Mario Sénéchal

Preoperative Posterior Leaflet Angle Accurately Predicts Outcome After Restrictive Mitral Valve Annuloplasty for Ischemic Mitral Regurgitation

Background— Ischemic mitral regurgitation (MR) often persists after restrictive mitral valve annuloplasty, in which case it is associated with worse clinical outcomes. The goal of the present study was to determine whether persistence of MR and/or clinical outcome could be predicted from preoperative analysis of mitral valve configuration. Methods and Results— In 51 consecutive patients undergoing restrictive annuloplasty for ischemic MR, posterior leaflet (PL) angle, anterior leaflet angle, coaptation distance, and tenting area were quantified by echocardiography before surgery (6±3 days), and MR severity was assessed before and early after surgery (9±4 days). Postoperatively, persistence of mild to moderate MR (vena contracta >3 mm) was observed in 11 (22%) of the patients. The best predictor of postoperative persistence of MR was a PL angle ≥45 degrees (sensitivity 100%, specificity 97%, positive predictive value 92%, negative predictive value 100%). Patients with persistent MR had markedly lower 3-year event-free survival (26±20%) compared with those with nonpersistent MR (75±12%, P=0.01). Preoperative presence of a PL angle ≥45 degrees also was associated with a markedly lower 3-year event-free survival (22±17% versus 76±12%; P<0.001). Conclusions— In patients undergoing restrictive annuloplasty for ischemic MR, persistence of MR and 3-year event-free survival can accurately be predicted by preoperative analysis of mitral valve configuration. Patients with a PL angle ≥45 degrees (ie, with high PL restriction) should thus be considered poor candidates for this procedure, and concomitant or alternative procedures should be contemplated.

Outcome of Patients With Aortic Stenosis, Small Valve Area, and Low-Flow, Low-Gradient Despite Preserved Left Ventricular Ejection Fraction

OBJECTIVES The aim of this case match study was to compare the outcome of patients with paradoxical low-flow (left ventricular ejection fraction [LVEF] ≥50% but stroke volume index <35 ml/m(2)), low-gradient (mean gradient [MG] <40 mm Hg), a priori severe (aortic valve area [AVA] ≤1.0 cm(2)) aortic stenosis (AS) (PLG-SAS group) with that of patients with a severe AS (AVA ≤1.0 cm(2)) and consistent high-gradient (MG ≥40 mm Hg) (HG-SAS group) and with that of patients with a moderate AS (AVA >1.0 cm(2) and MG <40 mm Hg) (MAS group). BACKGROUND In patients with preserved LVEF, a discordance between the AVA (in the severe range) and the gradient (in the moderate range) raises uncertainty with regard to the actual severity of the stenosis and thus the therapeutic management of the patient. METHODS In a prospective cohort of AS patients with LVEF ≥50%, we identified 187 patients in the PLG-SAS group. These patients were retrospectively matched: 1) according to the gradient, with 187 patients with MAS; and 2) according to the AVA, with 187 patients with HG-SAS. RESULTS Patients with PLG-SAS had reduced overall survival (1-year: 89 ± 2%; 5-year: 64 ± 4%) compared with patients with HG-SAS (1-year: 96 ± 1%; 5-year: 82 ± 3%) or MAS (1-year: 96 ± 1%; 5-year: 81 ± 3%). After adjustment for other risk factors, patients with PLG-SAS had a 1.71-fold increase in overall mortality and a 2.09-fold increase in cardiovascular mortality compared with the 2 other groups. Aortic valve replacement was significantly associated with improved survival in the HG-SAS group (hazard ratio: 0.18; p = 0.001) and in the PLG-SAS group (hazard ratio: 0.50; p = 0.04) but not in the MAS group. CONCLUSIONS Prognosis of patients with paradoxical low-flow, low-gradient severe AS was definitely worse than those with high-gradient severe AS or those with moderate AS. The finding of a low gradient cannot exclude the presence of a severe stenosis in a patient with a small AVA and preserved LVEF and should mandatorily prompt further investigation.

Restrictive annuloplasty for ischemic mitral regurgitation may induce functional mitral stenosis.

OBJECTIVES The purpose of this study was to evaluate mitral valve hemodynamic performance and functional capacity in patients with ischemic mitral regurgitation (MR) who underwent restrictive mitral valve annuloplasty (MVA). BACKGROUND Restrictive MVA combined with coronary artery bypass graft is the conventional approach for the surgical management of patients with ischemic MR. We hypothesized that the restriction of the mitral annulus could cause an obstruction to antegrade mitral flow that may affect the patients functional capacity. METHODS A dobutamine stress echocardiography (DSE) and a 6-min walk test (6MWT) were performed in 24 patients with ischemic MR 13 +/- 3 months after restrictive MVA and coronary artery bypass graft and in 20 control patients with coronary artery disease matched for age, gender, and left ventricular ejection fraction. RESULTS None of the 24 MVA patients had significant MR after operation. Compared with control patients, MVA patients had significantly (p < 0.001) higher resting and stress peak gradients (rest: 13 +/- 4 mm Hg vs. 4 +/- 1 mm Hg; DSE: 19 +/- 6 mm Hg vs. 6 +/- 3 mm Hg) and systolic pulmonary arterial pressures (PAP) (rest: 42 +/- 13 mm Hg vs. 27 +/- 8 mm Hg; DSE: 58 +/- 12 mm Hg vs. 38 +/- 11 mm Hg) and lower (p = 0.01) 6MWT distance (358 +/- 95 m vs. 433 +/- 61 m). The resting peak mitral gradient correlated with systolic PAP (r = -0.67; p = 0.001) and 6MWT distance (r = -0.78; p < 0.0001) in the MVA group. CONCLUSIONS The results suggest that performing a restrictive MVA in patients with ischemic MR may create a functional mitral stenosis. This hemodynamic sequel is associated with higher PAP and a worse functional capacity.

Mitral Repair versus Replacement for Ischemic Mitral Regurgitation Comparison of Short-Term and Long-Term Survival

Background— When compared to mitral valve replacement (MVR), mitral valve repair (MVRp) is associated with better survival in patients with organic mitral regurgitation (MR). However, there is an important controversy about the type of surgical treatment that should be used in patients with ischemic MR. The objective of this study was to compare the postoperative outcome of MVRp versus MVR in patients with ischemic MR. Methods and Results— Preoperative and operative data of 370 patients with ischemic MR who underwent mitral valve surgery were prospectively collected and retrospectively analyzed. MVRp was performed in 50% of patients (n=186) and MVR in 50% (n=184). Although operative mortality was significantly lower after MVRp compared to MVR (9.7% versus 17.4%; P=0.03), overall 6-year survival was not statistically different between procedures (73±4% versus 67±4%; P=0.17). After adjusting for other risk factors and propensity score, the type of procedure (MVRp versus MVR) did not come out as an independent predictor of either operative (OR, 1.5; 95% CI, 0.7–2.9; P=0.34) or overall mortality (HR, 1.2; 95% CI, 0.7–1.9; P=0.52). Conclusion— As opposed to what has been reported in patients with organic MR, the results of this study suggest that MVRp is not superior to MVR with regard to operative and overall mortality in patients with ischemic MR. These findings provide support for the realization of a randomized trial comparing these 2 treatment modalities.

Ischemic Mitral Regurgitation: A Complex Multifaceted Disease

Ischemic mitral regurgitation (MR) is a complex multifactorial disease that involves global and regional left ventricular remodeling as well as dysfunction and distortion of the components of the mitral valve including the chordae, annulus and leaflets. This is a frequent (13–59%) complication of myocardial infarction, which is associated with a poor prognosis. The suboptimal results obtained with the most commonly used surgical strategy, that is, restrictive annuloplasty combined with coronary artery bypass graft, emphasize the need to develop alternative or concomitant surgical techniques that directly target the causal mechanisms of the disease. A comprehensive assessment of mitral valve configuration and left ventricular geometry and function prior to surgery as well as an accurate quantification of MR severity at rest and during exercise may help improve patient risk stratification and better individualize the surgical strategy based on the patient’s specific characteristics. The purpose of this review is to summarize the current state of knowledge with regard to the definition, prevalence, mechanisms, outcome and treatment of ischemic MR.

Validation of Conventional and Simplified Methods to Calculate Projected Valve Area at Normal Flow Rate in Patients With Low Flow, Low Gradient Aortic Stenosis: The Multicenter TOPAS (True or Pseudo Severe Aortic Stenosis) Study

BACKGROUND It has been previously demonstrated that a new index of aortic stenosis (AS) severity derived from dobutamine stress echocardiography (DSE), the projected aortic valve area (AVA) at a normal transvalvular flow rate (AVA(proj)), is superior to traditional Doppler echocardiographic indices to discriminate true severe from pseudosevere low-gradient AS. The objectives of this study were to prospectively validate the diagnostic and prognostic value of AVA(proj) in a large series of patients and to propose a new clinically applicable simplified method to estimate AVA(proj). METHODS AVA(proj) was calculated in 142 patients with low-flow AS using 2 methods. In the conventional method, AVA was plotted against mean transvalvular flow (Q) at each stage of DSE, and AVA at a standardized flow rate of 250 ml/s was projected from the slope of the regression line fitting the plot of AVA versus Q: AVA(proj) = AVA(rest) + slope x (250 - Q(rest)). In the simplified method, using this equation, the slope of the regression line was estimated by dividing the DSE-induced change in AVA from baseline to the peak stage of DSE by the change in Q. RESULTS There was a strong correlation between AVA(proj) calculated by the two methods (r = 0.95, P < .0001). Among the 142 patients, 52 underwent aortic valve replacement and had underlying AS severity assessed by the surgeon. Conventional and simplified AVA(proj) demonstrated similar performance in discriminating true severe from pseudosevere AS (percentage of correct classification of AVA(proj) < or = 1 cm(2), 94% and 92%, respectively) and were superior to traditional dobutamine stress echocardiographic indices (percentage of correct classification, 60%-77%). Both conventional and simplified AVA(proj) correlated well with valve weight (r = 0.52 and r = 0.58, respectively), whereas traditional dobutamine stress echocardiographic indices did not. In the 84 patients who were treated medically, conventional AVA(proj) < or = 1.2 cm(2) (hazard ratio, 1.65; P = .02) and simplified AVA(proj) < or = 1.2 cm(2) (hazard ratio, 2.70; P < .0001) were independent predictors of mortality. Traditional dobutamine stress echocardiographic indices were not predictive. CONCLUSION In patients with low-flow AS, AVA(proj) better predicts underlying AS severity and patient outcomes than traditional dobutamine stress echocardiographic indices. Simplified AVA(proj) is easier to calculate than conventional AVA(proj), facilitating the use of AVA(proj) in clinical practice.

Usefulness of Global Left Ventricular Longitudinal Strain for Risk Stratification in Low Ejection Fraction, Low-Gradient Aortic Stenosis Results From the Multicenter True or Pseudo-Severe Aortic Stenosis Study

Background—The objective of this study was to examine the impact of left ventricular (LV) global longitudinal strain (GLS) measured at rest and at dobutamine stress echocardiography on the outcome of patients with low LV ejection fraction and low-gradient aortic stenosis. Methods and Results—Among the 202 patients with low LV ejection fraction (⩽40%), low-gradient aortic stenosis (mean transvalvular gradient <40 mm Hg and indexed aortic valve area ⩽0.6 cm2/m2) prospectively enrolled in the multicenter True or Pseudo-Severe Aortic Stenosis study, 126 patients with resting GLS and 73 patients with stress GLS available were included in this substudy. Three-year survival rate was 49% in patients with rest GLS <|9|% compared with 68% in patients with GLS >|9|% (P=0.02). In a multivariable Cox model adjusted for age, coronary artery disease, projected aortic valve area at a normal flow rate and type of treatment (aortic valve replacement versus conservative), rest GLS <|9|% (hazard ratio, 2.18; P=0.015) remained independently associated with all-cause mortality. GLS <|10|% measured during dobutamine stress echocardiography was also independently associated with mortality (hazard ratio, 2.67; P=0.01). In the subset of patients with stress GLS (n=73), the &khgr;2 of the multivariable model to predict all-causes mortality was 21.96 for stress GLS versus 17.78 for rest GLS. Conclusions—GLS is independently associated with mortality in patients with low LV ejection fraction, low-gradient aortic stenosis. Stress GLS measured during dobutamine stress echocardiography may provide incremental prognostic value beyond GLS measured at rest. Hence, measurement of GLS at rest and during dobutamine stress echocardiography may be helpful to enhance risk stratification in low LV ejection fraction, low-gradient aortic stenosis. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01835028.

Continued Global Left Ventricular Remodeling Is Not the Sole Mechanism Responsible for the Late Recurrence of Ischemic Mitral Regurgitation after Restrictive Annuloplasty

BACKGROUND Recurrence of ischemic mitral regurgitation (MR) late after mitral valve annuloplasty (MVA) is generally believed to be due to continued left ventricular (LV) remodeling. The aim of this study was to determine if other mechanisms could be involved in MR recurrence. METHODS AND RESULTS Preoperative (10 +/- 11 days), early postoperative (6 +/- 4 days), and late postoperative (1.5 +/- 0.6 years) transthoracic echocardiograms of 26 patients (68 +/- 7 years, 23 male [88%]) who underwent restrictive MVA and coronary artery bypass graft surgery were reviewed. Mitral valve geometry and MR severity were assessed using anterior leaflet and posterior leaflet angles and the anterior leaflet concavity area, defined as the area enclosed between the AL and a line connecting the tip of the leaflet and its basal insertion at the annulus. Recurrent MR (vena contracta > 3 mm) was observed in 10 patients (38.5%). Among the 10 patients with recurrent MR, 5 had significant late postoperative increase in LV end-systolic (preoperative: 66 +/- 27 mL; early postoperative: 61 +/- 11 mL; late postoperative: 89 +/- 30 mL, P = .04) and end-diastolic (preoperative: 122 +/- 39 mL; early postoperative: 108 +/- 22 mL; late postoperative: 139 +/- 39 mL, P = .04) volumes and PL angle (early postoperative: 65 +/- 12 degrees; late postoperative: 77 +/- 8 degrees, P = .04), suggesting that recurrent MR is related to continued adverse LV remodeling and ensuing worsening of leaflet tethering. However, in the remaining 5 patients with recurrent MR, there was no significant change in LV end-systolic and end-diastolic volumes, but there was a significant increase in anterior leaflet concavity area (early postoperative: 6 +/- 11 mm(2); late postoperative: 50 +/- 3 mm(2), P = .012). CONCLUSION Although recurrent MR is often associated with continued adverse LV remodeling after restrictive MVA, this mechanism fails to explain all recurrences. In the absence of LV dilatation, recurrent MR might be explained by localized LV remodeling in the vicinity of papillary muscles resulting in increased AL tethering at the bending point.

Two-dimensional strain for the assessment of left ventricular function in low flow-low gradient aortic stenosis, relationship to hemodynamics, and outcome: a substudy of the multicenter TOPAS study.

Background— Decision making in patients with low flow–low gradient aortic stenosis mainly depends on the actual stenosis severity and left ventricular function, which is of prognostic importance. We used 2-dimensional strain parameters measured by speckle tracking at rest and during dobutamine stress echocardiography to document the extent of myocardial impairment, its relationship with hemodynamic variables, and its prognostic value. Methods and Results— In 47 patients with low flow–low gradient aortic stenosis, global peak systolic longitudinal strain (PLS) and peak systolic longitudinal strain rate (PLSR) were analyzed. PLS and PLSR at rest and peak stress were −7.56±2.34% and −7.41±2.89% (P=NS) and −0.38±0.12 s−1 and −0.53±0.18 s−1 (P<0.001), respectively. PLS and PLSR inversely correlated with left ventricular ejection fraction at rest (r s=−0.52; P<0.0001 and −0.38; P=0.008) and peak stress (r s=−0.39; P=0.007 and −0.45; P=0.002). The overall 2-year survival rate was 60%. Univariate predictors of survival were peak stress left ventricular ejection fraction (P=0.0026), peak stress PLS (P=0.0002), peak stress PLSR (P<0.0001), and N-terminal pro–B-type natriuretic peptide (P<0.0001). Three hierarchically nested multivariable Cox regression models were constructed—model 1: The Society of Thoracic Surgeons score as an indicator of clinical risk (area under the receiver operating characteristic=0.59); model 2: model 1+N-terminal pro–B-type natriuretic peptide and peak stress left ventricular ejection fraction (area under the receiver operating characteristic=0.83; incremental P<0.0001); model 3: model 2+peak stress PLSR (area under the receiver operating characteristic=0.89; incremental P=0.035). Conclusions— In patients with low flow–low gradient aortic stenosis, 2-dimensional strain parameters are strong predictors of outcome. Peak stress PLSR may add incremental prognostic value beyond what is obtained from N-terminal pro–B-type natriuretic peptide and peak stress left ventricular ejection fraction. A larger study is needed to confirm these findings.

End‐stage renal failure and cardiac mortality after heart transplantation

Abstract:  Background:  Coronary artery disease (CAD) is the leading cause of mortality after the first year of heart transplantation. End‐stage renal failure (ESRF) is more frequent because of long‐term survival. Impact of ESRF on cardiac mortality in heart transplant patients is unappreciated. The hypothesis of accelerated CAD in uremic patients has been suggested.