Overestimation of severity of ischemic/functional mitral regurgitation by color Doppler jet area

Color Doppler jet analysis is widely used to characterize the degree of mitral regurgitation (MR), but the validity of this approach in patients with ischemic or functional MR has not been established. It was hypothesized that color Doppler jet area overestimates the magnitude of MR of ischemic or functional origin. The severity of isolated MR in 170 patients was measured by using Doppler/echocardiography. Group 1 (n = 58) included patients with ischemic or functional MR, and group 2 (n = 112) included those with organic MR. The régurgitant jet area and 2 methods of quantitation (quantitative Doppler and quantitative 2-dimensional echocardiography) were measured simultaneously. In group 1, color jet area was larger (10.6 ± 5.3 vs 8.2 ±5.3 cm², p = 0.004) but corresponded to a smaller regurgitant volume and regurgitant fraction by quantitative Doppler (28 ± 14 vs 55 ± 46 ml, p = 0.0006, and 31 ± 12% vs 38 ± 20%, p = 0.02, respectively) and by quantitative 2-dimensional echocardiography (22 ± 11 vs 49 ± 40 ml, p < 0.0001, and 27 ± 12% vs 36 ± 20%, p = 0.005, respectively). Enlargement of the left-sided chambers was more marked in group 1. In ischemic/functional MR, the diagnosis of severe regurgitation by color Doppler (jet area >8 cm²) was confirmed by quantitative methods (regurgitant fraction ≥50%) in only 6% to 11% of patients, whereas it was confirmed in 60% to 73% of patients with organic MR (p < 0.001). In conclusion, in ischemic/functional MR versus organic MR, (1) a larger color jet area corresponds to a smaller regurgitant volume and fraction, and (2) contrary to established criteria most large jets (>8 cm²) do not correspond to severe MR. Therefore, quantitative methods should be used routinely to determine the severity of ischemic/functional MR.