1、EP show June 2004EP showThe EP show:Risk stratification for sudden death EP show June 2004EP showRisk stratification for sudden deathEP show June 2004EP showHistorical look at early markersBegan during the mid-1980s with a prospective study of about 1000 postinfarction patientsMeasured 24-hour Holte
2、r recordings for ventricular premature beat frequencyDetermined ejection fractionAscertained several other routine clinical parametersMossEP show June 2004EP showHistorical look at early markersFound inverse relationship between the ejection fraction and total mortality as well as sudden death Cut p
3、oint between 30%and 40%Recent studies,including MADIT I and II,grew out of this early workMossEP show June 2004EP showSerial electrophysiology testingMechanistically drivenSudden death in postinfarction patients predominately due to ventricular tachycardiaIf you could induce ventricular tachycardia
4、and introduce a drug that suppresses this ability,you could monitor efficacyGoldEP show June 2004EP showReviewing CASTCardiac Arrhythmia Suppression Trial(CAST)Large randomized trial that looked at whether suppressing ventricular ectopy after MI reduces sudden deathTrial stopped because antiarrhythm
5、ic agents associated with increased mortalityEP show June 2004EP showReviewing CASTThis set the stage for moving from antiarrhythmic agents to device therapy.MossEP show June 2004EP showReviewing CASTCould these results be related to the drugs selected?Subsequent trials confirmed that this was not t
6、he casePrystowskyEP show June 2004EP showMADIT IWould an ICD or conventional therapy improve survival in this high-risk population?Randomly assigned 196 patients with prior MI and:NYHA functional class 1,2,or 3 A left ventricular ejection fraction 35%An episode of asymptomatic unsustained ventricula
7、r tachycardia Inducible,nonsuppressible ventricular tachyarrhythmia on electrophysiologic studyEP show June 2004EP showMADIT I findingsGroupTotal deathsCardiac deathsDefibrillator1511Conventional therapy3927*Average 27-month follow-up EP show June 2004EP showMADIT IIn high-risk patients with prior M
8、I,prophylactic therapy with an ICD leads to improved survival compared with conventional medical therapyEP show June 2004EP showMUSTTMulticenter Unsustained Tachycardia Trial(MUSTT),a randomized controlled trialCan electrophysiologically guided antiarrhythmic therapy reduce the risk of sudden death?
9、Looked at coronary artery disease patients with a left ventricular ejection fraction 40%and asymptomatic unsustained ventricular tachycardiaEP show June 2004EP showMUSTTEnd pointCardiac arrest or arrhythmia deathEP-guided therapy(%)25No antiarrhythmic therapy(%)32Relative risk0.7395%CI0.53-0.99EP sh
10、ow June 2004EP showMUSTTTherapy with implantable defibrillators,but not with antiarrhythmic drugs,reduces the risk of sudden death in high-risk patients with coronary diseaseEP show June 2004EP showUnsustained VTI think its a relatively weak risk stratifier.And as you point out,it was both frustrati
11、ng and cumbersome.GoldEP show June 2004EP showMADIT IIRandomized trial evaluating the effect of an implantable defibrillator on survival1232 patients with prior MI and a left ventricular ejection fraction of 120 milliseconds and that they would revisit this when SCD-HeFT data were presented.MossEP s
12、how June 2004EP showSCD-HeFTSudden Cardiac Death in Heart Failure Trial(SCD-HeFT)Largest of the trials involving ICD therapy with a longer patient follow-up than previous studiesEP show June 2004EP showSCD-HeFTCompared all-cause mortality in 2500 patients With NYHA class 2 to 3 HF LVEF 35%Patients r
13、andomized to receive ICD,amiodarone,or placebo on top of standard medical therapyEP show June 2004EP showSCD-HeFT all-cause mortality 051015202530353 year(%)5 year(%)ICDAmiodaronePlaceboEP show June 2004EP showSCD-HeFTICD cuts all-cause mortality by 23%in NYHA class 2 to 3 heart failure EP show June
14、 2004EP showWhats a payer to do?The trials were designed specifically to answer the major question of defibrillators and their role to reduce total mortality.I think the trials,as you point out,are concordant in that regard,and I think that it would be reasonable that that would be an indicationfor
15、paying.GoldEP show June 2004EP showWhats a payer to do?Getting into subsets when its not really prespecified thats what youre looking for is potentially very treacherous and can be misleading.MossEP show June 2004EP showThe futureMany have become cynical as noninvasive test after noninvasive test fa
16、iled to live up to its expectationsBut I remain optimisticGoldEP show June 2004EP showQuestionAre there patients in MADIT II who are:Too healthy to benefit from an ICD?Too sick for one?PrystowskyEP show June 2004EP showLatest look at MADIT II The benefit from ICD was entirely in the patients who car
17、ried one or more risk factorsThe 20%of the population that carried no risk factors achieved no benefit whatsoeverMossEP show June 2004EP showSummarySeveral decades of research have put risk stratifiers to the testEjection fraction remains supreme as a noninvasive testWeve identified the benefactors
18、of ICD therapyAnd realized that antiarrhythmic drugs to prevent sudden death are not as important as once thoughtEP show June 2004EP showIn conclusionDespite so many noninvasive tests failing to live up to expectations,many still show promiseHot off the press!New soon-to-be-published data will show that combinations of risk stratifiers may help pinpoint patients who will derive the most and least benefit from an ICDPrystowsky
