<?xml version="1.0" encoding="utf-8"?>
<recommendedContent xmlns="http://api.mspoke.com">
    <recommendedItem id="20100101_19_458"
                     title="Calcium Scoring Misses 20% of CAD Cases (CME/CE)"
                     score="0.012"
                     href="http://www.medpagetoday.com/Cardiology/AcuteCoronarySyndrome/tb/18387?impressionId=1265750782123"
                     
      &lt;p&gt;Contrary to guidelines, the absence of coronary artery calcium doesn&apos;t rule out coronary artery disease in symptomatic patients, researchers found in a new study.&lt;/p&gt;
&lt;p&gt;In a multicenter clinical trial, 19% of patients with a coronary calcium score of 0 had stenosis of at least 50% in one or more coronary artery segments, according to Carlos E. Rochitte, MD, of the University of S&amp;#227;o Paulo, Brazil, and colleagues.&lt;/p&gt;
&lt;p&gt;Likewise, 20% of vessels seen to be totally occluded on revascularization had no calcium on scans, they reported in the Feb. 16 issue of the &lt;em&gt; Journal of the American College of Cardiology&lt;/em&gt;.&lt;/p&gt;
&lt;p&gt;&quot;The absence of coronary calcification should not be used as a gatekeeper and should not prevent a symptomatic patient from undergoing angiography,&quot; the researchers wrote.&lt;/p&gt;
&lt;p&gt;Currently, American Heart Association/American College of Cardiology guidelines suggest that excluding measurable coronary calcium could serve as an effective filter for sending patients on to invasive testing or admitting them.&lt;/p&gt;
&lt;p&gt;One systematic review of 18 studies had indicated that a zero calcium score had a negative predictive value of 93% for stenosis and a positive predictive value of 68% in symptomatic patients.&lt;/p&gt;
&lt;p&gt;However, in Rochitte&apos;s trial  --  CORE64 (Coronary Evaluation Using Multi-Detector Spiral Computed Tomography Angiography Using 64 Detectors)  --  the negative predictive value of a coronary calcium score of 0 was 68%, while the positive predictive value was 81%.&lt;/p&gt;
&lt;p&gt;Overall sensitivity to predict the absence of significant (at least 50%) stenosis was 45%, while specificity was 91%.&lt;/p&gt;
&lt;p&gt;&quot;This apparent lack of predictive value of a calcium scan should be enough to give a clinician pause,&quot; Rita F. Redberg, MD, of the University of California San Francisco, wrote in an accompanying editorial.&lt;/p&gt;
&lt;p&gt;Whatever the reason for the discrepancy, neither the trial nor the review provided any information on how coronary calcium scans add incrementally to traditional predictors of coronary artery disease, such as clinical assessment and stress testing, she said. Nor would she rule out their use entirely for patients with chest pain.&lt;/p&gt;
&lt;p&gt;&quot;Given the significant &lt;a href=&quot;http://www.medpagetoday.com/Cardiology/AcuteCoronarySyndrome/12732&quot; mce_href=&quot;http://www.medpagetoday.com/Cardiology/AcuteCoronarySyndrome/12732&quot; target=&quot;_blank&quot;&gt;radiation risks&lt;/a&gt; of coronary artery calcium scans, however, clinicians must use extreme caution when ordering such scans,&quot; Redberg cautioned.&lt;/p&gt;
&lt;p&gt;The prospective &lt;a href=&quot;http://www.medpagetoday.com/Radiology/DiagnosticRadiology/11927&quot; mce_href=&quot;http://www.medpagetoday.com/Radiology/DiagnosticRadiology/11927&quot; target=&quot;_blank&quot;&gt;CORE64 study&lt;/a&gt; was originally designed to compare diagnostic performance of CT and invasive angiography in symptomatic patients with suspected coronary artery disease. But it also included a coronary calcium scan up to 30 days prior to conventional angiography.&lt;/p&gt;
&lt;p&gt;Of the 291 patients included in the calcium score analysis (73% male, mean age 59.3), 56% had at least 50% coronary stenosis by conventional angiography and 45% had at least 70% stenosis.&lt;/p&gt;
&lt;p&gt;Calcium score only weakly correlated with the highest degree of coronary stenosis found in a patient. Its ability to predict presence of significant lesions was &quot;moderate&quot; (area under the receiver-operating characteristic curve 0.77, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.001).&lt;/p&gt;
&lt;p&gt;A non-zero score was associated with 8.1-fold likelihood of having at least 50% coronary stenosis (&lt;em&gt;P&lt;/em&gt;&amp;lt;0.001) after adjusting for age, sex, hypertension, dyslipidemia, family history of premature heart disease, diabetes, race, and hospitalization.&lt;/p&gt;
&lt;p&gt;Among the 100 patients who went on to revascularization within 30 days of angiography, 13% had a coronary calcium score of 0, 25% had a score of 1 to 10, and 44% had a score over 10 (&lt;em&gt;P&lt;/em&gt;&amp;lt;0.001 for trend).&lt;/p&gt;
&lt;p&gt;The fact that significant coronary artery disease occurred in the absence of calcification in almost 20% of patients should not be surprising, since coronary calcification is thought to occur late in the atherosclerotic process, while obstruction can occur earlier, Redberg asserted.&lt;/p&gt;
&lt;p&gt;The researchers also cautioned that the results would not apply to asymptomatic patients with intermediate risk for events, a group in which a score of 0 has been consistently shown to indicate low risk.&lt;/p&gt;
&lt;div style=&quot;float:left;border-style:solid;border-width:1px;border-color:#8dabbc;font-family:arial;font-size:12px;background-color:#DBE9F2;padding:5px;&quot;&gt;&lt;p&gt;The study was supported by grants from Toshiba Medical Systems, the Doris Duke Charitable Foundation, the National Heart, Lung, and Blood Institute, the National Institute on Aging, and the Donald W. Reynolds Foundation.&lt;/p&gt;&lt;p&gt;Rochitte reported no conflicts of interest. Co-authors reported financial relationships with Toshiba Medical Systems, Bayer, Schering, GE Healthcare, Bracco, Bristol-Myers Squibb, sanofi-aventis, and Vital Images.&lt;/p&gt;&lt;p&gt;Redberg provided no information on conflicts of interest.&lt;/p&gt;&lt;/div&gt;&lt;div style=&quot;clear:both;&quot;&gt;&lt;/div&gt;
    </recommendedItem>
    <recommendedItem id="20100101_19_348"
                     title="No Rebound Seen After Antiplatelet Withdrawal (CME/CE)"
                     score="0.009"
                     href="http://www.medpagetoday.com/Cardiology/PCI/tb/18226?impressionId=1265750782123"
                     
      &lt;p&gt;No evidence of a platelet aggregation rebound occurs with abrupt discontinuation of clopidogrel (Plavix) in patients undergoing percutaneous coronary intervention (PCI), investigators in a randomized clinical trial concluded.&lt;/p&gt;
&lt;p&gt;Values for adenosine diphosphate (ADP)-induced platelet aggregation did not differ significantly between patients whose clopidogrel therapy was withdrawn abruptly and those in whom clopidogrel was tapered before discontinuation, they wrote in an article in the Feb. 9 issue of the &lt;em&gt;Journal of the American College of Cardiology&lt;/em&gt;.&lt;/p&gt;
&lt;p&gt;The findings also showed that tapering of clopidogrel does not lead to lower platelet aggregation values after clopidogrel withdrawal, according to Dirk Sibbing, MD, of Technical University Munich in Germany, and colleagues&lt;em&gt;&lt;/em&gt;.&lt;/p&gt;
&lt;p&gt;&quot;The time course of platelet aggregation values  --  regardless of the device, the agonist, or the agonist concentration used  --  after clopidogrel cessation provides no evidence for the existence of a rebound phenomenon of platelets after discontinuing clopidogrel,&quot; they wrote in conclusion.&lt;/p&gt;
&lt;p&gt;For patients undergoing PCI, dual antiplatelet therapy with aspirin and clopidogrel has become the mainstay for prevention of thrombotic events. Lifelong aspirin therapy is recommended for patients after PCI, but clinical guidelines recommend discontinuation of clopidogrel after six or 12 months. The standard practice is to withdraw clopidogrel abruptly, the authors noted.&lt;/p&gt;
&lt;p&gt;Recent studies have shown a clustering of thrombotic events in the first few weeks after discontinuation of long-term clopidogrel therapy. The observations have led to the hypothesis of a rebound phenomenon of platelet aggregation. However, the hypothesis had not been examined specifically within the context of clopidogrel withdrawal.&lt;/p&gt;
&lt;p&gt;&quot;Because different studies have demonstrated that insufficient suppression of platelet reactivity to ADP is associated with an increased risk of thrombotic events after coronary stent placement, the observed clustering of adverse events reported in clinical studies might be related to an intermittent status of platelet hyperreactivity or so-called platelet rebound with very high ADP-induced platelet aggregation levels,&quot; the authors wrote.&lt;/p&gt;
&lt;p&gt;&quot;A tapering of clopidogrel treatment over a certain period of time before stopping the intake of the drug completely might provide a beneficial treatment strategy to attenuate this supposed rebound phenomenon of platelets.&quot;&lt;/p&gt;
&lt;p&gt;Sibbing and colleagues designed a randomized clinical trial to determine whether a rebound phenomenon exists after discontinuation of clopidogrel and whether the rebound can be attenuated by a clopidogrel-tapering regimen.&lt;/p&gt;
&lt;p&gt;The investigators enrolled 69 patients receiving clopidogrel in association with PCI procedures. In all cases, discontinuation of clopidogrel was planned.&lt;/p&gt;
&lt;p&gt;The patients were randomized to two strategies of discontinuation: tapering of the clopidogrel dose over four weeks, followed by discontinuation; or treatment for four weeks, as planned, followed by abrupt discontinuation.&lt;/p&gt;
&lt;p&gt;Investigators assessed platelet aggregation at enrollment and during weeks two through eight after randomization. Aggregation was assessed simultaneously by light transmission aggregometry (LTA) and multiple electrode aggregometry (MEA).&lt;/p&gt;
&lt;p&gt;The primary endpoint was the highest rate of ADP-induced platelet aggregation by LTA in weeks five through eight after clopidogrel withdrawal.&lt;/p&gt;
&lt;p&gt;Platelet aggregation by LTA peaked at 73% in the group that had clopidogrel abruptly withdrawn and at 69.3% in the tapering group, resulting in a nonsignificant difference (&lt;em&gt;P&lt;/em&gt;=0.21). The between-group values did not differ across the range of ADP concentrations used (1.25 to 20 &amp;#181;mol/L).&lt;/p&gt;
&lt;p&gt;Results by MEA were similar: The peak aggregation value associated with abrupt withdrawal was 925 AU x min compared with 890 AU x min with clopidogrel tapering (&lt;em&gt;P&lt;/em&gt;=0.55).&lt;/p&gt;
&lt;p&gt;Studies with different agonists of platelet aggregation also yielded similar results in the two patient groups.&lt;/p&gt;
&lt;p&gt;Despite finding no difference between the two strategies for clopidogrel withdrawal, the authors did not rule out the possibility of a beneficial effect of tapering clopidogrel.&lt;/p&gt;
&lt;p&gt;&quot;It could be hypothesized that, apart from the maximal values of platelet aggregation observed, a more gradual increase of platelet aggregation values achieved by a clopidogrel-tapering regimen is beneficial for the reduction of thrombotic events,&quot; the authors wrote.&lt;/p&gt;
&lt;p&gt;&quot;In fact, we observed a relatively rapid increase of platelet aggregation values in the [abrupt withdrawal] group of patients in our study. Whether this rapid increase might be disadvantageous in case of stopping clopidogrel treatment remains uncertain.&quot;&lt;/p&gt;
&lt;div style=&quot;float:left;border-style:solid;border-width:1px;border-color:#8dabbc;font-family:arial;font-size:12px;background-color:#DBE9F2;padding:5px;&quot;&gt;&lt;p&gt;The study was supported by Cordis, Medtronic, and Dynabyte.&lt;/p&gt;&lt;p&gt;Sibbing disclosed relationships with Dynabyte and Eli Lilly.&lt;/p&gt;&lt;p&gt;Co-author Adnan Kastrati disclosed relationships with Eli Lilly, sanofi-aventis, and Bristol-Myers Squibb.&lt;/p&gt;&lt;p&gt;Co-author Nicolas von Beckerath disclosed relationships with Eli Lilly and sanofi-aventis.&lt;/p&gt;&lt;/div&gt;&lt;div style=&quot;clear:both;&quot;&gt;&lt;/div&gt;
    </recommendedItem>
    <recommendedItem id="20100101_19_222"
                     title="Benefits of Cutting Down on Salt Quantified (CME/CE)"
                     score="-0.002"
                     href="http://www.medpagetoday.com/Cardiology/Prevention/tb/18075?impressionId=1265750782123"
                     
      &lt;p&gt;Cutting daily salt intake by 3 grams a day  --  about 30% of the current average  --  could prevent 32,000 strokes and 54,000 myocardial infarctions a year, if a computer model developed by researchers at the University of California, San Francisco accurately depicts the clinical impact of salt reduction.&lt;/p&gt;
&lt;p&gt;The results of the analysis, which used a computer simulation of heart disease in U.S. adults ages 35 to 84, also suggest that even a 1 gram per day reduction in salt over the next decade would be a more cost-effective strategy for treating hypertension than use of even the cheapest antihypertensive, wrote Kirsten Bibbins-Domingo, MD, PhD, and colleagues in a paper published online by the &lt;em&gt;New England Journal of Medicine.&lt;/em&gt;&lt;/p&gt;
&lt;p&gt;Lee Goldman, MD, MPH, of Columbia University, who co-authored the paper, told &lt;em&gt;MedPage Today&lt;/em&gt; that their study builds on what has long been known about the adverse health effects of salt on a society that believes it to be the spice of life.&lt;/p&gt;
&lt;p&gt;For example, Goldman said that most people seeking a healthy choice will check food labels and restaurant menus for calorie counts and trans fats, but will not pay attention to salt.&lt;/p&gt;
&lt;p&gt;This is not the first time a call for salt reduction has been issued. As recently as last November, a meta-analysis published in &lt;em&gt;BMJ &lt;/em&gt;suggested that cutting salt intake in half  --  a reduction of about 5 grams a day or roughly a teaspoonful  --  would lower the stroke rate by 23% and reduce overall cardiovascular disease by as much as 17%.&lt;/p&gt;
&lt;p&gt;Americans, like those in many Western countries, take in an average of about 10 g of salt a day; whereas the World Health Organization recommends only 5 g per day, and the U.S. Department of Agriculture recommends daily intake be limited to 5.8 g.&lt;/p&gt;
&lt;p&gt;Bibbins-Domingo and colleagues reported that a 3 gram per day reduction in dietary salt would &quot;save 194,00 to 392,00 quality-adjusted life-years and $10 billion to $24 billion in healthcare costs annually.&quot;&lt;/p&gt;
&lt;p&gt;In an editorial that accompanied the study, Lawrence J. Appel, MD, MPH, and Cheryl A.M. Anderson, PhD, MPH, of Johns Hopkins University, wrote that &quot;the evidence supporting the call to reduce salt intake as a means of preventing cardiovascular disease is compelling.&quot;&lt;/p&gt;
&lt;p&gt;They concluded with this admonition: &quot;As we deliberate healthcare reform, let us not neglect this inexpensive, yet highly effective public health intervention for the prevention of disease.&quot;&lt;/p&gt;
&lt;p&gt;It should be noted that Appel was also first author on a position paper from the American Society of Hypertension that also called for salt reduction as public policy.&lt;/p&gt;
&lt;p&gt;Franz H. Messerli, MD, director of the hypertension program at St. Luke&apos;s-Roosevelt Hospital and a colleague of Goldman&apos;s, said the computer model used in the study was impressive but probably underestimates the benefit of reducing dietary salt &quot;because salt reduction has been shown to have a direct (blood pressure independent) effect on the heart, the brain, the kidneys, and also reduces stomach cancer and osteoporosis  --  factors that were not considered in this analysis.&quot;&lt;/p&gt;
&lt;p&gt;But Messerli found it difficult to lead the victory parade, noting &quot;this is a modeling study and statements such as &apos;A modest reduction of 1 gm per day would be more cost-effective than using medication to lower blood pressure in all persons with hypertension&apos; are to be taken with a good grain of salt.&quot;&lt;/p&gt;
&lt;p&gt;Messerli&apos;s measured response was not echoed by his colleagues in the hypertension world.&lt;/p&gt;
&lt;p&gt;For example, Henry Black, MD, president of the American Society of Hypertension, and director of hypertension research at the New York University School of Medicine said that, although the paper extended the findings of many other studies, it is &quot;more comprehensive and is especially useful by comparing the benefits of [sodium] and [salt] reduction to those of other widely accepted public health approaches that the public and governmental bodies have embraced, including drug treatment.&quot;&lt;/p&gt;
&lt;p&gt;Clyde Yancy, MD, president of the American Heart Association, said that while the study was a computer modeling analysis that may be as good as it gets because &quot;it would be impossible to do a randomized trial in large numbers of high versus low sodium consumption, and the use of modeling with reasonable assumptions represents a solid if not ideal alternative.&quot;&lt;/p&gt;
&lt;p&gt;Moreover, Yancy argued that &quot;the costs and effort involved in setting and/or changing policy&quot; require strong imperatives, and he thought the data reported today &quot;provide that imperative.&quot;&lt;/p&gt;
&lt;p&gt;Three grams of salt comes to about a teaspoonful, but Goldman said it was foolish to think of sodium reduction in terms of such measurements because so much sodium comes from processed foods and from restaurant food. Achieving the needed reduction requires a concerted national effort.&lt;/p&gt;
&lt;p&gt;Bibbins-Domingo noted that their study was limited &quot;by any uncertainty concerning the data entered into the model.&quot;&lt;/p&gt;
&lt;p&gt;Also they noted that they did not &quot;account fully for the possible effects of salt reduction that are unrelated to control of blood pressure  --  for example, potential improvements in outcomes for the increasing numbers of patients with heart failure or prevention of other serious conditions, such as end-stage renal disease.&quot;&lt;/p&gt;
&lt;div style=&quot;float:left;border-style:solid;border-width:1px;border-color:#8dabbc;font-family:arial;font-size:12px;background-color:#DBE9F2;padding:5px;&quot;&gt;&lt;p&gt;The study was supported in part by a grant from the American Heart Association Western States Affiliate and a grant from the University of California, San Francisco Clinical and Translational Sciences Institute.&lt;/p&gt;&lt;p&gt;The authors said they had &quot;no potential conflicts of interest relevant to this article.&quot;&lt;/p&gt;&lt;/div&gt;&lt;div style=&quot;clear:both;&quot;&gt;&lt;/div&gt;&lt;p&gt;&lt;em&gt;This article was developed in collaboration with ABC News. &lt;/em&gt;&lt;img src=&quot;http://www.medpagetoday.com/upload/2009/10/1/14357_1.jpg&quot; mce_src=&quot;http://www.medpagetoday.com/upload/2009/10/1/14357_1.jpg&quot; alt=&quot;&quot;&gt;&lt;/p&gt;
    </recommendedItem>
    <recommendedItem id="20100101_19_150"
                     title="Circulatory Effects Seen with A-Bomb Radiation (CME/CE)"
                     score="-0.004"
                     href="http://www.medpagetoday.com/Cardiology/Atherosclerosis/tb/17977?impressionId=1265750782123"
                     
      &lt;p&gt;Survivors of the atomic bomb blasts at Hiroshima and Nagasaki have an increased risk of dying from heart disease and stroke, researchers found.&lt;/p&gt;
&lt;p&gt;The estimated excess relative risk per Gy was 9% for stroke and 14% for heart disease (&lt;em&gt;P&lt;/em&gt;&amp;#8804;0.02 for both), Yukiko Shimizu, DMSc, of the Radiation Effects Research Foundation in Hiroshima, and colleagues reported online in &lt;em&gt;BMJ&lt;/em&gt;.&lt;/p&gt;
&lt;p&gt;Significant estimated increases in risk started at doses of 0.5 Gy and higher.&lt;/p&gt;
&lt;p&gt;&quot;The effect of radiation on risk of circulatory disease is potentially a very important public health concern,&quot; the researchers wrote.&lt;/p&gt;
&lt;p&gt;&quot;Given the widespread use of multiple computed tomography scans, and other relatively high-dose diagnostic medical procedures, as well as radiotherapy that exposes the heart, the implications are substantial insofar as effects occur at doses under 1 Gy.&quot;&lt;/p&gt;
&lt;p&gt;But they cautioned that &quot;robust confirmatory evidence from other studies is needed.&quot;&lt;/p&gt;
&lt;p&gt;To explore the relationship between radiation exposure and circulatory disease, Shimizu and colleagues looked at more than 50 years of data from the Life Span Study, which has prospectively followed survivors of the atomic bomb blasts in Japan since 1950.&lt;/p&gt;
&lt;p&gt;The analysis included 86,611 individuals who were exposed to radiation at doses ranging from 0 to more than 3 Gy, although 86% received less than 0.2 Gy.&lt;/p&gt;
&lt;p&gt;Through 2003, 9,622 of the participants died from stroke and 8,463 died from heart disease.&lt;/p&gt;
&lt;p&gt;For stroke, a quadratic formula fit the data better than a linear dose-response model, indicating relatively low risk of stroke at lower radiation doses. The linear dose-response model provided the best fit to the data for heart disease, suggesting an excess risk even at lower doses. However, there was not a significant increase in estimated risk for exposures less than 0.5 Gy.&lt;/p&gt;
&lt;p&gt;Adjusting for smoking, alcohol intake, education, occupation, obesity, and diabetes had very little effect on the risk estimates, the researchers wrote.&lt;/p&gt;
&lt;p&gt;To control for the possible misclassification of cancers as circulatory diseases, the researchers re-ran their analysis after excluding those individuals with a history of cancer.&lt;/p&gt;
&lt;p&gt;In this analysis, the excess relative risk for stroke became nonsignificant (&lt;em&gt;P&lt;/em&gt;=0.11), but that for heart disease remained significant (&lt;em&gt;P&lt;/em&gt;=0.03).&lt;/p&gt;
&lt;p&gt;In an accompanying editorial, Mark Little, PhD, of Imperial College London, said the study &quot;adds to a growing body of evidence suggesting an association between cardiovascular disease and exposure to low-moderate levels of radiation, as well as the well-known (and mechanistically well-understood) association at high doses.&quot;&lt;/p&gt;
&lt;p&gt;&quot;However,&quot; he continued, &quot;statistical associations do not prove a causal association, and it is unclear whether the biological mechanisms operating at high doses of radiation apply to low doses.&quot;&lt;/p&gt;
&lt;p&gt;Previous studies, including some randomized controlled trials, have linked high doses of radiation from treatment for Hodgkin&apos;s disease and breast cancer to excess deaths from cardiovascular disease.&lt;/p&gt;
&lt;p&gt;Studies looking at lower doses, however, have yielded mixed results.&lt;/p&gt;
&lt;p&gt;James Thrall, MD, radiologist-in-chief at Massachusetts General Hospital and chair of the American College of Radiology&apos;s board of chancellors, said the results of the current study were not surprising.&lt;/p&gt;
&lt;p&gt;&quot;We have known for a long time that sufficient radiation can have adverse effects on the circulation,&quot; Thrall said in an interview.&lt;/p&gt;
&lt;p&gt;However, he noted that significant associations among the atomic bomb survivors were identified only for doses higher than 0.5 Gy, which is roughly equal to 500 mSv.&lt;/p&gt;
&lt;p&gt;Radiation exposure from typical CT scans ranged from 2 to 31 mSv in a recent study. (See &lt;a href=&quot;http://www.medpagetoday.com/Radiology/DiagnosticRadiology/17530&quot; mce_href=&quot;http://www.medpagetoday.com/Radiology/DiagnosticRadiology/17530&quot; target=&quot;_blank&quot;&gt;CT Scans May Deliver Higher-than-Expected Radiation Doses&lt;/a&gt;)&lt;/p&gt;
&lt;p&gt;Thrall said that risk of circulatory disease is not a consideration when clinicians are weighing the risks and benefits of a CT scan.&lt;/p&gt;
&lt;p&gt;&quot;And I would say that this article does not suggest that that&apos;s a serious concern.&quot;&lt;/p&gt;
&lt;p&gt;The potential mechanisms underlying the association between radiation exposure and circulatory disease remains unclear, but the researchers said &quot;evidence suggests that pro-inflammatory responses to radiation, cellular loss or functional changes in the endothelium, or microvascular damage&quot; may be involved.&lt;/p&gt;
&lt;p&gt;The editorialist Little noted, however, &quot;although we have evidence for [inflammation&apos;s] involvement in the development of cardiovascular disease at high doses of radiation, the mechanism is unclear at low and moderate doses, particularly for occupational exposure, where people receive on average much less than one electron track per cell per day.&quot;&lt;/p&gt;
&lt;p&gt;The study authors noted some limitations of the study: &lt;ul&gt; &lt;li&gt;The ascertainment of circulatory disease from death certificates has limited diagnostic accuracy.&lt;/li&gt; &lt;li&gt;Analyses for potential confounders were incomplete.&lt;/li&gt; &lt;li&gt;There were uncertain associations for exposures below 0.5 Gy.&lt;/li&gt; &lt;li&gt;There is inadequate information about biological mechanisms.&lt;/li&gt; &lt;li&gt;Generalizability to Western populations is uncertain.&lt;/li&gt; &lt;/ul&gt;&lt;/p&gt;
&lt;p&gt;Little also pointed to the selection of patients, particularly in the early years of follow-up, as a weakness because these individuals would have been exposed to war and stressful conditions, which increase the risk of cardiovascular disease.&lt;/p&gt;
&lt;div style=&quot;float:left;border-style:solid;border-width:1px;border-color:#8dabbc;font-family:arial;font-size:12px;background-color:#DBE9F2;padding:5px;&quot;&gt;&lt;p&gt;The Radiation Effects Research Foundation in Hiroshima and Nagasaki is a private nonprofit foundation funded by the Japanese Ministry of Health, Labor, and Welfare and the U.S. Department of Energy, the latter in part through the National Academy of Sciences.&lt;/p&gt;&lt;p&gt;Neither the study authors nor the editorialist reported any conflicts of interest.&lt;/p&gt;&lt;/div&gt;&lt;div style=&quot;clear:both;&quot;&gt;&lt;/div&gt;
    </recommendedItem>
    <recommendedItem id="20090101_2_335"
                     title="CT Procedure Effective for Detecting Pulmonary Embolism"
                     score="-0.005"
                     href="