Echocardiographic characteristics predicting efficacy of drug therapy in patients with hypertrophic obstructive cardiomyopathy.
BACKGROUND
The efficacy of long-term drug therapy for patients with hypertrophic obstructive cardiomyopathy (HOCM) remains unclear. This study was performed to characterize the echocardiographic findings of patients responsive to drug therapy.


METHODS
Left ventricular outflow tract (LVOT) gradient and morphologic characteristics of the septum, posterior wall, and mitral valve were measured echocardiographically in 35 Japanese patients. The mean follow-up time was 41+/-22 months.


RESULTS
Long-term drug therapy was effective in 14 patients and ineffective in 21 patients. Five of the refractory patients required mitral valve replacement to become free of symptoms. Only 5 of 21 patients whose LVOT gradient was 100 mm Hg were responsive to drug therapy, whereas 9 of 14 patients whose LVOT gradient was <100 mm Hg were responsive to drug therapy. Seven of eight patients with an asymmetric septal hypertrophy (ASH) ratio >==1.3 and LVOT gradient <100 mm Hg were responsive to drug therapy. Only 3 of 16 patients with an ASH ratio <1.3 were responsive to drug therapy. There was no correlation between the efficacy of drug therapy and the morphology of the mitral valve or the width of the LVOT.


CONCLUSIONS
Our results demonstrate that drug therapy effectively reduces the LVOT gradient in patients with asymmetric septal hypertrophy and a less severe LVOT gradient.
Shimaya
Kazuhiro
K
Department of Cardiology, The Heart Institute of Japan, Tokyo Women's Medical University, Japan. Kazuhiro_Shimaya@hm.honda.co.jp
Kurihashi
Akira
A
Fuda
Yuji
Y
Yajima
Toshitaka
T
Yamami
Nobuo
N
Shiga
Tsuyoshi
T
Sakomura
Yasunari
Y
Matsuda
Naoki
N
Ishizuka
Naoko
N
Kasanuki
Hiroshi
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging / Q000188:drug therapy