Left main trunk coronary artery dissection as a consequence of inaccurate coronary computed tomographic angiography.

A 52-year-old woman presented to a community hospital with atypical chest pain. Her low-density lipoprotein cholesterol and high-sensitivity C-reactive protein levels were not elevated. She underwent cardiac computed tomography angiography, which showed both calcified and noncalcified coronary plaques in several locations. Her physicians subsequently performed coronary angiography, which was complicated by dissection of the left main coronary artery, requiring emergency coronary artery bypass graft surgery. Her subsequent clinical course was complicated, but eventually she required orthotopic heart transplantation for refractory heart failure. This case illustrates the hazards of the inappropriate use of cardiac computed tomography angiography in low-risk patients and emphasizes the need for restraint in applying this new technology to the evaluation of patients with atypical chest pain.

Coronary chronic total occlusion.

Chronic total coronary occlusions (CTOs) are a frequent finding in patients with coronary disease and remain one of the most challenging target lesion subsets for intervention. CTOs have been reported in approximately one-third of patients undergoing diagnostic coronary angiography. By nature of their complexity, CTO percutaneous interventions (PCIs) are associated with lower rates of procedural success, higher complication rates, greater radiation exposure, and longer procedure times compared with interventions in non-CTO stenoses. Despite these obstacles, reported benefits of successful CTO PCI include a reduction in symptoms and improvement in both ventricular function and survival. This article examines the technical challenges, procedural complications, and possible outcomes associated with CTO PCI.

Bare metal stent thrombosis 13 years after implantation.

There has been a great deal of recent controversy regarding the risk of very late stent thrombosis with drug eluting stents, especially in the context of antiplatelet therapy cessation. We report a case of very late stent thrombosis of a bare metal stent initially implanted for treatment of a myocardial infarction. The patient presented thirteen years later with a recurrent myocardial infarction three days after discontinuing aspirin. Angiography demonstrated thrombotic occlusion and severe underlying restenosis of the stent. To our knowledge, this is the latest bare metal stent thrombosis described in the world medical literature.

Pharmacologic therapy for coronary atherosclerosis in patients with Type 2 diabetes mellitus.

Accelerated progression of coronary atherosclerosis underlies the heightened cardiovascular risk observed in diabetic patients. As the worldwide prevalence of diabetes escalates in association with the incidence of abdominal obesity, the global burden of cardiovascular disease will continue to rise. Therapeutic strategies that have had the greatest cardiovascular benefit in diabetes have focused on lowering LDL-cholesterol and blood pressure, rather than glucose-lowering specifically. More recently, arterial wall imaging has helped characterize the natural history of coronary atherosclerosis in diabetes, the impact of associated risk factors and the influence of medical therapies.

Late diagnosis of multiple fibroelastomas in a 41-year-old woman with hypertrophic cardiomyopathy and atrial fibrillation.

A 39 year old woman with hypertrophic cardiomyopathy with severe latent obstruction and mitral regurgitation, presented with symptoms of dyspnea and atrial fibrillation, and developed an acute embolic stroke. After thrombolysis and complete neurologic recovery, a transesophageal echo revealed six mobile densities, on her mitral and aortic valves, and in the outflow tract. Surgical resection of multiple fibroelastomas, with septal myectomy, aortic and mitral valve replacement, and pulmonary vein ablation, led to clinical improvement. The etiology and pathogenesis of fibroelastomas are unknown; we speculate that their formation may be promoted by endocardial injury from surgery, radiation therapy, or the high velocity turbulent flow of valve dysfunction or outflow tract obstruction.

Long-term impact of drug-eluting stents versus bare-metal stents on all-cause mortality.

OBJECTIVES: Our purpose was to examine the incidence of all-cause mortality among drug-eluting stents (DES) and bare-metal stents (BMS) while adjusting for many confounding factors generally not considered in prior studies. BACKGROUND: DES use in the U.S. declined by up to 50% in recent years, primarily due to concerns about late stent thrombosis and possibly increased mortality. However, recent data suggest that DES are as safe as BMS and may actually be associated with a lower incidence of myocardial infarction and mortality. METHODS: All patients undergoing percutaneous coronary intervention with a DES or BMS alone from March 1, 2003, to June 30, 2007, at a tertiary care center were assessed. Multivariable Cox proportional hazards modeling was performed for overall and propensity-matched patients. Socioeconomic status was calculated using U.S. Census 2000 data. The primary end point was all-cause mortality. RESULTS: There were a total of 832 deaths over a 4.5-year interval among 8,032 patients. Of these, 6,053 received a DES and 1,983 patients had a BMS. All-cause mortality was significantly lower in unadjusted and adjusted Cox proportional models with DES (hazard ratio: 0.62, 95% confidence interval: 0.53 to 0.73; p < 0.001). Similarly, in the propensity-matched group, DES remained associated with lower mortality compared with BMS (adjusted hazard ratio: 0.54, 95% confidence interval: 0.45 to 0.66; p < 0.001). CONCLUSIONS: DES were associated with lower mortality in this "real-world" setting. However, despite multiple adjustments, potential confounding may still play a role.

Brain natriuretic peptides as biomarkers for atherosclerosis.

Identification of atherosclerotic risk factors provides targets for development of preventive therapies. Risk factor assessment permits evaluation of an individual's prospective risk of coronary heart disease (CHD). However, it has become apparent that traditional risk factors may not predict CHD in some patients. As a result, many individuals do not receive the benefit of intensive preventive strategies. Accordingly, considerable effort has focused on the identification of novel biomarkers to enhance risk stratification. Given its prognostic utility in heart failure and acute coronary syndrome, brain natriuretic peptide (BNP) and its amino-terminal fragment have received interest as possible biomarkers for CHD.

Comparison of percutaneous versus surgical revascularization of severe unprotected left main coronary stenosis in matched patients.

Coronary artery bypass grafting (CABG) has been the recommended treatment for patients with significant left main coronary artery (LMCA) stenosis. Advances in stent technology have invigorated investigations into the suitability of a percutaneous approach for these patients. Favorable short-term results from nonrandomized comparisons were previously reported. Patients (n = 97) who underwent percutaneous coronary intervention for severe (>70%) LMCA stenosis were matched in a 1:2 ratio with a cohort that underwent surgical revascularization (n = 190). The groups were similar for age, gender, European System for Cardiac Operative Risk Evaluation, left ventricular ejection fraction, history of myocardial infarction, and presence of renal disease. Kaplan-Meier estimates of 3-year mortality were similar for the PCI and CABG groups at 80% (95% confidence interval [CI] 68 to 88) versus 85% (95% CI 79 to 89, p = 0.14), respectively. Propensity score-adjusted 3-year mortality did not differ between groups (p = 0.22). Multivariable modeling identified only higher European System for Cardiac Operative Risk Evaluation (hazard rate 1.33, 95% CI 1.16 to 1.54, p <0.001) and the presence of diabetes mellitus (hazard rate 1.96, 95% CI 1.24 to 3.09, p = 0.004) as independent risks of mortality at 3 years. In conclusion, patients who underwent percutaneous revascularization of severe LMCA stenosis appeared to have 3-year survival equivalent to those who underwent CABG. Diabetes mellitus and advanced co-morbidity were the principal determinants of survival. These findings support the need for randomized trials with adequate follow-up to compare the 2 approaches.

The role of clopidogrel in the management of ischemic heart disease.

PURPOSE OF REVIEW: Platelet inhibition remains a key component in the prevention and treatment of ischemic heart disease. This review documents recent advances in the use of clopidogrel for the management of myocardial ischemia. RECENT FINDINGS: For the prevention of ischemic heart disease, the addition of clopidogrel is not superior to aspirin alone at reducing short or long-term major adverse cardiac events. In patients with ST-segment elevation myocardial infarction who receive thrombolytics, clopidogrel therapy confers broad benefits including survival when initiated at the time of presentation. Long-term administration of clopidogrel is necessary to prevent thrombotic complications following coronary stent placement. Overall, there are no major safety concerns across the spectrum of cardiac indications for clopidogrel. SUMMARY: Clopidogrel has become a cornerstone of therapy in the treatment of acute ischemic coronary syndromes and as prevention of thrombosis after coronary stenting. It has demonstrated safety and efficacy in most aspects of ischemic heart disease. Questions remain about optimal duration of therapy following deployment of drug-eluting stents.

Elevated creatine kinase-MB with normal creatine kinase predicts worse outcomes in patients with acute coronary syndromes: results from 4 large clinical trials.

BACKGROUND: The degree to which elevated creatine kinase (CK)-MB in the presence of normal CK is predictive of outcome is not well understood despite having been studied for decades. This analysis examined whether normal CK with elevated CK-MB in patients with non-ST-segment elevation acute coronary syndrome (NSTE ACS) is an independent predictor of worse outcomes. A concomitant goal was to contribute insight to the debate over how patients with NSTE ACS should be managed. METHODS: Data for 25,960 patients from the GUSTO IIb, PARAGON A and B, and PURSUIT trials were analyzed. Of these patients, 6402 were excluded from primary analysis because of missing (unmeasured) biomarkers. Patients with complete laboratory data (n = 19,558) were grouped by CK and CK-MB results. To confirm the primary analysis results, data from patients with missing biomarkers were used in an imputation model. RESULTS: Patients were categorized in 1 of 4 groups: normal CK + normal CK-MB; normal CK + elevated CK-MB; elevated CK + normal CK-MB; or elevated CK + elevated CK-MB. For the primary outcome, 180-day death, or myocardial infarction, Kaplan-Meier estimates were 14.9%, 20.8%, 14.5%, and 18.2%, respectively. Regardless of total CK, elevated CK-MB was associated with a 25% to 49% increased relative risk of worse outcomes. Findings from the analyses were verified by the multivariable model. CONCLUSIONS: CK-MB remains a reliable marker for myocardial necrosis and a strong predictor of worse prognosis. All patients with ACS should have CK-MB measurement to search for cardiac ischemia. Patients with elevated CK-MB should receive aggressive management commensurate with their increased risks.

Clinical use of enoxaparin in the management of non-ST segment elevation acute coronary syndromes.

Enoxaparin (Lovenox; Roule-Poulenc Rorer, Inc.), a low molecular weight heparin (LMWH), is commonly used in the management of non-ST-segment elevation acute coronary syndromes (NSTE ACS) based on clinical trial outcomes. It is one of a group of glycosaminoglycan compounds that accelerate the inactivation of factor Xa by inducing a conformational change in antithrombin. In contrast to unfractionated heparin (UFH), LMWH have greater bioavailability, a more predictable anticoagulant response, longer half-life and a higher proportion of anti-factor Xa to anti-factor IIa activity. As a consequence, laboratory monitoring of the anticoagulant effect is typically unnecessary. Antithrombin therapy with LMWH or UFH has the highest-level recommendation (IA) in the 2002 professional guidelines for the management of unstable angina and non-ST-elevation myocardial infarction, where enoxaparin has a IIA recommendation over UFH unless early coronary artery bypass surgery is planned. In a recent systematic overview of > 20,000 patients with NSTE ACS from six clinical trials, including conservative and invasively managed patients, enoxaparin provided a statistically significant reduction in 30-day death or nonfatal myocardial infarction (MI) compared with UFH with no significant excess in transfusions, or major bleeding. These data support the role of enoxaparin as an anti-coagulant in patients with NSTE ACS.