Tag Archives: Medtronic

BLOCK HF: CRT Superior To Conventional Pacing In Heart Failure Patients With AV Block Reply

by • Heart Failure, Heart Rhythms • Tags: , , , , , ,

 

Patients with atrioventricular (AV) block generally receive right ventricular pacing; cardiac resynchronization therapy (CRT) has been restricted to patients with a low ejection fraction and a wide QRS duration. However, RV pacing may worsen LV dysfunction in AV block patients with low ejection fractions. Previous studies have raised the possibility that these patients may benefit from biventricular pacing with a CRT device.

Now, results from the Medtronic-sponsored BLOCK HF (Biventricular versus Right Ventricular Pacing in Heart Failure Patients with Atrioventricular Block) trial, published in the New England Journal of Medicine, lend more support for the expansion of CRT devices into this population. Anne Curtis and colleagues randomized 691 patients to standard RV pacing or  biventricular pacing. After 37 months of followup, a primary outcome event– death, urgent care visit for heart failure that required intravenous therapy, or a 15% or more increase in the LV end-systolic volume index– occurred in 55.6% of the RV pacing group versus 45.8% in the biventricular pacing group (HR 0.74, CI 0.60-0.90).

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Click here to read the full post on Forbes.

 

Anne Curtis

 

 

 

 

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Guest Post: Case Report Of Durata Lead Failure Raises Fresh Concerns Reply

by • Heart Rhythms, Policy & Ethics • Tags: , , , ,

Editor’s Note: The following guest post is published with the permission of its author,  Edward J. Schloss, MD, (Twitter ID @EJSMD) the medical director of cardiac electrophysiology at Christ Hospital in Cincinnati, OH.

Case Report Of Durata Lead Failure Raises Fresh Concerns

by Edward J. Schloss, MD

 A case report of a failed St. Jude Medical Durata ICD lead was published yesterday, raising suspicions that this lead may share some of the same potential failure mechanisms of its troubled predecessor, the Riata lead.

St. Jude’s ICD lead troubles date back to early case reports involving the Riata and Riata ST leads that ultimately led to FDA recall in December 2011.  These leads have since been well documented to be subject both to increased electrical failures and structural breakdown of the lead as has been previously reported.

St. Jude’s Durata lead was designed as a successor to the Riata ST lead and continues to be marketed and implanted.  The Durata lead shared a similar design to the predecessor Riata ST lead with the most notable difference being the addition of a outer coating made of the proprietary co-polymer Optim.  This design modification has been promoted to improve abrasion resistance.  It is hoped that this modification, would prevent the most prominent failure mechanism of the Riata family, inside-out abrasion and cable externalization.
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FDA Issues Warning Letter To CoreValve Investigator Reply

by • Interventional Cardiology & Surgery, People, Places & Events, Policy & Ethics • Tags: , , , , , ,

The FDA has issued a warning letter to an investigator in the Medtronic CoreValve US Pivotal Trial. The letter cites numerous serious violations relating to the treatment of subjects in the trial testing the experimental Medtronic TAVI (transcatheter aortic valve implantation) device. The violations were uncovered during an FDA inspection last summer.

The subject of the FDA warning is Michael Ring, one of the two principal investigators of the CoreValve trial at the Providence Sacred Heart Medical Center site in Spokane, WA.

Click here to read the full story on Forbes. (Updated to include an additional comment from Dr. Ring.)

English: A warning sign with an exclamation mark

Small Study Explores Expanded Use For TAVI In Native Valve Aortic Regurgitation Reply

by • Interventional Cardiology & Surgery • Tags: , , , , ,

As transcatheter aortic valve implantation (TAVI) gains increasing acceptance, cardiologists and surgeons are exploring additional patient populations who may benefit from the procedure. A new paper in the Journal of the American College of Cardiology provides the first look at the use of TAVI in the small but important group of patients with pure, severe native aortic valve regurgitation (NAVR) who do not have aortic stenosis.

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The authors acknowledge that TAVI will likely be used sparingly in the NAVR population:

…although these results are encouraging for those patients who are truly ineligible for surgery, surgical valve replacement remains the gold standard for those who can undergo it, even at high risk. Furthermore, there is an increasing number of patients in whom the native aortic valve can be preserved during surgery.

Click here to read the full story on Forbes.

Promising One Year Results For Renal Denervation In Resistant Hypertension Spark Hype Reply

by • Interventional Cardiology & Surgery, People, Places & Events, Policy & Ethics, Prevention, Epidemiology & Outcomes • Tags: , , ,

Denervation of the renal sympathetic nerve may become an important new tool in the fight against resistant hypertension.  Previously, the main results of the Symplicity HTN-2 trial demonstrated that in selected patients renal denervation resulted in a large and highly significant reduction in systolic blood pressure (BP) at six months. Now, longer followup from the trial, published in Circulation, demonstrates that the benefits at 6 months extend to one year, and that control patients who crossed over to renal denervation also experienced large reductions in BP.

For 47 patients with resistant hypertension, the reduction in systolic BP at one year (−28.1 mm Hg) was similar to the reduction at 6 months (31.7 mm Hg). For 35 control patients  who crossed over to renal denervation after six months, mean systolic BP dropped from 190.0±19.6 before the procedure to 166.3±24.7 mm Hg. The authors reported one case of renal artery dissection in the crossover group, which was fixed with renal artery stenting, and one episode of hypotension, which was fixed with a medication adjustment.

The results, according to a clinical perspective accompanying the article, suggest that “radiofrequency ablation of renal nerves can significantly lower blood pressure in patients with systolic blood pressures >160 mm Hg with no loss of treatment effect through 1 year and thus may provide a safe and effective adjunctive therapy for treatment-resistant hypertensive patients.”

Comment: Excitement about renal denervation has been growing in recent years. At least some of the optimism may well be warranted. But, for now, the greatest danger is hype. Here’s the #4 item on the AHA’s list, released just this week, of the top advances of 2012:

“Disconnecting” the kidneys might be the key to treating high blood pressure

What does that mean, “the key to treating high blood pressure?” As an invasive procedure, renal denervation will never be more than a important therapeutic option after lifestyle and polypharmacy have failed. I applaud the AHA for highlighting this important new technology, but I think it should have used more cautious wording.

Get ready for much worse. Gullible or naive reporters and editors have already fallen into the trap. Here’s the headline and opening sentences of a story that appeared earlier today in TheStar.com:

Zapping kidneys with radio waves could cure high blood pressure, study finds

In what’s being described as a potential public health miracle, a new study shows that zapping the kidneys with radio waves can safely and dramatically lower blood pressure.

“It makes one dizzy to think about the next set of benefits that follow,” said Dr. Clyde Yancy, head of cardiology at Chicago’s Northwestern University.

This is almost a textbook example of how science and medicine stories should not be reported. It’s important to activate your BS detector whenever you see words like “cure” and “miracle” in a health story. Renal denervation is not a cure and it’s not a miracle. If things work out, it may represent a welcome and significant advance for some patients with resistant hypertension.

To be fair, the rest of the story contains some great quotes and perspective from Clyde Yancy. But by then the damage has been done. It’s impossible to be rational in the presence of cures and miracles. Of course, any reporter can slip at some point and buy into the hype. We’re not perfect. But it helps if the reporter has some prior knowledge and experience in the field. I’m assuming this reporter had little background in this field, since no experienced health reporter would describe renal denervation as “bathing the kidneys in radio waves.” It’s hard enough for physicians and grizzled journalists to figure this kind of stuff out. This is no spot for learning on the job.

But let’s not blame the reporter. He was probably just doing his job as best he could, on a deadline and with few resources. He should be congratulated for getting a good interview with Clyde Yancy. The larger problem here is the way most media treat health, medicine and science stories. Breakthroughs and cures aren’t everyday events, except in the filler pages of tabloids, and on news broadcasts and websites, where scientific inflation is an everyday occurrence. In this context, scientific reporting becomes, essentially, worthless. If everything is a breakthrough then nothing is a breakthrough.
Click here to read the Medtronic press release…

Guest Post: After an Unprecedented Request for a Retraction, A Close Look at the Data 3

by • Heart Rhythms, Policy & Ethics • Tags: , , , , , ,

Editor’s Note: The following guest post is published with the permission of its author,  Edward J. Schloss, MD, (Twitter ID @EJSMD) the medical director of cardiac electrophysiology at Christ Hospital in Cincinnati, OH.

After an Unprecedented Request for a Retraction, A Close Look at the Data

by Edward J Schloss MD

Last week, St. Jude Medical took the unusual step of requesting a retraction of an article accepted for publication in Heart Rhythm Journal.  In this article Deaths Caused by the Failure of Riata and Riata ST Implantable Cardioverter-Defibrillator Leads, Dr. Robert Hauser et al analyzed patient deaths in the FDA MAUDE database associated with St. Jude Medical and Medtronic ICD leads.  This week, Dr. Douglas Zipes, Heart Rhythm editor, declined that request. (Please see my previous Cardiobrief coverage of Hauser’s article.)

In a company news release, St. Jude accused Hauser’s group of “inaccurate facts and biased analysis.”  The sub-headline reads:  “Research undercounted and excluded MAUDE data reports for Medtronic resulting in substantial factual errors.”

St. Jude’s most prominent concern revolves around the number of reported deaths in the analysis of Riata/Riata ST leads and the comparison lead, Medtronic Quattro Secure.  St. Jude wrote: “using the same search criteria outlined in the manuscript, the company has identified that Dr. Hauser’s research substantially undercounted total deaths in the MAUDE database for Quattro Secure.”  St. Jude counts 377 deaths compared to Hauser’s 62.

In an effort to clarify the reasons for this discrepancy, I undertook an independent analysis of the facts available.  My sources are the original Hauser article and the PDF file from St. Jude listing the details of their database search.  I then examined the methodology of both database searches to compare consistency of data entry.  Finally, I performed an independent review of all MAUDE database entries supplied by St. Jude and attempted to classify the 377 deaths Quattro Secure deaths identified by St. Jude into Hauser’s defined categories:  lead-related, indeterminate, and not lead-related, using the methods he described in his paper.

I hypothesized that differences in search methodology may explain the large discrepancy in numbers of deaths found by Hauser and St. Jude.

Results

The Hauser study queried the MAUDE data using the “simple search feature” entering term “Quattro Secure death.”  Results were “refined” to include only model 6947 leads.  Finally, “Reports were excluded from the study if there was no known lead problem or allegation of lead malfunction, and if a returned product analysis found no anomalies that were not caused by the explant procedure.”  With this methodology, the query returned 62 Medtronic Quattro Secure deaths.

The St. Jude data collection methodology is discussed on page one of the PDF document.  The “simple search” function specified by Hauser is not used.  Rather in the standard search fields, individual entries are made for Brand:  Quattro, Manufacturer:  Medtronic, and Event:  Death.  Results were then refined to model 6947 excluding duplicates.  Also in contrast to the Hauser data, no pre-specified exclusions were indicated. This query listed 377 Medtronic Quattro Secure deaths.

Hauser categorized his 62 deaths as 5 (8%) lead-related, 25 (40%) indeterminate, and 32 (52%) not lead-related.

St. Jude did not categorize the 377 deaths. My individual analysis found 7 (2%) lead-related, 129 (34%) indeterminate, and 241 (64%) not lead-related. (Lead-related death MDR Identifiers were 71402, 1438305, 1523151, 1760409, 1944512, 2016463, and 2025526.) I have asked St. Jude for their own analysis of the data into these categories, but have not received a reply.

Discussion

My review confirmed significant methodological differences in the database query specified by Hauser and St. Jude that may explain the differences in the numbers of deaths reported.  This stands in contrast to St. Jude’s assertion that they used “the same search criteria outlined in the manuscript.”
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Round Two: Heart Rhythm Editor Rejects St Jude Request to Retract Riata Paper Reply

by • Heart Rhythms, People, Places & Events, Policy & Ethics • Tags: , ,

Douglas Zipes, the editor of Heart Rhythm, said the journal will not retract a controversial paper that has raised new safety concerns about St. Jude’s embattled Riata leads.

On Friday (as reported here) St. Jude issued a press release alleging numerous mistakes and oversights in an article by Robert Hauser published online in Heart Rhythm linking the company’s Riata and Riata ST leads to 20 or more deaths. The company publicly asked the journal, which is published by the Heart Rhythm Society, to retract the article.

On Tuesday, the New York Times reported that Zipes stood by the journal’s peer review process and would not retract the article. Zipes said there will be “some changes” to the article “involving what he called ‘inflection’” but that “‘the bulk of the manuscript stays as it is.”

Earlier Tuesday, St. Jude continued its assault on the Hauser article by issuing a press release and posting a link to findings from the MAUDE database. The company contended that Hauser had grossly undercounted the number of deaths tied to Medtronic’s Quattro Secure lead, thereby making its own Riata leads appear far worse by comparison.

Hauser and Zipes have not responded in detail to the St. Jude accusations, but Hauser told CardioBrief on Friday that the authors “stand by the conclusion of our study.” In a series of tweets, electrophysiologist Edward J Schloss (who has published guest posts about Riata on CardioBrief), noted that Hauser and St. Jude had applied different methodologies in their search of the MAUDE database, and that St. Jude may have failed to exclude Quattro deaths with no known lead problems.