Peripheral Artery Disease among a High-Risk Asian Population with Ischaemic Stroke, Cardiovascular Disease, or Diabetes Mellitus.

Background: Peripheral artery disease (PAD) affects more than 100 million people globally. Most PAD studies have been performed among predominantly White populations-less is known about other ethnicities. The aim of this cross-sectional study was to determine the prevalence and risk factors of PAD in a high-risk Asian population with ischaemic stroke (IS), myocardial infarction, unstable angina (CVD), or diabetes mellitus (DM). Methods: Patients admitted for IS, CVD, or DM were recruited. Data were collected on age, sex, body mass index (BMI), index condition (CVD, IS, DM), history of hypertension, DM, hypercholesterolaemia, cigarette smoking, and claudication. The Edinburgh Claudication Questionnaire was administered, the ankle brachial index (ABI) was determined, and PAD was diagnosed if ABI was ≤0.9. Results: Of the 450 subjects recruited, 150 were placed in each index disease group, the mean age was 61.9 ± 10.32 years, 43.1% were female, and the mean BMI was 23.9 ± 4.3. Hypertension was reported in 59.3%, DM in 63.6%, hypercholesterolaemia in 39.6%, and smoking in 42.9% of patients. The prevalence of PAD was 27.1%, 22.0% in IS, 29.3% in CAD, and 30.0% in DM. PAD was associated with increasing age (adjusted odds ratio (aOR) 1.04/year, 95% confidence interval [CI] 1.01-1.06; p < 0.001), reduced BMI (aOR 0.94, 95% CI 0.89-0.99; p = 0.026), DM (aOR 1.59, 95% CI 1.20-3.18; p = 0.007), and hypercholesterolaemia (aOR 1.82, 95% CI 1.17-2.28; p = 0.007). It was more frequent in non-lacunar versus lacunar acute IS, non-ST segment elevation versus ST-segment elevation acute myocardial infarction, and insulin-treated versus non-insulin-treated DM. Conclusions: Our study showed a high prevalence of PAD among high-risk Asian patients. This was associated with increasing age, DM, and hypercholesterolaemia and inversely associated with BMI. Different rates were found in sub-groups of IS, CVD, and DM. Systematic approaches were used to identify these high-risk individuals and to improve their outcomes.

A B-spline approach to phase unwrapping in tagged cardiac MRI for motion tracking.

A novel B-Spline based approach to phase unwrapping in tagged magnetic resonance images is proposed for cardiac motion tracking. A bicubic B-spline surface is used to model the absolute phase. The phase unwrapping problem is formulated as a mixed integer optimization problem that minimizes the sum of the difference between the spatial gradients of absolute and wrapped phases, and the difference between the rewrapped and wrapped phases. In contrast to the existing techniques for motion tracking, the proposed approach can overcome the limitation of interframe half-tag displacement and increase the robustness of motion tracking. The article further presents a hybrid harmonic phase imaging-B-spline method to take the advantage of the harmonic phase imaging method for small motion and the efficiency of the B-Spline approach for large motion. The proposed approach has been successively applied to a full set of cardiac MRI scans in both long and short axis slices with superior performance when compared with the harmonic phase imaging and quality guided path-following methods.

The relationship between CYP2C19 polymorphisms and ischaemic and bleeding outcomes in stable outpatients: the CHARISMA genetics study.

AIMS: Clinical trials have established the value of clopidogrel therapy in a wide spectrum of patients with cardiovascular diseases. Both loss- and gain-of-function single nucleotide variants of CYP2C19 genes have been identified that affect clopidogrel metabolism and anti-platelet response. We sought to determine the impact of CYP2C19 polymorphisms on ischaemic and bleeding events. METHODS AND RESULTS: A subset of patients from the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA) trial who consented to genotyping was analysed. Patients with clinically evident cardiovascular disease or multiple risk factors were enrolled in the trial. The rates of ischaemic and bleeding events were compared between carriers and non-carriers of loss-of-function and gain-of-function alleles in patients randomized to clopidogrel vs. placebo. A total of 4819 patients were genotyped and available for the analysis. Carriers of CYP2C19 loss-of-function alleles did not have an increased rate of ischaemic events. However, clopidogrel-treated patients did have a significantly lower rate of any bleeding in carriers: 36.1% (240/665) vs. 42.5% (681/1601) in non-carriers, HR: 0.80, 95% CI: 0.69-0.93, P = 0.003 (genotype/treatment interaction, P-value = 0.023). The CYP2C19 gain-of-function alleles did not affect ischaemic or bleeding endpoints. CONCLUSION: No relationship was seen between CYP2C19 status and ischaemic outcomes in stable patients treated with clopidogrel. There was, however, significantly less bleeding with clopidogrel in carriers of the loss-of-function allele, suggesting less anti-platelet response. Although several prior studies, including mainly stented patients, have emphasized the relationship between CYP2C19 loss-of-function alleles and efficacy of clopidogrel, this study of stable patients establishes a potential link with reduced bleeding complications. CLINICAL TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov number, NCT00050817.

Prevalence of diabetes and impact on cardiovascular events and mortality in patients with chronic coronary syndromes, across multiple geographical regions and ethnicities.

BACKGROUND: In contrast with the setting of acute myocardial infarction, there are limited data regarding the impact of diabetes mellitus on clinical outcomes in contemporary cohorts of patients with chronic coronary syndromes. We aimed to investigate the prevalence and prognostic impact of diabetes according to geographical regions and ethnicity. METHODS AND RESULTS: CLARIFY is an observational registry of patients with chronic coronary syndromes, enrolled across 45 countries in Europe, Asia, America, Middle East, Australia, and Africa in 2009-2010, and followed up yearly for 5 years. Chronic coronary syndromes were defined by ≥1 of the following criteria: prior myocardial infarction, evidence of coronary stenosis >50%, proven symptomatic myocardial ischaemia, or prior revascularization procedure.Among 32 694 patients, 9502 (29%) had diabetes, with a regional prevalence ranging from below 20% in Northern Europe to ∼60% in the Gulf countries. In a multivariable-adjusted Cox proportional hazards model, diabetes was associated with increased risks for the primary outcome (cardiovascular death, myocardial infarction, or stroke) with an adjusted hazard ratio of 1.28 (95% confidence interval 1.18, 1.39) and for all secondary outcomes (all-cause and cardiovascular mortality, myocardial infarction, stroke, heart failure, and coronary revascularization). Differences on outcomes according to geography and ethnicity were modest. CONCLUSION: In patients with chronic coronary syndromes, diabetes is independently associated with mortality and cardiovascular events, including heart failure, which is not accounted by demographics, prior medical history, left ventricular ejection fraction, or use of secondary prevention medication. This is observed across multiple geographic regions and ethnicities, despite marked disparities in the prevalence of diabetes. CLINICALTRIALS IDENTIFIER: ISRCTN43070564.

The influence of body mass index on mortality and bleeding among patients with or at high-risk of atherothrombotic disease.

AIMS: We aimed to determine the relationship between body mass index (BMI) and cardiovascular events among individuals with or at-risk of atherothrombotic disease. METHODS AND RESULTS: This was a prospective observational study of 15 532 patients enrolled in the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA) trial who were randomly assigned to clopidogrel or placebo, and followed-up for a median of 28 months for the occurrence of the primary endpoint (cardiovascular death, myocardial infarction, or stroke), all-cause mortality, and bleeding complications. Compared with the highest BMI quartile, the primary endpoint, cardiovascular, and all-cause mortality all occurred more frequently among patients in the lowest BMI quartile (about a third lower). The relationship between continuous BMI and adverse cardiovascular outcomes were presented as two linear spline terms with 29 kg/m(2) as the cut-point for all-cause mortality. Lower BMI was associated with an increase in moderate and severe bleeding complications, largely accounted for by those receiving dual-antiplatelet agents with the highest tertile aspirin dose. CONCLUSION: Adverse cardiovascular events and bleeding complications occurred more frequently among individuals with or at-risk for atherothrombotic disease and low BMI. Further studies should be directed to these patients to improve outcomes.

Incomplete inhibition of thromboxane biosynthesis by acetylsalicylic acid: determinants and effect on cardiovascular risk.

BACKGROUND: Incomplete inhibition of platelet thromboxane generation, as measured by elevated urinary 11-dehydro thromboxane B(2) concentrations, has been associated with an increased risk of cardiovascular events. We aimed to determine the external validity of this association in aspirin-treated patients enrolled in the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management and Avoidance (CHARISMA) trial and to determine whether there are any modifiable factors or interventions that lower urinary 11-dehydro thromboxane B(2) concentrations that could thereby reduce cardiovascular risk. METHODS AND RESULTS: Urinary 11-dehydro thromboxane B(2) concentrations were measured in 3261 aspirin-treated patients at least 1 month after they had been randomly assigned to placebo or clopidogrel. Baseline urinary 11-dehydro thromboxane B(2) concentrations in the highest quartile were associated with an increased risk of stroke, myocardial infarction, or cardiovascular death compared with the lowest quartile (adjusted hazard ratio 1.66, 95% CI 1.06 to 2.61, P=0.03). Increasing age, female sex, history of peripheral artery disease, current smoking, and oral hypoglycemic or angiotensin-converting enzyme inhibitor therapy were independently associated with higher urinary concentrations of 11-dehydro thromboxane B(2), whereas aspirin dose > or =150 mg/d, history of treatment with nonsteroidal antiinflammatory drugs, history of hypercholesterolemia, and statin treatment were associated with lower concentrations. Randomization to clopidogrel (versus placebo) did not reduce the hazard of cardiovascular events in patients in the highest quartile of urinary 11-dehydro thromboxane B(2) levels. CONCLUSIONS: In aspirin-treated patients, urinary concentrations of 11-dehydro thromboxane B(2) are an externally valid and potentially modifiable determinant of stroke, myocardial infarction, or cardiovascular death in patients at risk for atherothrombotic events.

Clopidogrel and aspirin versus aspirin alone for the prevention of atherothrombotic events.

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.).

Ethnic variation in adverse cardiovascular outcomes and bleeding complications in the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA) study.

BACKGROUND: Atherothrombosis is a common condition affecting individuals worldwide. Its impact on different ethnic groups receiving evidence-based therapy is unclear. We aimed to determine if ethnicity is an independent predictor for cardiovascular events and bleeding complications in a contemporary clinical trial on antiplatelet therapy. METHODS: This was a prospective observational study of 15,603 patients enrolled in the CHARISMA trial followed up every 6 months for a median of 28 months. The primary efficacy end point was the first occurrence of cardiovascular death, myocardial infarction, or stroke. The primary safety end point was bleeding. RESULTS: The cohort comprised 12,502 (80.1%) white, 486 (3.1%) black, 775 (5.0%) Asian, and 1,613 (10.3%) Hispanic patients. There was no difference in the occurrence of the primary composite end point among the 4 ethnic groups. Compared with Asians, cardiovascular and all-cause mortality occurred more frequently among black (adjusted hazard 2.19 and 2.04) and Hispanic (adjusted hazard, 1.83 and 1.69) patients. Although the occurrence of severe bleeding was similarly low among the 4 ethnic groups, Asian (adjusted hazard, 2.21) and black (adjusted hazard, 3.06) patients were more likely to have moderate bleeding complications than Hispanic patients. CONCLUSION: In this trial of individuals at risk of vascular events, ethnicity was not a significant, independent predictor of the primary composite cardiovascular event. However, ethnicity was a significant, independent predictor of the secondary outcomes, cardiovascular and all-cause mortality (blacks and Hispanics), and moderate bleeding complications (blacks and Asians).

Impact of sex, metabolic syndrome, and diabetes mellitus on cardiovascular events.

Although cardiovascular events occur more frequently among patients with metabolic syndrome (MS) or diabetes mellitus (DM), the impact of gender is unclear. We aimed to determine the relation of MS and DM on cardiovascular events between men and women. The National Health Survey of 1992 provided information on outcomes for 3,414 Singaporeans aged 18 to 69 years without cardiovascular diseases. Definition of MS was based on the National Cholesterol Education Program criteria. Cardiovascular events included hospital admissions for coronary heart disease, stroke, and cardiovascular mortality. The proportion of subjects with MS was 12.4%. After 10 years, the annual cardiovascular event rates (per 1,000 person-years) for men without DM were 3.0 and 15.9 among subjects without and with MS, respectively, and the respective rates for men with DM were 22.5 and 21.4. The corresponding rates for women were 0.9, 3.7, 5.3, and 21.5, respectively. Among nondiabetic subjects, cardiovascular events occurred more frequently among men than women among subjects with MS (adjusted hazard ratios [HRs] 4.71, 95% confidence interval [CI] 1.56 to 14.2) and those without MS (HR 3.35, 95% CI 1.78 to 6.31). Among patients with DM, cardiovascular events occurred more commonly among men than women without MS (HR 6.04, 95% CI 1.43 to 25.6). Rates for cardiovascular events were comparable between men and women with DM and MS (HR 0.98, 95% CI 0.48 to 1.99). In conclusion, the adverse impact of MS or DM was greater among men, and the presence of both conditions increases the risk substantially for cardiovascular events among women.

Routine functional testing after percutaneous coronary intervention: results of the aggressive diagnosis of restenosis in high-risk patients (ADORE II) trial.

BACKGROUND: It is unclear whether routine or selective functional testing is optimal following percutaneous coronary intervention (PCI) in high-risk patients. OBJECTIVES: The aim of this trial was to compare exercise endurance, functional status, and quality of life (QOL) among high-risk patients randomized to either routine or selective functional testing following PCI. METHODS: We randomized 84 patients to either routine or selective functional testing. Patients had one or more of the following: multivessel PCI, diabetes mellitus, left ventricular ejection fraction < 35%, and/or PCI of the proximal left anterior descending artery. Patients in the routine arm (n = 41) underwent maximum endurance exercise treadmill testing (ETT) with nuclear perfusion imaging at 1.5 and 6 months. Patients in the selective arm (n = 43) only underwent functional testing for a clinical indication. All patients underwent a maximum endurance ETT at 9 months. Exercise endurance, functional status, and QOL were assessed at 9 months. RESULTS: Most patients were middle-aged men (58 +/- 10 years old; 87% male) who underwent PCI with stenting (94%). Among routine functional testing patients, 27.0% and 41.9% had a positive functional test at 1.5 and 6 months, respectively. Exercise endurance was improved in the routine vs. selective arm at 9 months (metabolic equivalents: 10.3 +/- 2.6 vs. 8.6 +/- 3.0, P = 0.013). There was no difference in improvement from baseline for the Duke Activity Status Index, the Seattle Angina Questionnaire, or the SF-36. Nine-month cumulative incidences of cardiac procedures and clinical events were not significantly different. CONCLUSIONS: Routine functional testing following PCI in high-risk patients may lead to improved exercise endurance but not improved QOL.

Modification of the NCEP ATP III definitions of the metabolic syndrome for use in Asians identifies individuals at risk of ischemic heart disease.

The association between the metabolic syndrome (MS) to ischemic heart disease (IHD) has not been established prospectively in Asian populations. We carried out registry linkage, using unique national identity numbers, to identify incident IHD events in subjects without diabetes mellitus or IHD from two cross-sectional studies of Chinese, Malays and Asian Indians living in Singapore. The risk of IHD associated with the MS (NCEP ATP III criteria) was determined by Cox-proportional hazards regression before and after adjustment for age, sex, ethnic group and current cigarette smoking. We also assessed the utility of modified Asian criteria (reducing the waist circumference (WC) used to define central obesity to 90 cm in men and 80 cm in women) on the risk of IHD associated with the MS. This study provided 38,157.4 person-years in 4042 subjects who experienced 93 incident IHD events. MS (as defined by the NCEP ATP III criteria) was associated with increased risk of IHD (HR3.09; 95% CI 1.96-4.88). Those who satisfied only the modified Asian criteria, but not the NCEP ATP III criteria, were also at increased risk of IHD (HR 2.13; 95% CI 0.99-4.58). It would be appropriate to lower the cut-off for WC used for the diagnosis of the MS in such populations.

A global view of atherothrombosis: baseline characteristics in the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA) trial.

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.

Clinical impact of stent construction and design in percutaneous coronary intervention.

Convincing end point data demonstrating the anatomic and clinical superiority of stent placement compared with balloon angioplasty together with significant improvement in stenting technique and poststent management have resulted in an explosion in stenting procedures and the emergence of more than 40 stent types with disparate designs and material composition in clinical use. Structural nuances in design, composition, and coating of different stent models, however, have been shown to have a major influence on the risk of stent thrombosis, the degree of vessel wall injury, and subsequent intimal proliferation in the experimental model. There is now substantial amount of evidence to indicate that the same relationship between stent structural characteristics and vessel wall outcome holds true in humans. This article provides an up-to-date overview of the clinical impact of stent construction and design, including the clinical performance of drug-eluting stents.

Six-month outcomes of percutaneous transluminal coronary angioplasty in hypertensive patients: results from the ROSETTA registry. Routine Versus Selective Exercise Treadmill Testing After Angioplasty.

PURPOSE: Hypertension is an important risk factor for coronary artery disease. However, the impact of hypertension on the outcomes of patients undergoing percutaneous transluminal coronary angioplasty (PTCA) is unknown. Our purpose was to evaluate the association between hypertension and adverse outcomes and repeat cardiac procedures during the 6-month period after PTCA. METHODS: We studied 791 patients who were enrolled in the Routine Versus Selective Exercise Treadmill Testing After Angioplasty (ROSETTA) registry. This registry is a prospective multicenter study examining the use of functional testing after a successful PTCA. RESULTS: We compared 411 hypertensive patients (mean age 60.1 +/- 10 years, 31.1% female) with 380 normotensive patients (mean age 59.1 +/- 12 years, 16.2% female). Patients with hypertension had a higher 6-month rate of composite clinical events (unstable angina, myocardial infarction, death) than did normotensive patients (16.5% vs 10.5%, P =.017). In addition, there was a trend for hypertensive patients to have higher rates of cardiac procedures (angiography, repeat PTCA, coronary artery bypass graft surgery) compared with normotensive patients (19.8% vs 14.9%, P =.074). However, functional testing after PTCA was lower among hypertensive subjects (44.4% vs 54.0%, P =.008). Among the 411 hypertensive patients, a regression analysis showed that several variables were independently associated with increased 6-month adverse event rates, including pre-PTCA Killip class III-IV (odds ratio [OR] 5.7, 95% CI 1.7-19.0), Canadian Cardiovascular Society angina class III-IV (OR 2.1, 95% CI 1.1-4.2), unstable angina as the reason for PTCA (OR 2.3, 95% CI 1.2-4.3), peripheral vascular disease (OR 3.2, 95% CI 1.5-6.4), PTCA of a bypass graft (OR 3.1, 95% CI 1.2-7.6), and calcium antagonist usage at admission for the index PTCA (OR 1.9, 95% CI 1.1-3.4). CONCLUSIONS: During the 6-month period after a successful PTCA, patients with hypertension have significantly higher adverse event rates than do those without hypertension. Several clinical variables may help identify which hypertensive patients are at higher risk for clinical events.

Thrombin generation and fibrinolytic activities among patients receiving reduced-dose alteplase plus abciximab or undergoing direct angioplasty plus abciximab for acute myocardial infarction.

The purpose of this study was to determine the impact of these 2 reperfusion strategies (reduced-dose alteplase plus abciximab or direct angioplasty plus abciximab) on fibrinolytic and thrombin generation activities. The effect of reduced-dose alteplase plus abciximab and direct angioplasty plus abciximab on hemostatic factors is unknown. Of 70 patients with acute myocardial infarction of < or = 6 hours, 34 were randomized to reduced-dose alteplase (35 to 50 mg in 1 hour) and 36 to direct angioplasty. A standard bolus and infusion dose of abciximab was administered to all patients. Blood specimens were collected at baseline, and at 1, 4, 12, and 24 hours. The following parameters were assayed: fibrinogen, plasminogen and antiplasmin activities, tissue plasminogen activator antigen, D-dimer, prothrombin fragments F1 + 2, and thrombin/antithrombin III complexes. Among patients treated with reduced-dose alteplase plus abciximab, the fibrinogen level decreased by 28.4% in the first hour (11.7 +/- 3.4 vs 7.8 +/- 2.5 micromol/L, p <0.001). Correspondingly, plasminogen and antiplasmin activities decreased by 43.8% (p <0.001) and 59.1% (p <0.001), respectively. Prothrombin fragments F1 + 2 increased from 2.2 +/- 1.7 to 4.2 +/- 1.6 nmol/L (1 hour) (p <0.001) and thrombin/antithrombin III increased from 16.3 +/- 15.0 to 33.5 +/- 19.9 microg/L (1 hour) (p <0.001). Conversely, in the direct angioplasty group, there was a marginal elevation in fibrinogen level at 1 hour (10.2 +/- 2.4 vs 10.6 +/- 2.0 micromol/L, p = 0.064) despite a significant reduction in plasminogen and an increase in tissue plasminogen activator levels. There was no significant change in prothrombin fragments F1 + 2 and thrombin/antithrombin III levels. Thus, there was considerable fibrinolytic activity with reduced-dose alteplase plus abciximab; thrombin generation was not prevented. Among patients treated with direct angioplasty, there was some endogenous fibrinolytic activity, but there was no significant thrombin generation.

Comparison of event and procedure rates following percutaneous transluminal coronary angioplasty in patients with and without previous coronary artery bypass graft surgery [the ROSETTA (Routine versus Selective Exercise Treadmill Testing after Angioplasty) Registry].

To compare 6-month post-percutaneous transluminal coronary angioplasty (PTCA) outcomes and cardiac procedure use among patients with and without prior coronary artery bypass graft (CABG) surgery, we examined 791 patients who were enrolled in the Routine versus Selective Exercise Treadmill Testing after Angioplasty (ROSETTA) Registry. The ROSETTA Registry is a prospective, multicenter registry that examines the use of functional testing after successful PTCA. Most patients were men (76%, mean age 61 +/- 11 years) who underwent single-vessel PTCA (85%) with stent implantation (58%). Baseline and procedural characteristics differed between patients with a prior CABG (n = 131) and patients with no prior CABG (n = 660), including Canadian Cardiovascular Society angina class III to IV (60% vs 49%, respectively, p = 0.03) and stenosis involving the proximal left anterior descending coronary artery (10% vs 22%, p = 0.004). Event rates among patients with prior CABG were higher than among patients with no prior CABG, including unstable angina (19% vs 11%, p = 0.02), myocardial infarction (2% vs 1%, p = 0.2), death (4% vs 2%, p = 0.08), and composite clinical events (22% vs 12%, p = 0.003). Furthermore, patients with prior CABG had higher rates of follow-up cardiac procedures, including angiography (24% vs 14%, p = 0.008) and PTCA (13% vs 7%, p = 0.04), but not repeat CABG (2% vs 3%, p = 0.8). A multivariate analysis that included baseline clinical and procedural characteristics demonstrated that prior CABG was a significant independent predictor of clinical events and cardiac procedure use (odds ratio 2.3, 95% confidence interval 1.5 to 3.5, p = 0.0001). Within the prior CABG group, patients with a PTCA of a bypass graft had a higher composite clinical event rate than patients with a PTCA of a native vessel (32% vs 17%, p = 0.05). In contrast, patients with a PTCA of a native vessel had event rates similar to those of patients with no prior CABG (17% vs 12%, p = 0.2). Thus, post-CABG patients have an increased risk of developing a cardiac event or needing a follow-up cardiac procedure during the 6 months after PTCA.

Collapse pressures of biodegradable stents.

Biodegradable stent prototypes were produced from poly L-lactic acid polymers with different molecular weights. The effects of molecular weight, drug incorporation and stent design on the collapse pressure of the stents were evaluated. While molecular weights did not show a significant effect on the collapse pressure of the stents, drug incorporation at high percentage decreased the collapse pressure of the stents substantially. Cryogenic fracture surfaces showed significant drug agglomeration as the concentration increased. The design of the stent was also found to a have significant effect on the collapse pressure. The stent produced from the same material has a higher collapse pressure when the load bearing surface area is increased.

Combined fibrinolysis using reduced-dose alteplase plus abciximab with immediate rescue angioplasty versus primary angioplasty with adjunct use of abciximab for the treatment of acute myocardial infarction: Asia-Pacific Acute Myocardial Infarction Trial (APAMIT) pilot study.

We conducted a randomized feasibility pilot study comparing combined fibrinolysis with immediate rescue angioplasty vs. primary angioplasty with adjunctive abciximab in patients with acute myocardial infarction (AMI). Seventy patients with ST segment elevation AMI of