An appropriate indication for the initiation of beta-blocker therapy in dilated cardiomyopathy.
BACKGROUND
Although long-term treatment with beta-blockers has been shown to improve morbidity and mortality in dilated cardiomyopathy (DCM), patient responses are heterogeneous.


METHODS
To establish the appropriate indication for the initiation of beta-blocker therapy, we retrospectively analyzed 38 DCM patients treated with beta-blockers (metoprolol or carvedilol) and examined differences in baseline profiles between patients who could continue the therapy (responders) and those who could not (non-responders).


RESULTS
In 13 non-responders, the duration from onset of symptoms to beta-blocker initiation was longer (p < 0.05), systolic blood pressure was lower (p < 0.001), serum sodium concentration was lower (p < 0.05), left ventricular posterior wall thickness was thinner (p < 0.05), left ventricular end-diastolic pressure was higher (p < 0.05) and left ventricular wall stress was lower (p < 0.05) than in 25 responders. In 19 patients receiving carvedilol, 5 non-responders showed higher levels of human atrial natriuretic peptide (p < 0.05) and brain natriuretic peptide (p < 0.01) than 13 responders. Discriminant analysis with a linear discriminant function showed the following equation predicted response to beta-blocker therapy: h = 0.004 x systolic blood pressure - 0.002 x brain natriuretic peptide + 0.667 (R2 = 0.67, p < 0.001). The probability of predicting the response was 94.1% with h > or = 0.5.


CONCLUSIONS
We conclude that h > or = 0.5 is the appropriate indication for the initiation of beta-blocker therapy in DCM.
Morooka
Toshifumi
T
Department of Cardiovascular and Renal Medicine, Saga University Faculty of Medicine, Saga, Japan.
Inoue
Teruo
T
Kotooka
Norihiko
N
Fujimatsu
Daisuke
D
Komatsu
Aiko
A
Uchida
Fumi
F
Yoshida
Kazuyo
K
Hashimoto
Shigemasa
S
Hikichi
Yutaka
Y
Kato
Toru
T
Node
Koichi
K
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D009320:Atrial Natriuretic Factor / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013318:Stroke Volume / Q000187:drug effects; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000188:drug therapy; D017725:Ventricular Pressure / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D015415:Biomarkers; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor