The implantable cardioverter defibrillator is not enough: Ventricular Tachycardia Catheter Ablation in Patients with Structural Heart Disease Paolo Della Bella, MD Arrhythmia Department and Clinical Electrophysiology Laboratories Ospedale San Raffaele, IRCCS, Milan, Italy
Arrhythmia treatment with ICD Problems The effect on overall survival is overestimated because of: The number of ICD shocks on fast VT is an independent predictor of mortality Arrhythmic storms affect adversely the long term prognosis In patients presenting with tolerated VT the incidence of SCD in ICD recipients equals that of patients treated only with catheter ablation
Arrhythmia treatment with ICD Problems The effect on overall survival is overestimated because of: The number of ICD shocks on fast VT is an independent predictor of mortality Arrhythmic storms affect adversely the long term prognosis In patients presenting with tolerated VT the incidence of SCD in ICD recipients equals that of patients treated only with catheter ablation
ICD firing itself is associated to increased mortality JACC, 1999 Circulation 2004
N Engl J Med. 2008
N Engl J Med. 2008
Arrhythmia treatment with ICD Problems The effect on overall survival is overestimated because of: The number of ICD shocks on fast VT is an independent predictor of mortality Arrhythmic storms affect adversely the long term prognosis In patients presenting with tolerated VT the incidence of SCD in ICD recipients equals that of patients treated only with catheter ablation
Electrical Storm Electrical Storm represents a relatively frequent complication (10-20%) in ICD recipients; it is commonly defined as the occurrence of 3 or more distinct VT episodes in a 24 hour period, each resulting in a DC shock. Refractory VTs are the most frequent arrythmia causing ES ES is an acute clinical emergency, and has been recognized as a significant independent predictor of cardiac death over the medium term in survivors (30 to 40% at two years), mainly due to arrhythmia recurrences External rescue DC shock
Electrical Storm a relatively frequent complication affecting ICD patients treated for secondary prevention of sudden cardiac death (about 20%) ES is a strong independent predictor of death in ICD patients (mortality between 38%-53%). Gatzoulis KA et al. Europace 2005; 7:184-92. Exner DV. et al. Circulation 2001; 103: 2066-71. Verma A et al. J C E 2004;15: 1265-70. cardiac death
317 ICD pts; causes of sudden cardiac death (90 pts, 28%) Mitchell LB, et al.; JACC 2002
Arrhythmia treatment with ICD Problems The effect on overall survival is overestimated because of: The number of ICD shocks on fast VT is an independent predictor of mortality Arrhythmic storms affect adversely the long term prognosis In patients presenting with tolerated VT the incidence of SCD in ICD recipients equals that of patients treated only with catheter ablation
Almendral J and Josephson M: Circulation 2007 In patients presenting with tolerated VT the incidence of SCD in ICD recipients equals that of patients treated only with catheter ablation Mean FU: 29 months
Cardiac Arrest or Death from Arrhythmia in the MUSTT trial -SCD in patients without ICD is 2.5% after acute success of CA at a mean 26 months follow up; -The rate of cardiac arrest or death from arrhythmia in patients with ICD in the MUST Study was 6% at 3 yrs and 9% at 5 yrs Buxton et al: N Engl J Med 1999
Solutions CATHETER ABLATION IS AN EFFECTIVE TREATMENT TO REDUCE ICD SHOCKS SUCCESSFUL CATHETER ABLATION PREVENTS ARRHYTHMIA STORM RECURRENCE AND RELATED MORTALITY
CATHETER ABLATION IS AN EFFECTIVE TREATMENT TO REDUCE ICD SHOCKS Reddy VY et al.; NEJM 2007
Carbucicchio C, Circulation 2008 Multiple morphologies and untolerated VT induction frequently occurr in patients with ES Catheter ablation is successsful in up to 72% of patients with ES
Carbucicchio C, Circulation 2008
Acute outcome of catheter ablation in 163 patients presenting with Arrhythmic storm/incessant VT (415 pts referred for VT between 2007-2010) 12; 7% 4; 2% 3; 2% 5; 3% 37; 23% 102; 63% 124 pts presenting with ES 39 pts presenting with incessant VT Initial DCM CAD IDCM ARVD VALVULAR HCM
Cumulative Arrhythmic and Heart Failure Death Among pts presenting with ES P=0.008
Treatment and acute outcome of VT catheter ablation (353 of 415 pts referred for VT between 2007-2010) N pts 300 284-79% 250 200 256-71% Endo RFCA Epi RFCA Surgical ablation 150 RFCA success (A class) 100 80-23% RFCA partial success (B Class) 50 46-12% Failure (C Class ) 0 23-6% 13-4% 16-5% Successful ablation of target VT - Control PES not performed
Long term results related to acute outcome N pts 300 3% 21% 250 200 150 ES recurrence Paroxysmal VT Recurrence No recurrence 100 76% 50 0 5% 30% 100% 9% 65% 81% Class A: 284 pts Class B: 46 pts Class C 13 pts non tested 16 pts In hospital recurrence of VT storm requiring REDO procedure in 14 pts (4%) In hospital recurrence of paroxysmal VT in 56 pts (15%)
Procedure-related complications Tab. 1 Vascular injury (not requiring surgery) 3% AV fistula/pseudoaneurysm (surgical repair) 2% Pericardial effusion Total 2% Cardiac tamponade 1% Cardiac tamponade (surgical repair) 0.4% Pulmonary edema 1% PEA 0.5% Subacute haemoperitoneum (injury to diafragmatic vessel during epicardal puncture) 0.2%
Mortality In Hospital death 7 Heart Failure Intraprocedure PEA 6 1 Long term follow up 28 ±6 months All cause death HF death Cardiac arrest 37 12 21
VT/VF Arrhythmia storm Need for an integrated approach Anaesthesiology support in the acute phase aimed to: Cardiorespiratory function support Sedation / reduction of sympathetic drive Hemodynamic support (IABP, ECMO) Recovery in the Intensive Care Unit in selected instances Mechanical support (VAD) Cardiac surgery to provide map guided arrhythmia surgery in selected cases.
The ICD is not enough Key issues ICD reprogramming CONCLUSIONS: Shocked VA episodes are associated with increased mortality risk. Shocked patients have substantially higher VA episode burden and poorer survival compared with ATP-only treated patients. Sweeney MO, et al. Heart Rhythm. Mar 2010
The ICD is not enough Key issues Optimize drug treatment Amiodarone and betablockers therapy lead to a reduction of appropriate ICD shocks comparable to SMASH trial (annual event rate: 6.7%), Hazard ratio: 0.3 (CI: 0.14-0.68) in patients receiving an ICD for primary SD prevention Connolly SJ, et al. The Optic study JAMA Jan 2006 But a rate of 18% /year of amiodarone discontinuation caused by side effect was observed in the same study!
Connolly SJ, et al. The Optic study JAMA Jan 2006
The ICD is not enough Key issues Open points: timing of catheter ablation is not well defined Should Substrate Ablation be performed in patients with old myocardial infarction after unstable VT/VF occurrence before planning an ICD implantation? Should VT Ablation be performed in all patients presenting with post-mi stable monomorphic VT before ICD implantation to reduce ICD therapies burden?
128 pts with previuos Myocardial infarction and severe LV dysfunction Enrollement criteria: 1) Indication to ICD implantation related to: -Spontaneous VF or unstable VT -Syncope and VT induction at EPS - Mean LVEF: 0.25 2) ICD implantation for primary prophylaxis and appropriate ICD therapy for a single event Randomized to: no treatment or substrate catheter ablation during sinus rhythm No AAds (except for betablockers) in control group!
No evidence of survival benefit Overall reduction of ICD therapies burden in the ablation group with respect to control group
No significant improvement of arrhythmia-free survival is demonstrated in the group of patients with severe LV dysfunction Kuck KH et al. Lancet. 2010
Conclusions Carefully define indications to ICD implantation Curative treatment should be considered earlier in the arrhythmia hystory and definitely after the first episode of appropriate shock Concomitant medical treatment is an option (no evidence at this time whether drug treatment should precede ablation) ICD programming to ATP: consider however that the powerful prognostic indicator is not only the mode of arrhythmia termination, but rather the associated arrhythmia burden