HRS 2012 research highlights:

A slideshow presentation

HRS 2012 Research Highlights

The Heart Rhythm Society (HRS) 2012 Scientific Sessions took

place in Boston, MA from May 9 through May 12, 2012.

Key presentations at the sessions included:

Riata ICD lead safety: Attendance was off the charts at the headliner

event

RAAFT 2: RF catheter ablation with pulmonary vein isolation is more

likely to suppress AF recurrences than standard drug therapy

Founder's Lectureship Award: HRS 2012 recipient Dr Michel

Haϊssaguerre

FIRM ablation: Patients who have undergone focal impulse and rotor

modulation (FIRM) ablation in addition to standard pulmonary vein

isolation (PVI) remain AF free more often than those treated with

standard PVI

PROTECT-AF: Watchman LAA closure device reduces the risk of

ischemic stroke in patients with AF, entirely without anticoagulation

PACES/HRS consensus statement on WPW: Consensus statement helps clarify which young people should undergo catheter

ablation

POSTERS: New research was highlighted at HRS's Poster Town

MagnaSafe Registry: Findings show that MRI with pacers and ICDs are safe, with a few minor issues

STARTER: "Sweet spot" for echo-guided CRT lead placement explored in trial

Douglas P. Zipes Lectureship Award: This year's recipient was Dr Dan Roden

AF ablation: Reaching first-line status

AF summit: Tools and technologies for AF ablation

Riata ICD lead failure

A highly promoted late-breaking trial, as well as several

abstracts, attempted to define the nature and scope of the

problem with the recalled Riata ICD leads

Details: In December 2011, the Riata line of implantable

defibrillator leads (St Jude Medical) was officially recalled

because of a high risk of failure. The conductor wires can erode

through their silicone insulation and "externalize," sometimes

causing electrical abnormalities, lead malfunction, or possibly

high-voltage shorts. At HRS 2012, the Riata failure rates and

mechanisms took center stage, as groups lined up to report

their experiences with the leads, abstract after abstract, as well

as a highly promoted late-breaking trial.

"In my mind, cables that externalize, which people have called a cosmetic problem, are a lead failure. It's not how the lead

was designed to function," said Dr Laurence M Epstein (Brigham and Women's Hospital, Boston). "One of the concerns I

have is that we don't fully understand the mechanism of why these leads are failing, and I think that's really important for us

to understand moving ahead."

See: Riata revelations: ICD lead failure rates, mechanisms take HRS center stage

RAAFT 2

Radiofrequency catheter ablation with pulmonary vein isolation is

more likely to suppress AF recurrences than standard drug

therapy

Results: Radiofrequency (RF) catheter ablation with pulmonary vein

isolation is not only safe as a first-line treatment for paroxysmal or

persistent atrial fibrillation (AF), it's more likely to suppress AF

recurrences than is standard antiarrhythmic drug (AAD) therapy,

suggests a randomized trial with a two-year follow-up, one of the

longest for an AF-ablation trial. A single ablation procedure reduced the

risk of AF recurrence by a significant 44% compared with AAD.

Importantly, in the second Radiofrequency Ablation vs

Antiarrhythmic Drugs as First-Line Therapy of Atrial Fibrillation

(RAAFT 2) trial, which followed all patients with transtelephonic

monitoring (TTM), RF ablation's significant advantage over AAD was in

reducing bouts of AF that were either symptomatic or asymptomatic.

"So to be able to claim victory with ablation, you really need to monitor these patients very judiciously," said RAAFT 2 co–principal

investigator Dr Carlos Morillo (Hamilton Health Sciences-McMaster University, ON). Ablation also significantly cut the frequency of

solely symptomatic AF, he said. "These findings support the indication of radiofrequency pulmonary vein isolation as first-line therapy in

patients with paroxysmal atrial fibrillation."

See: RAAFT 2: Catheter ablation can be first line of defense against paroxysmal AF

Founder's lectureship award

HRS 2012 Recipient: Dr Michel Haϊssaguerre

Results: The Founders' lecture was delivered

by Dr Michel Haϊssaguerre, from Hôpital

Cardiologique du Haut-Lévèque, who discussed

the past, present, and future of AF and catheter

ablation.

See: AF Summit: Current, Evolving and

Futuristic Therapies for AF

FIRM ablation

Patients who have undergone focal impulse and rotor modulation

(FIRM) ablation in addition to standard pulmonary vein isolation

(PVI) remain AF free more often than those treated with standard

PVI

Results: Dr Sanjiv Narayan (University of California, San Diego VA

Medical Center) presented a technique called FIRM ablation. This

technique involves placing commercially available multipole basket

catheters into the atria. During AF, the signals are sent to an

investigational computer system, which then displays optical images

and movies of the activation. Distinct geographic "areas of interest" in

either the right or left atrium can be seen in almost all cases of AF.

Sometimes the rotors are located in areas typically targeted during

pulmonary vein isolation (PVI), but in many cases they are not. Most

remarkably, his prior work has shown that when these areas are

ablated, AF terminates. Patients who have undergone focal impulse and

rotor modulation (FIRM) ablation in addition to standard PVI remain AF

free more often than those treated with standard PVI.

Dr Narayan presented new data on the acute termination of AF with FIRM-guided ablation. In a cohort of patients with advanced AF,

he showed that rotors or focal impulses could be seen in 98%. Ablation at these focal sites terminated, slowed, or converted AF to

flutter in 88% of patients. Almost half converted to sinus rhythm. In one case, ablation for only one minute converted the patient to

sinus rhythm.

See: Turning the AF ablation world upside down—FIRM ablation

PROTECT-AF

Watchman LAA closure device reduces the risk of ischemic stroke in

patients with AF, entirely without anticoagulation

Results: The Watchman left atrial appendage (LAA) closure device cuts the

risk of ischemic stroke in patients with atrial fibrillation (AF), entirely without

oral anticoagulation, suggests the observational ASA-Plavix (ASAP)

Registry. These results add to what had been observed in the Watchman's

main randomized trial, Embolic Protection in Patients with Atrial

Fibrillation (PROTECT-AF), in which patients with the device took warfarin

for at least the first six weeks.

PROTECT-AF found the device noninferior to standard warfarin therapy for

protection against stroke, cardiovascular death, or systemic embolism in

patients with AF and a CHADS2 score >1. Patients getting the Watchman in

ASAP, who took clopidogrel for six months and aspirin indefinitely but

without ever going on warfarin, still showed only a 1.7% rate of ischemic

stroke—compared with 2.2% in the PROTECT-AF Watchman group, 7.3% in

historical controls with ASAP-comparable CHADS2 scores taking aspirin

alone, and 5.0% in such controls taking aspirin plus clopidogrel.

The findings, said Dr Vivek Y Reddy (Mount Sinai School of Medicine, New York, NY) when presenting the analysis, cast doubt on the

need for even temporary warfarin in patients implanted with the Watchman. Most strokes related to thrombus forming at the device would

occur in the first six months after Watchman implantation, Reddy speculated; so if anything, eliminating the early warfarin might raise the

stroke risk, not lower it. Given the low stroke rate seen in the ASAP registry, Reddy said, "It's not clear how important that 45 days of

warfarin is. In fact, it's not clear that six months of [clopidogrel] helped at all."

See: Without warfarin, Watchman still prevents strokes, says registry

PACES/HRS consensus statement on WPW

Consensus statement helps clarify which young people should undergo

catheter ablation

Results: A "first-of-its-kind" consensus statement on the management of

asymptomatic patients with Wolff-Parkinson-White (WPW) syndrome should help

clarify which young people should undergo catheter ablation. The guidance is

explicitly directed at physicians treating young patients with WPW and defines

young people as between eight and 21. At the crux of the document is the

question of just when physicians should intervene—and when they shouldn't—in

young people found, on ECGs, to have the signature electrocardiographic WPW

pattern. These are increasingly important questions, given increased emphasis

on preparticipation screening for sports in young people.

The expert consensus statement, a joint effort of the Pediatric and Congenital

Electrophysiology Society (PACES) and the HRS, estimates that from one to

three young people per 1000 likely have WPW, although many—around 65%—

are asymptomatic.

"While it is a small chance that an asymptomatic young person could end up having a life-threatening heart event, the number is not zero,"

said lead author on the statement, Dr Mitchell I Cohen (Phoenix Children's Hospital, AZ). "Yet, catheter ablation for every child who has

ever had a WPW pattern is also not the answer."

See: Joint PACES/HRS expert consensus statement offers guidance in the treatment of asymptomatic young patients with WPW

See: New guidance for young people with Wolff-Parkinson-White (WPW) syndrome

Poster Town

New research highlighted

An overwhelming number of posters were presented at the

Poster Town in the HRS 2012 Exhibit Hall. Poster sessions were

available to attendees throughout the conference, as well as

moderated poster sessions and interactive abstract poster

sessions.

Noteworthy topics included: Placing the ECG leads in the right

place to avoid false diagnoses; PVC morphology and duration

may predict the presence of cardiomyopathy; AF ablation may

not yield good results for patients with sleep apnea and

metabolic syndrome; LAA isolation is a good thing because

patients showed a higher three-year success rate; and a single

case of atrial-esophageal fistula presented following standard

cryoballoon ablation.

See: HRS 2012 poster highlights: ECGs, PVCs, OSA,

Debates in AF ablation, and the dangers of cryoablation

MagnaSafe Registry

Findings show that MRI with pacers and ICDs are safe, with

a few minor issues

Results: Interim findings from the MagnaSafe Registry show

there were no important safety issues but some alterations in

programming and transient impedance changes during

nonthoracic magnetic resonance imaging (MRI) in patients with

pacemakers and implantable cardioverter defibrillators (ICDs).

No instances of imaging-associated death, device failure,

generator or lead replacement, loss of capture, or electrical reset

occurred with MRI, which was performed consistently at 1.5 T. Of

less apparent significance, the battery-voltage changes seen in

12% of ICDs and device parameter changes seen in a tenth of

pacemaker and a third of ICD patients.

"We can't say whether any of those changes were clinically significant in any way," said Dr Debra Doud (Scripps Clinic, La Jolla, CA).

But whether or not there are advantages to such devices, "there still will be a large number of patients with non-MRI-conditional devices

who need to undergo an MR scan for one reason or another. And certainly [going ahead with the scan] is much safer than lead

extraction and putting in an MR-conditional device for patients who already have a device. The one population of [device] patients we

had to exclude was those with ICDs who were pacemaker-dependent," because devices from some manufacturers don't allow ICD

functions to be disabled without turning off the pacing functions.

See: MRI with pacers, ICDs: Safe, a few minor issues, says MagnaSafe registry

STARTER

"Sweet spot" for echo-guided CRT lead placement explored

in trial

Results: Patients are more likely to respond to cardiac

resynchronization therapy (CRT), clinically and in terms of

reverse remodeling, if speckle-tracking echocardiography guides

the placement of their pacing leads. For echo guidance in the

trial, called Speckle Tracking Assisted Resynchronization

Therapy for Electrode Region (STARTER), leads were

positioned at or close to the myocardial site of latest mechanical

activation for each patient individually. Those whose lead

positions were tailored that way, compared with standardized

positioning without echo guidance, benefited with significantly

improved ventricular end-systolic volumes and survival without

heart-failure hospitalization.

"A substantial proportion of patients, about one-third, do not respond to CRT therapy, and we don't know who those people

are," said Dr Samir Saba (University of Pittsburgh, PA). "Now we are starting to understand better. Once we know where the

leads should be appropriately placed, for that specific patient, we achieve better results."

See: "Sweet spot" for echo-guided CRT lead placement explored in trial

Douglas P Zipes Lectureship Award: Dr Dan Roden

Results: The lectureship award named for Douglas P

Zipes recognizes an individual who has contributed to

the advancement of cardiac electrophysiology in the

area of basic science. This year's award recipient was

Dr Dan M. Roden (Vanderbilt University School of

Medicine, Nashville, TN), who gave the lecture "Heart

to heart: Treating arrhythmias using personalized

medicine." The award was presented as part of the

Basic/Translational Science Forum on Wednesday,

May 9th, 2012 at 3pm.

See: Heart Rhythm 2012 Program eBook p.27

Roden's research lauded by Heart Rhythm

Society

AF ablation: Reaching first-line status

Results: For the past few years, the evidence base supports the

role of catheter ablation in AF patients who have done poorly

with medicines. But has catheter ablation progressed enough to

offer it as a first-line therapy? The North American expert task

force guidelines call for trying an antiarrhythmic drug before

ablation; the more lenient European guidelines allow us to offer

catheter ablation as first-line therapy. Which is the best

approach?

An important multicenter study, RAAFT 2, supports the notion

that AF ablation (pulmonary vein isolation [PVI])—as a first-line

therapy—has made the transition to the front line. The RAAFT

2 trial demonstrated that low-risk symptomatic patients with AF

(87% paroxysmal) treated with standard catheter-based PVI

had less AF and fewer complications than did those treated with

AF drugs. Adverse events occurred in 7.7% of patients who had

ablation compared with 19.7% of those treated with medicine.

Although preliminary, this study will have a significant impact. The results of RAAFT 2 add more information to an already-

complex decision-making process. Until Dr Narayan's FIRM ablation becomes mainstream, AF ablation remains a daunting

challenge. Always important is the doctor-patient relationship, but never more so in cases when life-threatening therapies are

used for non–life-threatening diseases.

See: Has ablation reached first-line status?

AF Summit: Tools and technologies for AF ablation

Results: "The AF summit: Tool and technologies for

AF ablation" was a state-of-the-art update concerning

the tools and technologies that are available for use in

the field of AF ablation. Operators learned about

which tools to use and how to use them to achieve

maximum success. The topics included the

importance of PV isolation and the limitations of

current technologies in achieving permanent PV

isolation; contact force in lesion creation and the

available knowledge as to whether newly available

force-sensing catheters improve outcomes; and the

current and future role of remote navigation

technologies in AF ablation.

See: AF summit: Tools and technologies for AF

ablation

For more information

Complete HRS 2012 coverage on

theheart.org

HRS 2012 Scientific Sessions

Credits and disclosures

Journalist:

Steve Stiles, theheart.org

Fremont, CA

Disclosure: Steve Stiles has no relevant financial relationships to

disclose.

Blogger:

Dr John Mandrola

Louisville, KY

Disclosure: John Mandrola has no relevant financial relationships to

disclose.

Editor:

Shelley Wood

Managing Editor, heartwire

theheart.org

Kelowna, BC

Disclosure: Shelley Wood has disclosed no relevant financial

relationships.

Contributors:

Steven Rourke

Manager, Editorial programming theheart.org

Montreal, QC

Disclosure: Steven Rourke has disclosed no relevant financial relationships.

Katherin Vasilopoulos

Montreal, QC

Disclosure: Katherin Vasilopoulos has no relevant financial relationships to disclose.

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