Myocardial contractile reserve determined by dobutamine stress Tc-99m tetrofosmin quantitative gated SPECT predicts late spontaneous improvement in cardiac function in patients with recent-onset dilated cardiomyopathy.
BACKGROUND
We evaluated whether dobutamine stress technetium 99m tetrofosmin (DSTF) quantitative gated single photon emission computed tomography (QGS) could predict late spontaneous improvement of cardiac function in patients with idiopathic dilated cardiomyopathy (DCM).


RESULTS
The study included 26 patients with recently diagnosed (<2 months) idiopathic DCM and a left ventricular ejection fraction (LVEF) lower than 45%. DSTF-QGS was performed in all patients to measure LVEF at rest and during dobutamine infusion (10 microg. kg(-1). min(-1)). LVEF and left ventricular end-diastolic volume (LVEDV) were determined by echocardiography, and New York Heart Association (NYHA) functional class was estimated at baseline and after 1 year. After 1 year of treatment, the echocardiographic LVEF improved by greater than 5% in 13 patients (group A) but did not improve in the remaining 13 patients (group B). At baseline, the echocardiographic LVEF, LVEDV, and NYHA functional class were similar in both groups. However, there was a greater increase in the LVEF during the dobutamine infusion portion of the DSTF-QGS (DeltaLVEF) in group A than in group B (13.1% +/- 5.9% vs 2.6% +/- 4.1%, P <.0001). If a critical value for the DeltaLVEF of 7.0% was used to predict improvement in LVEF after treatment, the sensitivity was 84.7% and the specificity was 84.7%. LVEDV and NYHA functional class improved to a greater extent in group A than in group B.


CONCLUSIONS
DSTF-QGS can be used to predict late spontaneous improvement in cardiac function and symptoms after treatment in patients with idiopathic DCM.
Kasama
Shu
S
Second Department of Internal Medicine, Gunma University School of Medicine, Maebashi, Japan. s-kasama@bay.wind.ne.jp
Toyama
Takuji
T
Kumakura
Hisao
H
Takayama
Yoshiaki
Y
Ichikawa
Shuichi
S
Suzuki
Tadashi
T
Kurabayashi
Masahiko
M
D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000627:therapeutic use; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D004280:Dobutamine; D005080:Exercise Test; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D020127:Recovery of Function; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D013318:Stroke Volume; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000209:etiology
D000889:Anti-Arrhythmia Agents; D000959:Antihypertensive Agents; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D004280:Dobutamine; C078700:technetium tc-99m tetrofosmin