PMC

Right ventricular ejection fraction versus pulmonary regurgitant fraction. (A) Ejection fraction and pulmonary regurgitant fraction determined by angiocardiography or densitometry. (B) Ejection fraction and pulmonary regurgitant fraction determined by MRI.

Scatter plot of diastolic-systolic time-velocity integral (DSTVI) vs. pulmonary regurgitant fraction (r=0.62, p= 0.0001).

a Regurgitant volume as a function of regurgitant severity; b left ventricular stroke work; and c stroke volume and ejection fraction as a function of regurgitant volumes under aortic and mitral regurgitation conditions; d left ventricular stroke volume as a function of left ventricular stroke work. AR aortic regurgitation; MR mitral regurgitation; SV stroke volume; EF ejection fraction; RV regurgitant volume; RF regurgitant fraction

Aortic regurgitant fraction was the best predictor of clinical outcome; area under the curve (AUC) on receiver operating characteristics analysis 0.93 (p<0.0001), with a specificity of 93% and sensitivity of 78% for predicting the progression to symptoms and surgery. Survival without surgery was 88% for patients with a regurgitant fraction <37%, compared to 6% for those with a regurgitant fraction ≥37% (see figure ). Regurgitant volume >38mls and regurgitant volume index >25mls/m² were also good predictors (AUC 0.91 and 0.90 respectively), though regurgitant fraction had significantly greater predictive power (odds ratio 1.26 compared to 1.09 for regurgitant volume). LV volumetric indices also predicted outcome, but less strongly than measures of regurgitation: LV end-diastolic volume >267mls (AUC 0.85), LV end-systolic volume >88mls (AUC 0.78). Regurgitant fraction and volume were the only independent outcome predictors on multiple logistic regression analysis. The predictive ability of CMR applied to patients with both moderate and severe aortic regurgitation on echocardiography. Supporting data also comes from a comparison with patients already planning to undergo surgery at the time of CMR scanning, which showed similar regurgitant fractions in the surgical group (mean ±SD: 45.4 ±12.1%) compared to the initially asymptomatic patients who developed symptoms or other indications for surgery (42.8 ±10.4%); p=0.32. Subjects who remained asymptomatic had a significantly lower regurgitant fraction: 25.3 ±8.6% (p<0.0001 vs. both the planned surgical group and the symptom progression group)