Normalized end-systolic volume and pre-load reserve predict ventricular dysfunction following surgery for aortic regurgitation independent of body size.
Pre-operative end-systolic volume (ESV) is predictive of outcome after surgery for severe aortic regurgitation. ESV is influenced by body size and reflects function and afterload, but not pre-load. Left ventricular (LV) chamber size and function were measured in 40 patients (ages 10 to 64 years) by echocardiography before and 7 months after operation and expressed as z-scores in addition to simple indexing. A functional pre-load index, a marker of pre-load reserve, was calculated. Independent risk factors for post-operative LV dysfunction included higher post-operative ESV z-score (odds ratio [OR]: 3.3, p = 0.006) and lower functional pre-load index (OR: 0.3, p = 0.03). ESV per square meter had similar power to the ESV z-score. The ESV uncorrected for body size underestimated risk in smaller patients and overestimated risk in larger patients (p < 0.002). Pre-load reserve is an independent risk factor for LV dysfunction after aortic valve surgery in patients with severe aortic regurgitation. Failure to correct ESV for body size introduces systematic bias to risk assessment.
Green Lane Paediatric and Congenital Cardiac Service, Starship Children's Hospital, Auckland, New Zealand. tomg@adhb.govt.nz
Thomas L
TL
Gentles
John K
JK
French
Irene
I
Zeng
Paget F
PF
Milsom
A Kirsten
AK
Finucane
Nigel J
NJ
Wilson
D000293:Adolescent; D000328:Adult; D001022:Aortic Valve Insufficiency / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D049628:Body Size; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D002648:Child; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013318:Stroke Volume; D016896:Treatment Outcome; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D016277:Ventricular Function, Left; D055815:Young Adult