In patients with LF/LGAS without CR on DSE, AVR is associated with better outcome compared with medical management. Surgery should not be withheld from this subset of patients solely on the basis of lack of CR on DSE.

Background-Dobutamine stress hemodynamics (DSH) has the potential to stratify operative risk in low-gradient aortic stenosis (AS), but little is known about the relation between left ventricle contractile reserve and postoperative left ventricular ejection fraction (LVEF). We sought to assess the value of DSH to predict postoperative improvement in LVEF. Methods and Results-Sixty-six consecutive patients with symptomatic severe AS (aortic valve area Յ1 cm 2 ), LVEF Յ40%, and mean pressure gradient Յ40 mm Hg prospectively enrolled in the French multicenter study on low-gradient AS and who survived to aortic valvular replacement (AVR) were included. Preoperative contractile reserve was present in 46 patients (group I; 70%) and absent in 20 patients (group II; 30%). In the overall sample, 58% of patients improved by 2 New York Heart Association (NYHA) classes after AVR. Mean LVEF improved from 29Ϯ6% to 47Ϯ11% (PϽ0.0001). LVEF improved by Ն10 EF units in 38 patients (83%) in group I and in 13 patients (65%) in group II. Mean LVEF improvement was similar in the 2 groups (19Ϯ10% versus 17Ϯ11%; Pϭ0.54). On multivariable analysis, multivessel coronary artery disease (Pϭ0.05) and baseline mean transaortic pressure gradient (Pϭ0.01) were related to LVEF improvement, whereas contractile reserve was not. Conclusions-LVEF increases in the majority of patients with low-gradient AS who survive after AVR. Although the absence of contractile reserve on DSH is related to high operative mortality, it does not predict the absence of LVEF recovery in patients surviving to AVR. These data further support the concept that surgery should not be contraindicated on the basis of absence of contractile reserve alone.

Background-The prognostic value of dobutamine stress hemodynamic data in the setting of low-gradient aortic stenosis has been addressed in small, single-center studies. Larger studies are needed to define the criteria for selecting the patients who will benefit from valve replacement.

The regurgitant jet width at its origin measured by transesophageal Doppler color flow imaging provides a simple and useful method of measuring the severity of mitral regurgitation, and it may allow differentiation between mild and severe mitral regurgitation.

Outcomes after surgery for low-gradient AS were prospectively assessed in 152 consecutive patients from seven institutions. There were 113 men (74%); mean age was 72 years (64-76); valve area, 0.7 cm(2) (0.6-0.8); left ventricular (LV) ejection fraction 0.31 (0.25-0.37) and baseline mean transaortic pressure gradient (MPG), 30 mmHg (25-35) Among 139 patients with available prosthetic valve effective orifice area (EOA), PPM (defined by an indexed EOA < or = 0.85 cm(2)/m(2)) was present in 79 patients (57%) and had no significant impact on post-operative mortality. Independent predictors of overall mortality were LV contractile reserve [hazard ratio (HR) 0.52; 95% confidence interval (CI) 0.35-0.78; P = 0.002], associated coronary artery bypass grafting (HR 1.87; 95% CI 1.24-2.82; P =0.003), baseline MPG (per 1 mmHg decrease to 10 mmHg; HR 1.03; 95% CI 1.01-1.06; P = 0.021), previous cancer (HR 2.13; 95% CI 1.05-4.29; P = 0.037), and logistic EuroSCORE (per 1% increase; HR 1.02; 95% CI 1.01-1.04; P = 0.040). CONCLUSION In this large multicentre series of patients with low-gradient AS, we found that PPM (moderate in most cases) had no influence on post-operative mortality. Therefore, the performance of more complex interventions in order to avoid moderate PPM may not be justified in the setting of low-gradient AS, because their higher risk probably outweighs the expected benefit.

No abstract

In patients with valvular regurgitation, the regurgitation jet can be observed by Doppler color flow imaging. Vena contracta is defined as the narrowest part of the jet, just distal to the regurgitant orifice. Vena contracta dimensions reflect the severity of regurgitation. Vena contracta diameter, usually easy to measure in clinical practice, is well correlated with the effective regurgitant orifice area and the regurgitant volume. Cutoff values have been determined to identify severe regurgitation for mitral, aortic, and tricuspid valves. In clinical practice, determination of vena contracta diameter is a useful and simple method for assessment of valvular regurgitation. In the future, assessment of complex jet regurgitations will probably benefit from the contribution of three-dimensional Doppler flow imaging, which should improve the performances of the method.

Exercise transthoracic echocardiography (ExE) was recently proposed to evaluate tolerance and help risk stratification of mitral regurgitation (MR). Few data are available on the feasibility of Doppler echocardiographic recordings at exercise in daily practice in both secondary and primary MR. Comprehensive resting and ExE were performed in 72 unselected patients (age 59 ± 15 years, 62 % men), with no or minimal symptoms, with at least moderate (mean effective regurgitant orifice area (ERO) = 36 ± 14 mm(2)) primary or secondary MR in two French university hospitals. At rest, quantification of ERO was more challenging in semi-supine position than in classic left lateral decubitus position (55/72; 76 % vs 66/72; 92 %; p = 0.012), particularly in mitral valve (MV) prolapse (35/47; 74 %). During exercise, ERO was only obtained in 30/55 (55 %) patients and was more difficult to assess in MV prolapse than in rheumatic or ischemic MR (respectively in 43, 67 and 88 %, p = 0.046). At peak exercise, ERO was more frequently obtained in symptomatic than asymptomatic patients (77 vs 37 %, p = 0.046) because peak heart rate was lower (113 ± 20 vs 133 ± 23 bpm, p = 0.026). Systolic pulmonary artery pressure (SPAP) was obtained in 69 patients (96 %) at rest and in 60 patients (83 %) at peak exercise (Pex). LV contractile reserve (CR), monitored in all patients (100 %), was found in 51/72 patients (71 %). In daily ExE, monitoring of the CR and SPAP appeared less challenging than MR quantification by the PISA method. Monitoring of ERO was more feasible in ischemic MR than in MV prolapse.