BLOCK HF: A “Game Changer” For Cardiac Pacing 3

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. Dr. Schloss was an investigator in the BLOCK HF trial.

In what has been described as a “game changer” for the field of cardiac pacing, the BLOCK HF trial was reported at today’s AHA Scientific Sessions showing benefit of biventricular pacing over conventional RV pacing in patients with AV block and LV dysfunction.

Since the development of pacemakers over 50 years ago, doctors have treated patients with AV block with right ventricular pacing. Until about 10 years ago, this was felt to be harmless and potentially beneficial.  Pacing algorithms were designed to force right ventricular pacing and create what was termed a “physiologic AV delay” in the hopes that controlling the timing of atrial and ventricular contraction would improve hemodynamics.

The DAVID trial, reported in 2003, turned the conventional wisdom upside-down, and first clearly showed the hazards of unnecessary RV pacing.  DAVID was designed with the hypothesis that dual chamber pacing in patients receiving ICDs without bradycardia indications would result in improved hemodynamics and therefore improved outcomes as compared to conventional backup ventricular pacing.  To the surprise of the investigators, the opposite proved true.  The group receiving dual chamber pacing had about a 40% increase in mortality and heart failure hospitalization as compared to the minimal pacing group over one year.  As this data was confirmed with additional trials, doctors moved to minimize right ventricular pacing in their patients and new minimal pacing algorithms were developed by industry.

Paralleling the movement to minimize right ventricular pacing, the technique of cardiac resynchronization therapy (CRT) for treatment of heart failure took off.  Here the benefit of pacing right and left ventricles together was established for patients with heart failure and evidence of dyssnchronous ventricular contraction.

The BLOCK HF trial was planned to test the hypothesis that biventricular pacing would be superior to right ventricular pacing in patients with left ventricular dysfunction and heart block requiring pacing.  Enrollment began in December 2003.

BLOCK HF enrolled patients indicated for ventricular pacing due to AV block who had at least mild LV dysfunction (LVEF <50% on optimal HF medical therapy) and NYHA functional class I-III.  All patients then received biventricular devices (pacer or ICD depending on clinical indication) and then were randomized in blinded fashion to conventional dual chamber (RA-RV) pacing vs. biventricular (RA-RV&LV) pacing.  Primary endpoint was the time to first event: total mortality, heart failure exacerbation requiring acute care or >= 15% increase in echocardiographic left ventricular end-systolic volume.

Enrollment and follow up continued with serial echoes and clinical assessments for over seven years with mean follow up just over three years.  The sample size was determined by a pre-specified adaptive statistical analysis that took into account the results of repeated interim analyses.  The study would complete for success, hazard or futility.  A total of 691 patients completed randomization and were included in the final analysis (with 102 exited or lost to follow up).  The study population was predominantly male with average age in 70s, and NYHA class II predominated.  LVEF was average 43% in the pacemaker group and 33% in the ICD group.

In the final analysis, biventricular pacing led to a 26% reduction in the combined endpoint of death, heart failure exacerbation or LV enlargement.  Excluding the echo endpoint, the clinical parameters remained favorable, with a 27% reduction in death or heart failure exacerbation.  The heart failure curves diverge early and remain parallel and the mortality curves diverge at about four years and continue to separate.

In last night’s investigator meeting, Dr. Anne Curtis, the study PI, called BLOCK HF a “game changer” that could lead to a new indication for biventricular pacing in patients with heart block and LV dysfunction.  She acknowledged the limitations of the trial including a high crossover rate (predominantly RV to BiV) and some missing echo data.  The very long follow up, however, could be interpreted as an advantage for the trial.

As an investigator in the trial, I was very eager to see this data and encouraged by the results.  The trial was slow to enroll with very long follow up and we were just happy to see it reach fruition.  Over the years, I’ve seen numerous patients develop heart failure after initiation of conventional pacing and it’s good to know that we may be able to prevent this if a new indication arises from the BLOCK HF data.

As in all trials, we will need to be cautious in the application of the data.  BLOCK HF should not spell the end for right ventricular pacing.  For those patients with normal LV function or those who get minimal ventricular pacing (such as sick sinus patients), conventional RV pacing is still appropriate and avoids the additional cost complexity and hazard of adding an LV lead.

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Guest Post: New Questions Raised About Latest Generation St. Jude ICD Leads Reply

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.

 New Questions About Latest Generation ICD Leads From St. Jude

by Edward J. Schloss

A highly anticipated study analyzing failures of St. Jude Durata and Riata ST Optim ICD leads was published online today in Europace by prominent electrophysiologist and ICD critic Dr. Robert Hauser along with associates from the Minneapolis Heart Institute.

Over the last year St. Jude Medical has been beset with bad news about their ICD leads.  Until recently, the criticism has been confined to issues surrounding their older generation Riata and Riata ST leads (see my coverage in Cardiobrief).  These leads have been shown to be prone to both structural and electrical failures at an increased rate compared to competitive leads.  St. Jude has staunchly defended their newer generation Durata and Riata ST Optim leads, which have an additional layer of Optim copolymer insulation coating which they believe will decrease failures by improving abrasion resistance.  Last week, however, FDA issued a new request for post-market studies including X-ray surveillance of these leads, calling them “sufficiently similar” to Riata and Riata ST to merit increased scrutiny.

Today’s study from Hauser serves as another blow to St. Jude, and may affect implanter confidence in current generation Durata leads.  In the study, Hauser queried the FDA MAUDE database for “abrasion analysis” and reported detailed results.  He found 15 Riata ST Optim and 37 Durata reports.  The predominant abnormality in both groups was external abrasion (i.e. can/lead, or lead/lead), although several internal abrasions were also found.  Most of these abrasions resulted in clinically relevant electrical abnormalities such as low voltage oversensing resulting in inappropriate shocks.  One high voltage failure during a spontaneous ventricular arrhythmia resulted in an ineffective shock and subsequent patient death.

Hauser shied away from making comparisons to other leads in the current study and did not make any attempt to calculate an incidence of lead failure, recognizing the limitations inherent in analysis of a voluntary database.  This stands in contrast to his last Riata/Riata ST MAUDE analysis which provoked a firestorm of criticism including a request for article retraction from St. Jude Medical.
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Guest Post: FDA Clarifies Riata Imaging Recommendations 1

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.

Additional clarity regarding yesterday’s St. Jude Riata/Riata ST imaging recommendations has arrived in the form of another FDA Safety Communication available at the FDA web site.

According to the FDA, Riata and Riata ST leads “have an increased risk of premature insulation failure that can impact the lead’s ability to function properly.”  They add that there is currently insufficient information to determine the natural history of these insulation failures and risk factors that lead to failure.

FDA recommends physicians perform systematic imaging of their patients with Riata and Riata ST leads because”

“We believe that assessing the current condition of Riata and Riata ST leads is likely to help health care providers develop individualized plans for their patients, which may include recommendations on the frequency of remote monitoring and the necessity and frequency of repeat imaging.”

Specific recommendations of imaging are also spelled out.  Acceptable techniques include:

  • 2 view Chest X-Ray.  OK to use study obtained in last 3-6 months.  Recommend working with radiologist to obtain and interpret images.
  • Fluoroscopy

FDA also suggests that after this initial imaging, physicians “may consider performing fluoroscopy of the lead at the time of the generator replacement to check the lead condition.”  They also believe it is reasonable to repeat imaging to follow up manifest visual abnormalities.

Guidelines for management of specific clinical scenarios generally distill down to providing close follow up with attention to device performance.  They do not recommend extraction or replacement of leads with normal electrical function.

So where does this leave doctors and patients?  In an excellent perspective, cardiac electrophysiologist Dr. John Mandrola probably speaks for many of us when he writes of his frustration with these new mandates.  In medical school, we were taught never to get a test unless it influenced the subsequent management of the patient.  As John writes, “nobody knows the best way to manage these leads. Not the professors, not us masters of obvious in the clinical world, and surely not the amalgamizers in cubicles at the FDA.”  FDA indicates that physicians should develop “individualized plans for their patients.”  No room, however, is given to the thoughtful provider who may feel that his individualized treatment plan might best not include performing routine x-ray imaging.

Guest Post: FDA Calls For X-Ray Screening Of Riata Leads And Additional Followup Studies 1

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.

St. Jude’s troubled implantable defibrillator leads came under a fresh layer of scrutiny today with new FDA imaging recommendations and post-market study requirements.  For the first time, the newer generation Durata and Riata ST Optim leads have been placed under enhanced review.

The problems with St. Jude’s ICD leads date back to the first reports of Riata model lead externalization in 2010.  By December 2011, FDA had issued a class I recall of both Riata and Riata ST models based on the growing body of evidence that these leads had potential for insulation breakdown.  Additional studies have now also shown increased electrical abnormalities of these leads.  Next generation Durata leads, while sharing significant structural similarities to Riata and Riata ST have thus far performed well in prospective trials (See my earlier post about the full scope of the problem.)

FDA Calls for X-Ray Screening of Riata and Riata ICD Leads

Today FDA issued a press release calling for patients to undergo “x-ray or other imaging alternatives” to look for externalization of St. Jude Riata and Riata ST leads.  Specific timing and frequency of testing is not stated and no recommendations are given as to how to act on abnormal findings.  In the release, FDA indicates that x-ray information “will help health care providers develop individualized patient treatment plans.” These recommendations may come as a bit of a surprise to the electrophysiology community.  Routine screening for externalization, while favored in some centers, has not been recommended by St. Jude Medical or the Heart Rhythm Society.  At the Riata Leads Summit this past January, only about half of physician attendees polled planned to do this screening, as I previously reported. 

The link between externalization and lead failure remains uncertain.  During a St. Jude’s sponsored webinar posted last month, Dr. Neal Kay reported “more than 85% of the externalized conductors continue to function normally.”  Later in the lectures, numerous discussants referred to Riata externalization as “cosmetic.”  St. Jude’s data from the Riata Lead Evaluation Study showed externalization rates of 24% in Riata and 9.3% in Riata ST based on prospective fluoroscopic data, but electrical data from that trial is still being collected and has not yet been reported.  A recent VA trial reported increased electrical failures in these leads, but did not include x-ray evaluations.
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Guest Post: Is It The Right Time To Introduce Real Supervision Into Medical Practice? 1

Editor’s Note: Dr. Schloss, the medical director of cardiac electrophysiology at Christ Hospital in Cincinnati, OH, originally submitted the following post as a comment on my previous post in which I compared HCA to Barclays and JP Morgan. I’d be very eager to hear responses from other physicians about this subject.

Is It The Right Time To Introduce Real Supervision Into Medical Practice?

by Dr. Edward J. Schloss

One thing hospitals and banks have in common is that the quality of their work is obscure and not easily measured by the consumer. Systematic abuses can go undetected without direct supervision and public reporting.

At least a banker’s work is directly supervised by their peers. In a hospital, there is no direct supervision on the actions of the doctors. It is quite easy to work alongside another doctor for years without really knowing how good or bad they are. Current quality measures are easily gamed and do not really measure what they are intended to measure. Any practicing physician will tell you that.

Because our patients are not able to evaluate the quality of their care and external quality metrics are so poor, I wonder if the time might be right to introduce real supervision into medical practice. In his excellent piece in the New Yorker this week, Atul Gawande spends some time discussing ICU doctor supervision via the electronic ICU system. It may be time to extend this type of “check and balance” system into more clinical arenas. Imagine a physician supervisor making rounds into cath labs and ORs, reviewing charts and interviewing MDs. This sort of thing would likely be resisted by many doctors, but would be a better way to pick up outliers than computerized checklists.

Now that most doctors are employees of hospital systems, it would be feasible to set up such a supervision system (assuming federal privacy rules don’t get in the way).

Guest Post: An Electrophysiologist Looks At The New HRS/ACCF Pacemaker Guidelines Reply

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.

Overview of the New HRS/ACCF Pacemaker Guidelines

by Edward J Schloss MD 

Since the development of the first dual chamber pacemakers in the 1980s, doctors have had the choice of using single or dual chamber devices in patients with traditional pacing indications. Although a number of pacemaker guideline consensus statements have been published over the years, none have provided specific guidance on specific device type or pacing mode selection.

This week the Heart Rhythm Society and American College of Cardiology Foundation published online the HRS/ACCF Expert Consensus Statement on Pacemaker Device and Mode Selection.  The authors intend this to be a supplement to the 2008 published pacemaker guidelines and classify indications in similar fashion, ranging from Class I (general agreement regarding benefit) to Class III (not useful, or harmful).  Biventricular pacing is not addressed in these documents, having been covered elsewhere .

The document is concise and clearly stated, and I would refer all those close to the field to the link above.  Below, I will add my own brief summary and comments.
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New ICD Lead Technology Creates New Set of Problems: A Perspective From One Electrophysiologist 1

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.

Why I Don’t Like DF-4: A Personal Perspective

by Edward J Schloss MD 

Since the first human implantable cardioverter defibrillator (ICD) implant in 1980, there have been a wealth of technological advances that have allowed these devices to become a standard therapy in the treatment of patients at risk for sudden cardiac arrest.  Some of these, such as non-thoracotomy lead systems and biphasic waveforms have revolutionized the industry.  Others, such as downsized lead caliber have added risk without clear benefits.

The DF-4 ICD lead is one of the latest technologies to be approved in cardiac rhythm management.  DF-4 refers to the type of pulse generator connector on these leads.  All three major US ICD vendors have FDA approved DF-4 ICD leads, and these have been generally been well received by the implanting physician community.  In this perspective, I endeavor to show that it may be appropriate to temper this enthusiasm.

Historical Background and Lead Design

Early ICDs required open chest surgery to implant and were offered only to high-risk cardiac arrest survivors.  In the early 1990s, transvenous lead ICD systems eliminated the need for thoracotomy or sternotomy. Soon thereafter, these leads were coupled with downsized ICD generators and advanced shock waveforms resulting in significant improvements in implant safety and success.  As device indications expanded into primary prevention after the MADIT and SCD-HeFT trials, ICD implantation exploded in the US.
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Single Case Report Casts New Doubts About St. Jude Durata ICD Leads 1

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.

As if on cue, just as the train pulled into the Nice-Ville station for this week’s Cardiostim 2012 meeting on the French Riviera, my Twitter stream and email lit up with news about a MAUDE case report about an externalized Durata:

Non invasive programmed stimulation of icd, revealed undersensing of ventricular fibrillation after induction. Fluoroscopy of lead revealed externalization of conductors. The externalization was confirmed at lead extraction. The externalization was adjacent to the distal coil of the lead.

Wall Street reacted promptly with a 6% drop in St. Jude’s stock price on Tuesday.

Though not widely reported, this was not the first report of an externalized Durata. As I reported previously, at the Riata Lead Summit in Minneapolis in January, St. Jude presented a case of a patient in Alaska with an externalized Durata lead.  At that point, the company was able to dampen negative reaction with an analysis indicating that the externalization was caused by abrasion of the lead in an “outside-in” fashion from contact with a tricuspid valve annuloplasty ring.

Why did this new Durata story provoke such a strong reaction?

• The new MAUDE report arrived without any explanation or reaction from St. Jude Medical.  The first references came from the financial analyst community and filtered out through online sources such as Twitter and Cafepharma.com.  There have been no additional details beyond the brief summary in MAUDE .  St. Jude Medical seemed to be as surprised as everyone else. A St. Jude spokesperson told Reuters: “We will make every effort to learn more about the report as quickly as possible.”

• This is the first important new development since last month’s Heart Rhythm Society Meeting in Boston.  At that meeting, as reported in Med City News, Charles Love of Ohio State, offered a favorable perspective on Durata. This was counterbalanced by unfavorable data about the prior generation Riata lead and a scathing commentary by ICD watchdog Robert Hauser, as I then reported.

• The report comes on the eve of the Cardiostim Meeting here in Nice.  This meeting serves as a European counterpart to last month’s HRS sessions and will provide a ready forum for reaction and consensus building.

• St. Jude has waged an aggressive defense of Durata, promoting “0% Externalized Conductors” in promotional materials (see photo at bottom).  This “all-in” stance may have created lofty expectations for this lead’s performance.  Even a single unsubstantiated case report therefore could create an unfavorable reaction.

It remains to be seen if this case report will be the “tip of the iceberg” or an isolated phenomenon. Its validity is even being questioned, as FDA cannot reveal its source and the details of the report have not yet been made available.

Those of us who have followed medical device failures closely over the years should know not to react too quickly to case reports.  It seemed inevitable to me that there would be at least some Durata externalization reports given that lead’s similarity in design to the Riata ST lead. However, a single case report, or even a few cases reports, do not provide sufficient evidence to indict Durata at this time.  More information may arrive soon in the form of an expected paper from Dr. Hauser on Durata electrical failures in the MAUDE database.

(Photo of Durata promotional truck at HRS courtesy of Dr. Wes)

Robert Hauser, ICD Watchdog, Offers Viewpoint On Riata Controversy At HRS Reply

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.

Robert Hauser, ICD Watchdog, Offers Viewpoint On Riata Controversy At HRS

by Edward J Schloss MD

The St. Jude Riata ICD lead controversy took center stage at last week’s Heart Rhythm Scientific Sessions in Boston, as previously reported here.  Near the end of the meeting a leading figure in the field, Dr. Robert Hauser, of the Minneapolis Heart Institute, summarized the current state of the Riata crisis and discussed its broader implications. Hauser has played key roles in the Riata and several other similar, highly disturbing cases, including those involving the Sprint Fidelis ICD leads and the Prizm 2 DR ICD device malfunction.

In a troubling revelation near the end of his talk, Hauser suggested that St. Jude’s problems may not end with the now discontinued Riata leads, and that the company’s Durata leads may have failure mechanisms not previously reported.

Hauser first discussed an abstract from Steinberg and associates from Quebec.  These investigators used chest x-rays rather than fluoroscopy to detect Riata externalizations:

They, like others, found a far higher incidence of externalized conductors than what has been reported by St. Jude Medical.  And frankly, this and other reports presented at this meeting raise serious questions about the accuracy of the data that the manufacturer has communicated to us.  What we learned today is that this externalized cable process is time dependent.  It seems to be occurring more frequently in the 1580 leads, particularly in the 8 French, and that with time we are going to see progression.  The fact that these investigators were able to use special chest radiographs to identify externalized conductors is interesting and deserves further study by comparing the sensitivity and specificity of their technique to high-resolution cine-flouroscopy

Hauser then discussed the Riata extraction experience from Royal Victoria Hospital in Belfast, and then offered some practical advice:
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Guest Post: Shedding Light On Riata At The Heart Rhythm Society Meeting 2

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.

Shedding Light On Riata At The Heart Rhythm Society Meeting

by Edward J Schloss MD

This morning in Boston, HRS 2012 sessions began with a state of the art session on St. Jude ICD leads.  Riata, Riata ST and Durata are being discussed at the first large electrophysiology meeting since this lead came under FDA recall.

It was obvious at the outset, that this is a vital topic to the EP community.  Those who didn’t arrive early were relegated to a remote viewing station.  Even there, the crowd was very large and engaged.

Kenneth Ellenbogen started the presentation with updated data on the VA Riata and Riata ST leads.  Interestingly, this data actually showed an increased failure rate of Riata ST as compared to Riata.  This stands in distinction to data from the Minneapolis Multicenter Data presented later in the late breaking trials session.

Things got interesting with the discussions of the clinical aspects of Riata lead management.  Dr. Larry Epstein of Boston highlighted potential management strategies.  He advised against placement of a sensing lead alone if the lead is failed.  In explaining why “I’m scared about Riata,” he gave the account of a patient with completely normal lead parameters that fortuitously suffered a cardiac arrest in his hospital.  The ICD was ineffective at terminating the arrhythmia and the patient had to be externally defibrillated.  To screen for these sort of silent lead failures, he performs fluoroscopy and high-energy shock delivery on his Riata leads before scheduled generator changes.

Dr. Roger Carillo of Miami outlined his approach to Riata lead management as well.  He expressed concern over the potential for thrombus formation on externalized leads.  He advocated routine fluoroscopic exams on all Riata leads.  He then performs transeophageal echo on externalized leads and anticoagulates those with thrombus.  He presented a step-by-step account of the unique challenges of Riata lead extraction.  Warning of a variety of pitfalls and complications, he added, “if you fail to follow any of these steps, the lead will not forgive you.”

The session ended with more calming words from Charles Love of Columbus.  In his talk on Durata leads, he repeatedly emphasized “it is a very, very different lead.”  He spent some time going over the design of all St. Jude leads and pointed out the potential benefit of the Optim insulation coating added to Durata and Riata ST Optim leads.  Active registries on these newer leads continue to show robust performance approaching 5 years.  He did acknowledge the small numbers of leads in late follow up.  But in the question and answer section, not all were convinced.  Dr. Larry Epstein stated, “I still have issues with trust.”

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

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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Guest Post: Lessons from the Riata Recall– Part III 1

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.

Lessons from the Riata Recall– Part III

by Edward J Schloss MD

In two earlier posts on Cardiobrief (here and here), I have written in some detail about the St. Jude Riata/Riata ST lead recalls.  In these pieces, I’ve summarized what we know about the design of these leads and their clinical performance. Ultimately I hope this updated information allows clinicians and other interested parties to make intelligent decisions regarding lead follow up and new lead model selection.

This week we’ve seen new important information that sheds additional light on the performance of Riata and Riata ST. As is often the case, new information leads to both new answers and new questions.

Accepted for publication in Heart Rhythm are two new manuscripts that reference these leads.  From frequent contributor Robert Hauser and his group at Minneapolis Heart Institute Foundation comes this review of ICD lead related deaths from the FDA MAUDE database.  Also accepted for publication is a prospective series of Riata and Riata ST leads that underwent fluoroscopic and electrical evaluation from Parvathaneni et al at Vanderbilt.

Hauser’s study has been previously reported on this site (20 Deaths Linked to New Problem with Riata Leads).  It is notable for being one of the first Riata studies focusing on electrical, rather than structural failures.  In the study, 22 (since corrected to 20 by St. Jude review) deaths discovered in the voluntary FDA MAUDE database were linked to failure of the Riata or Riata ST lead.  Interestingly, nearly all deaths appear to be due to failure of the high voltage portion of the lead, and most were directly linked to insulation abrasion.  This is a failure mechanism not commonly seen with other ICD leads, as noted in the article’s comparison to Medtronic Quattro Secure leads (in which failure of the low voltage conductors is the dominant mechanism).  Hauser estimated that failure of the St. Jude leads had an incidence “about 9 times greater than Quattro.”

Close reading of the Hauser data raises some interesting and, at times, troubling points:
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Guest Post: More Lessons From the Riata ICD Lead Recall 7

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. This post is longer and far more technical than most of the content published on CardioBrief. Due to the extraordinary nature of the material, however, I believe this post will likely be of considerable interest to many cardiovascular healthcare professionals.

More Lessons From the Riata ICD Lead Recall

by Edward J. Schloss, MD

In an earlier guest post (What are the Lessons of the Riata ICD Lead Recall?) I summarized points from Robert Hauser’s  important perspective in the New England Journal of Medicine regarding the St. Jude Riata ICD lead recall. In this followup, I’d like to discuss St. Jude’s responses to this piece and place the arguments into a broader context.

Last week Mark Carlson MD, Chief Medical Officer of St. Jude Medical, posted a response to Hauser’s perspective, and he made similar points in a letter subsequently published in NEJM. In the original response, Carlson writes “we believe that there were inaccuracies and omissions in the editorial that are important to recognize in order to more fully understand this issue.”

Major points of disagreement in the two pieces include:

  1. Timing of the initiation of a prospective trial looking at Riata externalizations and failures.
  2. Similarities and differences between the currently marketed Durata lead and it’s recalled predecessor Riata ST.
  3. Robustness of the existing St. Jude lead surveillance systems.

Having looked at this issue in some depth, I feel it would be reasonable for me to weigh in on these matters.

Regarding the timing of the recent trial, Dr. Carlson writes:
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Guest Post: Report from the Riata ICD Lead Summit 8

Second update: Click here to review the slides from the meeting (posted by the Minneapolis Heart Institute),

Update: Click here to read a statement from St Jude Medical in response to this post.

Editor’s Note: Edward J. Schloss (Twitter ID @EJSMD), the medical director of cardiac electrophysiology at the Christ Hospital in Cincinnati, OH, returned yesterday from the Riata ICD Lead Summit. Dr. Schloss has kindly forwarded his summary of the meeting to CardioBrief. “As the audience was restricted to clinicians and St. Jude personnel, this may be the first and only public account of this meeting,” wrote Dr. Schloss. (As the editor of CardioBrief, I would like to express my keen disappointment that a meeting of this general importance was closed to outside observers, including journalists, analysts, and representatives from other companies.)

 Report from the Riata ICD Lead Summit

by Dr. Edward J. Schloss

Sixty-three registered health care professionals and St. Jude Medical industry representatives gathered today at the Minneapolis Airport Marriott Hotel for the Riata ICD Lead Summit. This conference, organized by The Minneapolis Heart Institute Foundation and Mayo Clinic, was organized to review available data and develop a consensus regarding St. Jude ICD leads currently on recall or subject to increased scrutiny.

Course directors Robert G. Hauser, MD and David L. Hayes, MD presided over a series of lectures and panels of experts in the field.

Dr. Hayes first polled the conference attendees about the current landscape. A full 35% of attendees thought Riata leads posed a greater concern to them than the Medtronic Fidelis recall. In addition, 41% felt enough concern about the currently marketed Durata lead that they have elected not to implant this lead. The Durata lead, although not on recall, shares many design elements with the Riata ST.

Dr. Hauser reviewed available clinical and engineering data. The failures of Riata leads appears to be due to a unique “inside-out” form of lead insulation abrasion. In some, but not all cases, lead cables have been shown to externalize. Commonly, however, externalization is not associated with failure and vice versa. There is no single common sign of lead failure on electrical measurements.
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