Irrigated radiofrequency catheter ablation guided by electroanatomic mapping for recurrent ventricular tachycardia after myocardial infarction: the multicenter thermocool ventricular tachycardia ablation trial.
BACKGROUND
Recurrent ventricular tachycardia (VT) is an important cause of mortality and morbidity late after myocardial infarction. With frequent use of implantable cardioverter-defibrillators, these VTs are often poorly defined and not tolerated for mapping, factors previously viewed as relative contraindications to ablation. This observational multicenter study assessed the outcome of VT ablation with a saline-irrigated catheter combined with an electroanatomic mapping system.


RESULTS
Two hundred thirty-one patients (median LV ejection fraction, 0.25; heart failure in 62%) with recurrent episodes of monomorphic VT (median, 11 in the preceding 6 months) caused by prior myocardial infarction were enrolled. All inducible monomorphic VTs with a rate approximating or slower than any spontaneous VTs were targeted for ablation guided by electroanatomic mapping during sinus rhythm and/or VT. Patients were not excluded for multiple VTs (median, 3 per patient) or unmappable VT (present in 69% of patients). Ablation abolished all inducible VTs in 49% of patients. The primary end point of freedom from recurrent incessant VT or intermittent VT after 6 months of follow-up was achieved for 123 patients (53%). In 142 patients with implantable cardioverter-defibrillators before and after ablation for intermittent VT who survived 6 months, VT episodes were reduced from a median of 11.5 to 0 (P<0.0001). The 1-year mortality rate was 18%, with 72.5% of deaths attributed to ventricular arrhythmias or heart failure. The procedure mortality rate was 3%, with no strokes.


CONCLUSIONS
Catheter ablation is a reasonable option to reduce episodes of recurrent VT in patients with prior myocardial infarction, even when multiple and/or unmappable VTs are present. This population remains at high risk for death, warranting surveillance and further study.
Stevenson
William G
WG
Cardiovascular Division, Brigham and Women's Hospital, Boston, MA 02115, USA. wstevenson@partners.org
Wilber
David J
DJ
Natale
Andrea
A
Jackman
Warren M
WM
Marchlinski
Francis E
FE
Talbert
Timothy
T
Gonzalez
Mario D
MD
Worley
Seth J
SJ
Daoud
Emile G
EG
Hwang
Chun
C
Schuger
Claudio
C
Bump
Thomas E
TE
Jazayeri
Mohammad
M
Tomassoni
Gery F
GF
Kopelman
Harry A
HA
Soejima
Kyoko
K
Nakagawa
Hiroshi
H
D000368:Aged; D018780:Body Surface Potential Mapping / Q000295:instrumentation / Q000379:methods*; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods* / Q000401:mortality; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods*; D009203:Myocardial Infarction / Q000150:complications / Q000401:mortality / Q000601:surgery*; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000401:mortality / Q000601:surgery*