Microalbuminuria and cardiovascular risk assessment in primary hypertension: should threshold levels be revised?
BACKGROUND
Urinary albumin excretion and left ventricular mass are related to each other and to the risk of cardiovascular events in patients with primary hypertension. We aimed to identify a lower threshold for albuminuria that might improve detection of patients with left ventricular hypertrophy (LVH) and cost-effectiveness in cardiovascular risk assessment.


METHODS
Albuminuria and left ventricular mass index were assessed in 448 untreated, nondiabetic patients with primary hypertension. The impact that lower albuminuria cut-off levels might have on detecting LVH was evaluated with regard to test cost and sensitivity. This was done by a diagnostic algorithm consisting of albuminuria evaluation followed by echocardiography in the presence of normoalbuminuria.


RESULTS
The area under the ROC curve of albuminuria in predicting LVH was 0.73. Using a lower albumin to creatinine ratio threshold than what is recommended by the guidelines (ie, 11.5 mg/g), the sensitivity and specificity of albuminuria in identifying patients with LVH was 39% and 92%, respectively, which translated to positive and negative predictive values of 76% and 69%, respectively. When considering only patients without electrocardiographically detected LVH, routine screening for albuminuria, followed by echocardiography in the presence of albuminuria <or = 11.5 mg/g, allowed us to decrease the number of echocardiograms by 23%.


CONCLUSIONS
Adopting a lower threshold to define microalbuminuria could prove to be cost-effective for assessing cardiovascular risk in hypertensive patients.
Ratto
Elena
E
Department of Cardio-Nephrology, Azienda Ospedaliera Universitaria San Martino, Genoa, Italy.
Leoncini
Giovanna
G
Viazzi
Francesca
F
Vaccaro
Valentina
V
Parodi
Angelica
A
Falqui
Valeria
V
Bezante
Gian Paolo
GP
Tomolillo
Cinzia
C
Deferrari
Giacomo
G
Pontremoli
Roberto
R
D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000175:diagnosis*; D001794:Blood Pressure; D002319:Cardiovascular System / Q000503:physiopathology; D004452:Echocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications*; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012680:Sensitivity and Specificity