Long-term prognostic importance of resting heart rate in patients with left ventricular dysfunction in connection with either heart failure or myocardial infarction: the DIAMOND study.
BACKGROUND
Elevated resting heart rate is associated with increased mortality in a variety of cardiac diseases, but comparisons between different clinical settings are lacking. We investigated the long-term prognostic importance of resting heart rate in patients hospitalized with left ventricular dysfunction in connection with either heart failure (HF) or myocardial infarction (MI).


METHODS
In the Danish Investigations and Arrhythmia ON Dofetilide (DIAMOND) study; patients with left ventricular dysfunction were randomized to Dofetilide (class III antiarrhythmic drug) or placebo. One part of the study enrolled 1518 patients with HF and another 1510 patients with MI. Mortality analyses were performed using multivariable adjusted Cox proportional hazard models.


RESULTS
During 10 years of follow-up, 1076 (72%) patients with MI and 1336 (89%) patients with HF died. In multivariable adjusted models, every increment in baseline heart rate of 10 bpm was associated with an increase in mortality in both MI-patients (hazard ratio, 1.14; 95%-confidence interval (CI): 1.09-1.19; P<.0001) and HF-patients (hazard ratio, 1.10; CI: 1.06-1.15; P<.0001). The importance of resting heart rate on short-term prognosis was stronger in the MI patients compared to the HF patients (P<.0001 for interaction). There was no interaction between heart rate and beta-blockade, and inclusion of beta-blockade in the model did not change the results.


CONCLUSIONS
Resting heart rate was independently associated with increased risk of overall mortality. The prognostic importance of resting heart rate is stronger in patients with MI compared to patients with HF, especially in the short term.
Fosbøl
Emil Loldrup
EL
The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, DK 2100 Copenhagen, Denmark. ELF@heart.dk
Seibaek
Marie
M
Brendorp
Bente
B
Moller
Daniel Vega
DV
Thune
Jens Jakob
JJ
Gislason
Gunnar H
GH
Torp-Pedersen
Christian
C
Køber
Lars
L
D000368:Aged; D000369:Aged, 80 and over; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000150:complications*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000150:complications*; D011379:Prognosis; D016016:Proportional Hazards Models; D015996:Survival Rate; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality*