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Reliability of new and old Doppler echocardiographic indexes of the severity of aortic stenosis in patients with a low cardiac output.

Abstract

BACKGROUND
In addition to the conventional "flow-corrected" parameters (continuity equation and aortic valve resistance), new and simpler Doppler echocardiographic indexes of the severity of aortic stenosis have recently been introduced. These measures can be classified as "function-corrected" indexes (fractional shortening-velocity ratio and ejection fraction-velocity ratio) and "pressure-corrected" indexes (percent stroke work loss). Little information however is available about the diagnostic accuracy of each of these parameters in identifying patients with severe aortic stenosis in low-flow states, in which the diagnosis and clinical decision-making are more difficult and challenging.
METHODS
We analyzed 161 patients with aortic stenosis (96 males, 65 females, mean age 68 +/- 9 years) and a low cardiac output (thermodilution cardiac index < or = 2.5 l/min/m2). All patients underwent both cardiac catheterization and echocardiography within 48 hours one of the other. The invasive Gorlin valve area was used as gold standard (severe aortic stenosis = Gorlin < or = 0.8 cm2). Echocardiographic indexes were assessed by an investigator who was unaware of the hemodynamic findings.
RESULTS
The mean Gorlin aortic valve area was 0.7 +/- 0.3 cm2; cardiac catheterization allowed the identification of 129 patients with severe aortic stenosis and of 32 with mild-to-moderate aortic stenosis. The diagnostic accuracy of the Doppler gradient alone was low (sensitivity 55%). The best linear correlation with the Gorlin value was found using the "function-corrected" ejection fraction-velocity ratio (r = 0.85). Similarly, the best combination of sensitivity and specificity in identifying patients with severe aortic stenosis, as assessed by cardiac catheterization, was observed using the ejection fraction-velocity ratio (sensitivity 87%, specificity 88%).
CONCLUSIONS
In patients with aortic stenosis and a low cardiac output, the "function-corrected" ejection fraction-velocity ratio offers the better diagnostic accuracy, as compared with the cardiac catheterization valve area calculation.

Authors

Antonini-Canterin F, Huang G, Cervesato E, Faggiano P, Pavan D, Piazza R, Burelli C, Cassin M, Macor F, Zardo F, Nicolosi GL

Institution

Division of Cardiology, A.R.C., S. Maria degli Angeli Hospital, Pordenone, Italy. antcant@adriacom.it

Source

Italian heart journal : official journal of the Italian Federation of Cardiology 3:4 2002 Apr pg 248-55

MeSH

Aged
Aortic Valve
Aortic Valve Stenosis
Blood Flow Velocity
Cardiac Output, Low
Echocardiography, Doppler
Female
Heart Catheterization
Hemodynamics
Humans
Male
Myocardial Contraction
ROC Curve
Sensitivity and Specificity

Pub Type(s)

Journal Article

Language

eng

PubMed ID

12025374