Randomized, double-blind, multicenter study of the Endeavor zotarolimus-eluting phosphorylcholine-encapsulated stent for treatment of native coronary artery lesions. Clinical and angiographic results of the ENDEAVOR II Trial.

AIM: The use of the Endeavor stent might reduce restenosis and stent thrombosis at 9 months. METHODS: Patients (n =1,197) treated for single coronary artery stenosis were enrolled in a prospective, randomized, double-blind study and randomly assigned to receive the Endeavor zotarolimus-eluting phosphorylcholine polymer-coated stent (n= 598) or the same bare metal stent but without the drug or the polymer coating (n=599). RESULTS: The 2 groups were well matched in baseline characteristics. Diabetes was present in 20.1% of patients; the mean reference vessel diameter was 2.75 mm; and the mean lesion length was 14.2 mm. The primary end point of target vessel failure at 9 months was reduced from 15.1% with the bare metal stent to 7.9% with the Endeavor (P=0.0001), and the rate of major adverse cardiac events was reduced from 14.4% with the bare metal stent to 7.3% with the Endeavor (P=0.0001). Target lesion revascularization was 4.6% with Endeavor compared with 11.8% with the bare metal stent (P=0.0001). The rate of stent thrombosis was 0.5% with the Endeavor, which was not significantly different from 1.2% with the bare metal stent. In 531 patients submitted to angiographic follow-up, late loss was reduced from 1.03+/-0.58 to 0.61+/-0.46 (P<0.001) in stent and from 0.72+/-0.61 to 0.36+/-0.46 (P<0.001) in segment. The rate of in-segment restenosis was reduced from 35% to 13.2% with Endeavor (P<0.0001). There was no excessive edge stenosis, aneurysm formation, or late acquired malposition by intravascular ultrasound imaging. Differences in clinical outcome were maintained at 12 and 24 months (P<0.0001). CONCLUSIONS: Compared with bare metal stents, the Endeavor stent is safe and reduces the rates of clinical and angiographic restenosis at 9, 12, and 24 months.

The exclusion of patients with chronic kidney disease from clinical trials in coronary artery disease.

Chronic kidney disease (CKD) is associated with a high risk of death from coronary artery disease and may modify the response to standard cardiovascular therapies. Treatment of subjects with CKD should ideally be based on evidence from randomized, clinical trials, but how often subjects with CKD have been excluded from these trials is uncertain. We undertook this study in order to quantify how often subjects with moderate to advanced CKD were excluded from large cardiovascular trials. MEDLINE and the reference list of selected articles were searched in order to identify large, randomized, controlled trials of five different coronary artery disease therapies published between 1998 and 2005. Exclusion criteria and reported clinical characteristics of subjects were abstracted. Rates of exclusion and reporting of baseline characteristics of study participants were compared for CKD, diabetes, history of smoking, and hypertension. Eighty-six trials randomizing 411 653 patients were identified. More than 80% of trials excluded subjects with end-stage renal disease and 75.0% excluded patients with CKD. Subjects with diabetes, hypertension, or a history of smoking were excluded less than 4% of the time. Baseline renal function of study participant was reported in only 7% of trials. Patients with CKD are frequently excluded from coronary artery disease trials and renal function of randomized subjects is rarely reported. These findings reinforce the notion that available data on the treatment of coronary artery disease in subjects with CKD have significant limitations and should be generalized to the treatment of subjects with CKD cautiously.

Coronary artery stenting in the aged.

OBJECTIVES: The study compared the safety and efficacy of coronary artery stenting in aged and nonaged patients and identified predictors of adverse clinical outcomes. BACKGROUND: Limited data are available on the outcomes of stenting in the aged (> or = 80 years) compared to nonaged patients. METHODS: The study was a pooled analysis of 6,186 patients who underwent coronary artery stenting in six recent multicenter trials. A clinical events committee adjudicated clinical end points, and quantitative angiography was performed by an independent core laboratory. RESULTS: There were 301 (4.9%) aged patients (> or = 80 years). Compared to nonaged patients, aged patients had a higher prevalence of multivessel disease (16.5% vs. 9.6%, p = 0.001), unstable angina (50.8% vs. 42.1%, p = 0.003), moderate to severe target lesion calcification (30.4% vs. 15.3%, p = 0.001) and smaller reference vessel diameter (2.90 mm vs. 2.98 mm, p = 0.004). Procedural success rate (97.4% vs. 98.5%, p = 0.14) was similar in the two groups. In-hospital mortality (1.33% vs. 0.10%, p = 0.001), bleeding complications (4.98% vs. 1.00%, p < 0.001) and one-year mortality (5.65% vs. 1.41%, p < 0.001) were significantly higher for the aged patients. Clinical restenosis was similar for the two groups (11.19% vs. 11.93%, p = 0.78). Advanced age, diabetes, prior myocardial infarction and presence of three-vessel disease were independent predictors of long-term mortality. CONCLUSIONS: Coronary artery stenting can be performed safely in patients > or = 80 years of age, with excellent acute results and a low rate of clinical restenosis, albeit with higher incidences of in-hospital and long-term mortality, and vascular and bleeding complications compared to nonaged patients.

Economic assessment of rheolytic thrombectomy versus intracoronary urokinase for treatment of extensive intracoronary thrombus: Results from a randomized clinical trial.

BACKGROUND: Despite advances in mechanical and pharmacologic therapy, thrombus-containing lesions are at high risk for adverse events and remain a challenging subset for percutaneous coronary revascularization. Recently, rheolytic thrombectomy with the AngioJet device has been shown to safely remove intracoronary thrombus, but the overall cost-effectiveness of this technique is unknown. METHODS: We determined in-hospital and 1-year follow-up costs for 349 patients with overt intracoronary thrombus who were randomly assigned to treatment with intracoronary urokinase (6- to 30-hour infusion followed by definitive revascularization; n = 169) or immediate thrombectomy with the AngioJet device (n = 180) as part of the Vein Graft AngioJet Study (VeGAS) 2 trial. Catheterization laboratory costs were based on measured resource utilization and 1998 unit costs, whereas all other costs were estimated from hospital charges and cost center-specific cost-to-charge ratios. RESULTS: Compared with urokinase, rheolytic thrombectomy reduced the incidence of periprocedural myocardial infarction (12.8% vs 30.3%, P <.001) and major hemorrhagic complications (2.8% vs 11.2%, P <.001) and shortened length of stay by nearly 1 day (4.2 vs 4.9 days; P =.02). As a result, AngioJet treatment reduced procedural costs, hospital room/nursing costs, and ancillary costs with resulting hospital cost savings of approximately $3500 per patient during the initial hospitalization ($15,311 vs $18,841, P <.001). These cost savings were maintained at 1 year of follow-up ($24,389 vs $29,109, P <.001). CONCLUSIONS: Compared with standard treatment with intracoronary urokinase, rheolytic thrombectomy both improves clinical outcomes and reduces overall medical care costs for patients with extensive intracoronary thrombus.

Impact of smoking on clinical and angiographic restenosis after percutaneous coronary intervention: another smoker's paradox?

BACKGROUND: Recent studies have suggested that smokers may require less frequent repeated revascularization after percutaneous coronary intervention (PCI) compared with nonsmokers. However, the mechanism of this phenomenon is unknown. METHODS AND RESULTS: We examined the association between smoking and restenosis using pooled data from 8671 patients treated with PCI in 9 multicenter clinical trials. Clinical restenosis was examined in the cohort of 5682 patients who were assigned to clinical follow-up only. Angiographic restenosis was evaluated in the subset of 2989 patients who were assigned to mandatory angiographic restudy. Among those patients assigned to clinical follow-up only, target lesion revascularization (TLR) occurred in 6.6% of smokers and 10.1% of nonsmokers (P<0.001). After adjustment for baseline clinical and angiographic differences, the rate of TLR remained significantly lower in smokers with an adjusted relative risk of 0.69 (95% CI, 0.54 to 0.88). Among the angiographic cohort, there were no differences in the rates of angiographic restenosis or follow-up diameter stenosis in either univariate or multivariate analyses. This dissociation between clinical and angiographic restenosis was explained in part by reduced sensitivity to restenosis on the part of smokers and by the greater reluctance of smokers to seek medical attention despite recurrent angina. CONCLUSIONS: In patients undergoing contemporary PCI, cigarette smoking is associated with a lower rate of subsequent TLR without affecting angiographic restenosis. These findings have important implications for the follow-up of smokers after PCI and suggest that cross-study comparisons of rates of clinical restenosis must account for the potential confounding effect of smoking.

Stent thrombosis in the modern era: a pooled analysis of multicenter coronary stent clinical trials.

BACKGROUND: There are limited studies of stent thrombosis in the modern era of second-generation stents, high-pressure deployment, and current antithrombotic regimens. METHODS AND RESULTS: Six recently completed coronary stent trials and associated nonrandomized registries that enrolled 6186 patients (6219 treated vessels) treated with >/=1 coronary stent followed by antiplatelet therapy with aspirin and ticlopidine were pooled for this analysis. Within 30 days, clinical stent thrombosis developed in 53 patients (0.9%). The variables most significantly associated with the probability of stent thrombosis were persistent dissection NHLBI grade B or higher after stenting (OR, 3.7; 95% CI, 1.9 to 7.7), total stent length (OR, 1.3; 95% CI, 1.2 to 1.5 per 10 mm), and final minimal lumen diameter within the stent (OR, 0.4; 95% CI, 0.2 to 0.7 per 1 mm). Stent thrombosis was documented by angiography in 45 patients (0.7%). Clinical consequences of angiographic stent thrombosis included 64.4% incidence of death or myocardial infarction at the time of stent thrombosis and 8.9% 6-month mortality. CONCLUSIONS: Stent thrombosis occurred in <1.0% of patients undergoing stenting of native coronary artery lesions and receiving routine antiplatelet therapy with aspirin plus ticlopidine. Procedure-related variables of persistent dissection, total stent length, and final lumen diameter were significantly associated with the probability of stent thrombosis. Continued efforts to eliminate this complication are warranted given the serious clinical consequences.

Preintervention arterial remodeling affects clinical outcome following stenting: an intravascular ultrasound study.

OBJECTIVES: The study was done to elucidate the relationship between baseline arterial remodeling and clinical outcome following stenting. BACKGROUND: The impact of preintervention arterial remodeling on subsequent vessel response and clinical outcome has been reported following nonstent coronary interventions. However, in stented segments, the impact of preintervention remodeling on clinical outcome has not been clarified. METHODS: Preintervention remodeling was assessed in 108 native coronary lesions by using intravascular ultrasound (IVUS). Positive remodeling (PR) was defined as vessel area (VA) at the target lesion greater than that of average reference segments. Intermediate or negative remodeling (IR/NR) was defined as VA at the target lesion less than or equal to that of average reference segment. Remodeling index expressed as a continuous variable was defined as VA at the target lesion site divided by that of average reference segments. RESULTS: Positive remodeling was present in 59 (55%) and IR/NR in 49 (45%) lesions. Although final minimal stent areas were similar (7.76 +/- 1.80 vs. 8.09 +/- 1.90 mm2, p = 0.36), target vessel revascularization (TVR) rate at nine-month follow-up was significantly higher in the PR group (22.0% vs. 4.1%, p = 0.01). By multivariate logistic regression analysis, higher remodeling index was the only independent predictor of TVR (p = 0.02). CONCLUSIONS: Lesions with PR before intervention appear to have a worse clinical outcome following IVUS-guided stenting. Intravascular ultrasound imaging before stenting may be helpful to stratify lesions at high risk for accelerated intimal proliferation.

Results of the study to determine rotablator and transluminal angioplasty strategy (STRATAS).

Rotational atherectomy is used to debulk calcified or complex coronary stenoses. Whether aggressive burr sizing with minimal balloon dilation (<1 atm) to limit deep wall arterial injury improves results is unknown. Patients being considered for elective rotational atherectomy were randomized to either an "aggressive" strategy (n = 249) (maximum burr/artery >0.70 alone, or with adjunctive balloon inflation < or = 1 atm), or a "routine" strategy (n = 248) (maximum burr/artery < or =0.70 and routine balloon inflation > or =4 atm). Patient age was 62 +/- 11 years. Fifty-nine percent routine and 60% aggressive strategy patients had class III to IV angina. Fifteen percent routine and 16% aggressive strategy patients had a restenotic lesion treated; lesion length was 13.6 versus 13.7 mm. Reference vessel diameter was 2.64 mm. Maximum burr size (1.8 vs 2.1 mm), burr/artery ratio (0.71 vs 0.82), and number of burrs used (1.9 vs 2.7) were greater for the aggressive strategy, p <0.0001. Final minimum lumen diameter and residual stenosis were 1.97 mm and 26% for the routine strategy versus 1.95 mm and 27% for the aggressive strategy. Clinical success was 93.5% for the routine strategy and 93.9% for the aggressive strategy. Creatine kinase-myocardial band (CK-MB) was >5 times normal in 7% of the routine versus 11% of the aggressive group. CK-MB elevation was associated with a decrease in rpm of >5,000 from baseline for a cumulative time >5 seconds, p = 0.002. At 6 months, 22% of the routine patients versus 31% of the aggressive strategy patients had target lesion revascularization. Angiographic follow-up (77%) showed minimum lumen diameter to be 1.26 mm in the routine group versus 1.16 mm in the aggressive group, and the loss index 0.54 versus 0.62. Dichotomous restenosis was 52% for the routine strategy versus 58% for the aggressive strategy. Multivariable analysis indicated that left anterior descending location (odds ratio 1.67, p = 0.02) and operator-reported excessive speed decrease >5,000 rpm (odds ratio 1.74, p = 0.01) were significantly associated with restenosis. Thus, the aggressive rotational atherectomy strategy offers no advantage over more routine burr sizing plus routine angioplasty. Operator technique reflected by an rpm decrease of >5,000 from baseline is associated with CK-MB elevation and restenosis.

Rheolytic thrombectomy during percutaneous revascularization for acute myocardial infarction: experience with the AngioJet catheter.

BACKGROUND: Although balloon angioplasty and stenting are effective in the treatment of acute myocardial infarction (MI), reduced coronary flow and distal embolization frequently complicate interventions when thrombus is present. Adjunctive treatment with mechanical thrombectomy devices may reduce these complications. METHODS AND RESULTS: We evaluated the angiographic and clinical outcomes of 70 patients with acute MI (16% with cardiogenic shock) and with angiographically evident thrombus who were treated with AngioJet rheolytic thrombectomy followed by immediate definitive treatment. Procedure success (residual diameter stenosis <50% and Thrombolysis in Myocardial Infarction [TIMI] flow > or =2 after final treatment) was achieved in 93.8%. Clinical success (procedure success without major in-hospital cardiac events) was achieved in 87.5%, with an in-hospital mortality rate of 7.1%. Final TIMI 3 flow was achieved in 87.7%. AngioJet treatment resulted in a mean thrombus area reduction from 73.2 +/- 64.6 mm(2) at baseline to 15.5 +/- 30.1 post-thrombectomy (P <.001). Subsequent definitive treatment included stenting in 67% and balloon angioplasty alone in 26% of patients. Procedural complications included distal embolization in six patients and perforation in two patients. There were no further major adverse events during 30-day follow-up. CONCLUSION: Rheolytic thrombectomy can be performed safely and effectively in patients with acute MI, allowing for immediate definitive treatment in thrombus-containing lesions.

Comparison of endocardial electromechanical mapping with radionuclide perfusion imaging to assess myocardial viability and severity of myocardial ischemia in angina pectoris.

The assessment of left ventricular electromechanical activity using a novel, nonfluoroscopic 3-dimensional mapping system demonstrates considerable differences in electrical and mechanical activities within regions of myocardial infarction or ischemia. We sought to determine whether these changes correlate with indexes of myocardial perfusion, viability, or ischemia. A 12-segment comparative analysis was performed in 61 patients (45 men, 61 +/- 12 years old) with class III to IV angina, having reversible and/or fixed myocardial perfusion defects on single-photon emission computed tomographic perfusion imaging. A dual-isotope protocol was used, consisting of rest and 4-hour redistribution thallium images followed by adenosine technetium-99m sestamibi imaging. Average rest endocardial unipolar voltage (UpV) and local shortening (LS) mapping values were compared with visually derived perfusion scores. There was gradual and proportional reduction in regional UpV and LS in relation to thallium-201 uptake score at rest (p = 0.0001 and p = 0.0002, respectively) and redistribution studies (p = 0.0001 and p = 0.003, respectively). UpV > or = 7.4 mV and LS > or = 5.0% had a sensitivity of 78% and 65%, respectively, with a specificity of 68% and 67% for detecting viable myocardium. UpV values of 12.3 and 5.4 mV had 90% specificity and sensitivity, respectively, to predict viable tissue. UpV, but not LS, values differentiated between normal segments and those with adenosine-induced severe perfusion defects (11.8 +/- 5.3 vs 8.8 +/- 4.1 mV, p = 0.005). Catheter-based left ventricular assessment of electromechanical activity correlates with the degree of single-photon emission computed tomographic perfusion abnormality and can identify myocardial viability with a greater accuracy than myocardial ischemia.

Immediate and late clinical outcomes of carotid artery stenting in patients with symptomatic and asymptomatic carotid artery stenosis: a 5-year prospective analysis.

BACKGROUND: Carotid stenting is a less invasive percutaneous procedure than carotid endarterectomy for the treatment of carotid stenosis. Reports suggest that it can be performed with periprocedural complication rates similar to those of carotid endarterectomy. The purpose of this study was to determine short- and long-term outcomes in the largest prospective cohort of carotid stenting patients. METHODS AND RESULTS: This study followed 528 consecutive patients (604 hemispheres/arteries) undergoing carotid stenting. There was a 0.6% (n=3) fatal stroke rate and 1% (n=5) nonstroke death rate at 30 days. The major stroke rate was 1% (n=6), and the minor stroke rate was 4.8% (n=29). The overall 30-day stroke and death rate was 7.4% (n=43). Over the 5-year study period, the 30-day minor stroke rate improved from 7.1% (n=7) for the first year to 3.1% (n=5) for the fifth year (P:<0.05 for trend). The best predictor of 30-day stroke and death was age >/=80 years. After the 30-day period, the incidence of fatal and nonfatal stroke was 3.2% (n=31). On Kaplan-Meier analysis, the 3-year freedom from ipsilateral or fatal stroke was 92+/-1%. CONCLUSIONS: Experience from a single group of operators demonstrates that carotid stenting can be performed with an acceptable 30-day complication rate. Late follow-up also demonstrates a low rate of fatal and nonfatal stroke. These results suggest that carotid stenting may be comparable to carotid endarterectomy, and it underscores the clinical equipoise and premise for the National Institute of Health-supported, randomized Carotid Revascularization Endarterectomy Versus Stent Trial comparing carotid stenting with carotid endarterectomy.

Localized intracoronary gamma-radiation therapy to inhibit the recurrence of restenosis after stenting.

BACKGROUND: Although the frequency of restenosis after coronary angioplasty is reduced by stenting, when restenosis develops within a stent, the risk of subsequent restenosis is greater than 50 percent. We report on a multicenter, double-blind, randomized trial of intracoronary radiation therapy for the treatment of in-stent restenosis. METHODS: Of 252 eligible patients in whom in-stent restenosis had developed, 131 were randomly assigned to receive an indwelling intracoronary ribbon containing a sealed source of iridium-192, and 121 were assigned to receive a similar-appearing nonradioactive ribbon (placebo). RESULTS: The primary end point, a composite of death, myocardial infarction, and the need for repeated revascularization of the target lesion during nine months of follow-up, occurred in 53 patients assigned to placebo (43.8 percent) and 37 patients assigned to iridium-192 (28.2 percent, P=0.02). However, the reduction in the incidence of major adverse cardiac events was determined solely by a diminished need for revascularization of the target lesion, not by reductions in the incidence of death or myocardial infarction. Late thrombosis occurred in 5.3 percent of the iridium-192 group, as compared with 0.8 percent of the placebo group (P=0.07), resulting in more late myocardial infarctions in the iridium-192 group (9.9 percent vs. 4.1 percent, P=0.09). Late thrombosis occurred in irradiated patients only after the discontinuation of oral antiplatelet therapy (with ticlopidine or clopidogrel) and only in patients who had received new stents at the time of radiation treatment. CONCLUSIONS: Intracoronary irradiation with iridium-192 resulted in lower rates of clinical and angiographic restenosis, although it was also associated with a higher rate of late thrombosis, resulting in an increased risk of myocardial infarction. If the problem of late thrombosis within the stent can be overcome, intracoronary irradiation with iridium-192 may become a useful approach to the treatment of in-stent restenosis.

Final results of a randomized trial comparing the NIR stent to the Palmaz-Schatz stent for narrowings in native coronary arteries.

The NIR stent is a novel second generation tubular stent that was designed to overcome some of the limitations of the earlier Palmaz-Schatz (PS) stent design. The NIR Vascular Advanced North American (NIRVANA) trial randomized 849 patients with single coronary lesions to treatment with the NIR stent or the PS stent. The study was an "equivalency" trial, designed to demonstrate that the NIR stent was not inferior to (i.e., equivalent or better than) the PS stent, for the primary end point of target vessel failure (defined as death, myocardial infarction, or target vessel revascularization) by 9 months. Successful stent delivery was achieved in 100% versus 98.8%, respectively, with a slightly lower postprocedural diameter stenosis (7% vs. 9%, p = 0.04) after NIR and PS stent placement, respectively. Major adverse cardiac events (death, myocardial infarction, repeat target lesion revascularization) were not different at 30 days (4.3% vs. 4.4%). The primary end point of target vessel failure at 9 months was seen in 16.0% of NIR versus 17.2% of PS patients, with the NIR proving to be equal or superior to the PS stent (p <0.001 by test for equivalency). Angiographic restudy in 71% of a prespecified cohort showed no significant difference in restenosis (19.3% vs 22.4%). Thus, the NIR stent showed excellent deliverability with slightly better acute angiographic results and equivalent or better 9-month target vessel failure rate when compared with the PS stent.

Final results of a randomized trial comparing the MULTI-LINK stent with the Palmaz-Schatz stent for narrowings in native coronary arteries.

The MULTI-LINK (ML) stent is a novel second generation coronary stent. The ACS MultiLink Stent Clinical Equivalence in De Novo Lesions Trial (ASCENT) randomized 1,040 patients with single, de novo native vessel lesions to treatment with the ML stent or the benchmark Palmaz-Schatz (PS) stent, to demonstrate that the ML stent was not inferior to (i.e., equivalent or better than) the PS stent in terms of target vessel failure by 9 months. Successful stent delivery was achieved in 98.8% versus 96.9% of patients, with a slightly lower postprocedural diameter stenosis (8% vs 10%, p = 0.04), and no difference in 30-day major adverse cardiac events (5.0% vs 6.5%) for the ML stent versus the PS stent. The primary end point of target vessel failure at 9 months was seen in 15.1% of ML-treated patients versus 16.7% of PS-treated patients, with the ML proving to be equal or superior to the PS stent (p <0.001 by test for equivalency). In a prespecified subset, angiographic restudy showed a nonsignificant trend for reduced ML restenosis (16.0% vs 22.1%). Thus, the ML stent showed excellent deliverability and acute results, with 9-month clinical and 6-month angiographic outcomes that were equivalent or better than the PS stent.

Cardiac surgery report cards: comprehensive review and statistical critique.

Public report cards and confidential, collaborative peer education represent distinctly different approaches to cardiac surgery quality assessment and improvement. This review discusses the controversies regarding their methodology and relative effectiveness. Report cards have been the more commonly used approach, typically as a result of state legislation. They are based on the presumption that publication of outcomes effectively motivates providers, and that market forces will reward higher quality. Numerous studies have challenged the validity of these hypotheses. Furthermore, although states with report cards have reported significant decreases in risk-adjusted mortality, it is unclear whether this improvement resulted from public disclosure or, rather, from the development of internal quality programs by hospitals. An additional confounding factor is the nationwide decline in heart surgery mortality, including states without quality monitoring. Finally, report cards may engender negative behaviors such as high-risk case avoidance and "gaming" of the reporting system, especially if individual surgeon results are published. The alternative approach, continuous quality improvement, may provide an opportunity to enhance performance and reduce interprovider variability while avoiding the unintended negative consequences of report cards. This collaborative method, which uses exchange visits between programs and determination of best practice, has been highly effective in northern New England and in the Veterans Affairs Administration. However, despite their potential advantages, quality programs based solely on confidential continuous quality improvement do not address the issue of public accountability. For this reason, some states may continue to mandate report cards. In such instances, it is imperative that appropriate statistical techniques and report formats are used, and that professional organizations simultaneously implement continuous quality improvement programs. The statistical methodology underlying current report cards is flawed, and does not justify the degree of accuracy presented to the public. All existing risk-adjustment methods have substantial inherent imprecision, and this is compounded when the results of such patient-level models are aggregated and used inappropriately to assess provider performance. Specific problems include sample size differences, clustering of observations, multiple comparisons, and failure to account for the random component of interprovider variability. We advocate the use of hierarchical or multilevel statistical models to address these concerns, as well as report formats that emphasize the statistical uncertainty of the results.

Randomized comparison of GR-II stent and Palmaz-Schatz stent for elective treatment of coronary stenoses.

BACKGROUND: This prospective multicenter randomized clinical trial was designed to evaluate the long-term angiographic and clinical outcomes of elective treatment with the GR-II stent compared with the Palmaz-Schatz (PS) stent in patients with coronary stenoses. METHODS AND RESULTS: Seven hundred fifty-five patients with myocardial ischemia and de novo native coronary stenoses in 3- to 4-mm vessels were randomly assigned to the PS (375 patients) or the GR-II stent (380 patients). The primary end point was 12-month target lesion revascularization (TLR)-free survival. Angiography was performed at baseline and at follow-up in the first 300 consecutive patients to assess the frequency of angiographic restenosis. Procedure success was 98.5% for the GR-II stent and 99.4% for the PS stent (P:=0.19). At 30 days, patients assigned to the GR-II stent had a higher stent thrombosis rate (3.9% versus 0.3% for PS stent, P:<0.001) and TLR rate (3.9% versus 0.5% for PS stent, P:<0.001). The GR-II group had a higher follow-up restenosis frequency (47.3% versus 20.6% for the PS group, P:<0.001) and a lower 12-month TLR-free survival rate (71.7% versus 83.9% for the PS group, P:<0. 001). Multivariate logistic regression analysis identified a smaller final stent minimal lumen diameter (odds ratio [OR] 2.49, 95% CI 1. 56 to 3.98; P:<0.001), diabetes mellitus (OR 2.14, 95% CI 1.42 to 3. 22; P:<0.001), and use of the GR-II stent (OR 1.78, 95% CI 1.20 to 2. 64; P:<0.01) as independent determinants of 12-month TLR. CONCLUSIONS: On the basis of these long-term follow-up data, we conclude that use of the GR-II stent should be limited to the acute treatment of abrupt or threatened closure after failed conventional balloon angioplasty procedures.