Prognostic value of exercise stress echocardiography in patients with secondary mitral regurgitation: a long-term follow-up study.

BACKGROUND: Secondary mitral regurgitation (MR) remains a challenging problem in the diagnosis and treatment of patients with heart failure. Although it is well known that secondary MR is dynamic, the impact of the severity of MR during exercise on long-term outcome has not been fully evaluated. The aim of the present study was to investigate the prognostic value of exercise stress echocardiography (ESE) in patients with secondary MR. METHODS: This prospective study included 118 consecutive patients with secondary MR and left ventricular dysfunction (mean ejection fraction at rest: 38 ± 14%) who underwent semi-supine ESE. Their major cardiovascular events (MACE) including cardiac death were followed up for a median of 41.7 (range: 6-128) months. RESULTS: MR significantly increased from rest to exercise (effective regurgitant orifice: 0.18 ± 0.09 vs. 0.25 ± 0.12 cm2, P < 0.001). The prevalence of severe MR was higher during exercise than those at rest (37% vs. 56%, P < 0.001). During follow-up, MACE occurred in 49 patients (41.5%) including 12 cardiac deaths. Cox proportional-hazard multivariate analysis revealed that older age and MR severity during exercise were significantly associated with increased risk of MACE (hazard ratio: 1.04 and 8.4, respectively, both P < 0.05). CONCLUSIONS: ESE provides prognostic information in patients with secondary MR that is useful for predicting long-term outcome.

Direct Comparison of Severity Grading Assessed by Two-Dimensional, Three-Dimensional, and Doppler Echocardiography for Predicting Prognosis in Asymptomatic Aortic Stenosis.

BACKGROUND: Reliable assessment of aortic stenosis (AS) severity relies on stroke volume (SV) determination using Doppler echocardiography, but it can also be estimated with two-dimensional/three dimensional echocardiography (2DE/3DE). The aim of this study was to compare SV measurements and AS subgroup classifications among the three modalities and determine their prognostic strength in asymptomatic AS. METHODS: We prospectively enrolled 359 patients with asymptomatic AS. SV was determined using three methods, and the patients were divided into four AS subgroups according to indexed aortic valve area (iAVA) and SV index (SVI) determined by each method and mean pressure gradient. The primary end point was major adverse cardiovascular events (MACEs), which included cardiac death, ventricular fibrillation, heart failure, and aortic valve replacement. We also assessed the presence or absence of upper septal hypertrophy. RESULTS: Doppler-derived SVI was significantly larger than that derived from 2DE/3DE with modest correlations (r = 0.33 and 0.47). Thus, group classification varied substantially by modality. During the median follow-up period of 17 months, 112 patients developed a major adverse cardiovascular event. Although iAVA assessed by Doppler echocardiography had a significantly better net reclassification improvement compared with iAVA by 2DE or 3DE, prognostic values were nearly identical among the three methods. Ventricular septal geometry affected the accuracy of risk stratification. CONCLUSIONS: AS severity grading varied considerably according to the methods applied for calculating SV. Thus, SV measurements are not interchangeable, even though their prognostic power is similar. Hence, examiners should select one of the three methods to assess AS severity and should use the same method in longitudinal examinations.

Geometry of the left ventricular outflow tract assessed by 3D TEE in patients with aortic stenosis: impact of upper septal hypertrophy on measurements of Doppler-derived left ventricular stroke volume.

BACKGROUND: It is unclear how upper septal hypertrophy (USH) affects Doppler-derived left ventricular stroke volume (SV) in patients with AS. The aims of this study were to: (1) validate the accuracy of 3D transesophageal echocardiography (TEE) measurements of the left ventricular outflow tract (LVOT), (2) evaluate the differences in LVOT geometry between AS patients with and without USH, and (3) assess the impact of USH on measurement of SV. METHODS: In protocol 1, both 3D TEE and multi-detector computed tomography were performed in 20 patients with AS [aortic valve area (AVA) ≤ 1.5 cm2]. Multiplanar reconstruction was used to measure the LVOT short and long diameters in four parts from the tip of the septum to the annulus. In protocol 2, the same 3D TEE measurements were performed in AS patients (AVA ≤ 1.5 cm2, n = 129) and controls (n = 30). We also performed 2D and 3D transthoracic echocardiography in all patients. RESULTS: In protocol 1, excellent correlations of LVOT parameters were found between the two modalities. In protocol 2, the USH group had smaller LVOT short and long diameters than the non-USH group. Although no differences in mean pressure gradient, or SV calculated with the 3D method existed between the two groups, the USH group had greater SV calculated with the Doppler method (73 ± 15 vs. 66 ± 15 ml) and aortic valve area (0.89 ± 0.26 vs. 0.73 ± 0.24 cm2) than the non-USH group. CONCLUSIONS: 3D TEE can provide a precise assessment of the LVOT in AS. USH affects the LVOT geometry in patients with AS, which might lead to inaccurate assessments of disease severity.