Prediction of functional capacity by low-dose dobutamine stress echocardiography in chronic heart failure.
OBJECTIVE
The aim of this study was to determine if low-dose dobutamine stress echocardiography (LD-DSE) is associated with functional capacity in unselected elderly patients with chronic heart failure.


METHODS
This was a prospective trial. Thirty five consecutive patients were included, with age >65 years and left ventricular dysfunction (12 ischemic), by blindly assessed LD-DSE and cardiopulmonary exercise testing (CPT). Contractile reserve was defined as a change (D) in wall motion score index (WMSI) = or <0.2 at peak dose dobutamine. At CPT treadmill exercise time, peak VO2, %Vo2 and VE/VCO2 slope were determined. Preserved functional capacity was defined as percent of maximal predicted O2 consumption (%VO2) >80%. Baseline NT-proBNP plasma levels were assessed.


RESULTS
CPT variables were not related to clinical and baseline echocardiography characteristics but were related to DWMSI (exercise time, P=0.004; peak VO2, P=0.008; %VO2, P<0.001; VE/Vco2, P<0.001). Contractile reserve was present in 16 of 17 patients with preserved functional capacity (sensitivity=94%) and in 2 of 13 patients without (specificity=85%). Baseline NT-proBNP levels were lower in patients with contractile reserve (476+/-365 pg/mL) than in those without (1 345+/-1 219 pg/mL) (P=0.019), but were mildly related to CPT variables (P=0.049 and 0.027 with exercise time and %VO2, respectively).


CONCLUSIONS
Contractile reserve elicited at LD-DSE is associated with functional capacity in unselected elderly patients with chronic heart failure.
Natali
R
R
Division of Heart Failure and Cardiac Rehabilitation, Department of Cardiovascular Surgery, Sacro Cuore Catholic University, Rome, Italy. rosaria.natali@rm.unicatt.it
Lotrionte
M
M
Marchese
N
N
Di Giannuario
G
G
Brugaletta
S
S
Pisanello
C
C
Comerci
G
G
Savino
M
M
Lombardo
A
A
Forni
F
F
Vigna
C
C
Loperfido
F
F
D000318:Adrenergic beta-Agonists; D000368:Aged; D002908:Chronic Disease; D004280:Dobutamine; D004452:Echocardiography / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D010446:Peptide Fragments / Q000097:blood; D011446:Prospective Studies; D012129:Respiratory Function Tests; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis
D000318:Adrenergic beta-Agonists; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D004280:Dobutamine