The Doctor's Channel - Emergency Medicine

Longer follow-up confirms advantage of sirolimus-eluting vs bare metal stents

2010-03-10T16:43:41+00:00

NEW YORK (Reuters Health) – Three years after ST-segment elevation myocardial infarction (STEMI), sirolimus-eluting stents still provide better protection against major adverse cardiovascular events compared to bare metal stents, new research shows.

The findings are based on 3 years of data from the randomized SESAMI trial. The 1-year results from SESAMI indicated superior outcomes with sirolimus-eluting stents.

Until now, however, long-term safety and efficacy data for sirolimus-eluting stents in STEMI patients came only from registries, according to author Dr. Carmine Musto, from San Camillo Hospital, Rome, and colleagues.

As reported in the February 23rd Journal of the American College of Cardiology, SESAMI included 320 patients, with long-term data available for more than 97% in each group.

The primary outcome – the incidence of major adverse cardiovascular events at 3 years – was 12.7% with sirolimus-eluting stents vs 21% with bare metal stents (p = 0.034). The endpoint was a composite of cardiac and noncardiac death, Q-wave and non-Q-wave infarction, coronary artery bypass graft surgery, or target lesion revascularization.

Patients with sirolimus-eluting stents also had significantly lower rates of target lesion revascularization (7% vs. 13.5%, p = 0.048), target vessel revascularization (8% vs. 16%, p = 0.027), and target vessel failure (11.5% vs. 20.5%, p = 0.028) compared to patients with bare metal stents.

In addition, significantly more sirolimus-treated patients were alive and free from these adverse outcomes (87% to 93%, depending on the event) compared to patients with bare metal stents (79% to 86.5%; p < 0.05). Prevention of target lesion revascularization drove the benefit of the drug-eluting stents, and this was first apparent in the first year of follow-up.

After clopidogrel was discontinued, the two groups had similar cumulative rates of death and recurrent myocardial infarction, the report indicates.

The study had two principal limitations, the authors note. First, it examined only clinical endpoints. Second, it was not powered to detect differences in cardiac event rates between 12 and 36 months.

Reference:
J Am Coll Cardiol 2010;55:810-814.

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Melamine-related kidney stones can be managed conservatively

2010-03-10T16:32:38+00:00

NEW YORK (Reuters Health) - Kidney stones linked to melamine-tainted infant milk formula can usually be managed conservatively, Chinese authors report. For infants with renal failure, hemodialysis without surgery was usually adequate.

In August 2008, Chinese officials reported that melamine had been illegally added to some milk-based formulas to increase the protein content. Since then, several young children who drank the tainted milk have died and thousands have developed kidney stones. (See Reuters Health reports September 12 and December 2, 2008.)

In a paper scheduled for publication in the April Journal of Urology, Dr. Jian Guo Wen and colleagues at the First Affiliated Hospital of Zhengzhou University report that in their region, more than 3,000 children came for free medical evaluations after ingesting melamine-tainted formula. In 165, the researchers diagnosed melamine related urinary stones. Fifty children (mean age 23.4 months) had bilateral stones.

The children in this subgroup drank the formula for an average of roughly one year, the authors said. Thirty-one had symptoms, including altered frequency of urination, crying at urination or unexplained crying, and oliguria or anuria. Twenty-eight had mildly acidic urine (pH 6 or less), and 11 had renal failure.

Thirty-three patients had stones ranging from 4-10 mm in diameter (based on ultrasound findings); the other youngsters had smaller calculi. The stones - mainly uric acid and melamine -- were radiolucent on plain x-ray but clearly visible on CT.

Management consisted of hydration, IV sodium bicarbonate 5% to raise urine pH, and an antispasmodic drug (anisodamine 0.1-0.3 mg/kg or atropine 0.1-0.2 mg/kg) to help the stones pass.

Eight of the 11 children with renal failure received up to four sessions of hemodialysis. One patient required ureteral catheterization for a week to drain the renal pelvis.

Children remained in the hospital for an average of 8 days; by discharge, all clinical symptoms resolved. No patient died. Within a month, 33 children passed their stones; in the other 17 youngsters, the stones became smaller.

Despite the good outcomes, the authors advise that "these children need to be monitored for long-term effects of melamine-tainted mild formula consumption."

In a short editorial comment, Dr. John C. Pop at Vanderbilt Children's Hospital, Nashville, Tennessee, disagrees with using hemodialysis to treat renal failure in these children. Instead, he advocates "stenting to relieve the obstruction, followed by conservative treatment" until the stones resolve. He would reserve hemodialysis for patients whose renal insufficiency persists.

Dr. Wen's team defends its management decisions, noting that not all the hemodialysis patients had significant ureteral obstruction. "Hemodialysis was performed according to the regimen issued by the Ministry of Health," and parents of the patients opted for this treatment instead of stenting.

Reference:
J Urol 2010;183:1533-1538.

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Emboli filters during PCI lead to higher risk of stent thrombosis

2010-03-09T16:49:30+00:00

NEW YORK (Reuters Health) - Using a distal filter to protect against emboli during coronary stent implantation increases long-term rates of stent thrombosis and target vessel revascularization, investigators in Denmark report.

Randomized trials have shown no benefit of distal protection in the short or intermediate term after percutaneous coronary intervention (PCI), Dr. Anne Kaltoft from Aarhus University Hospital, Skejby, and her associates note. Their article in the Journal of the American College of Cardiology for March 2 reports their 15-month follow-up of patients treated for ST-elevation myocardial infarction in the DEDICATION trial.

Patients received aspirin, clopidogrel, and unfractionated heparin in advance of the procedure. If a cardiologist believed that a wire filter could be advanced (based on pre-dilation and initial visualization of the peripheral vascular bed), the researchers then randomized the patient either to distal protection (n = 312) or conventional treatment (n = 314).

In the distal protection group, filter placement was attempted in 304 patients (97%) and was successful in 254 patients (81%).

But filter protection afforded no benefit at either 30 days, 6 months, or 15 months later, the researchers said.

Nine cases of definite stent thrombosis occurred in the protection group and one in the control group (2.9% vs 0.3%, p = 0.01).

The rate of target lesion revascularization was also significantly increased in the distal protection group (12.5% vs 7%, p = 0.05), as was the rate of target vessel revascularization (15.4% vs 8.3%, p < 0.01).

The two groups had similar rates of myocardial infarction and mortality.

Dr. Kaltoft's team suggests that vessel spasm in response to filter placement could lead "to an underestimation of the vessel diameter and to undersizing of the implanted stent, a known predictor of early stent thrombosis." Other possibilities include damage to the vessel wall at the site of filter deployment or stent apposition during filter retrieval.

Similarly, damage to the vessel wall from pre-dilation or during placement of the filter could increase restenosis rates and the need for repeat revascularization.

Whatever the cause, the authors conclude, "Routine use of a filter wire in its present form cannot be advocated and probably should be avoided with primary PCI for ST-elevation myocardial infarction."

Reference:
J Am Coll Cardiol 2010;55:867-871.

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Magnetic stimulation shows promise for migraine with aura

2010-03-08T19:29:41+00:00

NEW YORK (Reuters Health) – A portable magnetic stimulation device is a promising noninvasive, drug-free treatment for acute migraine with aura, according to a March 4th online report in The Lancet Neurology.

However, although the single-pulse transcranial magnetic stimulation (TMS) was more effective than sham treatment, most patients still had some pain, the report indicates.

Transcranial magnetic stimulation has been “tested in individuals with migraine based on the hypothesis that a fluctuating magnetic field…applied to the back of the head, would induce electrical current and disrupt cortical spreading depression,” lead author Dr. Richard B. Lipton, from Albert Einstein College of Medicine, Bronx, New York, and co-researchers explain.

In the current study, Dr. Lipton’s team assessed response rates in 201 patients with migraine with aura who took home the hand-held Cerena Transcranial Magnetic Stimulator for TMS, or an identical sham device.

Over the 3-month study period, patients treated up to three migraine attacks while experiencing aura. Thirty-seven participants did not treat a migraine attack and were excluded from further analysis.

The main outcome -- no pain 2 hours after the first attack – occurred in 39% of TMS patients and 22% of sham treatment patients (p = 0.0179). Rates of sustained pain-free response at 24 hours were 29% vs. 16% and at 48 hours, 27% vs. 13% (p < 0.05 for both).

Non-inferiority analysis indicated that TMS was at least as effective as sham treatment in combating nausea, photophobia, and phonophobia.

No serious device-related events occurred, and the rate and severity of events was comparable in each patient group.

“For patients who commonly have aura as a signal of an impending migraine, treatment with single-pulse TMS may abort progression of the attack and abate disabling pain and other symptoms,” the authors conclude.

Because there is evidence of cortical spreading depression in migraine without aura, it is possible that TMS may be an effective treatment for these headaches as well, they add.

In an editorial, Dr. Hans-Christoph Diener of University Hospital Essen in Germany writes that with more research, “the use of TMS could be a major step forward in the treatment of migraine with aura, particularly in patients in whom presently available drug treatment is ineffective, poorly tolerated, or contraindicated.”

Reference:
Lancet Neurol 2010.

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Ethosuximide beats lamotrigine and valproic acid for childhood absence epilepsy

2010-03-05T21:46:36+00:00

NEW YORK (Reuters Health) – Ethosuximide and valproic acid are more effective than lamotrigine for treating childhood absence epilepsy, the most common pediatric epilepsy syndrome, according to a report in The New England Journal of Medicine for March 4.

Of the two favored drugs, ethosuximide may be preferred due to a lower rate of attentional dysfunction, the findings suggest.

Each of the three drugs is often used as initial monotherapy for childhood absence epilepsy, “but definitive evidence of their relative efficacy is lacking,” lead author Dr. Tracy A. Glauser, from Cincinnati Children’s Hospital, Ohio, and colleagues note.

The current study randomized 453 newly diagnosed children to treatment with either ethosuximide (Zarontin), lamotrigine (Lamictal), or valproic acid (Depakote). The researchers increased the dose until the child was seizure free, the maximum allowable or highest tolerable dose was reached, or it was clear that treatment had failed.

At 16 weeks, more than half the children taking ethosuximide (53%) and valproic acid (58%) were free of treatment failure, compared to only 29% of children taking lamotrigine (p < 0.001).

Children on valproic acid had a higher rate of attentional dysfunction than children on ethosuximide: 49% vs. 33% (p = 0.03).

Rates of discontinuation for adverse effects, were similar with the three agents, the report indicates.

“This is an age when the newest therapy is assumed to more effective and better tolerated than older therapies,” Dr. Eileen P. G. Vining, from Johns Hopkins University School of Medicine, Baltimore, comments in a related editorial.

But in this case, she continues, the researchers’ “robust evaluation” of the three anticonvulsants has shown “the winner” to be ethosuximide, a “drug from the 1950s and the oldest of the three.”

Reference:
N Engl J Med 2010;362:790-799,843-845.

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Aspirin prophylaxis not useful for asymptomatic vascular disease

2010-03-05T21:36:50+00:00

NEW YORK (Reuters Health) – Asymptomatic patients with a low ankle brachial index don’t seem to get cardiovascular protection from aspirin, randomized trial results suggest.

The subjects came from a cohort of nearly 29,000 men and women ages 50 to 75 years enrolled in a community health registry in Scotland. All were free of clinical cardiovascular disease at baseline, and each agreed to ankle brachial index screening. The 3350 individuals with an index of no more than 0.95 took either 100 mg of aspirin daily, or placebo, for the next 8.2 years, on average.

In the Journal of the American Medical Association for March 3, lead author Dr. F. Gerald R. Fowkes, from the University of Edinburgh and colleagues report that 357 subjects met the main endpoint (a composite of coronary events, stroke, or revascularization). Rates per 1000 person-years were similar with aspirin (13.7) and placebo (13.3).

Rates of a secondary outcome – a composite of the main endpoint plus angina, intermittent claudication, or transient ischemic attack – were also comparable: 22.8 vs. 22.9 per 1000 person-years with aspirin vs placebo, respectively.

All-cause mortality was similar as well, with 12.8 deaths per 1000 person-years in the aspirin group and 13.5 in the placebo group.

Subjects treated with aspirin were 71% more likely than those given placebo to experience major hemorrhage requiring admission to the hospital: 2.5 vs. 1.5 per 1000 person-years.

“Based on the trial conducted by Fowkes et al and other similar studies, aspirin appears to have marginal benefits for reducing initial cardiovascular events when used for patients without clinically evident cardiovascular disease and is associated with higher rates of bleeding in these patients,” Dr. Jeffrey S. Berger, from New York University School of Medicine, comments in a related editorial.

Dr. Fowkes and colleagues conclude that “given the increased level of risk among those with a low ankle brachial index, the use of alternative therapies, such as statins or more potent antiplatelet agents without attendant hemorrhagic risks may usefully be considered.”

Reference:
JAMA 2010;303:841-848,880-882.

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Four clinical factors help rule out bacterial conjunctivitis in kids

2010-03-04T19:12:12+00:00

NEW YORK (Reuters Health) – Four clinical factors can help rule out bacterial conjunctivitis in children, New York City researchers say.

The four factors are: age at least 6 years, only watery discharge (or no discharge), no glued eyes in the morning, and presentation between April and November, according to Dr. James A. Meltzer and colleagues from Jacobi Medical Center in the Bronx.

Children who met all four of these criteria had more than a 90% likelihood of a negative culture for bacterial conjunctivitis, the investigators report in the March issue of the Archives of Pediatrics and Adolescent Medicine.

The researchers say the goal of their study -- which involved 368 patients ages 6 months to 17 years -- was to determine whether a low risk of bacterial conjunctivitis could be predicted based on history and physical examination findings.

They note that up to 80% of the time, conjunctivitis in children is bacterial. But since there are no guidelines to help distinguish bacterial from nonbacterial cases, most clinicians prescribe antibiotics for all cases of acute conjunctivitis, even though “bacterial resistance to antibiotic drugs is an ever-increasing problem, and there is a nationwide effort to find conditions for which antibiotic drug use can be restricted.”

The children in the study had come to the authors’ pediatric emergency department with conjunctival erythema, eye discharge, or both. Any child with eye trauma, chemical exposure, contact lens use, or antibiotic use in the last 5 days was excluded. The study group was 52.7% male and the median age was 3 years.

For each child, the treating clinician completed a checklist of signs and symptoms and collected a conjunctival swab for bacterial culture.

Roughly 35% of subjects had negative conjunctival cultures. Using the researchers’ model, children with none of the specified characteristics had an 11.8% rate of negative cultures, compared to a 76.4% rate in children with three factors and a 92.3% likelihood of negative cultures for children whose eye conditions met all four criteria.

“If these findings are validated in other populations, we may be able to limit routine antibiotic drug administration for children with acute conjunctivitis,” the authors conclude.

Reference:
Arch Pediatr Adolesc Med 2010;164:263-267.

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Without thrombolysis, women fare worse than men after stroke

2010-03-04T15:20:25+00:00

NEW YORK (Reuters Health) – Thrombolysis is a must for female stroke patients if they are to achieve the same outcomes as men, according to a March 2nd report in the Neurology.

“Women need to be treated for stroke as soon as possible,” senior author Dr. Michael D. Hill, from the University of Calgary, Alberta, Canada, said in a statement. “We found that women who weren’t treated had a worse quality of life after stroke than men. However, the good news is that women who were treated responded just as well as men to the treatment.”

The findings are drawn from registry data on 2113 stroke patients treated all across Canada, from June 2001 to February 2002 and from June to December 2002. Women accounted for 43.5% of the cohort.

The primary outcomes were the score on the Stroke Impact Scale-16 score and mortality at 6 months.

Without tissue plasminogen activator (tPA), 70% of men but only 58% of had good outcomes, defined as a score of at least 75 on the Stroke Impact Scale-16 (p < 0.001). With tPA thrombolysis, however, women were just as likely as men to have good outcomes.

Mortality was comparable for men and women whether or not tPA was used.

After adjusting for age, stroke severity, and the time from symptom onset to arrival in the emergency department, gender was found to influence the Stroke Impact Scale-16 score, but not mortality.

Exactly why untreated women fare worse than untreated men is unclear, Dr. Hill said in the statement.

Biologic reasons could explain the difference, he noted. Or older women might be less likely than older men to have a surviving spouse who can assist them in their stroke recovery. In addition, post-stroke depression, which can slow recovery, is more common in women.

Reference:
Neurology 2010;74:767-771.

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Montelukast cuts recurrent wheezing with RSV bronchiolitis

2010-03-02T20:08:06+00:00

NEW YORK (Reuters Health) - Montelukast (Singulair), a leukotriene receptor antagonist, can help prevent recurrent wheezing episodes after respiratory syncytial virus (RSV) bronchiolitis, new research shows.

From earlier work, the researchers knew that airway levels of cysteinyl leukotriene correlated with eosinophil numbers in RSV bronchiolitis. The goal of the present study was to see if reduction of leukotriene levels with montelukast might reduce eosinophil degranulation, which in turn would help reduce recurrent wheezing.

To this end, Dr. Chang-Keun Kim, from Inje University Sanggye Paik Hospital in Seoul, Korea, and colleagues conducted a randomized trial in 200 infants, 6 to 24 months of age, who were hospitalized with a first episode of acute RSV bronchiolitis. Daily for three months, the babies received either oral montelukast 4 mg or placebo. Eosinophil degranulation was assessed by serum levels of eosinophil-derived neurotoxin.

The researchers report their findings in the February 22nd online issue of the Journal of Pediatrics.

At the end of the treatment period, eosinophil-derived neurotoxin levels had decreased significantly in the montelukast group (p < 0.01) and increased significantly in the placebo group (p < 0.0001), the researchers report. Neurotoxin levels remained significantly lower in the montelukast group at 12 months. (Twelve-month data was available for 79 babies in the treatment group and 71 in the placebo group.)

Infants in the montelukast group had significantly fewer recurrent wheezing episodes (p = 0.039), but the significant difference between the groups only emerged after 9 to 12 months. Although this may not seem like strong supporting evidence for montelukast, the authors note this is likely because of the short observation period.

The results "suggest that eosinophil degranulation is important in the pathogenesis of severe RSV disease and that therapies that inhibit degranulation of eosinophils warrant further investigation," the authors said.

Also, they point out, infants with high levels of eosinophil-derived neurotoxin at 3 months seems to be at increased risk for recurrent wheezing. "Although subsequent wheezing may also be caused by other acute viral infections, we suggest 3-month eosinophil-derived neurotoxin levels may be a useful biomarker for predicting recurrent wheezing in children with post-RSV bronchiolitis," the researchers conclude.

The study was funded, in part, by Merck, the maker of Singulair.

Reference:
J Pediatr 2010.

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Surgery favored over stenting for symptomatic carotid stenosis

2010-03-02T20:01:51+00:00

NEW YORK (Reuters Health) - Interim data from a 3-year trial of stenting versus endarterectomy for symptomatic carotid stenosis suggests that for now at least, surgery should remain the procedure of choice.

The report, which appears in the February 26th online issue of The Lancet, presents the 120-day rates of stroke, death, or procedural myocardial infarction (MI) from the ongoing International Carotid Stenting Study (ICSS).

Overall, the ICSS includes 1713 patients randomized to undergo stenting or endarterectomy for symptomatic carotid stenosis.

Dr. Martin M. Brown, from University College London, and colleagues report that by 120 days, the rate of disabling stroke or death in the stenting group was 4.0% compared with 3.2% in the surgery group (HR, 1.28). The corresponding stroke, death, or procedural MI rates were 8.5% and 5.2% (HR, 1.69, p = 0.006).

Compared with surgery patients, patients with stents were nearly twice as likely to have a stroke during follow-up and almost three times as likely to die from any cause.

More procedural myocardial infarctions occurred in the surgery group than in the stenting group (4 vs. 3) - but all of these events in the stenting group were fatal, whereas none of the surgery patients died from procedure-related MI.

Cranial nerve palsy was less common with stenting than with surgery: 1 vs. 45. Likewise, fewer stenting patients had hematomas: 31 vs. 50 events.

In addition, an ICSS substudy that focused on magnetic resonance imaging results -- also appearing online February 26th, but in The Lancet Neurology - found fewer new ischemic brain lesions in the endarterectomy group versus the stenting group.

The substudy featured 124 stenting patients and 107 surgery patients who underwent diffusion-weighted MRI within the week before treatment and 1-3 and 27-33 days afterward.

Lead author Dr. Leo H Bonati from Hospital Basel, Switzerland and colleagues report that in the first few days after treatment, the percentage of patients with new ischemic brain lesions was much higher in the stenting group: 50% vs. 17% (p < 0.0001). The difference was even more pronounced when the analysis was limited to centers that typically use cerebral protection devices: 73% vs. 17%.

At 1 month, 33% of stenting patients had evidence of persistent brain injury, versus 8% of surgery patients (p = 0.0003).

In an editorial in The Lancer Neurology, Dr. Klaus Groschel, from Georg-August-Universitat Gottingen, Germany, comments that the present findings suggest that "the widespread use of carotid stenting, especially its routine use as first-choice treatment for symptomatic carotid stenosis, does not seem to be justified for the time being."

Currently, he notes, the bulk of data supports endarterectomy over stenting. However, he emphasizes that this does not necessarily mean the two approaches can't co-exist, as certain patients may be better served by stenting.

Reference:
Lancet 2010.
Lancet Neurology 2010.

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