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The success of device-based research in the clinical neurosciences has overshadowed a critical and emerging problem in the biomedical research environment in the United States. Neuroprosthetic devices, such as deep brain stimulation (DBS), have been shown in humans to be promising technologies for scientific exploration of neural pathways and as powerful treatments. Large device companies have, over the past several decades, funded and developed major research programs. However, both the structure of clinical trial funding and the current regulation of device research threaten investigator-initiated efforts in neurologic disorders. The current atmosphere dissuades clinical investigators from pursuing formal and prospective research with novel devices or novel indications. We review our experience in conducting a federally funded, investigator-initiated, device-based clinical trial that utilized DBS for thalamic pain syndrome. We also explore barriers that clinical investigators face in conducting device-based clinical trials, particularly in early-stage studies or small disease populations. We discuss 5 specific areas for potential reform and integration: (1) alternative pathways for device approval; (2) eliminating right of reference requirements; (3) combining federal grant awards with regulatory approval; (4) consolidation of oversight for human subjects research; and (5) private insurance coverage for clinical trials. Careful reformulation of regulatory policy and funding mechanisms is critical for expanding investigator-initiated device research, which has great potential to benefit science, industry, and, most importantly, patients.

Background Dual antiplatelet therapy with clopidogrel plus low-dose aspirin has not been studied in a broad population of patients at high risk for atherothrombotic events. Methods We randomly assigned 15,603 patients with either clinically evident cardiovascular disease or multiple risk factors to receive clopidogrel (75 mg per day) plus low-dose aspirin (75 to 162 mg per day) or placebo plus low-dose aspirin and followed them for a median of 28 months. The primary efficacy end point was a composite of myocardial infarction, stroke, or death from cardiovascular causes. Results The rate of the primary efficacy end point was 6.8 percent with clopidogrel plus aspirin and 7.3 percent with placebo plus aspirin (relative risk, 0.93; 95 percent confidence interval, 0.83 to 1.05; P = 0.22). The respective rate of the principal secondary efficacy end point, which included hospitalizations for ischemic events, was 16.7 percent and 17.9 percent (relative risk, 0.92; 95 percent confidence interval, 0.86 to 0.995; P = 0.04), and the rate of severe bleeding was 1.7 percent and 1.3 percent (relative risk, 1.25; 95 percent confidence interval, 0.97 to 1.61 percent; P = 0.09). The rate of the primary end point among patients with multiple risk factors was 6.6 percent with clopidogrel and 5.5 percent with placebo (relative risk, 1.2; 95 percent confidence interval, 0.91 to 1.59; P = 0.20) and the rate of death from cardiovascular causes also was higher with clopidogrel (3.9 percent vs. 2.2 percent, P = 0.01). In the subgroup with clinically evident atherothrombosis, the rate was 6.9 percent with clopidogrel and 7.9 percent with placebo (relative risk, 0.88; 95 percent confidence interval, 0.77 to 0.998; P = 0.046). Conclusions In this trial, there was a suggestion of benefit with clopidogrel treatment in patients with symptomatic atherothrombosis and a suggestion of harm in patients with multiple risk factors. Overall, clopidogrel plus aspirin was not significantly more effective than aspirin alone in reducing the rate of myocardial infarction, stroke, or death from cardiovascular causes. (ClinicalTrials.gov number, NCT00050817.)

Objectives We studied the outcome of diabetics enrolled in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) V trial to assess whether the combination of half-dose reteplase and abciximab provides any propitious benefits over standard fibrinolytic therapy in diabetic patients. Background Diabetics with acute ST-segment elevation myocardial infarction (MI) have a worse outcome compared with nondiabetics. Higher-risk patients are usually more likely to benefit from advances in medical therapy. Methods We analyzed diabetic patients enrolled in the GUSTO V trial to assess the outcome of those randomized to the combination of half-dose reteplase and abciximab versus those randomized to reteplase. We also evaluated whether any differences existed in presentation and outcome of MI among the diabetics versus the nondiabetics enrolled in the study. Results The trial enrolled 13,782 nondiabetics and 2,633 diabetics. Compared to nondiabetics, diabetics had a significantly higher mortality at 30 days (8.5% vs. 5.1%, p Conclusions Compared to nondiabetics, diabetics continue to have a worse outcome with MI. Although combination therapy did not provide a survival benefit, nonfatal ischemic outcomes, including reinfarction, recurrent ischemia, and urgent revascularization, were substantially reduced.

BACKGROUND The clinical guidelines for unstable angina (UA) and non-ST elevation myocardial infarction (NSTEMI) published in 1994 by the Agency for Health Care Policy Research (AHCPR) were intended to help improve treatment. No large study, however, has evaluated the effect of the guidelines on clinical practice METHODS We compared the treatment of 3,318 patients admitted with UA/NSTEMI in the preguideline Thrombolysis in Myocardial Infarction (TIMI) III Registry (1990-1993) and 2,948 patients enrolled in the postguideline Global Unstable Angina Registry and Treatment Evaluation (GUARANTEE) Registry (1995-1996). RESULTS More patients in GUARANTEE received guideline-recommended medication than did those in TIMI III, specifically beta-blockers (50.9% vs. 40.7%, P < 0.001), heparin (63.3% versus 57.5%, P < 0.001), and the combination of aspirin, heparin, and beta-blockers on admission plus aspirin at discharge (26.9% vs. 18.8%, P < 0.001). These changes were similar in all subgroups, but the greatest improvement in medication use was seen in patients admitted to a tertiary care hospital and in those with a final diagnosis of NSTEMI, i.e., with positive cardiac markers. Conversely, fewer patients in GUARANTEE who fulfilled AHCPR criteria for catheterization underwent the procedure (62.3% in GUARANTEE tertiary centers vs. 44.6% in GUARANTEE nontertiary centers vs. 66.0% in TIMI, P < 0.001). CONCLUSION After publication of clinical guidelines for UA/NSTEMI, more patients received appropriate pharmacologic treatment, but a significant number of patients remained under-treated. Efforts to improve compliance with guideline recommendations via education and critical pathways are warranted, especially in nontertiary care settings.

Background and Methods: Because time to presentation to the hospital affects time to treatment and is known to be important in acute myocardial infarction, we evaluated this variable in patients with unstable angina/non-ST segment elevation myocardial infarction (UA/NSTEMI). Among 2909 consecutive patients with UA/NSTEMI admitted to 35 hospitals in 6 geographic regions of the United States, we compared patients with acute (onset of pain 12 hours) unstable angina.

Background . Abciximab during percutaneous coronary revascularization reduces ischemic complications, but concern exists regarding increased bleeding risk should emergency coronary surgical procedures be required. Methods . Outcomes were assessed among 85 patients who required coronary artery bypass grafting operations after coronary intervention in two randomized placebo-controlled trials of abciximab. Comparisons were made between patients in the pooled placebo and abciximab groups. Results . The incidence of coronary surgical procedures was 2.17% and 1.28% among patients randomized to placebo and abciximab, respectively ( p = 0.021). Platelet transfusions were administered to 32% and 52% of patients in the placebo and abciximab groups, respectively ( p = 0.059). Rates of major blood loss were 79% and 88% in the placebo and abciximab groups, respectively ( p = 0.27); transfusions of packed red blood cells or whole blood were administered in 74% and 80% of patients, respectively ( p = 0.53). Surgical reexploration for bleeding was required in 3% and 12% of patients, respectively. Death and myocardial infarction tended to occur less frequently among patients who had received abciximab. Conclusions . Urgent coronary artery bypass grafting operations can be performed without an incremental increase in major hemorrhagic risk among patients on abciximab therapy.

Background —Stenting likely decreases the need for target-vessel revascularization procedures in diabetic patients compared with balloon angioplasty. However, the efficacy of stenting with platelet glycoprotein IIb/IIIa blockade has not yet been assessed in diabetics. Methods and Results —We analyzed the outcomes of 491 diabetic patients within the multicenter Evaluation of Platelet IIb/IIIa Inhibitor for Stenting Trial (EPISTENT). Diabetic patients were a prospectively defined subset: 173 were randomized to stent-placebo, 162 to stent-abciximab, and 156 to balloon angioplasty–abciximab. The main end point for this analysis was combined 6-month death, myocardial infarction (MI), or target-vessel revascularization (TVR). The composite end point occurred in 25.2% of stent-placebo, 23.4% of balloon-abciximab, and 13.0% of stent-abciximab patients ( P =0.005). Abciximab therapy, irrespective of revascularization strategy (stent or balloon angioplasty), resulted in a significant reduction in the 6-month death or MI rate: 12.7% for stent-placebo, 7.8% for balloon angioplasty–abciximab, and 6.2% for the stent-abciximab group ( P =0.029). The 6-month TVR rate was 16.6% for stent-placebo, 18.4% for balloon-abciximab, and 8.1% for stent-abciximab ( P =0.021). Compared with stent-placebo, stent-abciximab therapy was associated with a significant increase in angiographic net gain (0.88 versus 0.55 mm; P =0.011) and a decrease in the late loss index (0.40 versus 0.60 mm; P =0.061). The 1-year mortality rate for diabetics was 4.1% for stent-placebo and 1.2% for stent-abciximab patients ( P =0.11). Conclusions —The combination of stenting and abciximab therapy among diabetics resulted in a significant reduction in 6-month rates of death, MI, and TVR compared with stent-placebo or balloon-abciximab therapy.

Background Prior studies, usually conducted with the use of insurance databases, have shown differences in the use of cardiac procedures between black patients and white patients hospitalized with various types of coronary artery disease. However, few data are available in prospectively collected cohorts of patients with unstable angina or on the use of appropriate medications or interventions. Methods and Results We evaluated 2948 consecutive patients with unstable angina admitted to 35 hospitals across the United States in 1996, comparing nonwhite and white patients. Seventy-seven percent of patients were white, 14% were black, 4% were Hispanic, 1% were Asian, and 3% were other or unknown race. Differences were seen in coronary risk profile, with a higher incidence of hypertension and diabetes mellitus in nonwhites. Cardiac catheterization was performed less often in nonwhites compared with whites (36% vs 53%, P = .001). Even in patients meeting the criteria for appropriate catheterization in the Agency for Health Care Policy Research unstable angina guidelines, fewer nonwhites underwent catheterization (44% vs 61%, P = .001), but among these, fewer nonwhites had significant coronary stenosis (72% vs 90%, P = .001). However, among patients catheterized who had indications for revascularization, angioplasty and coronary artery bypass grafting were performed equally often in nonwhites and whites. Conclusions Current guidelines would recommend more aggressive use of cardiac catheterization for nonwhite patients. However, our findings suggest that racial differences may need to be included in the diagnostic and interventional algorithms. (Am Heart J 1999;138:1065-72.)

Summary Background We assessed in a randomised trial the long-term outcomes for potent adjunctive antiplatelet therapy given at the time of coronary stenting. Methods In 63 hospitals in the USA and Canada, 2399 patients were randomly assigned stenting with abciximab, stenting with placebo, or balloon angioplasty with abciximab. Standard adjunctive therapy with aspirin, tictopidine, and heparin was used. The major outcomes of death and myocardial infarction were assessed at 1-year follow-up by intention to treat We also investigated the 1-year costeffectiveness of combined stenting and abciximab therapy. Findings At 1-year follow-up, eight (1·0%) of 794 patients in the stent plus abciximab group had died, compared with 19 (2·4%) of 809 in the stent plus placebo group (hazard ratio 0·43 [95% CI 0·19–0·97], p=0·037). The combined endpoint of death or large myocardial infarction occurred in 42 (5·3%) and 89 (11·0%), respectively (0·46 [0·32–0·67], p Interpretation Coronary stenting with abciximab, compared with stenting alone or balloon angioplasty with abciximab, is associated with improved survival and is an economically attractive therapy by conventional standards.

Few data are available in prospectively collected cohorts of patients with unstable angina pectoris or on the use of appropriate medications or interventions. Accordingly, we evaluated 2,948 consecutive patients with unstable angina admitted to 35 hospitals in the United States in 1996, and comparing men and women (39% of the patients were women). Differences were seen in coronary risk profiles with a higher incidence of systemic hypertension, diabetes mellitus, and a family history of coronary disease in women. Women were less likely to receive Agency for Health Care Policy Research (AHCPR) recommended pharmacologic treatment than men. Cardiac catheterization, coronary angioplasty, and bypass was performed less often in women compared with men (44% vs. 53%, p = 0.002; 12% vs. 18%, p = 0.02; 7% vs. 10%, p = 0.001, respectively). At catheterization, women were more likely to have no significant coronary artery disease (25% vs. 14%, p = 0.001). Although fewer women than men fulfilled the AHCPR criteria for cardiac catheterization (54% vs. 64%, p = 0.001), a similar rate of men and women with positive criteria underwent catheterization and angioplasty. However, fewer women with positive criteria underwent bypass surgery (36% vs. 46%, p = 0.03). More men "ruled-in" for a myocardial infarction at admission (13% vs. 8%, p = 0.001), but there was no difference in recurrent angina, in-hospital myocardial infarction, or death. Despite different epidemiologic profiles and less evidence of coronary artery disease by noninvasive and invasive tests, women and men had similar outcomes.

Background Inhibition of the platelet glycoprotein IIb/IIIa receptor with the monoclonal-antibody fragment abciximab reduces the acute ischemic complications associated with percutaneous coronary revascularization, whereas coronary-stent implantation reduces restenosis. We conducted a trial to determine the efficacy of abciximab and stent implantation in improving long-term outcome. Methods A total of 2399 patients were randomly assigned to stent implantation and placebo, stent implantation and abciximab, or balloon angioplasty and abciximab. The patients were followed for six months. Results At six months, the incidence of the composite end point of death or myocardial infarction was 11.4 percent in the group that received a stent and placebo, as compared with 5.6 percent in the group that received a stent and abciximab (hazard ratio, 0.47; 95 percent confidence interval, 0.33 to 0.68; P

Background —Blockade of the platelet glycoprotein IIb/IIIa receptor with the monoclonal antibody fragment abciximab was shown in a placebo-controlled randomized trial to reduce the incidence of acute ischemic complications within 30 days among a broad spectrum of patients undergoing percutaneous coronary revascularization. The durability of clinical benefit in this setting has not been established. Methods and Results —A total of 2792 patients enrolled in the Evaluation in PTCA to Improve Long-term Outcome with abciximab GP IIb/IIIa blockade (EPILOG) trial were followed with maintenance of double-blinding for 1 year. Patients had been assigned at the time of their index coronary interventional procedure to receive placebo with standard-dose, weight-adjusted heparin (100 U/kg initial bolus), abciximab with standard-dose, weight-adjusted heparin, or abciximab with low-dose, weight-adjusted heparin (70 U/kg initial bolus). The primary outcome was the composite of death, myocardial infarction, or urgent repeat revascularization by 30 days; this composite end point and its individual components were also assessed at 6 months and 1 year. Rates of any repeat revascularization (urgent or elective), target vessel revascularization, and a composite of death, myocardial infarction, or any repeat revascularization were also reported. Follow-up at 1 year was 99% complete for survival status and 97% complete for other end points. By 1 year, the incidence of the primary composite end point was 16.1% in the placebo group, 9.6% in the abciximab with low-dose heparin group ( P P Conclusions —Acute reductions in ischemic events after percutaneous coronary intervention by abciximab are sustained over follow-up to at least 1 year. Early periprocedural myocardial infarctions suppressed by this therapy are associated with long-term mortality rates.

Objectives. The purpose of this study was to investigate whether or not there is an association between managed care insurance and the delivery and outcome of care in patients presenting with unstable angina. Background. The proportion of U.S. patients with managed care health insurance is increasing. This may be associated with recent improvements in the control of health care costs. It is unknown whether or not there is a difference in process of care in angina patients presenting with managed care versus fee-for-service health insurance. Methods. We compared baseline characteristics, process and outcome of care in 636 patients with managed care insurance (MC) and 1,404 patients with fee-for-service (FFS) insurance who presented with unstable angina to 35 hospitals participating in the global Unstable Angina Registry and Treatment Evaluation (GUARANTEE) Registry. Results. Although, there was little difference in baseline characteristics and hospital treatments between cohorts, MC patients were more likely to be discharged on guideline-recommended medications (aspirin and beta-adrenergic blocking agents). In addition, FFS patients were more likely to undergo cardiac catheterization (odds ratio = 1.25 95% confidence interval = 1.1 to 1.5), but not revascularization during the hospitalization. There was no difference in hospital mortality (0.9% versus 1.2% in MC versus FFS; p = 0.60). Conclusions. In patients admitted with suspected unstable angina, MC patients are less likely to undergo coronary angiography, but are more likely to be discharged on indicated medications.

Percutaneous cardiopulmonary bypass is a new technique for supporting systemic blood flow during high-risk coronary angioplasty procedures. This mechanical alternative, unlike traditional methods, is not limited by dependency on adequate left ventricular stroke volume. Percutaneous cardiopulmonary bypass support offers new and demanding challenges in the care of this high-risk group of patients.

The clinical guidelines for unstable angina (UA) and non-ST elevation myocardial infarction (NSTEMI) published in 1994 by the Agency for Health Care Policy Research (AHCPR) were intended to help improve treatment. No large study, however, has evaluated the effect of the guidelines on clinical practiceWe compared the treatment of 3,318 patients admitted with UA/NSTEMI in the preguideline Thrombolysis in Myocardial Infarction (TIMI) III Registry (1990-1993) and 2,948 patients enrolled in the postguideline Global Unstable Angina Registry and Treatment Evaluation (GUARANTEE) Registry (1995-1996).More patients in GUARANTEE received guideline-recommended medication than did those in TIMI III, specifically beta-blockers (50.9% vs. 40.7%, P0.001), heparin (63.3% versus 57.5%, P0.001), and the combination of aspirin, heparin, and beta-blockers on admission plus aspirin at discharge (26.9% vs. 18.8%, P0.001). These changes were similar in all subgroups, but the greatest improvement in medication use was seen in patients admitted to a tertiary care hospital and in those with a final diagnosis of NSTEMI, i.e., with positive cardiac markers. Conversely, fewer patients in GUARANTEE who fulfilled AHCPR criteria for catheterization underwent the procedure (62.3% in GUARANTEE tertiary centers vs. 44.6% in GUARANTEE nontertiary centers vs. 66.0% in TIMI, P0.001).After publication of clinical guidelines for UA/NSTEMI, more patients received appropriate pharmacologic treatment, but a significant number of patients remained under-treated. Efforts to improve compliance with guideline recommendations via education and critical pathways are warranted, especially in nontertiary care settings.

We studied the outcome of diabetics enrolled in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) V trial to assess whether the combination of half-dose reteplase and abciximab provides any propitious benefits over standard fibrinolytic therapy in diabetic patients.Diabetics with acute ST-segment elevation myocardial infarction (MI) have a worse outcome compared with nondiabetics. Higher-risk patients are usually more likely to benefit from advances in medical therapy.We analyzed diabetic patients enrolled in the GUSTO V trial to assess the outcome of those randomized to the combination of half-dose reteplase and abciximab versus those randomized to reteplase. We also evaluated whether any differences existed in presentation and outcome of MI among the diabetics versus the nondiabetics enrolled in the study.The trial enrolled 13782 nondiabetics and 2633 diabetics. Compared to nondiabetics, diabetics had a significantly higher mortality at 30 days (8.5% vs. 5.1%, p0.001) and at 1 year (12.7% vs. 7.5%, p0.001). Among the diabetic subset, no significant difference existed in the incidence of 30-day (8.8% vs. 8.2%, p = 0.52) or 1-year mortality (13.0% vs. 12.4%, p = 0.62) among patients randomized to reteplase compared to those receiving combination of abciximab and reteplase. The incidence of reinfarction (2.5% vs. 4.3%, p = 0.013), recurrent ischemia (11.8% vs. 14.9%, p = 0.017), and urgent revascularization (10.9% vs. 13.3%, p = 0.055) at seven days was lower in diabetics treated with the combination therapy.Compared to nondiabetics, diabetics continue to have a worse outcome with MI. Although combination therapy did not provide a survival benefit, nonfatal ischemic outcomes, including reinfarction, recurrent ischemia, and urgent revascularization, were substantially reduced.

Background The manifestations of atherothrombosis such as myocardial infarction, ischemic stroke, limb ischemia, or cardiovascular death pose a global health care burden. Additional therapies to decrease ischemic events in patients with established vascular disease or at risk for developing vascular disease are necessary. We sought to characterize the risk factors and treatments of a diverse contemporary population of patients with atherothrombosis. Methods The CHARISMA trial has enrolled 15 603 patients from around the world. Patients with established coronary, cerebrovascular, or peripheral arterial disease, or those at high risk of developing atherothrombosis due to multiple risk factors, have been randomized to receive either the adenosine diphosphate receptor antagonist clopidogrel or placebo, in addition to background therapy with low- to moderate-dose aspirin. Results A high percentage of enrolled patients are being treated with statins and angiotensin-converting enzyme inhibitors. In the CHARISMA population, a total of 75.6% of the population had an abnormal body mass index: 42.2% were overweight and 33.4% were obese, with particularly high rates in the United States, especially of morbid obesity. Correspondingly, the prevalence of diabetes was 42%. Conclusion The CHARISMA trial will further characterize atherothrombosis and provide insight into the role of dual antiplatelet therapy in improving outcomes in patients with multiple risk factors or established vascular disease. Of note, the rates of obesity and diabetes in patients with atherothrombosis throughout the world are particularly alarming.

ContextAmong patients with acute myocardial infarction, combination reperfusion therapy with a platelet glycoprotein IIb/IIIa receptor inhibitor (abciximab) and a half dose of a plasminogen activator (reteplase) did not significantly reduce mortality at 30 days compared with a full dose of reteplase. Rates of nonfatal ischemic complications were significantly diminished.ObjectiveTo determine if the beneficial effects of abciximab and reteplase (combination therapy) on early nonfatal complications would translate into a reduction in the risk of death by 1 year.Design, Setting, and PatientsOne-year follow-up of a randomized controlled trial (Global Use of Strategies To Open Coronary Arteries [GUSTO] V). Of 16 588 patients who had been treated in 820 community and referral hospitals in 20 countries between July 1999 and February 2001, mortality data were available for 16 453 (99.2%).InterventionPatients were randomly assigned to receive (intravenously) a standard dose of reteplase (two 10-U boluses, 30 minutes apart) or the combination of a standard dose of abciximab (0.25 mg/kg bolus, 0.125 µg/kg per minute infusion [maximum 10 µg/min for 12 hours]) and a half dose of reteplase (two 5-U boluses, 30 minutes apart).Main Outcome MeasureOne-year all-cause mortality rates.ResultsAll-cause mortality at 1 year occurred in 692 (8.38%) of 8260 patients in the reteplase group and 698 (8.38%) of the 8328 patients in the combination therapy group (hazard ratio [HR], 1.00; 95% confidence interval [CI], 0.90-1.11; P>.99). Reinfarction within the first 7 days occurred in 3.5% of patients in the reteplase group and 2.3% of patients in the combination therapy group, and was significantly associated with 1-year mortality (22.6% in patients with reinfarction vs 8.0% in patients without reinfarction; HR, 3.08; 95% CI, 2.53-3.75; P

The purpose of this study was to evaluate the success rate, complication profile and predictors of outcome of rotational atherectomy (RA) after guidewire crossing of chronic total occlusions (CTO). 145 total occlusions were treated in 139 procedures between 1988 and 1993. Of these, there were 112 single lesion procedures. Compared to pts with non-total occlusions (NTOI, pts with CTO were more likely to be male, younger and have a prior MI, but less likely to present with unstable angina or to have diabetes. Lesions were more likely type C (68.7% vs 15.1%, P l 0.0001) and longer (14.8 ± 7.8 vs 8.0 ± 5.6 mm, p l 0.0001). Mean baseline stenosis was 100.0%. Post-Rotablator stenosis was 45.6 ± 17.5%. Post-adjunctive balloon stenosis was 24.6 ± 15.9% while final residual stenosis was 26.9 ± 16.8%. The maximum mean burr size was 1.8 ± 0.26 mm while average vessel diameter was 2.74 ± 0.65 mm. Success without major complications occurred in 91.0%. Dissection occurred in 18.0%, acute in-lab closure in 3.6%, post-Cath lab reocclusion in 3.6%, emergency bypass surgery on 0%, death in 1.4% and NOMI in 4.3% of pts. Based on 49.2% angiographic follow-up, restenosis occurred in 62.5% of pts. Univariate predictors of RA success were pt age (p = 0.02), lesion eccentricity (p = 0.04) and vessel diameter (p = 0.02). In a multivariable logistic regression model, only larger vessel diameter remained as an independent predictor of success (2.8 ± 0.6 vs 2.0 ± 0.5 mm). Older age (p = 0.04) and diabetes (p = 0.01) were univariate predictors of restenosis. However, in the final multivariable logistic model, only diabetes remained a significant predictor. In conclusion, RA for the treatment of CTO has acceptable success and restenosis. Non-diabetics with relatively larger vessel diameter appear to benefit most.