Download Should we achieve the target doses of beta

Should We Achieve the Target Doses of Beta-blockers
in Chronic Heart Failure Patients with Adequate Heart Rate Control?
Krit Leemasawat, MD; Arintaya Phrommintikul, MD; Rungsrit Kanjanavanit, MD; Wanwarang Wongcharoen, MD;
Kan Okonogi, MD; Lalita Yongsmith, MD; Sirilak Yooprasert, MD; and Apichard Sukonthasarn, MD
Faculty of Medicine, Chiang Mai University, Thailand
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Recent studies indicated that heart rate was an important target for chronic heart
failure treatment, whereas the importance of doses of beta-blockers was still
uncertain. We conducted a retrospective study to determine the survival prognosis
of achieving the target doses of beta-blockers in chronic heart failure patients with
adequate heart rate control.
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Methods
We screened for symptomatic chronic heart failure patients with reduced left
ventricular ejection fraction (<0.40) (HFrEF) and newly initiated beta-blocker
treatment (bisoprolol, carvedilol, metoprolol tartrate, or nebivolol) with at least 1
year follow-up in Maharaj Nakorn Chiang Mai Hospital between the year 2000 and
2010. Among 3,754 HFrEF patients, 325 patients were eligible and were classified
into 4 groups, according to heart rate control (<70 vs. ≥70 beats per minute) and
target beta-blocker dose (achieved vs. not achieved) (Figure 1). The endpoint of the
study was all-cause mortality.
Survival
Purpose
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0.4
(I) HR +, BB +
(II) HR +, BB -
(III) HR -, BB +
(IV) HR -, BB -
0.2
0
0
500
1,000
1,500
2,000
33
65
26
36
21
40
14
23
Time (days)
Results
Baseline heart rate was similar in all groups. The patients in group which the target
beta-blocker dose was not achieved were older (63.0 vs. 58.3 years, P=0.004), had
more frequent history of myocardial infarction (59.8% vs. 43.0%, p=0.007), had
lower prevalence of hypertension (40.6% vs. 62.5%, p<0.001), and had lower
baseline blood pressure (systolic BP 119.4 vs. 126.3 mmHg, P=0.005 and diastolic BP
68.3 vs. 74.5 mmHg, P<0.001). The baseline LV ejection fraction, NYHA functional
class, and concomitant medication were not different among groups. The median
follow-up was 49.4 months (IQR 29.1-71.2). The annual all-cause mortality was
significantly lower in the group (I) than in the other groups (Figure 1). After
adjusting for possible confounding factors, the difference among groups remained
significant (p=0.028). Incidence of symptomatic bradycardia and heart block was
higher in the adequate heart rate control group (10.5% vs. 2.8%, p=0.008).
Number at risk
(I)
50
(II)
131
(III)
46
(IV)
98
47
113
45
85
41
93
33
61
Figure 1 Cumulative Kaplan-Meier Estimates of Rates of All-Cause Mortality, According to Study Groups*
*BB +: achieved target beta-blocker dose, BB -: not achieved target beta-blocker dose, HR +: adequate heart rate control,
HR -: inadequate heart rate control. P=0.032.
Conclusions
The greatest survival prognosis was observed in HFrEF patients who both had
adequate heart rate control and achieved the target doses of beta-blockers. Both
heart rate and beta-blocker dose were important targets for chronic heart failure
treatment.
Supported by the Faculty of Medicine Fund for medical research, Faculty of Medicine, Chiang Mai University