Should We Achieve the Target Doses of Beta-blockers

1
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
Purpose 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 Methods We
screened for symptomatic chronic heart failure
patients with reduced left ventricular ejection
fraction (lt0.40) (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 (lt70 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. 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,
P0.004), had more frequent history of myocardial
infarction (59.8 vs. 43.0, p0.007), had lower
prevalence of hypertension (40.6 vs. 62.5,
plt0.001), and had lower baseline blood pressure
(systolic BP 119.4 vs. 126.3 mmHg, P0.005 and
diastolic BP 68.3 vs. 74.5 mmHg, Plt0.001). 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
(p0.028). Incidence of symptomatic bradycardia
and heart block was higher in the adequate heart
rate control group (10.5 vs. 2.8, p0.008).
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