Category Archives: Heart Rhythms

Athletes With Defibrillators Don’t Need To Quit Sports Reply

by • Heart Rhythms, Policy & Ethics, Prevention, Epidemiology & Outcomes • Tags: , , , , , , ,

Although the American College of Cardiology and the European Society of Cardiology now advise people with ICDs not to participate in vigorous sports, a new study offers strong support for people with ICDs who want to take part in sports. Although a large number of people with ICDs are elderly heart failure patients who are unlikely to want to participate in sports, ICDs are also implanted in young and otherwise healthy people with genetic diseases that leave them at high risk for lethal arrhythmias.

Now findings from the ICD Sports Safety Registry, published in Circulation, provide vital new information about this important topic. The registry, which was performed with the assistance of patient advocacy groups, included 372 ICD patients between 10 and 60 years of age who participated in sports more vigorous than golf or bowling. The most common reasons for having an ICD among people in the registry were long-QT syndrome in 73 people, hypertrophic cardiomyopathy in 63 people, and arrhythmogenic right ventricular cardiomyopathy in 55. 60 subjects were college age or younger who took part in competitive sports.

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Click here to read the full post on Forbes.

 

HOLLAND, MI - MARCH 7: Fennville High School ...

 

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Study Questions Role Of Dual-Chamber ICDs For Primary Prevention Reply

by • Heart Rhythms • Tags: , , , , ,

Dual-chamber ICDs are implanted in a majority of primary prevention patients without a pacing indication who receive an ICD. Although there are a number of theoretical advantages with dual-chamber devices, these devices are more likely to cause complications. Although CMS requires providers to justify the medical necessity of dual-chamber devices, current guidelines from the AHA/ACC and HRS do not specify a single-chamber device.

In a new study published in JAMA, Pamela Peterson and colleagues analyzed data from 32,000 primary prevention patients without a pacing indication who were enrolled in the National Cardiovascular Data Registry (NCDR). 38% received a single-chamber device and 62% received a dual-chamber device. At 1 year there wereno significant differences in mortality, all-cause hospitalization, or heart failure hospitalization between the two groups. However, patients in the dual-chamber group had a higher risk of complications, including a highly significant increase in the 90 day risk of mechanical complications requiring reoperation (1.43% in the single-chamber group versus 2.02% in the dual-chamber group, p < 0.001). A very similar pattern emerged when the investigators performed an analysis that matched patients in the two groups with a propensity model. The analysis suggested “that the choice of a dual-chamber device is relatively random with respect to patient characteristics.

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Click here to read the full story on Forbes.

 

 

Novel Leadless Pacemaker Makes Debut At HRS 2013 Reply

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

First results in human patients of a novel leadless pacemaker were presented last week at the HRS meeting in Denver by Vivek Reddy.  Pacemaker leads are the most common source of complications associated with pacemakers today. The self-contained device is delivered via catheter to the right ventricle, to which it is attached with a fixation mechanism.  The device is manufactured by Nanostim, Inc, a small company which is being acquired by St. Jude Medical.

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Click here to read the full story on Forbes.

 

 

Leadless

 

Encouraging 4 Year Results For Watchman Device In AF Patients Reply

by • Heart Rhythms, Interventional Cardiology & Surgery, Policy & Ethics • Tags: , , , , ,

Encouraging long-term results from the PROTECT AF trial comparing the Watchman left atrial appendage closure device to warfarin in atrial fibrillation patients were presented yesterday at the Heart Rhythm Society meeting in Denver.

Previously, the main results of the trial, published in the Lancet, demonstrated that the Watchman was noninferior to warfarin, but the total number of events in the trial was small. In addition, there were more safety problems, as might be expected, in the early days after implantation. The FDA required the company to perform a confirmatory trial. That trial, PREVAIL, has been the subject of considerable controversy. Now, long term followup of PROTECT AF may help better understand the risks and benefits of the device.

Vivek Reddy presented 4 year followup results from PROTECT AF. The primary efficacy endpoint– the combined rate of all stroke, cardiovascular or unexplained death and systemic embolism– occurred in  2.3% of the device group versus 3.8% of the warfarin group (RR 0.60, CI 0.41-1.05).

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Click here to read the full story on Forbes.

 

 

 

Another Disappointing Study For Fish Oil Supplements 3

by • Heart Failure, Heart Rhythms, Prevention, Epidemiology & Outcomes • Tags: , , , , , ,

Another large study has failed to find any benefits  for  fish oil supplements. The Italian Risk and Prevention Study, published in the New England Journal of Medicine, enrolled 12,513 people who had not had a myocardial infarction but had evidence of atherosclerosis or had multiple cardiovascular risk factors. The patients were randomized to either a fish oil supplement (1 gram daily of n-3 fatty acids) or placebo.

After 5 years of followup, the primary endpoint– the time to death from cardiovascular causes or admission to the hospital for cardiovascular causes– had occurred in 11.7% of the fish oil group versus 11.9% of the placebo group (adjusted hazard ratio 0.97, CI 0.88-1.08, p=0.58). There were no significant differences in any of the prespecified secondary endpoints.

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Click here to read the full post on Forbes, including comments from James Stein and Dariush Mozaffarian

A typical softgel

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

 

 

 

 

Registry Study Offers Reassurance About Safety And Efficacy Of Dabigatran Reply

by • Heart Rhythms, Prevention, Epidemiology & Outcomes • Tags: , , , ,

As the first new oral anticoagulant since warfarin, dabigatran (Pradaxa, Boehringer-Ingelheim) has been subject to intense concerns over its safety and efficacy in a real-world population. Last November an FDA investigation found no indication that bleeding rates for dabigatran were any higher than bleeding rates for warfarin. A new study from Scandinavia, published in the Journal of the American College of Cardiology (see note at bottom of story), provides more real-world information that helps to confirm the safety and efficacy of the new drug.

Using data from the Danish Registry of Medicinal Product Statistics, researchers compared 4978 patients treated with dabigatran to 8936 matched patients who received warfarin. They found similar rates of stroke or systemic embolism and major bleeding with dabigatran and warfarin. In addition, mortality, intracranial bleeding, pulmonary embolism,and myocardial infarction were significantly lower in the dabigatran-treated group.

Here are the adjusted hazard ratios (and 95% confidence intervals) for dabigatran 110 mg and 150 mg, respectively, compared with warfarin:

  • Stroke: 0.73 (0.53 -1.00), 1.18 (0.85 – 1.64)
  • Systemic embolism: 0.60 (0.19 – 1.60), 1.00 (0.26 – 3.35)
  • Death: 0.79 (0.65 – 0.95), 0.57 (0.40 – 0.80)
  • MI: 0.30 (0.18 – 0.49), 0.40 (0.21 – 0.70)
  • Pulmonary embolism: 0.33 (0.12 – 0.74), 0.24 (0.06 – 0.72)
  • Intracranial bleeding: 0.24 (0.08 – 0.56), 0.08 (0.01 – 0.40)
  • Major bleeding: 0.82 (0.59 -1.12), 0.77 (0.51 – 1.13)

The authors concluded that ”previous concerns about an excess of bleeding events or myocardial infarction amongst dabigatran treated patients were not evident in this propensity-matched comparison against warfarin in a large post-approval registry study.” However, they noted one limitation of their study: The Danish AF patients included in the study were at lower risk and had a lower event rate than the patients studied in the pivotal RE-LY randomized trial of dabigatran.

Note to readers: This study is now available on Science Direct and the manuscript has been posted on CardioSource. Due to technical problems the article will be published online in the Journal of the American College of Cardiology website on Wednesday, April 10.

 

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.
Click to continue reading…

FDA Proposes Higher Regulatory Scrutiny For Automatic External Defibrillators Reply

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

Automated external defibrillators (AEDs) will have a more difficult time getting on the market if a new FDA proposal is finalized. The agency today proposed a new rule that will require AED manufacturers to submit pre-market approval (PMA) applications.

“Automated external defibrillators save lives,” said cardiologist William Maisel, deputy director of science and chief scientist at the FDA’s Center for Devices and Radiological Health, in an FDA press release. “However, the agency is concerned about the number of recalls and manufacturing problems that have been associated with these devices and we’re committed to working with manufacturers to address these issues.”

Click here to read the full story on Forbes.

 

#984 Airport not in Japan

CHMP And FDA Diverge On Mipomersen And Rivaroxaban Reply

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

The US FDA and Europe’s Committee for Medicinal Products for Human Use (CHMP) have taken opposite views of two important and controversial new cardiovascular drugs. Although earlier this month the FDA rejected– for the second time– an ACS indication for the oral anticoagulant rivaroxaban (Xarelto), CHMP announced today that it had adopted a positive opinion for the same indication. In contrast, although the FDA recently approved the new cholesterol-lowering agent mipomersen (Kynamro, Isis and Genzyme), CHMP, after reviewing its previous negative position, reaffirmed today that it would not recommend approval of the drug in Europe.

Click here to read the full post on Forbes.

 

European Medicines Agency

 

FDA Officials Calm Concerns Over Excessive Bleeding With Dabigatran 1

by • Heart Rhythms, Policy & Ethics, Prevention, Epidemiology & Outcomes • Tags: , , , , , ,

Concerns over excessive bleeding complications with dabigatran (Pradaxa, Boehringer Ingelheim) as compared with warfarin are most likely due to the heightened sensitivity and vigilance that can accompany a new drug, according to FDA officials in a perspective published online in the New England Journal of Medicine.

“We believe that the large number of reported cases of bleeding associated with dabigatran provides a salient example of stimulated reporting,” write Mary Ross Southworth, Marsha Reichman, and Ellis Unger. “In this case, such reporting provided a distorted estimate of the comparative bleeding rates associated with dabigatran and warfarin in clinical practice.”

Click here to read the full story on Forbes.

 

Following An Embargo Break PREVAIL Trial Won’t Be Presented At ACC 2

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

UPDATED–The already complicated story behind the PREVAIL trial, which was designed to confirm the safety and efficacy of the Watchman left atrial appendage closure device, just got even more complicated. This morning, after the trial’s sponsor, Boston Scientific, prematurely distributed to investors a press release summarizing the results of the trial, the ACC announced that the scheduled presentation of the results at the main opening session of the meeting would not take place.

 

By way of background, last week the trial’s sponsor, Boston Scientific, first announced that the  principal investigator of the trial, David Holmes, would only “present the acute procedural safety results” from the trial. Then the company reversed itself two days later and announced that Holmes would present all three co-primary endpoints.

Holmes intended presentation this morning at the ACC in San Francisco makes clear why there was so much confusion. (The slides from his presentation have been made available to the media.) Although the trial results appear largely positive, the trial missed one of its three primary endpoints, and experts will likely spend a lot of time and energy trying to interpret the results.

Click here to read the full story on Forbes.

Stop Sign

 

 

 

ACC Prevails Upon Boston Scientific To Present More Data At Late Breaker Reply

by • Heart Rhythms, Interventional Cardiology & Surgery, People, Places & Events, Policy & Ethics

In an unusual reversal of a statement it made two days ago, Boston Scientific announced this afternoon that it would present all three co-primary endpoints of the PREVAIL clinical trial this Saturday at the American College of Cardiology scientific sessions in San Francisco. The PREVAIL trial, which was designed to confirm the safety and efficacy of the Watchman left atrial appendage closure device, is one of the most highly-anticipated late-breaking clinical trials at the ACC this year.

As reported here yesterday, earlier this week Boston Scientific said that the principal investigator of the trial, David Holmes, would only “present the acute procedural safety results.” This was a highly unusual development, since late-breaking clinical trial sessions are intended to provide the medical community with its first look at the main results of important clinical trials. By all accounts, the ACC was unhappy with the Boston Scientific announcement and initiated discussions with the company shortly after the announcement.

Click here to read the full story on Forbes.

 

FDA Approves Second Generation MRI-Friendly Pacemaker System Reply

by • Heart Rhythms • Tags: , , ,

Medtronic announced today that the FDA had approved its Advisa DR MRI SureScan, a next generation pacemaker system specifically designed and tested for use with MRI scanners. The system, which Medtronic said would be launched immediately, includes the Advisa MRI device and two CapSureFix MRI SureScan leads.

 Click here to read the full post on Forbes.

Medtronic Advisa

Rivaroxaban Effective In Medically Ill Patients But At High Bleeding Cost Reply

by • Heart Rhythms, Prevention, Epidemiology & Outcomes • Tags: , , , , ,

The recent arrival of novel oral anticoagulants has provided important new options for venous thromboembolism (VTE) treatment and prevention. New indications for these drugs have been granted for patients with atrial fibrillation and following orthopedic surgery. But an additional indication, for acutely ill medical patients at risk for VTE, does not appear likely in the near future, as a new trial published in the New England Journal of Medicine shows that one of these novel drugs, though effective at preventing VTE, also resulted in a significant increase in bleeding risk.

In the Multicenter, Randomized, Parallel Group Efficacy and Safety Study for the Prevention of Venous Thromboembolism in Hospitalized Acutely Ill Medical Patients Comparing Rivaroxaban with Enoxaparin (MAGELLAN), first presented at the American College of Cardiology meeting in 2011, more than 8,000 medically ill patients were randomized to subcutaneous enoxaparin for 1o days or oral rivaroxaban for 35 days.

Click here to read the full post in Forbes.

Should Physicians Be Business Partners With Medical Device Salesmen? Reply

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

Should a Florida cardiologist co-own a business running frozen yogurt shops with a medical device salesman? That’s the question raised by reporter John Dorschner in a story posted by the Miami Herald yesterday:

 

“Mark Sabbota, a Hollywood cardiologist, regularly implants $5,000 pacemakers in patients at Memorial hospitals in South Broward — generating, last year alone, more than a half-million dollars in sales for a manufacturer called St. Jude Medical.

Sabbota, public records show, also happens to be partners with a St. Jude sales rep in two corporations that run frozen yogurt shops.”

 

Click here to read the full story on Forbes.

 

English: Yogurt, Yogurtland, Frozen Desserts

 

 

Trials Of Niacin And Atrial Fibrillation Device Will Headline American College Of Cardiology Program Reply

by • Heart Failure, Heart Rhythms, Interventional Cardiology & Surgery, MI/ACS, People, Places & Events • Tags: , , , , ,

Two big trials will highlight this year’s American College of Cardiology meeting in March in San Francisco. First is the PREVAIL trial testing Boston Scientific‘s long-anticipated Watchman left atrial appendage closure device for stroke prevention in patients with atrial fibrillation. Second is  the detailed presentation of the controversial failed HPS2-THRIVE trial of extended-release niacin and laropiprant.

Read my complete story on Forbes, along with a list of the late-breakers. 

ACC.13 logo

 

FDA Releases St. Jude Warning Letter Reply

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

The FDA on Tuesday released the full text of a warning letter sent last week to St. Jude Medical. The company had previously disclosed the existence of the letter in an SEC filing but did not make clear the full extent of the FDA warning. The letter from the FDA is the latest in a series of setbacks and challenges to the company’s Durata and Riata ICD leads.

Click here to read the full post on Forbes.

Screen Shot 2013-01-16 at 12.34.00 AM

 

Richard Lehman On ICDs In Clinical Practice And Serelaxin For HF Reply

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

This week in CardioExchange Richard Lehman is not quite as funny as most weeks (perhaps he’s still recovering from New Years’ celebrations?), but he has some interesting and useful comments on a JAMA study comparing real world patients in registries to patients in clinical trials and an impressive Lancet study testing the role of the novel agent serelaxin in acute heart failure.

“So after much hard work and statistical legerdemain, the study shows that the mortality of real-life heart failure patients after ICD implantation for primary prevention is the same as that in the trials, and less than that of the control patients in the trials. Which I guess is a useful thing to know.”

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 ”I don’t think that by itself it changes practice in any way, but it does show that recombinant human relaxin 2, serelaxin, is an interesting new treatment that deserves further study in heart failure.”

 

 

What’s Next for the iPhone ECG Following Regulatory Clearance? 2

by • Heart Rhythms • Tags: , , , , ,

from Medical Device and Diagnostic Industry:

What’s Next for the iPhone ECG Following Regulatory Clearance?

 The user base and functionality of mobile ECG technology is set to expand.

“After recently winning FDA clearance and CE Mark certification, the iPhone ECG from AliveCor (San Francisco, CA), is poised to kickstart a disruption of the traditional ECG market.”

….

“In November 2011, Topol used the device to diagnose a myocardial infarction while on a plane en route from Virginia to San Diego. The plane made an emergency landing and the patient survived the ordeal.”

Click here for the entire article from Medical Device and Diagnostic Industry.

FDA Approves Eliquis (Apixaban) For Stroke Prevention In AF 2

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

The FDA has finally approved apixaban (Eliquis, Bristol Myers Squibb and Pfizer) to reduce the risk of stroke and systemic embolism in patients with non-valvular atrial fibrillation. The action comes after the widely-anticipated drug had been plagued by delays at the FDA but well before the PDUFA deadline of March 17, 2013. Eliquis is the latest member of the new generation of oral anticoagulants, which also includes dabigatran (Pradaxa, Boehringer Ingelheim) and rivaroxaban (Xarelto, Johnson & Johnson).

The FDA said that apixaban should not be taken by patients with prosthetic heart valves or by patients with AF caused by a heart valve problem. (Recently the FDA added a contraindication to the dabigatran label against using the drug in patients with mechanical heart valves.) The FDA said that the most serious risk associated with apixaban, as with other anticoagulants, is bleeding, including life-threatening and fatal bleeding. Patients taking apixaban will receive a patient Medication Guide. The FDA is advising health care professionals to counsel patients about the signs of symptoms of possible bleeding.

The FDA approval was based largely on the results of the highly positive ARISTOTLE trial which found that apixaban was superior to warfarin in AF patients. The FDA will likely allow BMS and Pfizer to claim that apixaban is superior to warfarin, as the press release states that “patients taking Eliquis had fewer strokes than those who took warfarin.”

Click here to download a PDF of the package insert.

Click here to read the FDA press release…

Pradaxa To Be Contraindicated In Patients With Mechanical Heart Valves 1

by • Heart Rhythms, Interventional Cardiology & Surgery, Policy & Ethics • Tags: , , , , , , ,

Boehringer Ingelheim is starting to inform physicians about a new contraindication for its oral anticoagulant drug Pradaxa (dabigatran). The company has told investigators in trials utilizing dabigatran that it will shortly be sending a “Dear Doctor Letter,” also known as a Direct Healthcare Professional Communication (DHPC), to healthcare professionals. The letter will inform physicians that Pradaxa is now contraindicated in patients with mechanical heart valves. The change was based on a recent decision of the FDA, BI told its investigators.

The FDA action follows a similar decision by the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency, which announced last week that it had recommended that Pradaxa be contraindicated in patients with prosthetic heart valves.

Both the FDA and the CHMP actions appear to be based on findings from the RE-ALIGN trial in patients with mechanical heart valves, which Boehringer Ingelheim announced last week had been stopped prematurely. (Click here for the CardioBrief story.) As reported here in October, the company had previously terminated one arm of the study after an interim review of the data by the trial’s Data Safety Monitoring Board

One cardiologist who is a dabigatran investigator told CardioBrief that the label change

is consistent with the findings in Re-Align, although I wish it were presented and published in a peer reviewed journal. I do understand the urgency on behalf of the FDA to ensure that the use does not stray beyond its labeling for A-fib given both the prospective, randomized data from Re-Align and case reports of strokes on Pradaxa with mechanical valves. I don’t think this is the final word on Pradaxa (or other new generation anticoagulants), but if we are to use them, the doses will undoubtedly be different, and presumably higher, than the doses used for A-fib. The question is whether one can find a dose that prevents thromboembolic strokes with the new generation anticoagulants at an acceptable level of bleeding. It’s also worth noting that they did not recommend Pradaxa in patients with bioprosthetic valves, but didn’t absolutely contraindicate it. Yet.

Boehringer Ends Phase 2 Trial Of Dabigatran In Mechanical Valve Patients 2

by • Heart Rhythms, Interventional Cardiology & Surgery, Prevention, Epidemiology & Outcomes • Tags: , , , , , , , , , ,

Boehringer Ingelheim today announced that it had discontinued a phase 2 trial of its anticoagulant drug dabigatran (Pradaxa) in patients with mechanical heart valves. As reported here in October, the company had previously terminated one arm of the study after an interim review of the data by the trial’s Data Safety Monitoring Board

The RE-ALIGN trial was an open-label, 12-week randomized comparison of warfarin and dabigatran in 400 patients who received a mechanical valve. The first arm randomized patients during their initial hospital stay. The second arm randomized patients more than 3 months after their surgery.

Despite the recent advent of novel oral anticoagulants, the much-maligned warfarin remains the only current option available for patients who have received a mechanical valve. Now the first trial to explore this indication for one of the newer oral anticoagulants has been stopped.

In October Boehringer told members of its speakers bureau that the post-surgery arm of the trial had been terminated due to “lower than projected plasma levels of dabigatran in this population, and an imbalance in reports of thromboembolic events (primarily strokes).” At that time the company said the second arm of the trial would continue.

Dabigatran has been approved in Europe, but not in the United States, for venous thromboemoblism (VTE) prevention after knee and hip replacement surgery. Rivaroxaban (Xarelto) has been approved for both VTE prevention in the United States and Europe. To date there have been no head-to-head comparisons of the newer anticoagulants.

According to a recent study in Circulation: Cardiovascular Quality and Outcomes dabigatran now has about 19% of the oral anticoagulant market, mostly for the approved treatment of AF “but increasingly for off-label indications” as well. A recent letter in the Journal of the American College of Cardiology provided information about the off-label use of dabigatran in two mechanical valve patients. Both patients developed thrombosis after switching to dabigatran from warfarin. The authors noted that “while there is a wealth of data and clinical experience on dosing and therapeutic response to warfarin in this context, these data are unavailable for dabigatran.” Although newer anticoagulants “hold tremendous promise for mechanical valve anticoagulation… there is a need for dose-finding studies and clinical trials to demonstrate safety and efficacy in this setting.”
Click here to read the press release from Boehringer…

No Surprise: Smoking and Sudden Cardiac Death Closely Tied 2

by • Heart Rhythms, Prevention, Epidemiology & Outcomes • Tags: , , ,

Although cigarette smoking has long been linked to cardiovascular (CV) disease and sudden cardiac death (SCD),  the precise contribution of smoking, and the effect of smoking discontinuation, on SCD has not been clear. Now a new report from the Nurses’ Health Study published in Circulation: Arrhythmia & Electrophysiology provides new clarity about the relationship between smoking and SCD.

“Cigarette smoking is a known risk factor for sudden cardiac death, but until now, we didn’t know how the quantity and duration of smoking affected the risk among apparently healthy women, nor did we have long-term follow-up,” said lead investigator Roopinder Sandhu, in an AHA press release.

Dr. Sandhu and colleagues analyzed data from more than 100,000 women without known CV disease or cancer.  During 30 years of followup there were 351 incident SCDs. Compared to women who never smoked, the risk of SCD was significantly elevated in current smokers (relative risk 2.44) and former smokers (RR 1.40).

The number of cigarettes smoked each day was correlated with the increase in SCD risk, but even women who smoked only 1-14 cigarettes per day had a significant 1.84-fold increase in risk. Women who smoked more than 25 cigarettes a day had a 3.3-fold increase in risk. Smoking duration was also significant, resulting in an 8% increase in SCD risk for every 5 years of smoking.

Women who quit smoking reduced their SCD risk. After 15 years the reduction in risk achieved statistical significance, and by 20 years the risk was similar to women who had never smoked.

In an exploratory analysis, women smokers with coronary heart disease (CHD) had a much higher incidence of SCD than women without CHD. Women with CHD who quit smoking did not enjoy the same immediate reduction in SCD risk as observed in women without CHD.

“Sudden cardiac death is often the first sign of heart disease among women, so lifestyle changes that reduce that risk are particularly important,” said Dr. Sandhu. “Our study shows that cigarette smoking is an important modifiable risk factor for sudden cardiac death among all women. Quitting smoking before heart disease develops is critical.”
Click here to read the AHA press release…

BLOCK HF: A “Game Changer” For Cardiac Pacing 2

by • Heart Failure, Heart Rhythms • 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. 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.