What resting heart rate should one aim for when treating patients with heart failure with a beta-blocker? Experiences from the Metoprolol Controlled Release/Extended Release Randomized Intervention Trial in Chronic Heart Failure (MERIT-HF).
OBJECTIVE
The goal of this study was to explore the question: what resting heart rate (HR) should one aim for when treating patients with heart failure with a beta-blocker?


BACKGROUND
The interaction of pretreatment and achieved resting HR with the risk-reducing effect of beta-blocker treatment needs further evaluation.


METHODS
Cardiovascular risk and risk reduction were analyzed in five subgroups defined by quintiles (Q) of pretreatment resting HR in the Metoprolol Controlled Release/Extended Release Randomized Intervention Trial in Chronic Heart Failure (MERIT-HF).


RESULTS
Mean baseline HR in the 5 Qs were 71, 76, 81, 87, and 98 beats/min; achieved HR 63, 66, 68, 72, and 75 beats/min; and net change -8, -10, -11, -13, and -14 beats/min, respectively. Baseline HR was related to a number of baseline characteristics. Cardiovascular risk was no different in Q1 to Q4 (placebo groups) but increased in Q5 (HR above 90 beats/min). No relationship was observed between the risk-reducing effect of metoprolol controlled release/extended release (CR/XL) and baseline HR in the five Qs of baseline HR, or achieved HR, or change in HR during follow-up, respectively.


CONCLUSIONS
Metoprolol CR/XL significantly reduced mortality and hospitalizations independent of resting baseline HR, achieved HR, and change in HR. Achieved HR and change in HR during follow-up were closely related to baseline HR; therefore, it was not possible to answer the question posed. Instead, one has to apply a very simple rule: aim for the target beta-blocker dose used in clinical trials, and strive for the highest tolerated dose in all patients with heart failure, regardless of baseline and achieved HR.
Gullestad
Lars
L
Baerums Sykehus, Baerum, Norway.
Wikstrand
John
J
Deedwania
Prakash
P
Hjalmarson
Ake
A
Egstrup
Kenneth
K
Elkayam
Uri
U
Gottlieb
Stephen
S
Rashkow
Andrew
A
Wedel
Hans
H
Bermann
Georgina
G
Kjekshus
John
J
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003692:Delayed-Action Preparations; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006760:Hospitalization; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D008875:Middle Aged; D011446:Prospective Studies; D012146:Rest / Q000502:physiology*; D018570:Risk Assessment; D016896:Treatment Outcome
D000319:Adrenergic beta-Antagonists; D003692:Delayed-Action Preparations; D008790:Metoprolol