patients). The 8 significant predictors found were thienopyridine therapy discontinuation before 6 months, insulin-requiring diabetes, smoker at baseline, left main stent placement, multiple stent placement, lesion length >28 mm, moderate to severe lesion calcification, and reference vessel diameter <3 mm. Model discrimination was high, indicated by an area under the receiver-operator characteristic curve of 0.819. Stratification of patients into low-, medium-, and high-risk groups showed that ST developed in 0.8% of patients with a score <6, 3.6% of patients with a score of 7 to 13, and 12.6% of patients with a score >or=14. In conclusion, using 8 readily available clinical and angiographic characteristics, we defined an ST risk score for patients receiving a DES during the first year. Analysis of patients from ARRIVE 1 and 2 showed that most (73%) were in the lowest risk category, with 25% in the moderate risk category. Less than 2% were at highest risk of developing ST.

A polymer-based, paclitaxel-eluting stent in patients with coronary artery disease.

BACKGROUND: Restenosis after coronary stenting necessitates repeated percutaneous or surgical revascularization procedures. The delivery of paclitaxel to the site of vascular injury may reduce the incidence of neointimal hyperplasia and restenosis. METHODS: At 73 U.S. centers, we enrolled 1314 patients who were receiving a stent in a single, previously untreated coronary-artery stenosis (vessel diameter, 2.5 to 3.75 mm; lesion length, 10 to 28 mm) in a prospective, randomized, double-blind study. A total of 652 patients were randomly assigned to receive a bare-metal stent, and 662 to receive an identical-appearing, slow-release, polymer-based, paclitaxel-eluting stent. Angiographic follow-up was prespecified at nine months in 732 patients. RESULTS: In terms of base-line characteristics, the two groups were well matched. Diabetes mellitus was present in 24.2 percent of patients; the mean reference-vessel diameter was 2.75 mm, and the mean lesion length was 13.4 mm. A mean of 1.08 stents (length, 21.8 mm) were implanted per patient. The rate of ischemia-driven target-vessel revascularization at nine months was reduced from 12.0 percent with the implantation of a bare-metal stent to 4.7 percent with the implantation of a paclitaxel-eluting stent (relative risk, 0.39; 95 percent confidence interval, 0.26 to 0.59; P<0.001). Target-lesion revascularization was required in 3.0 percent of the group that received a paclitaxel-eluting stent, as compared with 11.3 percent of the group that received a bare-metal stent (relative risk, 0.27; 95 percent confidence interval, 0.16 to 0.43; P<0.001). The rate of angiographic restenosis was reduced from 26.6 percent to 7.9 percent with the paclitaxel-eluting stent (relative risk, 0.30; 95 percent confidence interval, 0.19 to 0.46; P<0.001). The nine-month composite rates of death from cardiac causes or myocardial infarction (4.7 percent and 4.3 percent, respectively) and stent thrombosis (0.6 percent and 0.8 percent, respectively) were similar in the group that received a paclitaxel-eluting stent and the group that received a bare-metal stent. CONCLUSIONS: As compared with bare-metal stents, the slow-release, polymer-based, paclitaxel-eluting stent is safe and markedly reduces the rates of clinical and angiographic restenosis at nine months.

Polymer-based paclitaxel-eluting stents reduce in-stent neointimal tissue proliferation: a serial volumetric intravascular ultrasound analysis from the TAXUS-IV trial.

OBJECTIVES: The aim of this study was to use serial volumetric intravascular ultrasound (IVUS) to evaluate the effects of polymer-based, paclitaxel-eluting stents on in-stent neointima formation and late incomplete stent apposition. BACKGROUND: The TAXUS-IV trial demonstrated that the slow-release, polymer-based, paclitaxel-eluting stent reduces angiographic restenosis and the need for repeat revascularization procedures. Serial IVUS studies reveal details of the pattern of vascular responses provoked by stent implantation that provide insight into device safety and efficacy. METHODS: In the TAXUS-IV trial, patients were randomized to the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or a bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). As part of a formal substudy, complete volumetric IVUS data were available in 170 patients, including 88 TAXUS patients and 82 controls, at implantation and at nine-month follow-up. RESULTS: No baseline differences were present in the clinical characteristics or IVUS parameters between the control and TAXUS groups. At nine-month follow-up, IVUS lumen volumes were larger in the TAXUS group (123 +/- 43 mm(3) vs. 104 +/- 44 mm(3), p = 0.005), due to a reduction in neointimal volume (18 +/- 18 mm(3) vs. 41 +/- 23 mm(3), p < 0.001). Millimeter-by-millimeter analysis within the stent demonstrated uniform suppression of neointimal growth along the entire stent length. Late lumen loss was similar at the proximal edge of the stent between the two groups, and reduced with the TAXUS stent at the distal edge (p = 0.004). Incomplete stent apposition at nine months was observed in only 3.0% of control and 4.0% of TAXUS stents (p = 0.12). CONCLUSIONS: Polymer-based, paclitaxel-eluting TAXUS stents are effective in inhibiting neointimal tissue proliferation, and do not result in late incomplete stent apposition.

Comparative early and late outcomes after primary percutaneous coronary intervention in ST-segment elevation and non-ST-segment elevation acute myocardial infarction (from the CADILLAC trial).

We determined the outcomes of patients with acute ST-segment elevation (STE) myocardial infarction (STEMI) and non-STEMI (NSTEMI) after primary percutaneous coronary intervention (PCI). The prognosis after primary PCI in STEMI has been extensively studied and defined. Outcomes of patients who undergo primary PCI for NSTEMI are less well established. In total, 2,082 patients with ongoing chest pain for > 30 minutes consistent with acute MI were randomized to balloon angioplasty versus stenting, each with/without abciximab. Of 1,964 patients, STEMI was present in 1,725 (87.8%) and NSTEMI in 239 (12.2%). Compared with STEMI, those with NSTEMI were more likely to have delayed time-to-hospital arrival (2.4 vs 1.8 hours, p = 0.0002) and increased door-to-balloon time (3.2 vs 1.9 hours, p < 0.0001). Patients with NSTEMI were more likely to have Thrombolysis In Myocardial Infarction grade 3 flow at baseline (37.3% vs 19.4%, p < 0.0001) and higher ejection fraction (58.7% vs 55.8%, p = 0.001), but similar rates of postprocedural Thrombolysis In Myocardial Infarction grade 3 flow. At 1 year, patients with NTEMI had similar mortality (3.4% vs 4.4%, p = 0.40) but higher rates of major adverse cardiac events (24.0% vs 16.6%, p = 0.007) that was driven by more frequent ischemic target vessel revascularization (21.8% vs 11.9%, p <0.0001). In conclusion, patients with acute MI without STE who are treated with primary PCI have marked delays to treatment, similar late mortality, and increased rates of ischemic target vessel revascularization compared with patients with STEMI, despite more favorable angiographic features at presentation and similar reperfusion success. The adverse prognosis of patients with NSTEMI should be recognized and efforts made to decrease reperfusion times.

One-year clinical results with the slow-release, polymer-based, paclitaxel-eluting TAXUS stent: the TAXUS-IV trial.

BACKGROUND: The safety and efficacy of the slow-release, polymer-based, paclitaxel-eluting stent after implantation in a broad cross section of de novo coronary lesions at 1 year are unknown. METHODS AND RESULTS: In the TAXUS-IV trial, 1314 patients with single de novo coronary lesions 10 to 28 mm in length, with reference-vessel diameter 2.5 to 3.75 mm, coverable by a single study stent, were prospectively randomized to the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or an identical-appearing bare-metal EXPRESS stent. By actuarial analysis, the TAXUS stent compared with the bare-metal stent reduced the 12-month rates of target-lesion revascularization by 73% (4.4% versus 15.1%, P<0.0001), target-vessel revascularization by 62% (7.1% versus 17.1%, P<0.0001), target-vessel failure by 52% (10.0% versus 19.4%, P<0.0001), and composite major adverse cardiac events by 49% (10.8% versus 20.0%, P<0.0001). The 1-year rates of cardiac death (1.4% versus 1.3%), myocardial infarction (3.5% versus 4.7%), and subacute thrombosis (0.6% versus 0.8%) were similar between the paclitaxel-eluting and control stents, respectively. Between 9 and 12 months, there were significantly fewer myocardial infarctions (0% versus 1.1%, P=0.007), target-vessel revascularizations (2.4% versus 5.8%, P=0.002), and major adverse cardiac events (2.4% versus 6.3%, P=0.0009) in the paclitaxel-eluting stent than in the control stent group, respectively. CONCLUSIONS: The relative efficacy reported at 9 months for the polymer-based, paclitaxel-eluting TAXUS stent compared with the EXPRESS stent is preserved and continues to increase at 1 year, with no safety concerns apparent.

Usefulness of a cobalt chromium coronary stent alloy.

The cobalt chromium Guidant Multi-Link Vision coronary stent was deployed in 267 patients as part of a multicenter international registry. Major adverse cardiovascular events were infrequent, and late (180 days) quantitative angiography demonstrated binary (>50%) in-stent restenosis in 15.7% of patients. This registry establishes the safety and efficacy of this alloy as a coronary stent platform.