Long-term survival in patients treated with cardiac resynchronization therapy: a 3-year follow-up study from the InSync/InSync ICD Italian Registry.
BACKGROUND
Studies reporting the long-term survival of patients treated with cardiac resynchronization therapy (CRT) outside the realm of randomized controlled trials are still lacking. The aim of this study was to quantify the survival of patients treated with CRT in clinical practice and to investigate the long-term effects of CRT on clinical status and echocardiographic parameters.


METHODS
The study population consisted of 317 consecutive patients with implanted CRT devices from eight Italian University/Teaching Hospitals. The patients were enrolled in a national observational registry and had a minimum follow-up of 2 years. A visit was performed in surviving patients and mortality data were obtained by hospital file review or direct telephone contact.


RESULTS
During the study period, 83 (26%) patients died. The rate of all-cause mortality was significantly higher in ischemic than nonischemic patients (14% vs 8%, P = 0.002). Multivariate analysis showed that ischemic etiology (HR 1.72, CI 1.06-2.79; P = 0.028) and New York Heart Association (NYHA) class IV (HR 2.87, CI 1.24-6.64; P = 0.014) were the strongest predictors of all-cause mortality. The effects of CRT persisted at long-term follow-up (for at least 2 years) in terms of NYHA class improvement, increase of left ventricular ejection fraction, decrease of QRS duration (all P = 0.0001), and reduction of left ventricular end-diastolic and end-systolic diameters (P = 0.024 and P = 0.011, respectively).


CONCLUSIONS
During long-term (3 years) follow-up after CRT, total mortality rate was 10%/year. The outcome of ischemic patients was worse mainly due to a higher rate of death from progressive heart failure. Ischemic etiology along with NYHA class IV was identified as predictors of death. Benefits of CRT in terms of clinical function and echocardiographic parameters persisted at the time of long-term follow-up.
Gasparini
Maurizio
M
IRCCS Istituto Clinico Humanitas, Rozzano (Milan), Italy. maurizio.gasparini@humanitas.it
Lunati
Maurizio
M
Santini
Massimo
M
Tritto
Massimo
M
Curnis
Antonio
A
Bocchiardo
Mario
M
Vincenti
Antonio
A
Pistis
Gianfranco
G
Valsecchi
Sergio
S
Denaro
Alessandra
A
D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000401:mortality*; D015897:Comorbidity; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000517:prevention & control*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012042:Registries / Q000706:statistics & numerical data*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate; D018487:Ventricular Dysfunction, Left / Q000401:mortality* / Q000517:prevention & control*