Elevated B-type natriuretic peptide is associated with increased in-hospital mortality or cardiac arrest in patients undergoing implantable cardioverter-defibrillator implantation.

BACKGROUND: The implantable cardioverter-defibrillator (ICD) is the most effective treatment for preventing arrhythmic deaths in patients with heart failure, but periprocedural complications, including in-hospital mortality or cardiac arrest, may occur, and little is known about risk factors. We asked whether elevated B-type natriuretic peptide (BNP) level is associated with increased risk of in-hospital mortality or cardiac arrest in patients undergoing ICD implantation. METHODS AND RESULTS: From the National Cardiovascular Data Registry ICD Registry, we identified 53 198 patients who received ICD implants and underwent preoperative BNP measurement from 2006 to 2008. The patients were categorized into 4 groups by BNP levels (<100, 100 to <300, 300 to <1000, and ≥1000 pg/mL). Complication rates were compared among groups, and odds ratios for in-hospital mortality or cardiac arrest were estimated by multiple hierarchical logistic regressions. There were 2952 complications reported, including 510 in-hospital deaths and 365 cardiac arrests. The rate of in-hospital mortality or cardiac arrest significantly increased with elevated BNP level (P<0.001). The adjusted odds ratios of in-hospital mortality or cardiac arrest were statistically significant in all 3 higher BNP groups [odds ratio (95% CI), 1.99 (1.17 to 3.39), 2.49 (1.50 to 4.13), and 4.25 (2.57 to 7.06) in the second, third, and fourth groups using <100 as reference]. Among subgroups, the association was more significant in men, patients with renal dysfunction, and patients undergoing biventricular ICD implantation. CONCLUSIONS: Elevated BNP level was significantly associated with increased risk of in-hospital mortality or cardiac arrest in patients undergoing ICD implant. Strategies aimed at reducing preprocedural BNP or creating systems to manage procedural risk merit further investigation.

Bivalirudin compared with IIb/IIIa inhibitors in patients with in-stent restenosis undergoing intracoronary brachytherapy.

BACKGROUND: Bivalirudin is replacing heparin in percutaneous coronary interventions (PCIs), including vascular brachytherapy (VBT). The aim of the study was to compare bivalirudin with eptifibatide in patients with in-stent restenosis (ISR) undergoing PCI and VBT. METHODS: One hundred forty-four patients treated with bivalirudin as a single antithrombotic agent were compared with 150 patients treated with eptifibatide. Bivalirudin as a bolus of 0.75 mg/kg followed by 1.75 mg/kg/h infusion until the end of the procedure, and eptifibatide as a double bolus of 180 microg/kg followed by 2 microg/kg/min infusion for 18 h after the procedure were used. The main outcome measures were in-hospital events and 30-day clinical outcomes. RESULTS: Baseline clinical characteristics were similar except that patients in the eptifibatide group were younger (P=.02) and had more saphenous vein graft lesions (P<.001). Patients in the bivalirudin group had a higher number of lesions in the right coronary artery (P<.001) and a higher number of vessels treated (P<.001). Postprocedure creatinine phosphokinase (CPK)-MB levels were significantly lower in the bivalirudin group (P<.03). In-hospital events showed significantly less minor bleeding (P=.01) and a trend toward lower major bleeding and major adverse cardiac events (MACE) in the bivalirudin group (P=.06). Thirty-day outcomes showed a significantly lower incidence of non-Q-wave myocardial infarction (MI) in the bivalirudin group (P=.004). CONCLUSION: Bivalirudin, as a single antithrombotic agent during PCI and VBT, is associated with significantly lower postprocedural CPK-MB elevation, minor bleeding complications, 30-day non-Q-wave MI rates, and a trend toward lower major bleeding and in-hospital MACE when compared with eptifibatide.

Brachytherapy and bivalirudin evaluation study.

BACKGROUND: Bivalirudin is shown to be a competent substitute for heparin in percutaneous coronary intervention (PCI). The safety and efficacy of bivalirudin in patients undergoing PCI and vascular brachytherapy (VBT) are not known. This study aimed to assess the safety and efficacy of bivalirudin as a single antithrombotic agent in patients undergoing PCI and VBT. METHODS: A total of 152 patients enrolled in the Brachytherapy and Bivalirudin Evaluation Study underwent PCI and VBT with either gamma (n = 8) or beta radiation (n = 144). The main outcome measures were in-hospital events and 30-day clinical outcomes. All patients were treated with bivalirudin (0.75 mg/kg bolus and 1.75 mg/kg per hour infusion for beta radiation, 1 mg/kg bolus and 2.5 mg/kg per hour infusion for gamma radiation) as a single antithrombotic agent during the entire procedure. RESULTS: Baseline clinical and angiographic characteristics were similar between the 2 groups. More than 90% of the patients received beta radiation. In-hospital events showed a higher prevalence of acute procedural intracoronary thrombosis in patients treated with gamma- vs beta radiation (25% vs. 0.7%, P < .001). Thirty-day outcomes including death, Q-wave, and non-Q-wave myocardial infarctions, subacute stent thromboses, and repeat revascularizations were similar in both groups. CONCLUSION: Bivalirudin, as a single antithrombotic agent during PCI and VBT with beta emitters, may be used safely, but its use in the setting of PCI and gamma radiation may not be acceptable due to an increased incidence of acute procedural intracoronary thrombosis.

Selective versus exclusive use of sirolimus-eluting stent implantation in multivessel coronary artery disease.

Sirolimus-eluting stents (SESs; Cypher) have demonstrated a significant reduction in restenosis rates when compared to bare metal stents (BMSs). The purpose of this study was to evaluate the strategy of exclusive use of two SESs versus the combination of one BMS and one SES for two-vessel coronary artery disease (CAD). It was found that the selective use of one SES combined with one BMS in patients undergoing percutaneous coronary intervention that requires more than one stent is safe, feasible, and associated with favorable procedural, 30-day, and 6-month clinical outcomes when compared to the exclusive use of SESs.

Three-year follow-up after intravascular gamma-radiation for in-stent restenosis in saphenous vein grafts.

The Washington Radiation for In-Stent Restenosis Trial in Saphenous Vein Grafts (SVG WRIST) demonstrated safety and efficacy of intravascular radiation therapy (IRT) for the treatment of in-stent restenosis (ISR) in SVG at 12 months. In this study, we aimed to examine whether the safety and efficacy of IRT is durable up to 36 months. One hundred twenty patients with diffuse ISR in SVG underwent balloon angioplasty, laser or atherectomy ablation, and/or additional stenting. After successful intervention, patients were randomly assigned in a double-blind fashion to intravascular treatment with a ribbon containing either iridium (Ir)-192 (n = 60) or nonradioactive seeds (n = 60). The prescribed dose at 2 mm from the source was either 14 or 15 Gy in vessels 2.5-4.0 mm or 18 Gy in vessels > 4.0 mm in diameter. At 36 months, target lesion revascularization (TLR; 43% vs. 66%; P = 0.02) and target lesion revascularization-major adverse cardiac event (TLR-MACE; 49% vs. 71%; P = 0.02) rates continued to be lower in the IRT group, but both target vessel revascularization (TVR; 59% vs. 71%; P = 0.17) and TVR-MACE (63% vs. 77%; P = 0.11) rates were not. In SVG WRIST, patients with ISR treated with IRT had a marked reduction in the need for repeat TLR at 36 months, with sustained clinical benefit at 3 years despite late recurrences, which were more pronounced in the radiation group.

Safety of percutaneous coronary intervention alone in symptomatic patients with moderate and severe valvular aortic stenosis and coexisting coronary artery disease: analysis of results in 56 patients.

Whether percutaneous coronary intervention (PCI) alone is safe in patients with moderate or severe aortic stenosis (AS) and coexisting coronary artery disease (CAD), and whether aortic valve replacement (AVR) can be deferred in patients with moderate AS by undergoing PCI alone is not known. We conducted a retrospective study of surgically inoperable patients with AS who underwent PCI (moderate AS, n = 28; and severe AS, n = 28) and compared to those with AVR (n = 55). The clinical characteristics, procedural complications, in-hospital and long-term clinical outcomes of PCI were compared. Baseline and procedural characteristics were similar except that lower age, hypertension, and renal impairment were seen in the AVR group. In-hospital complications were comparable among the 3 groups. Six-month and 1-year rates of myocardial infarction (MI), non-Q-wave MI, death and out-of-hospital death were similar between AVR and moderate AS patients (p = NS) and significantly high (p < 0.04) in patients with severe AS. On multivariate analysis, severe AS was the only significant predictor of 6-month and 1-year mortality. Our study suggests that PCI is safe in patients with moderate AS and coexisting CAD but is associated with poor outcomes in patients with severe AS.

Angiographic and clinical outcomes of late total occlusion versus treatment failure without late total occlusion in patients after intracoronary radiation therapy for in-stent restenosis.

This study aimed to compare the outcomes of patients with late total occlusion (LTO) versus patients with recurrence in the absence of LTO after intracoronary radiation therapy for in-stent restenosis. LTO, especially in the context of acute myocardial infarction, after intracoronary radiation therapy for in-stent restenosis, is associated with negative clinical outcomes after 6 and 12 months compared with in-stent restenosis without LTO.

Vascular complications following coronary intervention correlate with long-term cardiac events.

We aimed to study the consequences and late outcomes of patients who experienced peripheral vascular complications (PVCs) following percutaneous coronary interventions (PCI). A retrospective analysis of the medical records of 10,669 patients who underwent PCI and experienced PVC between 1995 and 2002 was conducted. One thousand ninety-six patients (10.27% of the study cohort) had PVC post-PCI. After PCI, patients with PVC had higher rates of in-hospital complications (P < 0.001) when compared to patients without PVC, including Q-wave myocardial infarction (MI; 1.2% vs. 0.3%), coronary artery bypass grafting (CABG; 3.8% vs. 0.6%), and death (4.0% vs. 1.0%). At 1-year follow-up, late complications of MI (37.4% vs. 25.4%), non-Q-wave MI (34.9% vs. 22.7%), death (12.9% vs. 5.9%), and CABG (5.7% vs. 4.5%) were higher (< 0.001) in patients with PVC compared to those without. Multivariate analysis identified PVC as a significant predictor of 1-year mortality (P = 0.045). This study underscores the need to make diligent efforts to minimize PVC and follow up these patients for future coronary events.

Impact of major side branch on periprocedural enzyme elevation and long-term outcome in patients undergoing percutaneous coronary intervention and brachytherapy for in-stent restenosis.

Side branch occlusion is 1 mechanism for the increase of creatine phosphokinase-MB after percutaneous coronary intervention and is associated with long-term adverse events. We studied 248 patients who underwent brachytherapy for in-stent restenosis with and without side branches, compared levels of creatine phosphokinase-MB with procedural, in-hospital, and long-term clinical outcomes, and found that patients with side branches have increased levels of creatine phosphokinase-MB after percutaneous coronary intervention and higher rates of restenosis, target vessel, and target lesion revascularization at 6-month follow-up.

The accuracy of electrocardiographic Q waves for the detection of prior myocardial infarction as assessed by a novel standard of reference.

BACKGROUND: The electrocardiogram (ECG) is valuable for the identification of prior myocardial infarction (MI) in individuals participating in epidemiologic studies or undergoing screening examinations. Although the Minnesota Code, a set of criteria for the interpretation of ECGs in such situations, is commonly used to identify MI in these settings, its accuracy is incompletely understood. HYPOTHESIS: We sought to test the accuracy of the Minnesota Code Q and QS criteria for MI against a new standard of reference, the presence of a perfusion defect on a resting myocardial scintigraphic image. METHODS: The resting myocardial scintigrams of all patients studied in our nuclear cardiology laboratory during 7 consecutive months were screened for the presence of perfusion defects. For each patient with such a defect, two individuals examined on the same day, who had no perfusion defect, were selected as controls. Electrocardiograms recorded within 30 days of the scintigraphy were read blindly by two of the authors using the Minnesota Code criteria for Q or QS waves indicative of MI. RESULTS: For 214 patients selected on the basis of their scintigraphic findings, a satisfactory ECG recorded within a month of the scintigraphy was also available. The overall sensitivity of the Q or QS criteria was 0.58 and the specificity was 0.75. As might be expected when only the most stringent criteria were applied, sensitivity was least and the specificity best. CONCLUSIONS: As in previous studies, in which necropsy material served as the standard of reference, sensitivity of the Q and QS criteria contained in the Minnesota Code is relatively modest and specificity is reasonable but not outstanding.

Comparison of baseline characteristics and one-year outcomes between African-Americans and Caucasians undergoing percutaneous coronary intervention.

The objectives of this study were to determine whether there are race-based differences in baseline characteristics and in short- or long-term outcomes after percutaneous coronary intervention (PCI). African-Americans have a higher incidence of coronary artery disease but are less likely to undergo coronary revascularization than Caucasians. Little is known about the profiles and outcomes of African-Americans who undergo PCI. Consecutive series of 1,268 African-Americans and 10,561 Caucasians with symptomatic coronary artery disease who underwent PCI between January 1994 and June 2001 were analyzed. Patients hospitalized for acute myocardial infarction were excluded. African-Americans were older, were more likely to be women, and had more co-morbid baseline conditions compared with Caucasians. Preprocedure lesion characteristics were similar with regard to vessel size, length, and complexity. The rate of clinical success did not differ between the groups. African-Americans experienced more in-hospital combined events of death and Q-wave myocardial infarction (p = 0.03). After propensity score adjustment, African-American race was not an independent predictor for in-hospital events. At 1 year, African-Americans had a slightly lower rate of target lesion revascularization and a 50% higher rate of death (9.8% vs. 6.4%, p <0.001), with a relative risk of 1.52 (95% confidence interval 1.22 to 1.89). In multivariate analysis, African-American race remained a significant predictor of increased 1-year mortality (hazard ratio 1.35, 95% confidence interval 1.06 to 1.71, p = 0.01). African-Americans undergoing angioplasty have more co-morbid baseline conditions than Caucasians. Despite similar clinical success, 1-year outcomes are impaired in African-Americans.

Incidence, predictors, and prognostic implications of bleeding and blood transfusion following percutaneous coronary interventions.

Bleeding related to percutaneous coronary intervention (PCI) occurs relatively frequently. We retrospectively investigated the incidence, predictors, and prognostic impact of periprocedural bleeding and transfusion in 10,974 patients who underwent PCI. Bleeding definitions were based on Thrombolysis In Myocardial Infarction (TIMI) criteria: (1) major bleeding (n = 588; 5.4%): if patients had a hemorrhagic stroke or if hematocrit decreased >15 points or by 10 to 15 points with clinical bleeding; (2) minor bleeding (n = 1,394; 12.7%): if hematocrit decreased <10 points with clinical bleeding or by 10 to 15 points without clinical bleeding; and (3) no bleeding (n = 8,992; 81.9%): if hematocrit decreased <10 points without clinical bleeding. Patients with major bleeding were older than patients with minor or no bleeding (67.8 +/- 11 vs 65.9 +/- 11 vs 63.6 +/- 11 years, respectively; p <0.001) and more often experienced intraprocedural complications, such as emergency use of an intra-aortic balloon pump (13.6% vs 6.5% vs 2.3%, respectively; p <0.001). Multivariate logistic regression analysis identified the use of an intra-aortic balloon pump (odds ratio [OR] 3.0, p <0.0001), procedural hypotension (OR 2.9, p <0.001), and age >80 years (OR 1.9 compared with age <50 years, p = 0.001) as the strongest predictors for major bleeding. Patients who had major bleeding had higher in-hospital and 1-year mortality compared with patients with minor or no bleeding. Bleeding was an independent predictor of in-hospital death. Thus, periprocedural major bleeding occurs relatively frequently and is associated with adverse outcomes. Patients >80 years of age who experience intraprocedural complications are at particularly high risk.

Comparison of effectiveness and safety of three different antithrombotic regimens (bivalirudin, eptifibatide, and heparin) in preventing myocardial ischemia during percutaneous coronary intervention.

The aim of this retrospective, observational analysis was to compare the efficacy and safety of 3 antithrombotic regimens: bivalirudin, eptifibatide plus heparin, and heparin alone, with emphasis on preventing interventional procedural creatinine kinase-MB fraction (CK-MB) release, and consequently, myocardial necrosis.

Percutaneous coronary intervention-associated nephropathy foreshadows increased risk of late adverse events in patients with normal baseline serum creatinine.

In patients with chronic renal insufficiency, further decline in renal function (DRF) after percutaneous coronary intervention (PCI) is accompanied not only by adverse in-hospital events but also by increased risk of mortality and myocardial infarction at 1 year. This analysis was undertaken to determine if patients with normal renal function who develop DRF after PCI have a comparable increase in risk of death and myocardial infarction at 1 year, and whether this risk is independent of in-hospital complications (death, myocardial infarction, urgent coronary artery bypass grafting). We performed a retrospective analysis of all patients from a single center who underwent successful PCI with no major in-hospital complications who had pre-PCI serum creatinine (SCr) /= 50% of baseline). They were more likely to be older, female, non-Caucasian, diabetic and/or hypertensive. They reported more prior cerebral or peripheral vascular events. They had undergone more complex PCI and were exposed to more radiographic contrast than the 96.5% who did not develop DRF. After adjustment for baseline variables, DRF remained an independent predictor of 1-year mortality, myocardial infarction, and target vessel revascularization. In patients without prior renal impairment, DRF post-PCI is rare but is associated with an increased risk of late adverse cardiac events similar to that in chronic renal insufficiency patients.

Impact of renal function on morbidity and mortality after percutaneous aortocoronary saphenous vein graft intervention.

BACKGROUND: Percutaneous coronary intervention in patients with chronic renal insufficiency (CRI) and native coronary artery disease is often problematic, marred by increased morbidity and mortality rates and a high incidence of restenosis and revascularization. However, little is known about the effect of CRI in patients who have undergone prior coronary artery bypass graft surgery and then undergo saphenous vein graft (SVG) intervention. METHODS: We analyzed the inhospital and 1-year outcomes of 1265 consecutive patients with normal renal function and varying degrees of renal insufficiency who underwent percutaneous SVG intervention and divided them into 4 groups on the basis of the calculated creatinine clearance (CrCl): group 1, CrCl > or =70 mL per minute (n = 626); group 2, CrCl 50 to 69 mL per minute (n = 357); group 3, CrCl 30 to 49 mL per minute (n = 228); and group 4, CrCl <30 mL per minute (n = 54). Patients undergoing dialysis replacement therapy were excluded from the study. RESULTS: Patients with lower CrCl more often were older, female, had diabetes mellitus, and had worse left ventricular function. Angiographic baseline characteristics were comparable among the 4 groups. Overall immediate procedural success was similar for all groups. Patients with a low CrCl had significantly higher inhospital overall and cardiac mortality rates (P <.001), including a significantly higher incidence of myocardial infarction, vascular complications, pulmonary edema, and renal function deterioration. At 1-year follow-up, the overall mortality rates remained significantly higher in patients with decreased CrCl, with an incremental rise in overall mortality rate associated with lower renal function (P <.001). CONCLUSIONS: This study suggests that renal function is a primary determinate of short- and long-term survival in patients undergoing percutaneous SVG intervention and that there is a clear relationship between CrCl and cardiovascular outcome.

Stroke complicating percutaneous coronary interventions: incidence, predictors, and prognostic implications.

BACKGROUND: Stroke associated with percutaneous coronary intervention (PCI) is an infrequent although devastating complication. We investigated the incidence, predictors, and prognostic impact of periprocedural stroke in unselected patients undergoing PCI. METHODS AND RESULTS: A total of 9662 patients who underwent 12 407 PCIs between January 1990 and July 1999 were retrospectively studied. Stroke was diagnosed in 43 patients (0.38% of procedures). Patients with stroke were older (72+/-11 versus 64+/-11 years, P<0.001), had lower left ventricular ejection fraction (42+/-12 versus 46+/-13%, P=0.04) and more diabetes (39.5% versus 27.2%, P=0.07), and experienced a higher rate of intraprocedural complications necessitating emergency use of intra-aortic balloon pump (IABP) (23.3% versus 3.3%, P<0.001). In-hospital mortality (37.2% versus 1.1%, P<0.001) and 1-year mortality (56.1% versus 6.5%, P<0.001) were higher in patients with stroke. Compared with hemorrhagic stroke, patients with ischemic stroke had higher rate of in-hospital major adverse cardiac events (57.1% versus 25%, P=0.037). Multivariate logistic regression analysis identified emergency use of IABP as the strongest predictors for stroke (OR=9.6, CI 3.9 to 23.9, P<0.001), followed by prophylactic use of IABP (OR=5.1), age >80 years (OR=3.2, compared with age <50 years), and vein graft intervention (OR=2.7). CONCLUSIONS: Stroke associated with contemporary PCI is associated with substantial increased mortality. Elderly patients who experience intraprocedural complications necessitating the use of IABP are at particularly high risk.

The effect of intracoronary radiation for the treatment of recurrent in-stent restenosis in patients with diabetes mellitus.

OBJECTIVES: The purpose of this study was to examine the effect of intracoronary radiation therapy (IRT) in diabetic patients with in-stent restenosis (ISR). BACKGROUND: Diabetic patients are at an increased risk for restenosis, repeat revascularization procedures and late mortality after percutaneous coronary interventions and stenting. Intracoronary radiation therapy, utilizing both gamma and beta-emitters, has been shown to reduce the rate of ISR. METHODS: The study group consisted of 749 consecutive patients with ISR who were treated with either IRT or placebo in randomized trials and registries at our center. Diabetic patients (252 radiation and 51 placebo) were compared with nondiabetic patients (371 radiation and 75 placebo). RESULTS: In-hospital outcomes were similar between diabetic and nondiabetic patients treated with and without radiation. At six-month clinical and angiographic follow-up, there was a significant reduction in the binary restenosis (63.8% vs. 15.7%, p < 0.0001), target lesion revascularization (66.7% vs. 17.6%, p < 0.0001) and target vessel revascularization (TVR) (70.6% vs. 22.9%, p < 0.0001) rates in diabetic patients treated with radiation compared to placebo. Comparisons between the placebo arms detected a trend towards higher restenosis (63.8% vs. 48.4% p = 0.13) and TVR (70.6% vs. 56.0%, p = 0.14) in diabetic versus nondiabetic patients. In contrast, diabetic and nondiabetic patients treated with IRT experienced similar restenosis (15.6% vs. 10.7% p = 0.33) and TVR (22.9% vs. 28.2% p = 0.41) rates. CONCLUSIONS: In diabetic patients with ISR, intracoronary radiation significantly reduced the recurrence of ISR compared to placebo. Additionally, similar rates of restenosis and revascularization procedures were achieved in irradiated diabetic and nondiabetic patients. In view of these results, IRT should be considered as a valuable therapeutic alternative in all diabetic patients with ISR.

Incidence, morphology, angiographic findings, and outcomes of intramural hematomas after percutaneous coronary interventions: an intravascular ultrasound study.

BACKGROUND: Intramural hematomas during percutaneous coronary intervention (PCI) have not been well studied. METHODS AND RESULTS: We used intravascular ultrasound to determine the incidence, morphology, and clinical features of post-PCI intramural hematomas. In 905 patients with 1025 consecutive native coronary artery, non-in-stent restenosis lesions undergoing PCI, 72 hematomas were detected in 69 arteries in 68 patients. The incidence of intramural hematomas per artery was 6.7% (69 of 1025); 36% (26 of 72) involved the proximal reference artery, 18% (13 of 72) were confined to the lesion, and 46% (33 of 72) involved the distal reference artery. The entry site from the lumen into the hematoma was identified in 86% of hematomas (62 of 72) and had the appearance of a dissection into the media. Conversely, a re-entry site was identifiable in only 8% (6 of 72). The axial extension of the hematoma was distal in 63% and proximal in 37%. In 60% of the hematomas (42 of 72) the angiogram had the appearance of a dissection; in 11% (8 of 72), it appeared to be a new stenosis; and in 29% (22 of 72), no significant abnormality was detected. Non-Q-wave myocardial infarctions occurred in 26% of patients (17 of 65). In 3 patients, the creatine kinase-MB was not measured during the hospital stay. Repeat revascularization occurred in 2 patients in-hospital, 2 additional patients at 1 month, and 8 additional patients at 1 year. There were 3 sudden deaths at 1 year. CONCLUSIONS: Intravascular ultrasound identified intramural hematomas after 6.7% of PCIs. The mechanism appeared to be a dissection into the media where blood accumulated because of a lack of re-entry. A third of ultrasound-identified hematomas showed no angiographic abnormalities. There was a high rate of non-Q-wave myocardial infarction, need for repeat revascularization, and sudden death in patients with hematomas.

Intravascular gamma radiation for in-stent restenosis in saphenous-vein bypass grafts.

BACKGROUND: Intracoronary radiation therapy is effective in reducing the recurrence of in-stent stenosis in native coronary arteries. We examined the effects of intravascular gamma radiation in patients with in-stent restenosis of saphenous-vein bypass grafts. METHODS: A total of 120 patients with in-stent restenosis in saphenous-vein grafts, the majority of whom had diffuse lesions, underwent balloon angioplasty, atherectomy, additional stenting, or a combination of these procedures. If the intervention was successful, the patients were randomly assigned in a double-blind fashion to intravascular treatment with a ribbon containing either iridium-192 or nonradioactive seeds. The prescribed dose, delivered at a distance of 2 mm from the source, was 14 to 15 Gy in vessels that were 2.5 to 4.0 mm in diameter and 18 Gy in vessels with a diameter that exceeded 4.0 mm. The primary end points were death from cardiac causes, Q-wave myocardial infarction, revascularization of the target vessel, and a composite of these events at 12 months. RESULTS: Revascularization and radiation therapy were successfully accomplished in all patients. At six months, the restenosis rate was lower in the 60 patients assigned to the iridium-192 group than in the 60 assigned to the placebo group (21 percent vs. 44 percent, P=0.005). At 12 months, the rate of revascularization of the target lesion was 70 percent lower in the iridium-192 group than in the placebo group (17 percent vs. 57 percent, P<0.001), and the rate of major cardiac events was 49 percent lower (32 percent vs. 63 percent, P<0.001). CONCLUSIONS: The results of our study support the use of gamma-radiation therapy for the treatment of in-stent restenosis in patients with bypass grafts.