Tei-index in symptomatic patients with primary and secondary mitral regurgitation

Abstract

Significant mitral regurgitation (MR) may result from primary valve dysfunction or develop secondary to ischemic or dilated cardiomyopathy. The index ‘isovolumic contraction time and isovolumic relaxation time divided by ejection time’ (ICT + IRT/ET, ‘Tei-index’) is a well established measure of global cardiac function in patients with dilated cardiomyopathy and cardiac amyloidosis. We sought to define the diagnostic value of the Tei-index in patients with significant MR of various origin. Sixteen asymptomatic control subjects (8 male (m)/8 female (f), age 62 ± 8 years, control group), 12 patients with primary MR (PMR) (mean grade 3.1 ± 0.3, due to rupture of the chordae tendineae (n = 2), flail leaflet (n = 1), valve prolaps (n = 6) or rheumatic degeneration (n = 3), 6 m/6 f, age 58 ± 18 years, NYHA class 2.5 ± 0.3, PMR group) and 25 patients with secondary MR (SMR) (mean grade 3.1 ± 0.3; due to ischemic (n = 14) or dilated cardiomyopathy (n = 10), 19 m/6 f, age 60 ± 11 years, NYHA class 3.1 ± 0.5, SMR group) underwent conventional two-dimensional (2D) and Doppler echocardiographic examination including measurement of the Tei-index. In the SMR group, left ventricular ejection fraction was reduced compared to the control and the PMR group (29 ± 13% vs. 59 ± 8% and 59 ± 8%, p < 0.001 for both comparisons). The E/A ratio was elevated in PMR and SMR groups in comparison to the control group (1.74 ± 0.44 and 1.70 ± 0.45 vs. 1.09 ± 0.28, p < 0.05). The Tei-index was easily and reproducibly measured in all study subjects. The mean value of the index was significantly elevated in the SMR group compared to control and PMR groups (0.87 ± 0.3 vs. 0.42 ± 0.07 and 0.38 ± 0.05, p < 0.001). The difference between the control group and the PMR group did not reach statistical significance. In MR patients, receiver operating characteristic curve analysis for the Tei-index yielded an area under the curve of 0.96 ± 0.03 for separating the PMR and the SMR group. Using a Tei-index ≥ 0.51 as a cutpoint, SMR was identified with a sensitivity of 92% and a specificity of 88%. In MR patients, a significant correlation between left ventricular end-systolic volume and the Tei-index was observed (r = 0.71, p < 0.01). The Tei-index is a feasible and sensitive indicator of overall cardiac dysfunction in severely symptomatic patients with significant MR secondary to ischemic or dilated cardiomyopathy. The index is in the normal range in symptomatic patients with PMR and preserved systolic function. The Tei-index differentiates between patients with SMR and PMR and may be useful in the work-up of such patients.