Plaque rupture and thrombosis are reduced by lowering cholesterol levels and crystallization with ezetimibe and are correlated with fluorodeoxyglucose positron emission tomography.

OBJECTIVE: This study evaluated effects of lipid lowering with ezetimibe on plaque burden and associated cholesterol crystallization and inflammation in a rabbit model of plaque disruption and thrombosis. METHODS AND RESULTS: Atherosclerotic rabbits (Group I, n=10 without; Group II, n=12 with ezetimibe, 1 mg/kg per day) were pharmacologically triggered for plaque disruption. Fluorodeoxyglucose positron emission tomography, RAM 11 macrophage staining, and serum inflammatory markers detected arterial inflammation. Serum and aortic wall cholesterol levels were measured, and thrombus area was planimetered. Cholesterol crystal density on aortic surface was scored (0 to +3) by scanning electron microscopy. Serum and aortic wall cholesterol, plaque area, and thrombosis area were significantly lower in Group II versus Group I (83.4±106.4 versus 608±386 mg/dL, P=0.002; 3.12±1.40 versus 9.39±5.60 mg/g, P=0.003; 10.84±1.6 versus 17.48±1.8 mm(2), P<0.001; and 0.05±0.15 versus 0.72±0.58 mm(2), P=0.01, respectively). There were significant correlations between crystal density and plaque area (r=0.75, P<0.003) and between crystal density and RAM 11 (r=0.82, P<0.001). Scanning electron microscopy demonstrated that there were fewer crystals in Group II versus Group I (+1.2±0.61 versus +2.4±0.63, P<0.001) and less inflammation detected by fluorodeoxyglucose positron emission tomography and RAM 11 (P<0.004 and P<0.04, respectively). CONCLUSIONS: Lowering cholesterol levels with ezetimibe reduced plaque burden, crystallization, and inflammation, preventing plaque disruption and thrombosis.

Safety and efficacy of thrombectomy in patients undergoing primary percutaneous coronary intervention for acute ST elevation MI: a meta-analysis of randomized controlled trials.

BACKGROUND: Clinical trials comparing thrombectomy devices with conventional percutaneous coronary interventions (PCI) in patients with acute ST elevation myocardial infarction (STEMI) have produced conflicting results. The objective of our study was to systematically evaluate currently available data comparing thrombectomy followed by PCI with conventional PCI alone in patients with acute STEMI. METHODS: Seventeen randomized trials (n = 3,909 patients) of thrombectomy versus PCI were included in this meta-analysis. We calculated the summary odds ratios for mortality, stroke, post procedural myocardial blush grade (MBG), thrombolysis in myocardial infarction (TIMI) grade flow, and post procedural ST segment resolution (STR) using random-effects and fixed-effects models. RESULTS: There was no difference in risk of 30-day mortality (44/1914 vs. 50/1907, OR 0.84, 95% CI 0.54-1.29, P = 0.42) among patients randomized to thrombectomy, compared with conventional PCI. Thrombectomy was associated with a significantly greater likelihood of TIMI 3 flow (1616/1826 vs. 1533/1806, OR 1.41, P = 0.007), MBG 3 (730/1526 vs. 486/1513, OR 2.42, P < 0.001), STR (923/1500 vs. 715/1494, OR 2.30, P < 0.001), and with a higher risk of stroke (14/1403 vs. 3/1413, OR 2.88, 95% CI 1.06-7.85, P = 0.04). Outcomes differed significantly between different device classes with a trend towards lower mortality with manual aspiration thrombectomy (MAT) (21/949 vs.36/953, OR 0.59, 95% CI 0.35-1.01, P = 0.05), whereas mechanical devices showed a trend towards higher mortality (20/416 vs.10/418, OR 2.07, 95% CI 0.95-4.48, P = 0.07). CONCLUSIONS: Thrombectomy devices appear to improve markers of myocardial perfusion in patients undergoing primary PCI, with no difference in overall 30-day mortality but an increased likelihood of stroke. The clinical benefits of thrombectomy appear to be influenced by the device type with a trend towards survival benefit with MAT and worsening outcome with mechanical devices.

Sodium bicarbonate-based hydration prevents contrast-induced nephropathy: a meta-analysis.

BACKGROUND: Contrast-induced nephropathy is the leading cause of in-hospital acute renal failure. This side effect of contrast agents leads to increased morbidity, mortality, and health costs. Ensuring adequate hydration prior to contrast exposure is highly effective at preventing this complication, although the optimal hydration strategy to prevent contrast-induced nephropathy still remains an unresolved issue. Former meta-analyses and several recent studies have shown conflicting results regarding the protective effect of sodium bicarbonate. The objective of this study was to assess the effectiveness of normal saline versus sodium bicarbonate for prevention of contrast-induced nephropathy. METHODS: The study searched MEDLINE, EMBASE, Cochrane databases, International Pharmaceutical Abstracts database, ISI Web of Science (until 15 December 2008), and conference proceedings for randomized controlled trials that compared normal saline with sodium bicarbonate-based hydration regimen regarding contrast-induced nephropathy. Random-effects models were used to calculate summary odds ratios. RESULTS: A total of 17 trials including 2,633 subjects were pooled. Pre-procedural hydration with sodium bicarbonate was associated with a significant decrease in the rate of contrast-induced nephropathy (odds ratios 0.52; 95% confidence interval 0.34-0.80, P = 0.003). Number needed to treat to prevent one case of contrast-induced nephropathy was 16 (95% confidence interval 10-34). No significant differences in the rates of post-procedure hemodialysis (P = 0.20) or death (P = 0.53) was observed. CONCLUSION: Sodium bicarbonate-based hydration was found to be superior to normal saline in prevention of contrast-induced nephropathy in this updated meta-analysis.

Association between admission neutrophil to lymphocyte ratio and outcomes in patients with acute coronary syndrome.

The neutrophil/lymphocyte ratio (NLR) has recently been described as a predictor of mortality in patients who undergo percutaneous coronary intervention. The aim of this study was to investigate the utility of admission NLRs in predicting outcomes in patients with acute coronary syndromes (ACS). A total of 2,833 patients admitted to the University of Michigan Health System with diagnoses of ACS from December 1998 to October 2004 were followed. Patients were divided into tertiles according to NLR. The primary end point was all-cause in-hospital and 6-month mortality. The ACS cohort comprised 564 patients with ST-segment elevation myocardial infarctions and 2,269 patients with non-ST-segment elevation ACS. Patients in tertile 3 had higher in-hospital (8.5% vs 1.8%) and 6-month (11.5% vs 2.5%) mortality compared with those in tertile 1 (p <0.001). After adjusting for Global Registry of Acute Coronary Events risk profile, patients in the highest tertile were at an exaggerated risk for in-hospital (odds ratio 2.04, p = 0.013) and 6-month (odds ratio 3.88, p <0.001) mortality. Admission NLR is an independent predictor of in-hospital and 6-month mortality in patients with ACS. This relatively inexpensive marker of inflammation can aid in the risk stratification and prognosis of patients diagnosed with ACS.

A prior myocardial infarction: how does it affect management and outcomes in recurrent acute coronary syndromes?

BACKGROUND: Despite improved secondary prevention efforts, acute coronary syndrome (ACS) recurrence among patients with prior history of coronary events remains high. The differences in presentation, management, and subsequent clinical outcomes in patients with and without a prior myocardial infarction (MI) and presenting with another episode of ACS remain unexplored. METHODS: A total of 3,624 consecutive patients admitted to the University of Michigan with ACS from January 1999 to June 2006 were studied retrospectively. In-hospital management, outcomes, and postdischarge outcomes such as death, stroke, and reinfarction in patients with and without a prior MI were compared. RESULTS: Patients with a prior MI were more likely to be older and have a higher incidence of diabetes mellitus, hypertension, hyperlipidemia, and peripheral vascular disease. In-hospital outcomes were not significantly different in the 2 groups, except for a higher incidence of cardiac arrest (4.3% versus 2.5%, p < 0.01) and cardiogenic shock (5.7% versus 3.9%, p = 0.01) among patients without a prior MI. However, at 6 mo postdischarge, the incidences of death (8.0% versus 4.5%, p < 0.0001) and recurrent MI (10.0% versus 5.1%, p < 0.0001) were significantly higher in patients with a prior history of MI compared with those without. CONCLUSION: Patients with prior MI with recurrent ACS remain at a higher risk of major adverse events on follow-up. This may be partly explained by the patients not being on optimal medications at presentation, as well as disease progression. Increased efforts must be directed at prevention of recurrent ACS, as well as further risk stratification of these patients to improve their overall outcomes.

GP IIb/IIIa inhibitors during primary percutaneous coronary intervention for STEMI: new trial and registry data.

Primary percutaneous coronary intervention (PCI) with adjunctive glycoprotein (GP) IIb/IIIa receptor inhibitor therapy administered in the cardiac catheterization laboratory is the optimal reperfusion strategy for patients with ST-elevation myocardial infarction. Most available data regarding these agents are from trials comparing abciximab to placebo alone. Noninferiority trials comparing small-molecule GP IIb/IIIa receptor inhibitors, such as tirofiban and eptifibatide with abciximab, have used markers for myocardial reperfusion as primary end points but are underpowered to detect significant differences in hard clinical outcomes. Such a trial would need to enroll a very large number of patients and thus make it practically impossible to perform. Registry data reveal that most patients undergoing primary PCI are treated with small-molecule GP IIb/IIIa receptor inhibitors in clinical practice, and no observed difference is observed in safety and efficacy when compared with patients treated with abciximab therapy.

Temporal trends in antiplatelet/antithrombotic use in acute coronary syndromes and in-hospital major bleeding complications.

Antithrombotic and antiplatelet agents are essential for the management of patients with acute coronary syndromes (ACSs). These pharmacologic agents have the potential for increased risk of bleeding. It is not clear if the increased uptake of these therapies has resulted in a clinically evident increase in bleeding complications over time. In this study, we included 3,193 consecutive patients who were admitted to the University of Michigan with an ACS (unstable angina or myocardial infarction) between January 1999 and December 2004. These patients were analyzed for temporal trends in antithrombotic and antiplatelet agent use, thrombolytic therapy, cardiac catheterizations, percutaneous coronary interventions, and major bleeding complications (including gastrointestinal, vascular access, and intracranial hemorrhage). We found a decreasing temporal trend in the incidence of major in-hospital bleeding complications (p <0.001) despite an increasing use of ticlopidine/clopidogrel (p <0.0001), unfractionated heparin (p <0.01), glycoprotein IIb/IIIa inhibitors (p <0.0001), and percutaneous coronary intervention (p <0.0001) in the management of patients with ACSs. In conclusion, major bleeding remains a significant complication of ACS management but has decreased significantly over time. We believe that this decreasing bleeding trend may be because of better identification of higher risk patients, attention to correct dosing, appropriate monitoring, and incorporation of various periprocedural strategies in routine clinical practice.

Effect of statins on cholesterol crystallization and atherosclerotic plaque stabilization.

Pleiotropic effects of statins have not been fully elucidated. Recently we demonstrated that cholesterol expands when crystallizing and may trigger plaque rupture. The present study evaluated the potential direct effects of statins in altering cholesterol crystallization as a possible mechanism for plaque stabilization independent of cholesterol lowering. Cholesterol powder was dissolved in oil with and without pravastatin, simvastatin, or atorvastatin (10 to 90 mg) and then allowed to crystallize to measure peak volume expansion (ΔVE) in graduated cylinders. Effect of ΔVE on fibrous membrane damage was also evaluated. Human coronary, carotid, and peripheral arterial plaques (65 plaques from 55 patients) were incubated with statin or saline solution using matched plaque segments to evaluate direct effects of statins on preformed crystals. Also, the effect of in vivo use of oral statins on crystal structure was examined by scanning electron microscopy and crystal content in plaques scored from 0 to +3. For all statins, ΔVE decreased significantly in a dose-dependent fashion (0.76 ± 0.1 vs 0 ml at 60 mg, p <0.001). By scanning electron microscopy crystal structure with statins had loss of pointed tip geometries, averting fibrous membrane damage. Cholesterol crystal density was markedly decreased and appeared dissolved in human plaques incubated with statins (+2.1 ± 1.1 vs +1.3 ± 1.0, p = 0.0001). Also, plaques from patients taking oral statins compared to controls had significantly more dissolving crystals (p = 0.03). In conclusion, statins decreased ΔVE by altering cholesterol crystallization and blunting sharp-tipped crystal structure and dissolving cholesterol crystals in human arteries in vivo and in vitro, providing plaque stabilization.

The impact of circulating cholesterol crystals on vasomotor function: implications for no-reflow phenomenon.

OBJECTIVES: The purpose of this study was to determine if cholesterol crystals can injure the endothelial surface by their jagged edges altering vasoreactivity and contributing to no-reflow after intervention. BACKGROUND: After plaque rupture, cholesterol crystals are released into the circulation and flow downstream contacting the arterial wall. METHODS: Both carotid arteries from 22 rabbits were placed in a dual perfusion chamber and challenged with norepinephrine followed by acetylcholine and nitroprusside. Arterial diameters were measured before and after exposure to cholesterol crystals or microspheres and compared with diameters of normal control arteries. Arteries were examined by light, confocal, atomic force and scanning electron microscopy. RESULTS: Pre-exposure mean arterial diameter was 2.33 ± 0.27 mm. With baseline norepinephrine there was vasoconstriction of 0.82 ± 0.19 mm, 0.79 ± 0.18 mm, and 0.83 ± 0.16 mm in lumen diameter in the crystal, microsphere, and control groups, respectively. After cholesterol crystals or microspheres, vasoconstriction was significantly less for cholesterol crystals but not for microspheres (0.71 ± 0.28 mm and 0.81 ± 0.15 mm; p < 0.02 and p = 0.68). After acetylcholine in the same artery, there was significantly less dilation before versus after crystals (0.49 ± 0.24 mm vs. 0.38 ± 0.22 mm, p = 0.04) but not with microspheres or in the control group. There was no significant difference after nitroprusside in any group, suggesting endothelial injury. By scanning electron microscopy, cholesterol crystals were found embedded in the intima with endothelial cell tears whereas the microsphere treatment and control groups had minimal or no injury (93% vs. 31% vs. 14%; p < 0.01). By atomic force microscopy, surface roughness was significantly greater with cholesterol crystals compared with microspheres or in control arteries (p < 0.05). CONCLUSIONS: Cholesterol crystals damaged the endothelium and reduced vasodilator response, potentially aggravating myocardial ischemia after interventions.

Short term and intermediate term comparison of endarterectomy versus stenting for carotid artery stenosis: systematic review and meta-analysis of randomised controlled clinical trials.

OBJECTIVE: To evaluate the relative short term safety and intermediate term efficacy of carotid endarterectomy versus carotid artery stenting. DESIGN: Systematic review and meta-analysis. DATA SOURCES: BIOSIS, Embase, Medline, the Cochrane central register of controlled trials, International Pharmaceutical Abstracts database, ISI Web of Science, and Google scholar and bibliographies, from 1 January 1990 to 25 July 2009. STUDY SELECTION: Randomised controlled trials comparing carotid endarterectomy with carotid artery stenting in patients with carotid artery stenosis with or without symptoms. DATA EXTRACTION: Primary end point was a composite of mortality or stroke. Secondary end points were death, stroke, myocardial infarction, or facial neuropathy (as individual end points), and mortality or disabling stroke (as a composite end point). DATA SYNTHESIS: 11 trials were included (4796 patients); 10 reported on short term outcomes (n=4709) and nine on intermediate term outcomes (1-4 years). The periprocedural risk of mortality or stroke was lower for carotid endarterectomy (odds ratio 0.67, 95% confidence interval 0.47 to 0.95; P=0.025) than for carotid stenting, mainly because of a decreased risk of stroke (0.65, 0.43 to 1.00; P=0.049), whereas the risk of death (1.14, 0.56 to 2.31; P=0.727) and the composite end point mortality or disabling stroke (0.74, 0.53 to 1.05; P=0.088) did not differ significantly. The odds of periprocedural myocardial infarction (2.69, 1.06 to 6.79; P=0.036) or cranial nerve injury (10.2, 4.0 to 26.1; P<0.001) was higher in the carotid endarterectomy group than in the carotid stenting group. In the intermediate term, the two treatments did not differ significantly for stroke or death (hazard ratio 0.90, 95% confidence interval 0.74 to 1.1; P=0.314). CONCLUSIONS: Carotid endarterectomy was found to be superior to carotid artery stenting for short term outcomes but the difference was not significant for intermediate term outcomes; this difference was mainly driven by non-disabling stroke. Significantly fewer cranial nerve injuries and myocardial infarctions occurred with carotid artery stenting.

Receipt of cardiac medications upon discharge among men and women with acute coronary syndrome and nonobstructive coronary artery disease.

BACKGROUND: Management of acute coronary syndrome (ACS) patients with nonobstructive epicardial coronary artery disease (CAD) remains poorly understood. HYPOTHESIS: Acute coronary syndrome patients with nonobstructive CAD are less likely to receive effective cardiac medications upon discharge from the hospital. METHODS: We identified patients hospitalized with ACS that underwent coronary angiography and had a 6-month follow-up. Patients were grouped by CAD severity: nonobstructive CAD (<50% blockage in all vessels) or obstructive CAD (> or =50% blockage in > or = 1 vessels). Data were collected on demographics, medications at discharge, and adverse outcomes at 6 months, for all patients. RESULTS: Of the 2264 ACS patients included in the study: 123 patients had nonobstructive CAD and 2141 had obstructive CAD. Cardiac risk factors including hypertension and diabetes were common among patients with nonobstructive CAD. Men and women with nonobstructive CAD were less likely to receive cardiac medications compared to patients with obstructive CAD including aspirin (87.8% vs 95.0%, P = 0.001), beta-blockers (74.0% vs 89.2%, P < 0.001), or statins (69.1% vs 81.2%, P = 0.001). No gender-related differences in discharge medications were observed for patients with nonobstructive CAD. However, women with nonobstructive CAD had similar rates of cardiac-related rehospitalization as men with obstructive CAD (23.3% and 25.9%, respectively). CONCLUSIONS: Patients with nonobstructive CAD are less likely to receive evidence-based medications compared to patients with obstructive CAD, despite the presence of CAD risk factors and occurrence of an ACS event. Further research is warranted to determine if receipt of effective cardiac medications among patients with nonobstructive CAD would reduce cardiac-related events.

A comparison of abciximab and small-molecule glycoprotein IIb/IIIa inhibitors in patients undergoing primary percutaneous coronary intervention: a meta-analysis of contemporary randomized controlled trials.

BACKGROUND: Current guidelines recommend abciximab as the preferred agent for patients undergoing primary percutaneous coronary intervention, yet small-molecule glycoprotein IIb/IIIa inhibitors are more commonly used in clinical practice. The objective of our meta-analysis was to evaluate for differences in clinical outcome between small-molecule glycoprotein IIb/IIIa inhibitors and abciximab in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. METHODS AND RESULTS: Five randomized trials (n=2138 patients) comparing tirofiban or eptifibatide with abciximab as an adjunctive therapy to primary percutaneous coronary intervention were included in this meta-analysis. Summary odds ratios (ORs) for 30-day death, reinfarction, and major bleeding were calculated using random- and fixed-effect models. There were no differences in 30-day mortality (1.9% for small molecule versus 2.3% for abciximab; OR, 0.84; 95% CI, 0.46 to 1.55; P=0.58), reinfarction (1.3% versus 1.2%; OR, 1.22; 95% CI, 0.51 to 2.91; P=0.69), or major bleeding (1.7% versus 1.3%; OR, 1.21; 95% CI, 0.58 to 2.49; P=0.61) between the 2 adjunctive strategies. Similarly, there was no significant difference in the incidence of death (3.9% versus 5%; OR, 0.77; 95% CI, 0.41 to 1.46; P=0.43) or reinfarction on follow-up at 8 months between small-molecule glycoprotein IIb/IIIa inhibitors and abciximab. CONCLUSIONS: In patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction, no difference in outcome could be identified in patients treated with small-molecule glycoprotein IIb/IIIa inhibitor or abciximab.

Efficacy of cilostazol in reducing restenosis in patients undergoing contemporary stent based PCI: a meta-analysis of randomised controlled trials.

AIMS: Cilostazol has been associated with reduction in restenosis in patients undergoing coronary and peripheral arterial angioplasty. Our objective was to evaluate the impact of cilostazol on restenosis in patients undergoing contemporary PCI with bare metal (BMS) or drug eluting stents (DES) and treated with aspirin and thienopyridine. METHODS AND RESULTS: Ten randomised trials (n=2,809 patients) comparing triple antiplatelet therapy (aspirin, thienopyridine and cilostazol) with standard dual antiplatelet therapy were included. Summary risk ratios for restenosis, late loss, target lesion revascularisation (TLR) and target vessel revascularisation (TVR) were calculated using fixed-effects models. Cilostazol was associated with a significant reduction in late loss in BMS (mean difference 0.24 mm, 95% CI 0.15-0.33, p<0.001) and DES groups (mean difference 0.12 mm, 95% CI 0.07-0.18, p<0.001). Cilostazol therapy was associated with a significant reduction in angiographic restenosis (Odds ratio [OR] 0.52, 95% CI 0.41- 0.66, p<0.001) with consistent benefits in patients treated with BMS (OR 0.49, 95% CI 0.35-0.70, p<0.001) or DES (OR 0.54, 95% CI 0.38-0.76, p=0.001). Addition of cilostazol to dual antiplatelet therapy was associated with a significant reduction in TLR (OR 0.38, 95% CI 0.25-0.58, p<0.001), with no difference in subacute stent thrombosis (OR 1.91, 95% CI 0.33-11.08, p=0.47), or major bleeding (OR 0.87, 95% CI 0.44-1.74, P=0.69) but with an increased risk of skin rash (OR 3.67, 95% CI 1.86-7.24, p<0.001). CONCLUSIONS: Cilostazol in addition to dual antiplatelet therapy is associated with a reduction in angiographic restenosis in patients undergoing stent based PCI. This inexpensive drug may be particularly beneficial in patients who are at high risk of restenosis and it should undergo further evaluation in large, definitive randomised controlled trials.

The relative renal safety of iodixanol compared with low-osmolar contrast media: a meta-analysis of randomized controlled trials.

OBJECTIVES: We sought to compare the nephrotoxicity of the iso-osmolar contrast medium, iodixanol, to low-osmolar contrast media (LOCM). BACKGROUND: Contrast-induced acute kidney injury (CI-AKI) is a common cause of in-hospital renal failure. A prior meta-analysis suggested that iodixanol (Visipaque, GE Healthcare, Princeton, New Jersey) was associated with less CI-AKI than LOCM, but this study was limited by ascertainment bias and did not include the most recent randomized controlled trials. METHODS: We searched Medline, Embase, ISI Web of Knowledge, Google Scholar, Current Contents, and International Pharmaceutical Abstracts databases, and the Cochrane Central Register of Controlled Trials from 1980 to November 30, 2008, for randomized controlled trials that compared the incidence of CI-AKI with either iodixanol or LOCM. Random-effects models were used to calculate summary risk ratios (RR) for CI-AKI, need for hemodialysis, and death. RESULTS: A total of 16 trials including 2,763 subjects were pooled. There was no significant difference in the incidence of CI-AKI in the iodixanol group than in the LOCM group overall (summary RR: 0.79, 95% confidence interval [CI]: 0.56 to 1.12, p = 0.19). There was no significant difference in the rates of post-procedure hemodialysis or death. There was a reduction in CI-AKI when iodixanol was compared with ioxaglate (RR: 0.58, 95% CI: 0.37 to 0.92; p = 0.022) and iohexol (RR: 0.19, 95% CI: 0.07 to 0.56; p = 0.002), but no difference when compared with iopamidol (RR: 1.20, 95% CI: 0.66 to 2.18; p = 0.55), iopromide (RR: 0.93, 95% CI: 0.47 to 1.85; p = 0.84), or ioversol (RR: 0.92, 95% CI: 0.60 to 1.39; p = 0.68). CONCLUSIONS: This meta-analysis including 2,763 subjects suggests that iodixanol, when compared with LOCM overall, is not associated with less CI-AKI. The relative renal safety of LOCM compared with iodixanol may vary based on the specific type of LOCM.

Does simplicity compromise accuracy in ACS risk prediction? A retrospective analysis of the TIMI and GRACE risk scores.

BACKGROUND: The Thrombolysis in Myocardial Infarction (TIMI) risk scores for Unstable Angina/Non-ST-elevation myocardial infarction (UA/NSTEMI) and ST-elevation myocardial infarction (STEMI) and the Global Registry of Acute Coronary Events (GRACE) risk scores for in-hospital and 6-month mortality are established tools for assessing risk in Acute Coronary Syndrome (ACS) patients. The objective of our study was to compare the discriminative abilities of the TIMI and GRACE risk scores in a broad-spectrum, unselected ACS population and to assess the relative contributions of model simplicity and model composition to any observed differences between the two scoring systems. METHODOLOGY/PRINCIPAL FINDINGS: ACS patients admitted to the University of Michigan between 1999 and 2005 were divided into UA/NSTEMI (n = 2753) and STEMI (n = 698) subpopulations. The predictive abilities of the TIMI and GRACE scores for in-hospital and 6-month mortality were assessed by calibration and discrimination. There were 137 in-hospital deaths (4%), and among the survivors, 234 (7.4%) died by 6 months post-discharge. In the UA/NSTEMI population, the GRACE risk scores demonstrated better discrimination than the TIMI UA/NSTEMI score for in-hospital (C = 0.85, 95% CI: 0.81-0.89, versus 0.54, 95% CI: 0.48-0.60; p<0.01) and 6-month (C = 0.79, 95% CI: 0.76-0.83, versus 0.56, 95% CI: 0.52-0.60; p<0.01) mortality. Among STEMI patients, the GRACE and TIMI STEMI scores demonstrated comparably excellent discrimination for in-hospital (C = 0.84, 95% CI: 0.78-0.90 versus 0.83, 95% CI: 0.78-0.89; p = 0.83) and 6-month (C = 0.72, 95% CI: 0.63-0.81, versus 0.71, 95% CI: 0.64-0.79; p = 0.79) mortality. An analysis of refitted multivariate models demonstrated a marked improvement in the discriminative power of the TIMI UA/NSTEMI model with the incorporation of heart failure and hemodynamic variables. Study limitations included unaccounted for confounders inherent to observational, single institution studies with moderate sample sizes. CONCLUSIONS/SIGNIFICANCE: The GRACE scores provided superior discrimination as compared with the TIMI UA/NSTEMI score in predicting in-hospital and 6-month mortality in UA/NSTEMI patients, although the GRACE and TIMI STEMI scores performed equally well in STEMI patients. The observed discriminative deficit of the TIMI UA/NSTEMI score likely results from the omission of key risk factors rather than from the relative simplicity of the scoring system.

The chimeric monoclonal antibody abciximab: a systematic review of its safety in contemporary practice.

BACKGROUND: Abciximab is a monoclonal antibody that prevents platelet aggregation by blocking platelet glycoprotein (GP) IIb/IIIa receptor. OBJECTIVE: To study the safety profile of this agent in contemporary clinical practice. METHODS: We evaluated efficacy and safety end points (major and minor bleeding, thrombocytopenia) in patients treated with abciximab and compared them to those treated with placebo in main randomized clinical trials of patients with acute coronary syndromes (ACS) or those undergoing percutaneous coronary intervention (PCI). RESULTS/CONCLUSION: Use of abciximab is associated with an improved outcome in high-risk patients undergoing PCI but with a worse outcome in ACS patients treated conservatively. Use of abciximab is associated with an acceptable safety profile even when used on a background of aspirin and high doses of thienopyridine but has a potential to increase thrombocytopenia and minor bleeding. Small molecule GP IIb/IIIa antagonists are increasingly preferred over abciximab in clinical practice, and recent observational data have demonstrated these agents to have a similar efficacy and safety profile. As an increasing number of agents are being evaluated for peri-PCI anti-thrombotic therapy, the role of abciximab is likely to be further restricted to the highest risk patients.

Do hemoglobin and creatinine clearance affect hospital readmission rates from a skilled nursing facility heart failure rehabilitation unit?

OBJECTIVES: Cardio renal anemia syndrome is being increasingly recognized in patients with congestive heart failure (CHF) and is associated with increased mortality and rehospitalization rates. Our objective was to assess the relationship between hemoglobin (Hb), creatinine clearance (C(Cr)), and hospital readmission in elderly patients enrolled in a skilled nursing facility (SNF)-based CHF rehabilitation unit. METHODS: We retrospectively identified 127 consecutive patients admitted to an SNF-based CHF rehabilitation unit between July 2001 and September 2002. The patients were grouped into quintiles of hemoglobin and creatinine clearance (C(Cr)) The rate of hospital readmission between quintiles of above variables was compared using the chi-square test. RESULTS: We found a higher prevalence of anemia than reported earlier in the literature for CHF patients discharged from hospital. Rehospitalization rates were increased two- and fivefold in lower compared to higher quintiles of hemoglobin and creatinine clearance, respectively. Anemia predicted rehospitalization in patients with renal dysfunction. CONCLUSION: Our study suggests an association between anemia and rehospitalization rates in patients with renal dysfunction enrolled in an SNF-based CHF rehabilitation unit.