Circulation. 2008;118:1307-1308
doi: 10.1161/CIRCULATIONAHA.108.190527
doi: 10.1161/CIRCULATIONAHA.108.190527
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(Circulation. 2008;118:1307-1308.)
© 2008 American Heart Association, Inc.
Clinical Summaries
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Particulate Air Pollution as a Risk Factor for ST-Segment Depression in Patients With Coronary Artery Disease |
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Particulate Air Pollution as...
Differential Citation Rates of...Of the >1 million patients who suffer a myocardial infarction in the United States each year, one quarter to one third of survivors will die within 12 months, and a significant proportion will experience reinfarction or sudden death over the ensuing years. We evaluated the association of elevated air pollution with ST-segment depression in 48 patients followed up after hospitalization for myocardial infarction, acute coronary syndrome without infarction, or stable coronary artery disease without acute coronary syndrome. An interquartile increase in the previous 24-hour mean black carbon, a marker for traffic pollution, was associated with a 1.50-fold increased risk of ST-segment depression
0.1 mm (95% CI, 1.19 to 1.89) and a –0.031-mm (95% CI, –0.042 to –0.019) decrease in half-hour–averaged ST-segment level (continuous outcome). Effects were greatest within the first month after hospitalization and for patients with myocardial infarction during hospitalization or with diabetes. Our study suggests that the effects of air pollution on increased risk of ST-segment depression and ischemia or myocardial inflammation may be heightened in the immediate period after an acute coronary event. During this period, cardiac risk might be reduced by reduction in pollution exposure, including exposure to traffic. See p 1314. |
Differential Citation Rates of Major Cardiovascular Clinical Trials According to Source of Funding: A Survey From 2000 to 2005 |
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Prior work indicates that therapeutic trials funded by for-profit organizations are more likely to report positive findings than trials funded by not-for-profit organizations. What impact, if any, funding source has on subsequent dissemination of trial data is uncertain. We assessed 303 consecutive superiority trials of cardiovascular medicine published between January 1, 2000, and July 30, 2005, in the Journal of the American Medical Association, The Lancet, and the New England Journal of Medicine and found that the median number of citations per publication per year was significantly higher for trials funded by for-profit organizations than for not-for-profit organizations (P=0.0007), an effect that was observed across all journals and all study design characteristics. Higher citation rates also were observed for industry-funded trials than for federally funded trials, even when the trials dealt with similar issues and were published back-to-back in the same journal. The only exception to this rule was observed among those trials that reported an unfavorable result; among such trials, citation rates were lower among industry-funded trials than among federally funded trials. Because postpublication dissemination of clinical trial results is important for quality practice but appears to be biased in favor of for-profit entities, consideration should be given to more extensive promotion of clinical trial results that are funded by not-for-profit organizations. See p 1321.
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Calcification of the Thoracic Aorta as Detected by Spiral Computed Tomography Among Stable Angina Pectoris Patients: Association With Cardiovascular Events and Death |
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Calcification of the thoracic aorta is associated with atherosclerotic risk factors. It is a common finding as an incidental finding in chest x-ray or in more advanced imaging techniques. Because only a few studies have investigated its clinical implications, this finding is usually overlooked and regarded as clinically insignificant. To assess the clinical importance of thoracic aortic calcification, we performed a pilot prospective study with stable angina pectoris patients who underwent chest spiral computed tomography and were evaluated for aortic calcification. In a follow-up period of 4.5 to 6 years, we found significant correlation between calcification of the thoracic aorta and death and cardiovascular events. The severity of calcification also was correlated with the events. These results are a pathfinder to understanding the clinical implications of thoracic aortic calcification and by that raise the question of whether the practicing clinician should modify the approach to the patient with aortic calcification by screening modalities, risk factor stratification, or treatment. This question has yet to be answered, and further evidence-based investigation is needed to determine the clinical outcome and management of the patient with thoracic aortic calcification. See p 1328.
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ST-Segment Recovery and Outcome After Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction: Insights From the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) Trial |
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In nearly 4900 patients from the APEX-AMI trial, 6 measures of ST-segment recovery after percutaneous coronary intervention (PCI) were derived from baseline and/or 30-minute post-PCI ECGs. These measures, from a core laboratory, were examined for their association with biomarker estimates of infarct size and 90-day clinical outcomes that included death and the composite of death, congestive heart failure, or shock. Incomplete ST-segment recovery, irrespective of method, was associated with poorer 90-day survival and clinical outcomes. The simple measure of residual ST-segment elevation in the most affected lead on the post-PCI ECG performed as well as more complex methods that required comparison of pre- and post-PCI ECGs or calculation of summed ST-segment deviation in multiple leads. Thus, single-lead ST-segment recovery is recommended as a simple, routine clinical tool for prognostic assessment in patients with ST-elevation myocardial infarction undergoing PCI. Such an approach may inform care decisions and healthcare resource use in these patients. See p 1335.
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Suppression of the JNK Pathway by Induction of a Metabolic Stress Response Prevents Vascular Injury and Dysfunction |
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Experimental and clinical studies defined endothelial dysfunction as an early marker of atherosclerotic vascular disease. Therefore, preservation of endothelial function is an important goal to avoid vascular disease and to improve prognosis. In the present study, we establish the activation of adenosine monophosphate–activated protein kinase (AMPK), a key enzyme in the adaptation to metabolic stress, as a way to prevent endothelial injury and finally vascular disease. Interestingly, antidiabetic drugs (metformin, glitazones) and statins have AMPK-activating properties, which may, at least in part, contribute to their desired metabolic effects. Our study also suggests that these drugs will exert beneficial effects on the vasculature through AMPK activation apart from those secondary to improved metabolic control. Because cardiovascular events largely determine the prognosis of patients with metabolic disorders, the choice of a drug with AMPK-activating properties seems reasonable because it will improve both endothelial function and metabolic control. See p 1347.
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Inhibition of Restenosis in Femoropopliteal Arteries: Paclitaxel-Coated Versus Uncoated Balloon: Femoral Paclitaxel Randomized Pilot Trial |
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Although recent data indicate that primary stent implantation improves morphological and clinical outcome in treating sclerosed femoropopliteal vessels, the problem of restenosis associated with interventional treatment remains to be solved. Two competing procedures for restenosis prevention involve the use of coated stents and covered stent grafts. Stents not only serve to stabilize a lesion after dilatation but also are approved to serve as carriers for the local delivery of antiproliferative drugs. The Femoral Paclitaxel (FemPac) Randomized Pilot Trial introduces a new method of drug delivery using standard angioplasty catheters as carriers. Whereas stents have a number of drawbacks, including the risk of fracture, material fatigue, and induction of local inflammation in the long run, and are less desirable in the treatment of in-stent restenosis, the concept of balloon-mediated short-time contact offers the chance to combine drug administration for the prevention of restenosis and optional stent placement if needed for lesion stabilization. With the coated-balloon approach, the vessel can be left in its native state if effective dilatation can be achieved without stent implantation. This new concept is currently under further investigation with ongoing trials in below-knee infraglenoidal angioplasty and several indications in the coronary arteries. See p 1358.
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Recurrent Thrombosis and Survival After a First Venous Thrombosis of the Upper Extremity |
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Little is known about the consequences of a first venous thrombosis of the upper extremity. Our study shows the incidence of, survival, and risk factors for recurrence in patients with a first venous thrombosis of the upper extremity. The risk of recurrence was high, with women, patients with body mass index
25 kg/m2, and patients with a first nonsubclavian vein thrombosis having a higher risk of recurrence. Patients with a first venous thrombosis of the arm have a poor vital prognosis. As expected, mortality was high in these patients because venous thrombosis of the upper extremity is a known complication in patients with malignancy. The results suggest that patients with a venous thrombosis of the upper extremity are different than patients with a venous thrombosis of the leg. For instance, the risk of gender is the opposite of what is found for patients with a venous thrombosis of the leg, and the incidence or recurrence is lower compared with recurrent venous thrombosis in patients with a venous thrombosis of the leg. Therefore, further research should be done on other risk factors and optimal treatment for patients with a venous thrombosis of the upper extremity. Differences in risk factors and incidence of recurrence suggest that it is a different disease that should be treated differently. See p 1366. |
Impact of Inherited Thrombophilia on Venous Thromboembolism in Children: A Systematic Review and Meta-Analysis of Observational Studies |
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The role of inherited thrombophilia in the onset and recurrence of pediatric venous thromboembolism (VTE) is unclear. Previous publications reporting the occurrence of inherited thrombophilia in pediatric patients with VTE consist largely of case reports and case series. Although there are a number of prospective and retrospective controlled studies, they generally suffer from methodological problems (often sample sizes that are too small) that preclude any from being definitive. As a result, physicians caring for children with VTE cannot appropriately decide on the utility of thrombophilia testing, leading some physicians to evaluate all such patients and others to perform no testing. Thus, we performed a meta-analysis to provide more definitive answers that can provide some guidance on this controversial issue. The results of this meta-analysis demonstrate that all thrombophilia traits included in the study are associated with the onset of VTE and most are associated with recurrence [except factor V Leiden and lipoprotein(a)]. These results suggest that thrombophilia testing based on the individual genetic background of the patient may be important in the management of children with VTE. See p 1373.
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