Consider The Evidence: Med/Peds Journal Roundup

September 11, 2009

the (new) Gardasil controversy

Filed under: immunity, JAMA, pediatrics, vaccines — medblog @ 3:19 pm

JAMA 8/19/09 – In case the Gardasil vaccine wasn’t already surrounded by enough controversy – now there is concern over its safety profile and the marketing practices of Merk. An article in JAMA presents the safety surveillance data for qHPV, finding that “Most of the AEFI rates were not greater than the background rates compared with other vaccines, but there was disproportional reporting of syncope and venous thromboembolic events”

An accompanying editorial discusses the extensive marketing to and through medical professional organizations via the use of manufacturer – designed educational matierials (i.e. brochures, posters, etc)

Some of the adverse event rates can sound pretty scary, especially the 32 reports of death and the elevated rates of VTE. But there are big  problems with the use of VAERS data to assess risk because the reporting comes from a variety of sources, with differing levels of detail and its hard to take away any understanding of causation at all. For example 90% of the patients with VTE had at least one other risk factor. It would be great to rely solely on the controlled safety trial data but they will never have the raw numbers to catch rare events that is found with broad observational data.

The other issue with Gardasil is that there are still many unanswered questions about efficacy. It is unclear what impact this will truly have on cervical cancer rates for many reasons. First, the duration of immunity is unclear. Second, there are several oncogenic strains of HPV that are not covered in the vaccine. And third, proper routine screening is readily available and significantly decreases the risk of developing cervical cancer. Just the fact that screening still has to be done regardless of vaccination status is going to make patients wonder about the point of even getting the vaccine.

All of this seems to add up to many potentially difficult conversations with parents to try to address in the context of a 15-minute office visit – but I’m pretty used to running behind at this point….

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July 18, 2007

Food for thought: Chocolate to lower BP?

Filed under: cardiovascular, hypertension, JAMA — medblog @ 9:34 am

JAMA 7/4/07 –  Maybe some wizard medicine applies to muggles as well… An article in JAMA by Taubert et al. tests the theory that flavonols found in dark chocolate may lower blood pressure

 The study population consisted of 44 otherwise healthy subjects with upper-range prehypertension or stage 1 hypertension. Patients with any other major medical problems including CVD, diabetes, hyperlipidemia, etc were excluded. Study design was an RCT with investigators blinded, but subjects not – because they couldnt disguise the white and the dark chocolate. Patients were also counseled to abstain from any other cocoa products during the study.  Participants were instructed to take one 5.6(white) or 6.3(dark)  gram piece of chocolate per day.

At 6 weeks – no statistical difference between groups.
12 weeks: dark chocolate group BP was down 2.4/1.3 mmHg from baseline.
At 18 weeks the BP difference in the dark chocolate group was – 2.9/1.9 mmHg.
The white chocolate group: no change.
    
Looks like we have a winner.

For the basic science portion of the study, researchers measured plasma S-nitrosoglutathione. Basically they postulate that this compound is an intermediary between nitric oxide stores and active NO in the endothelium. They also measured 8-isoprostane, a measure of oxidative stress. Levels of S-nitrosoglutathione were significantly increased only in the dark chocolate group. 8-isoprostane levels were unchanged with intervention in both groups. Investigators concluded that the effect of dark chocolate was more likley from stimulation of endothelial NO production rather than changes in redox equilibrium between thiol and nitrosothiols. Big words aside – it seemed to work… at least in a healthy, homogenous, untreated population with mild HTN – although I dont seem to have alot of those in my practice….

April 14, 2007

Preventing Post-Op A-fib

Filed under: Cardiology, JAMA — medblog @ 9:50 am

JAMA 4/11/07 – A rare surgery related article for today by Halonen(s) et al. from JAMA.

For unclear reasons the incidence of A-fib after CABG and valve surgery is pretty high (20-40%). One theory is that it is somehow related to an inflammatory response,  and maybe can be prevented with steroids.

This double blind RCT compared Q8 hr hydrocortisone for 3 days postop to placebo for the incidence of atrial fibrillation. They found the incidence of postoperative AF was significantly lower in the hydrocortisone group (30%) than in the placebo group (48%)  with a NNT of 5.6.  And the incidence of infection was similar in both groups.

Interesting because I remember blogging about an article that showed an increase in A-fib with pulse dose steroids in Annals last year. What gives? Well the prior study didnt involve surgery and it was observational – but I was still suprised at the opposite conclusions…. hopefully it will become more clear when the exact mechanism is better worked out

November 9, 2006

SIDS breakthrough? Mittens for stroke rehab

Filed under: JAMA, SIDS, stroke — medblog @ 11:26 am

JAMA (11/1)- An article in last weeks issue by Paterson, et al. is showing up in many news reports as a major advance in the understanding of sudden infant death syndrome (SIDS). The investigators explored the role of seritonergic(5-HT) neurons in the pathogenesis of the syndrome. Frankly, alot of it was basic science gobledygook to me but I got the idea that 1.) seretonin neurons in the medulla oblongata are involved with autonomic and respiratory function, 2.) postmortem exams of the brains of SIDS victims show significant differences in the number and location of 5-HT neurons, as well as lower relative density of seritonin transport protein. With 35% of the SIDS samples coming from premature babies, and the number of controls that were premature not being reported – I was left wondering if this was all confounded by normal developmental differences?

In a more immediately applicable study, Wolf et al. took about 200 stroke patients with hemiparesis and and had half of them put a restraining mitt on their good hand. Its called constraint-induced movement therapy (CIMT). The idea was to reinforce the connections to the affected limb by restricting use of the other limb. The subjects were 3 to 9 months out from the stroke. The CIMT group were supposed to wear the mitt during 90% of waking hours for 2 weeks. In addition they had daily task practice sessions with the paretic limb. The control group had usual care stroke rehab. In the end, the CIMT group had significantly better motor function that persisted at 1 year after therapy.

August 24, 2006

Can UF Heparin replace LMWH as subcu anticoagulation?

Filed under: JAMA, VTE — medblog @ 8:30 pm

JAMA 8/23 – Will Lovenox and Fragmin share the same fate as New Coke? A study by Kearon et al. investigated the use of Classic unfractionated heparin as a subcutaneous treatment without APTT monitoring. The study protocol treated DVT and PE with a twice daily subQ injection of UFH in much the same way Low Molecular Weigh Heparin is used currently, except for a weight adjustment. The results essentially show that UFH was equally effective as LMWH in preventing recurrent thromboembolism. Appparently the crazy unpredictable pharmacokinetics are not a big issue with the subcutaneous route. And the fact that UFH is about 50 times cheaper is a big plus.
The study was an open-label RCT and the outcome analysis was done by blinded investigators. About 70% of subjects were treated as outpatients. Apparently there were some problems with recruitment but the power was adequate to provide reliable results.

July 28, 2006

MDCT not quite ready for CAD screening

Filed under: Cardiology, JAMA — medblog @ 9:49 pm

JAMA 6/26 – Interventional radiologists can breathe a little easier…. for now. A study by Garcia and the CATSCAN investigators in JAMA explored the use of 16 row multidetector CT to assess for coronary artery stenosis. Having a non-invasive method to evaluate the condition would make life much easier for many thousands of CAD sufferers each year, not to mention fattening some radiologist pocketbooks.

But unfotunately, in a study of over 200 patients, the test was only moderately (89%) sensetive and not very specific (65%) in the detection of greater than 50% stenosis. In addition, only 71% of the lesions were evaluable. Clearly not ready for primetime yet, but the technology is probably not that far off.

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July 17, 2006

new drug to help smokers quit

Filed under: JAMA — medblog @ 11:27 pm

JAMA – With millions of smokers trying to quit, treatment of nicotine addiction has become a hotbed of research. Three articles in last week’s JAMA cover Varenicline, the first new drug made specifically to treat nicotine addiction.

Varenicline is a partial agonist at the nicotine receptor thought to be responsible for the reinforcing effects of the drug. This may result in the blunting of withdrawal symptoms while blocking activation by nicotine from cigarettes.

So how well did it work? Pretty well in fact. The articles indicated that Varenicline was (more…)

March 20, 2006

Plaque-busting with statins

Filed under: Cardiology, JAMA, statins — medblog @ 11:14 pm

JAMA 3/13 – Nissen et al. produce the latest, and largest of several trials documenting the effect of statin therapy on atherosclerotic plaques. The earlier studies suggested that intensive therapy with statins led to the decrease in atheroma volume. The authors of this study contend that their measurement parameters (taken via IVUS) were more rigorous than the past studies, allowing them to make a much more definitive conclusion on the issue.

A dramatic result of the study was the reduction median LDL-C levels by over 50% to approx 60mg/dl.“The achieved LDL-C levels were the lowest values ever observed in a statin atherosclerosis progression trial.” The mean change in atheroma volume in the most diseased 10-mm subsegment was –6.1 mm3. Change in total atheroma volume showed a 6.8% median reduction; with a mean reduction of –14.7 mm3. They conclude that, “When viewed in this context, the results of the current study demonstrate that there exists no apparent threshold LDL-C level beyond which the benefits of statin therapy are no longer evident. If regression of disease is the desired outcome, then lower LDL-C is better.”

Put them in the water…..

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March 11, 2006

Beverage Guidelines stir controversy; Java in JAMA

Filed under: caffeine, Coffee, diet, health, JAMA — medblog @ 6:41 am

A new set of beverage guidelines published in the American Journal of Clinincal Nutririon are causing quite a stir lately. The reccomendations encourage Americans to drink more water or tea and cut back significantly on sweetened sodas. An interesting detail is that the suggestions allow for more beer than lowfat milk on a daily basis. The prominent nutritionists that published the guidelines claim the study was not influenced by funding from the Lipton corporation.

While the above study cites data supporting the safety and possible benefits of caffeine consumption, an article in JAMA addresses the risk of MI from coffee intake. The study by Cornelis et al. links the risk of MI to those that are "slow" caffeine metabolizers. In the study, carriers of a specific CYP1A2 genotype that resulted in slower caffeine metabolism had an increased odds ratio of having an MI if they drank more than 2 cups of coffee per day.

February 28, 2006

G-CSF can’t stem the tide of Acute MI

Filed under: Cardiology, JAMA, myocardial infarction, stem cells — medblog @ 10:45 pm

JAMA 3/1 – Disappointing results from Zohlnhofer et al. in this weeks’ JAMA from a trial utilizing G-CSF to mobilize stem cells after acute MI (free full text avail.) Although some preliminary studies were promising, this is the first true RCT to address the subject. The researchers administered G-CSF 5 days after infarct and then followed up patients with T-99 scintigraphy, MRI, and/or angio. Although a significant increase of CD34+ cells was detected, indicating a surge of stem cells was mobilized – there was no significant difference in LVEF or infarct size at follow up. . . (more…)

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