JAMA news releases are made available to the public after 3 pm US Central time on the first 4 Tuesdays of each month. The Archives Journals news releases are made available to the public after 3 pm Central time on Mondays. We also provide a list of previous news releases.
THIS WEEK'S CONTENT
JAMA NEWS RELEASES
(Embargoed for Release: 3:00 p.m. CT, Tuesday, July 25, 2006)
JAMA NEWS RELEASES
TEST HELPS IDENTIFY PATIENTS AT LOW RISK FOR RECURRING BLOOD CLOTS
STUDY EXAMINES USEFULNESS OF CARDIAC CT SCAN FOR DETECTING BLOCKAGES IN CORONARY ARTERIES
EARLY—ONSET OF TYPE 2 DIABETES ASSOCIATED WITH INCREASED RISK OF KIDNEY DISEASE AND DEATH BEFORE AGE 55
JAMA REPORT (VIDEO NEWS RELEASE SCRIPT)
VIDEO: Windows Media | Quicktime
STUDY LOOKS AT ACCURACY OF HEART SCAN FOR DETECTING BLOCKED ARTERIES
INFORMATION CONTAINED IN THESE NEWS RELEASES IS PROTECTED BY COPYRIGHT. JOURNAL ATTRIBUTION IS REQUIRED.
Save the Date: JAMA will present new research on HIV/AIDS at a media briefing on Sunday, August 13, from 10 a.m. – 12:15 p.m., at the International AIDS Conference in Toronto. Program and registration information is included at the end of this email.
TV Note: This week's JAMA video news release is on the accuracy and usefulness of a cardiac CT scan for detecting blockages in coronary arteries. The release will be fed Tuesday, July 25, from 9:00 - 9:30 a.m. ET on Intelsat America 6 (formerly Telstar 6), Transponder 11 (C-Band) and from 2:00 - 2:30 p.m. ET on Intelsat America 6, Transponder 11 (C-Band). For more information, call 312/464-JAMA (5262).
Please Note: The FOR THE MEDIA Web site now has a search feature to enable media to find previous JAMA/Archives news releases on specific medical topics. This search feature link is located on the home page at www.jamamedia.org
JOURNALISTS CAN NOW ACCESS EMBARGOED JAMA/ARCHIVES STUDIES ONLINE
Go to www.jamamedia.org for more information and to apply for access.
Embargoed for Release: 3:00 p.m. CT, Tuesday, July 25, 2006
Media Advisory: To contact corresponding author Paul A. Kyrle, M.D., email: paul.kyrle{at}meduniwien.ac.at.
TEST HELPS IDENTIFY PATIENTS AT LOW RISK FOR RECURRING BLOOD CLOTS
CHICAGO—A test that measures the generation of a certain protein involved with blood clotting can help determine whether patients who have experienced a venous blood clot are at low risk of developing another blood clot, and thus avoiding anticoagulant treatment and its possible side effects, according to a study in the July 26 issue of JAMA.
Anticoagulant treatment for patients with venous thromboembolism (VTE - formation of blood clots, often involving the deep veins of the legs or in the lung) consists of heparin followed by vitamin K antagonists for at least 3 to 6 months. After discontinuation of anticoagulant treatment, a third of patients experience recurrence of VTE within the next 5 to 8 years, according to background information in the article. The case-fatality rate of recurrence is around 5 percent. Therefore, identification of patients who might benefit from indefinite anticoagulant treatment (i.e., patients in whom recurrent VTE is more likely than anticoagulation-associated severe bleeding) is now one of the foremost goals in thrombosis research. Because of the large number of risk factors, assessing the risk of recurrence in an individual patient is complex. A laboratory test that would detect multifactorial thrombophilia (increased tendency for blood clots) could help determine the overall risk of recurrent VTE.
Gregor Hron, M.D., of the Medical University of Vienna, Austria and colleagues conducted a study to determine whether by measuring thrombin generation (a protein in blood that causes clotting), patients with VTE could be stratified into high- and low-risk categories for recurrence of VTE. The study, conducted between July 1992 and July 2005, included 914 patients with first spontaneous VTE who were followed-up for an average of 47 months after discontinuation of vitamin K antagonist therapy. Thrombin generation was measured by a commercially available test.
Venous thromboembolism recurred in 100 patients (11 percent). The researchers found that patients without recurrent VTE had lower thrombin generation than patients with recurrence.
“In this large prospective cohort study, we found that patients with a first spontaneous VTE and peak thrombin generation of less than 400 nM [the measurement nanomolar] after discontinuation of vitamin K antagonists have a low risk of recurrence. According to Kaplan-Meier analysis, the likelihood of recurrent VTE in these patients was as low as 7 percent after 4 years ...Compared with patients who had higher levels, those with peak thrombin generation less than 400 nM had an almost 60 percent lower risk of recurrence. Most importantly, the group of patients with low peak thrombin generation represented two-thirds of the total patient population,” the authors write.
“...we believe that our findings are of major clinical relevance. Using a simple commercially available laboratory method developed to measure thrombin generation, we were able to identify patients in whom the long-term risk of recurrent VTE is almost negligible. Considering the incidence rates of severe or fatal hemorrhage related to anticoagulant therapy and the case-fatality rate of recurrent VTE, patients with low peak thrombin generation (less than 400 nM) would almost certainly not benefit from indefinite anticoagulant therapy. Consequently, extensive thrombophilia screening appears to be unnecessary in this large, low-risk patient group,” the researchers conclude.
(JAMA. 2006;296:397-402. Available pre-embargo to the media at www.jamamedia.org)
Editor's Note: Co-author Dr. Binder has reported that he is chief scientific officer for Technoclone GmbH, Vienna, Austria. For funding/support information, please see the JAMA article. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For More Information: Contact the JAMA/Archives Media Relations Department at 312/464-JAMA (5262) or email: mediarelations{at}jama-archives.org.
Go back to the top.
Embargoed for Release: 3:00 p.m. CT, Tuesday, July 25, 2006
Media Advisory: To contact Mario J. Garcia, M.D., call Kate Nagel at 216-445-6472.
STUDY EXAMINES USEFULNESS OF CARDIAC CT SCAN FOR DETECTING BLOCKAGES IN CORONARY ARTERIES
CHICAGO—Use of the 16-row multidetector computed tomography (CT) scan to detect narrowing of coronary arteries may result in a high number of cases in which the diagnosis cannot be determined, limiting the clinical usefulness of the test, according to a study in the July 26 issue of JAMA. However, the heart CT test may be useful in excluding coronary disease in selected patients.
Coronary artery disease is a leading cause of death and health care expenditure in Western countries. Establishing its anatomic diagnosis requires coronary angiography, a procedure that is costly and carries risks and discomfort, according to background information in the article. Recent technical advances with the non-invasive multidetector computed tomography (MDCT) have allowed for excellent visualization of the coronary arteries. MDCT is a form of diagnostic imaging in which a two-dimensional array of detector elements acquire images of multiple slices or sections of an artery or organ simultaneously. With a 16-row MDCT, 16 images are captured per rotation of the machine. Some previous studies have indicated promising results for this technology, but it remains uncertain whether their findings may be replicated in clinical centers with different levels of expertise.
Mario J. Garcia, M.D., of the Cleveland Clinic Foundation, and colleagues investigated the diagnostic accuracy of 16-row MDCT for the detection of obstructive coronary disease in a multicenter study. The study included 238 patients who were clinically referred for nonemergency coronary angiography from June 2004 through March 2005 at 11 participating sites. A total of 187 patients underwent contrast-enhanced MDCT and also had conventional angiography performed one to 14 days after MDCT. The results of these two tests were compared.
Of 1,629 nonstented coronary artery segments larger than 2 mm in diameter, there were 89 (5.5 percent) in 59 (32 percent) of 187 patients with stenosis (narrowing) of more than 50 percent by conventional angiography. Of 1,629 segments, 71 percent were evaluable on MDCT. The sensitivity (positive findings on MDCT and narrowed artery on angiogram) ranged from 89 percent to 94 percent, whereas the specificity (negative findings on MDCT and no narrowing on angiogram) ranged from 51 percent to 67 percent, in analyses that were based on vessel segments or based on individual patients.
The researchers write: “The results of this multicenter study demonstrate a higher number of false-positive and nonevaluable segments than previously reported with MDCT coronary angiography. Because the prevalence of obstructive coronary artery disease was significant (38 percent) in patients with nonevaluable segments, these patients would need to proceed to conventional angiography or additional noninvasive testing in clinical practice.” If all nonevaluable MDCT segments were excluded (or considered negative), 15 patients with stenosis of more than 50 percent would have been missed.
“Multidetector CT coronary angiography may be useful to exclude coronary artery disease in selected patients in whom a false-positive stress test result is suspected. Our results indicate that a negative MDCT coronary angiogram could have a significant discriminative power to exclude significant stenosis in patients with intermediate probability in the absence of nonevaluable segments,” the researchers write.
In this study population, if clinically implemented, a negative evaluable MDCT study may have avoided conventional angiography in 69 (37 percent) of 187 patients, while missing only 1 patient with single vessel obstructive disease (0.4 percent).
“In summary, the results of our study indicate that use of MDCT coronary angiography performed with 16-row scanners is limited by a high number of nondiagnostic cases. Thus, routine implementation of MDCT angiography as a primary diagnostic test to evaluate patients with suspected coronary artery disease would lead to an excessive use of conventional angiography, additional confirmatory noninvasive testing, or both. Nevertheless, the high sensitivity and negative predictive value of this test suggests that if selectively applied, MDCT may be a useful alternative to conventional angiography in selected patients with undetermined or suspected false-positive stress test results. Further studies are needed to determine if MDCT coronary angiography performed with newer 64-slice scanners provides improved performance characteristics that could justify routine clinical application as a primary diagnostic test.”
“...stress testing should remain as the primary diagnostic modality for this purpose until further data obtained with newer generation MDCT technology demonstrates improved performance characteristics,” the authors conclude.”
(JAMA. 2006;296:403-411. Available pre-embargo to the media at www.jamamedia.org)
Editor's Note: The funding for this study was provided by Philips Medical Systems (Highland Heights, Ohio). Co-author Dr. Hoffman reported receiving honoraria for lectures from Philips Medical Systems and Bracco. Please see the article for additional information, including other authors, author affiliations, financial disclosures and funding and support.
For More Information: Contact the JAMA/Archives Media Relations Department at 312/464-JAMA (5262) or email: mediarelations{at}jama-archives.org.
Go back to the top.
Embargoed for Release: 3:00 p.m. CT, Tuesday, July 25, 2006
Media Advisory: To contact Meda E. Pavkov, M.D., Ph.D., call Marcia Vital at 301-496-3583.
EARLY—ONSET OF TYPE 2 DIABETES ASSOCIATED WITH INCREASED RISK OF KIDNEY DISEASE AND DEATH BEFORE AGE 55
CHICAGO—Onset of type 2 diabetes before age 20 in a population of American Indians is associated with a substantially increased risk of end-stage kidney disease and death between 25 and 55 years of age, according to a study in the July 26 issue of JAMA.
The current increase in obesity prevalence in children and adolescents in many parts of the world has led to an increasing prevalence of type 2 diabetes mellitus in these age groups, according to background information in the article. The long-term outcome of persons with youth-onset type 2 diabetes mellitus is not clear.
Meda E. Pavkov, M.D., Ph.D., of the National Institutes of Health, and colleagues examined the impact of age at onset of type 2 diabetes mellitus on the incidence of end-stage renal disease (ESRD) and on natural causes of death in young and middle-aged American Indians. Type 2 diabetes has been increasingly diagnosed in children and adolescents and kidney disease is a major complication of diabetes mellitus in this population.
Participants in the study, conducted between 1965 and 2002, were divided into 2 groups: (1) youth-onset type 2 diabetes mellitus (onset at less than 20 years of age ) and; (2) older-onset type 2 diabetes mellitus (onset between 20 - 55 years of age).
Among the 1,856 diabetic participants, 96 had youth-onset type 2 diabetes mellitus. The researchers found that the sex-adjusted incidence rate of ESRD in youth-onset diabetes mellitus was 25 cases per 1,000 person-years; this rate was 8.4 times as high as in older-onset diabetes mellitus for ages 25 to 34 years, 5.0 times as high for ages 35 to 44 years, and 4.0 times as high for ages 45 to 54 years.
The age-sex–adjusted death rate in participants with youth-onset diabetes mellitus was 15.4 deaths per 1,000 person-years, which was 3.0 times as high as in nondiabetic participants and 2.1 times as high as in individuals with older-onset diabetes mellitus. The death rate in individuals with older-onset diabetes mellitus was 1.4 times as high as in the nondiabetic participants.
“The longer duration of diabetes mellitus by middle age in individuals diagnosed younger than age 20 years largely accounts for these outcomes,” the authors write.
“Because youth-onset diabetes mellitus leads to substantially increased complication rates and mortality in middle age, efforts should focus on preventing or delaying the onset of diabetes, delaying the onset of diabetic nephropathy, or both,” the researchers conclude.
(JAMA. 2006;296:421-426. Available pre-embargo to the media at www.jamamedia.org)
Editor's Note: This research was supported by the Intramural Research Program of the National Institute of Diabetes and Digestive and Kidney Diseases. Dr. Pavkov is supported by a mentor-based fellowship award from the American Diabetes Association. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For More Information: Contact the JAMA/Archives Media Relations Department at 312/464-JAMA (5262) or email: mediarelations{at}jama-archives.org.
Go back to the top.
JAMA REPORTS
VIDEO: Windows Media | Quicktime
STUDY LOOKS AT ACCURACY OF HEART SCAN FOR DETECTING BLOCKED ARTERIES
VIDEO:
B-ROLL
Film images of cardiac CT scan – color animation
Film images of cardiac CT scan – black and white image
AUDIO:
IF THE ARTERIES THAT CARRY BLOOD TO YOUR HEART BECOME BLOCKED, THAT INCREASES YOUR RISK OF HEART ATTACK. THERE ARE A FEW WAYS TO DETERMINE IF YOUR ARTERIES ARE BLOCKED.
VIDEO:
SOT/FULL
@ :11
Super: Samir Kapadia, M.D.
Cleveland Clinic cardiologist
Runs :09
AUDIO:
“We typically do angiography meaning we put catheters into the arteries and then inject dye to see if we can see different parts of the artery wall.”
VIDEO:
B-ROLL
Medical staff in scrubs in operating room preparing for procedure
Patient lying on “cot” in CT machine preparing for scan
AUDIO:
BUT THAT’S AN INVASIVE PROCEDURE, WHICH MEANS ENTERING THE BODY. HEART SCANS, OR CARDIAC C-T SCANS, ARE NOT INVASIVE, WHICH PATIENTS ARE MORE LIKELY TO WANT BECAUSE IT’S MORE COMFORTABLE. BUT DOES IT WORK AS WELL?
VIDEO:
SOT/FULL
@ :33
Super: Mario Garcia, M.D.
Cleveland Clinic Foundation
Runs :10
AUDIO:
“In this study we actually analyzed the accuracy of the first generation of cardiac CT for the detection of blockage in the coronary arteries.”
VIDEO:
B-ROLL
Dr. Garcia looking at images on computer screen
Image on screen Man in CT machine (“donut” through which he is going)
Film of invasive angiogram
GFX/JAMA COVER
AUDIO:
DR. MARIO GARCIA, OF THE CLEVELAND CLINIC FOUNDATION, IS PART OF THE STUDY OF THE FIRST GENERATION CARDIAC CT MACHINE, WHICH HAS SIXTEEN DETECTORS. IT CAPTURES SIXTEEN IMAGES OF THE HEART AND ARTERIES PER ROTATION OF THE MACHINE, SIMILAR TO THIS ONE. THE RESEARCHERS COMPARED SCANS AND INVASIVE ANGIOGRAMS FOR ALMOST TWO-HUNDRED PATIENTS FROM ELEVEN CENTERS AROUND THE WORLD. THEIR FINDINGS APPEAR IN JAMA, THE JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION.
VIDEO:
SOT/FULL
Mario Garcia, M.D.
Cleveland Clinic Foundation
Runs :10
AUDIO:
“If you have a positive result on a cardiac CT, the diagnosis could be in doubt, but if the result is negative, you virtually exclude the possibility of having a blockage.”
VIDEO:
B-ROLL
CT scan film
AUDIO:
IN OTHER WORDS, IF THE CT TEST SAYS YOU DON'T HAVE A BLOCKAGE, BELIEVE IT, BUT IF IT SAYS YOU DO, YOU CAN’T BE SO SURE IT’S RIGHT.
VIDEO:
SOT/FULL
Mario Garcia, M.D.
Cleveland Clinic Foundation
Runs :17
AUDIO:
“The results of our study would suggest that the use of 16-detector scanners should be used with caution or be very restricted because it could lead to false-positive interpretations.”
VIDEO:
B-ROLL
Man in CT scanner having scan
Tilt from computer screen through window to man having scan
Dr. Garcia with colleagues looking at scans on computer screens
C/u images on computer screen
AUDIO:
MANY CENTERS NOW USE THIS NEW GENERATION OF SCANNER THAT HAS SIXTY-FOUR DETECTORS. DR. GARCIA SAYS IT’S MORE ACCURATE THAN THE FIRST GENERATION, WHICH IS ONLY A FEW YEARS OLD ITSELF. HE SAYS PHYSICIANS SHOULD KEEP UP WITH EVOLVING MEDICAL TECHNOLOGY, AND PATIENTS SHOULD TRUST PHYSICIANS TO CHOOSE THE TEST THAT’S BEST FOR EACH CASE. THIS IS MAVIS PRALL WITH THE JAMA REPORT.
