Lower body mass index and atrial fibrillation as independent predictors for mortality in patients with implantable cardioverter defibrillator.
OBJECTIVE
To evaluate risk factors related to total mortality in an unselected population of patients implanted with a cardioverter defibrillator.


METHODS
Survival analysis was performed retrospectively investigating the records of 77 consecutive patients implanted with defibrillators (median 67 years, range 38-83 years; 63 men). All patients were followed regularly in 3-month intervals. The cause of mortality was assessed clinically, including post-mortem examination of device to assess possible arrhythmogenic death. Predictors were assessed by Kaplan-Meier analysis with log-rank tests and by Cox regression analysis (proportional hazards).


RESULTS
Defibrillator recipients had a mean (+/-standard deviation) ejection fraction of 34+/-13%, left ventricular end-diastolic dimension (LVEDD) of 6.24+/-0.8 cm, QRS duration of 129+/-34 ms, and body mass index (BMI) of 26.4+/-4.3 kg/m(2). Atrial fibrillation was present in 32 patients, paroxysmal fibrillation in 23, and permanent fibrillation in 9 patients. The estimate of mean survival time for all patients was 51.5 (95% confidence interval 46.6-56.5) months. During the study period 11/77 (14%) patients died. Mean follow-up time was 24.5 months (range 0.2-60.7) for survivors and 7.6 months (range 1.5-42) for non-survivors. Independent predictors of mortality were the NYHA class (P=0.004), BMI< or =26 kg/m(2) (P=0.024), presence of paroxysmal or permanent atrial fibrillation (P=0.014), and absence of arterial hypertension (P=0.010). LVEDD showed a weak significant effect on survival (P=0.049).


CONCLUSIONS
Patients with implantable cardioverter defibrillator and a normal to lower BMI or atrial fibrillation had a significantly higher overall mortality. These factors may be indicative of end stage heart failure or diseases associated with high sympathetic activation.
Schernthaner
Christiana
C
Department of Cardiology, Salzburger Landeskliniken, Paracelsus Private Medical University, Salzburg, Austria. c.schernthaner@salk.at
Pichler
Maximilian
M
Strohmer
Bernhard
B
D050153:Abdominal Fat; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy*; D015992:Body Mass Index; D002423:Cause of Death; D015331:Cohort Studies; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D016019:Survival Analysis