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.
Division of Heart Failure and Cardiac Rehabilitation, Department of Cardiovascular Surgery, Sacro Cuore Catholic University, Rome, Italy. rosaria.natali@rm.unicatt.it
R
R
Natali
M
M
Lotrionte
N
N
Marchese
G
G
Di Giannuario
S
S
Brugaletta
C
C
Pisanello
G
G
Comerci
M
M
Savino
A
A
Lombardo
F
F
Forni
C
C
Vigna
F
F
Loperfido
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