Benefit of cardiac resynchronization in elderly patients: results from the Multicenter InSync Randomized Clinical Evaluation (MIRACLE) and Multicenter InSync ICD Randomized Clinical Evaluation (MIRACLE-ICD) trials.
OBJECTIVE
Heart failure (HF) affects five million patients each year with both prevalence and incidence increasing with age. At least 20% of hospital admissions in patients > age 65 are due to HF. Cardiac resynchronization therapy (CRT) has been shown to improve HF symptoms and decrease mortality. However, little data are available which specifically address the effects of CRT in the elderly (>65).


METHODS
We performed an analysis of the NYHA III/IV 839 patients randomized in the MIRACLE (n = 470) and MIRACLE-ICD (n = 369) trials. Both included patients with moderate to severe HF, ejection fraction (EF) <or=35%, and QRS duration >or=130 msec. Patients were grouped by age <65, 65-75, and >75 years. For each group, patients with CRT activated (ON) were compared with patients with CRT inactivated (OFF) for end points at 6 months, including New York Heart Association (NYHA) functional class and EF.


RESULTS
Of the 839 patients, 368 were <65, 297 were 65-75, and 174 were >75 years old. Compared with controls, patients from all three age groups, whose CRT was activated, had statistically significant improvements in NYHA class (-0.84 for age <65, -0.78 for age 65-75, and -0.78 for age >75). All age groups with CRT ON also had statistically significant improvements in left ventricular EF (5.23%, 2.98%, and 4.03% respectively). There were no between group differences by age in LVEF improvement.


CONCLUSIONS
In elderly patients enrolled in the MIRACLE and MIRACLE-ICD trials, CRT resulted in significant improvements in NYHA class and LVEF, regardless of age. These data suggest that the full age range of patients with appropriate indications for implantation can benefit from CRT.
Kron
Jordana
J
Division of Cardiology, Virginia Commonwealth University, Richmond, VA, USA.
Aranda
Juan M
JM
Miles
William M
WM
Burkart
Thomas A
TA
Woo
Gregory W
GW
Saxonhouse
Sherry J
SJ
Sears
Samuel F
SF
Conti
Jamie B
JB
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D015897:Comorbidity; D005260:Female; D006333:Heart Failure / Q000453:epidemiology* / Q000517:prevention & control*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors; D017678:Sex Distribution; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D018487:Ventricular Dysfunction, Left / Q000453:epidemiology* / Q000517:prevention & control*