Please login or register to print this page.

Event News, Featured

Heart Rhythm Society Convention, Denver, Colorado 2010

The Heart Rhythm Society Convention is the largest cardiac electrophysiology meeting in the world attracting thousands of participants and experts from around the globe.

This report, by Dr Benedict M Glover (Senior Cardiac Electrophysiology Fellow) summarises the key elements of the convention focusing on late breaking trials, live cases and important developments.

Dr Ben Glover

The 31st Annual Heart Rhythm Convention took place on the great plains east of the Rocky Mountains in the city of Denver, Colorado.  As ever, it lived up to the usual expectations, providing a vast amount of information regarding recent clinical trials, current guidelines and more importantly an insight into the clinical decision making behind complex electrophysiological cases.

The opening session hosted by Dr Richard L Page and Dr Bruce L Wilkoff and featuring former US Senate majority leader Tom Daschle and political analyst for Fox News Juan Williams addressed the current debate surrounding health care reforms in the US. This provided an insightful perspective and lively discussion regarding the future developments and issues facing the medical community and in particular involving cardiac electrophysiology.  Clearly the fundamental goal of the Obama government is to implement a healthcare system which is easily accessible to the majority of the population and in particular the sizable number of individuals who currently have a relatively poor level of coverage including my cab driver who ran me to the meeting every morning and appeared to have exceptionally well informed opinions and strong views on this still rather divisive issue. Looking at all of this from the outside perhaps the National Health Service is not so bad after all.

Late Breaking Trials

There are always a number of important trials reported at this meeting encompassing both electrophysiology and device based studies.

One of the most anticipated was the Freedom Trial which was the first randomised multicentre study assessing the effect of frequent optimization of atrioventricular and interventricular delay intervals in cardiac resynchronisation therapy. In this study 1647 Patients were randomised to either optimisation every 3 months using the St Jude Medical algorithm QuickOpt or the control group which was decided by the cardiologist. Of interest there was no difference in terms of worsening heart failure between the two groups and this algorithm for optimisation did not appear to improve heart failure symptoms. This emphasises the fact that there is no easy equation to optimise programming and perhaps as physicians this needs to be performed on an individual basis and probably requires further evaluation.

There was also evidence showing a greater benefit from cardiac resynchronisation therapy in females rather than males in results from the MADIT-CRT study. In fact there was a significant reduction in all cause mortality in females which was not seen in males which was independent of QRS duration.   Although there are several postulated explanations for this there is no overall convincing reason to explain this difference and at present I do not think this will significantly alter our clinical practice.

The question of whether left ventricular pacing is superior to biventricular pacing was answered in the Greater-EARTH trial.  This study showed no additional benefit from left ventricular pacing in terms of exercise duration, LV ejection fraction or LV systolic volume.

There was a huge focus this year on methods to reduce ICD shocks.  A very large study involving 88,804 patients showed that strategic ICD programming reduces the incidence of shock delivery. By programming various and common parameters it was shown that SVT discriminators, programming of faster VT/VF detection rate, longer detection durations and ATP for fast VT all reduced the incidence of shocks with no overall adverse events.

Several interesting pharmacological trials were also presented. A fascinating study presented by Professor John Camm, comparing the efficacy and safety of vernakalant demonstrated superior efficacy over amiodarone for the acute conversion of recent onset AF over amiodarone. Both drugs were safe and well tolerated.

The Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II study) compared candesartan with amlodipine as antiarrhythmic therapy for the treatment of frequent paroxysmal AF in patients with a history of hypertension. There was no significant difference between the two groups in the frequency of the number of episodes of AF. Blood pressure control was better in the amlodipine arm. Both groups resulted in a similar reduction in the number of days in AF, quality of life and adverse effects.
The highly topical issue of the effects of omega-3 polyunsaturated fatty acids were studied in the prevention of AF after coronary artery bypass surgery in 260 patients. Unfortunately there was no significant difference between the two groups in the primary endpoint of post-CABG AF and no differences between the groups in terms of post-operative complications, length of stay in hospital and rehospitalisation rates.

Given that AF ablation may result in inflammatory changes within the left atrium which may cause arrhythmias it has been postulated that steroid injection following AF ablation may result in a reduction in these arrhythmias. A prospective double blind pilot study comparing intravenous steroid versus placebo showed a trend toward a significant decrease in severe arrhythmias in the first 6 weeks post-procedure. There was a significant reduction in need for cardioversion for symptomatic AF. Based on these findings, the routine use of IV steroid administration post ablation could be considered but a larger study is required.

Outstanding Presentations

Given the colossal volume of presentations it is impossible to encapsulate them all.  However some of the highlights of the meeting are summarised as follows.  One of the most popular and indeed one of my personal favourite talks was a presentation by Dr Gregory F. Michaud. A number of interesting cases were presented with audience interaction, each demonstrating several important SVT manoeuvres. This year a new manoeuvre was added to help distinguish between AVNRT and ORT.  Rather than our traditional approach where we entrain from the right ventricle and look at the termination this technique looks at the start of the ventricular pacing and the transition from fusion to resetting of the tachycardia.  If the tachycardia is reset before the transition zone then this is more likely to be consistent with an ORT. If the tachycardia is reset after the transition zone then this is more likely to represent AVNRT.  There were several cases shown to demonstrate this technique and by the end the audience appeared to be well versed in this manoeuvre being able to make the diagnosis in the majority of cases.

From a device perspective Dr Paul Friedman provided a concise overview of shock reduction in ICD therapy. In comparing an empiric programming approach where parameters are pre-set versus a physician tailored strategy it was shown that there was no difference in the time to first shock, whether appropriate or inappropriate.  In view of this it was suggested that we use an empiric strategy for primary prevention (detect only fast VT, detect only sustained VT, use ATP and SVT discriminators and have a high output first shock) and for secondary prevention (add in more zones, programme SVT discriminators and use more ATP in slower VT zones).It was also suggested that future useful developments may include internal haemodynamic sensors which may help determine the delivery of therapy based on an associated drop in blood pressure.

For all of us interested in lead extraction we were provided with a great case based overview by Dr Laurence M. Epstein. The main emphasis was on making the decision on an individual basis. One of the important highlights was that pocket infection, which was previously a class II indication for lead extraction is now class I, given the high risk of endocarditis if the lead is left in place.  Additionally it was felt that lead abandonment was probably not a great strategy as it often results in multiple leads needing extraction at a later stage which have been in place for a longer period of time and thus are associated with a higher risk of removal (ie early versus late delayed complications). The importance of performing these procedures in a large high volume centre was emphasized with overall risk comparable to AF ablation if performed by well trained operators.

Live Cases

These are always one of the most popular components of the convention providing a unique insight into clinical decision making and individual techniques which we may all consider amalgamating into our everyday practice.

One of the complex ablation cases presented involved the management of a left atrial tachycardia following previous AF ablation. The operators performed both entrainment and activation mapping and localised the tachycardia to the mitral valve annulus which was subsequently ablated resulted in termination of the tachycardia and conduction block.

A number of lead extraction cases were presented. The first case involved laser lead extraction of a fractured ICD lead.  Following application of laser through the innominate and into the superior vena cava the left heart border was not clearly demarcated and the left lung field darkened. There was no evidence of pericardial effusion on echocardiogram and chest compressions were administered as the blood pressure dropped.  Although it was initially thought to be a haemothorax, and managed as such the cause was ascertained to be a mucous plug in the left bronchus which improved with suction. Although the clinical condition improved the procedure was aborted. This complication was not directly related to the actual lead extraction, however this case demonstrated the potential risks involved with all complex cases and the importance of good preparation in order to assess all potential eventualities. The other lead extraction cases of a dual chamber biventricular system was performed with no complications.

Awards Ceremony and Presidents Reception

The mantle was passed on from the outgoing president Dr Richard L. Page to the new president Dr Douglas L. Packer. Awards were made to Dr Nabil E. El-Sherif for his pioneering work in cardiac pacing and electrophysiology. Dr David L. Hayes was given a distinguished teacher award and the distinguished scientist award went to Dr Yoram Rudy.

Overall this meeting provided me with a very valuable update in clinical electrophysiology and device therapy as well as providing a forum to meet friends and make research and clinical contacts. We all look forward to another great meeting in San Francisco 2011.

Published on: June 9, 2010

Members Area

Log in or Register now.

 For healthcare professionals only
Learning sky

SEARCH THE SITE

RSS FEED

Subscribe to our RSS feed
home

GET EXCLUSIVE UPDATES

Sign up for our regular email newsletters & be the first to know about fresh articles and site updates.

RECENT COMMENTS

    None Found

ENDORSED BY

  • ArrhythmiaAlliance
  • Stars
  • Anticoagulation Europe
  • Atrial Fibrillation Association
 

You are not logged in

You need to be a member to print this page.
Sign up for free membership, or log in.

You are not logged in

You need to be a member to download PDF's.
Sign up for free membership, or log in.