Noninvasive assessment of left ventricular stroke work index in patients with severe mitral regurgitation: correlation with invasive measurement and exercise capacity.
BACKGROUND
Noninvasively measured left ventricular stroke work index (LVSWI) may be an ideal indicator that can provide more relevant information about cardiac performance in severe mitral regurgitation (MR). We sought to correlate the noninvasive LVSWI with invasive measure of LVSWI and validate its clinical usefulness by comparing the noninvasive LVSWI with exercise capacity.


METHODS
Twenty-nine patients with severe MR who underwent cardiac catheterization and 61 patients with severe MR who underwent cardiopulmonary exercise test were evaluated for comparison of noninvasive LVSWI with invasive LVSWI via cardiac catheterization and peak exercise capacity, respectively.


RESULTS
Mean noninvasive LVSWI was 33.1 ± 9.7 g·m/m², which was in a good agreement with invasive LVSWI (34.9 ± 15.1 g·m/m², intraclass correlation coefficient = 0.72, P < 0.001). Noninvasive LVSWI (β= 0.35, P = 0.001) was independently related with peak exercise capacity. Indexed left atrial volume (β=-0.27, P = 0.042), mean blood pressure (β=-0.21, P = 0.030), age (β=-0.47, P < 0.001) estimated pulmonary artery systolic pressure (β=-0.21, P = 0.030) and male gender (β= 0.36, P = 0.001) were also independently associated with exercise capacity.


CONCLUSIONS
Noninvasive LVSWI has a good correlation with invasively measured LVSWI and is a clinically useful parameter for evaluating true cardiac performance in patients with severe MR.
Choi
Jin-Oh
JO
Division of Cardiology, Cardiac and Vascular Center, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Lee
Sang-Chol
SC
Choi
Soo Hee
SH
Kim
Sang Min
SM
Choi
Joon Hyouk
JH
Park
Jeong Rang
JR
Song
Bong Gun
BG
Chang
Sung-A
SA
Park
Sung-Ji
SJ
Park
Seung Woo
SW
Park
Pyo Won
PW
D004452:Echocardiography / Q000379:methods*; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications* / Q000175:diagnosis* / Q000503:physiopathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology* / Q000503:physiopathology