Usefulness of exercise-stress echocardiography for risk stratification of true asymptomatic patients with aortic valve stenosis.

Aims Abnormal exercise test defined as the occurrence of exercise limiting symptoms, fall in blood pressure below baseline, or complex ventricular arrhythmias is useful to predict clinical events in asymptomatic patients with aortic stenosis (AS). The purpose of this study was to determine whether exercise-stress echocardiography (ESE) adds any incremental prognostic value to resting echocardiography in patients with AS having a normal exercise response. Methods and results One hundred and eighty-six asymptomatic patients with at least moderate AS and preserved LV ejection fraction (>/=50%) were assessed by Doppler-echocardiography at rest and during a maximum ramp semi-supine bicycle exercise test. Fifty-one (27%) patients had an abnormal exercise test and were excluded from the present analysis. Among the 135 patients with normal exercise test, 67 had an event (aortic valve replacement motivated by symptoms or cardiovascular death) at a mean follow-up of 20 +/- 14 months. The variables independently associated with events were: age >/=65 years [hazard ratio (HR) = 1.96; 95% confidence interval (CI): 1.15-3.47; P = 0.01], diabetes, (HR = 3.20; 95% CI: 1.33-6.87; P = 0.01), LV hypertrophy (HR = 1.96; 95% CI: 1.17-3.27; P = 0.01), resting mean gradient >35 mmHg (HR = 3.60; 95% CI: 2.11-6.37; P < 0.0001), and exercise-induced increase in mean gradient >20 mmHg (HR = 3.83; 95% CI: 2.16-6.67; P < 0.0001). Conclusion The exercise-induced increase in transvalvular gradient may be helpful to improve risk stratification in asymptomatic AS patients with normal exercise response. These results thus suggest that ESE may provide additional prognostic information over that obtained from standard exercise testing and resting echocardiography.

Left Ventricular Thrombus in Myocardial Infarction After Successful Primary Percutaneous Coronary Intervention: Prevalence and Predictors-A Middle Eastern Single-Centre Experience.

BACKGROUND: Left ventricular thrombus (LVT) is a well-recognized complication of myocardial infarction that affects patient outcomes and warrants screening. METHODS: This retrospective study included 308 consecutive patients who presented with acute ST-elevation myocardial infarction and were treated with primary percutaneous coronary intervention. RESULTS: Early screening for LVT by echocardiography and cardiac magnetic resonance revealed the following: LVT (+) group (36 patients [11.7%]) and LVT (-) group (272 patients [88.3%]). The 2 powerful independent variables associated with LVT formation were left anterior descending-related infarct (odds ratio, 10.17; P < 0.0001) and severe left ventricular systolic dysfunction (odds ratio, 8.3; P = 0.0001). The lower the left ventricular ejection fraction, the higher the risk of LVT was. Multivessel coronary artery disease and the type of early invasive strategy (culprit lesion only vs complete revascularization) were not predictive of LVT. The impact of environment (i.e., hot climate, exercise) and dehydration on the risk of LVT formation is uncertain. CONCLUSION: Early LVT formation is a frequent complication in acute ST-elevation myocardial infarction despite timely intervention. Its independent predictors are left anterior descending-related infarct and severe left ventricular systolic dysfunction. In patients with multivessel coronary artery disease, there was no significant difference between lesion-only culprits and complete revascularization in reducing the risk of LVT development. Further studies in larger numbers of patients are needed because of the uncertainties regarding the links between the biological effects of the environment and the risk of LVT formation.

CONTEXTE: La thrombose du ventricule gauche (TVG) est une complication notoire de l'infarctus du myocarde qui influe sur l'évolution de l'état de santé du patient et nécessite un dépistage. MÉTHODOLOGIE: Cette étude rétrospective inclu 308 patients consécutifs ayant subi un infarctus aigu du myocarde avec élévation du segment ST et traité par une angioplastie coronaire percutanée primaire. RÉSULTATS: Le dépistage précoce de la TVG par échocardiographie et résonance magnétique cardiaque a révélé que 36 patients (11,7 %) présentaient une TVG, et 272 patients (88,3 %) n'en présentaient pas. Les deux variables indépendantes fortement associées à la TVG étaient l'infarctus dans le territoire de l'artère interventriculaire antérieure (rapport de cotes : 10,17; p < 0,0001) et une sévère dysfonction systolique ventriculaire gauche (rapport de cotes : 8,3; p = 0,0001). Plus la fraction d'éjection ventriculaire gauche était faible, plus le risque de TVG était élevé. La présence d'une coronaropathie multitronculaire et le type de stratégie de perfusion précoce (revascularisation de la coronaire responsable seulement ou revascularisation complète) ne permettaient pas de prédire la TVG. L'impact des facteurs environnementaux (p. ex. chaleur, effort physique) et de la déshydratation sur le risque de TVG est mal connu. CONCLUSION: La TVG précoce demeure une complication fréquente de infarctus aigu du myocarde avec elevation du segment ST malgré une intervention rapide. L'infarctus lié a l'artère interventriculaire antérieure et une sévère dysfonction systolique ventriculaire gauche sont les facteurs de prédiction indépendants de la TVG. Chez les patients présentant une coronaropathie multitronculaire, il n'y avait pas de différence significative entre l'effet de la revascularisation de la coronaire responsable seulement et celui de la revascularisation complète sur la réduction du risque de TVG. D'autres études auprès d'un plus grand nombre de patients s'imposent, en raison des incertitudes quand aux liens entre les effets biologiques des facteurs environnementaux et le risque de TVG.

Paradoxical low-flow, low-gradient severe aortic stenosis despite preserved ejection fraction is associated with higher afterload and reduced survival.

BACKGROUND: Recent studies and current clinical observations suggest that some patients with severe aortic stenosis on the basis of aortic valve area may paradoxically have a relatively low gradient despite the presence of a preserved left ventricular (LV) ejection fraction. The objective of the present study was to document the prevalence, potential mechanisms, and clinical relevance of this phenomenon. METHODS AND RESULTS: We retrospectively studied the clinical and Doppler echocardiographic data of 512 consecutive patients with severe aortic stenosis (indexed aortic valve area < or = 0.6 cm2 x m(-2)) and preserved LV ejection fraction (> or = 50%). Of these patients, 331 (65%) had normal LV flow output defined as a stroke volume index > 35 mL x m2, and 181 (35%) had paradoxically low-flow output defined as stroke volume index < or = 35 mL x m(-2). When compared with normal flow patients, low-flow patients had a higher prevalence of female gender (P<0.05), a lower transvalvular gradient (32+/-17 versus 40+/-15 mm Hg; P<0.001), a lower LV diastolic volume index (52+/-12 versus 59+/-13 mL x m(-2); P<0.001), lower LV ejection fraction (62+/-8% versus 68+/-7%; P<0.001), a higher level of LV global afterload reflected by a higher valvulo-arterial impedance (5.3+/-1.3 versus 4.1+/-0.7 mm Hg x mL(-1) x m(-2); P<0.001) and a lower overall 3-year survival (76% versus 86%; P=0.006). Only age (hazard ratio, 1.04; 95% CI, 1.01 to 1.08; P=0.025), valvulo-arterial impedance > 5.5 mm Hg x mL(-1) x m(-2) (hazard ratio, 2.6; 95% CI, 1.2 to 5.7; P=0.017), and medical treatment (hazard ratio, 3.3; 95% CI, 1.8 to 6.7; P=0.0003) were independently associated with increased mortality. CONCLUSION: Patients with severe aortic stenosis may have low transvalvular flow and low gradients despite normal LV ejection fraction. A comprehensive evaluation shows that this pattern is in fact consistent with a more advanced stage of the disease and has a poorer prognosis. Such findings are clinically relevant because this condition may often be misdiagnosed, which leads to a neglect and/or an underestimation of symptoms and an inappropriate delay of aortic valve replacement surgery.

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 > or = 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 > or = 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 > or = 45 degrees (ie, with high PL restriction) should thus be considered poor candidates for this procedure, and concomitant or alternative procedures should be contemplated.

B-type natriuretic peptide in low-flow, low-gradient aortic stenosis: relationship to hemodynamics and clinical outcome: results from the Multicenter Truly or Pseudo-Severe Aortic Stenosis (TOPAS) study.

BACKGROUND: The prognostic value of B-type natriuretic peptide (BNP) is unknown in low-flow, low-gradient aortic stenosis (AS). We sought to evaluate the relationship between AS and rest, stress hemodynamics, and clinical outcome. METHODS AND RESULTS: BNP was measured in 69 patients with low-flow AS (indexed effective orifice area < 0.6 cm2/m2, mean gradient < or = 40 mm Hg, left ventricular ejection fraction < or = 40%). All patients underwent dobutamine stress echocardiography and were classified as truly severe or pseudosevere AS by their projected effective orifice area at normal flow rate of 250 mL/s (effective orifice area < or = 1.0 cm2 or > 1.0 cm2). BNP was inversely related to ejection fraction at rest (Spearman correlation coefficient r(s)=-0.59, P<0.0001) and at peak stress (r(s)=-0.51, P<0.0001), effective orifice area at rest (r(s)=-0.50, P<0.0001) and at peak stress (r(s)=-0.46, P=0.0002), and mean transvalvular flow (r(s)=-0.31, P=0.01). BNP was directly related to valvular resistance (r(s)=0.42, P=0.0006) and wall motion score index (r(s)=0.36, P=0.004). BNP was higher in 29 patients with truly severe AS versus 40 with pseudosevere AS (median, 743 pg/mL [Q1, 471; Q3, 1356] versus 394 pg/mL [Q1, 191 to Q3, 906], P=0.012). BNP was a strong predictor of outcome. In the total cohort, cumulative 1-year survival of patients with BNP > or = 550 pg/mL was only 47+/-9% versus 97+/-3% with BNP < 550 (P<0.0001). In 29 patients who underwent valve replacement, postoperative 1-year survival was also markedly lower in patients with BNP > or = 550 pg/mL (53+/-13% versus 92+/-7%). CONCLUSIONS: BNP is significantly higher in truly severe than pseudosevere low-gradient AS and predicts survival of the whole cohort and in patients undergoing valve replacement.

Prognostic value of plasma B-type natriuretic peptide levels after exercise in patients with severe asymptomatic aortic stenosis.

BACKGROUND: Exercise-stress echocardiography is useful in management and risk stratification of patients with asymptomatic aortic stenosis (AS). Resting B-type natriuretic peptide (BNP) level is associated with increased risk of adverse events. The incremental prognostic value of BNP response during exercise is unknown. Objective The purpose of this study was to assess the usefulness of plasma level of BNP during exercise to predict occurrence of events in asymptomatic patients with severe AS. METHODS: Resting and exercise-stress echocardiographic data and plasma BNP levels were prospectively collected in 211 asymptomatic AS patients in whom 157 had severe AS with preserved LVEF in two centres. The study end-point was the occurrence of death or aortic valve replacement. RESULTS: Plasma BNP level increased from rest to exercise (p<0.0001). During a mean follow-up of 1.5 ±1.2 years, 87 patients with severe AS reached the predefined end-point. Higher peak-exercise BNP level was associated with higher occurrence of adverse events (p<0.0001). In multivariate analysis, second and third tertiles of peak-exercise BNP (T2: HR=2.9; p=0.002 and T3: HR=5.3; p<0.0001, respectively) were powerful predictors of events compared with the first tertile. Further adjustment for resting BNP provided comparable results (T2: HR=2.8; p=0.003 and T3: HR=5.0; p<0.0001). This relationship persisted in both subsets of patients with low or high resting BNP. CONCLUSIONS: This study reports that peak-exercise BNP level provides significant incremental prognostic value beyond what is achieved by demographic and echocardiographic data, as well as resting BNP level.

Stress echocardiography to assess stenosis severity and predict outcome in patients with paradoxical low-flow, low-gradient aortic stenosis and preserved LVEF.

The objective of this study was to examine the value of stress-echocardiography in patients with paradoxical low-flow, low-gradient (PLFLG) aortic stenosis (AS). The projected aortic valve area (AVAProj) at a normal flow rate was calculated in 55 patients with PLFLG AS. In the subset of patients (n = 13) who underwent an aortic valve replacement within 3 months after stress echocardiography, AVA(Proj) correlated better with the valve weight compared to traditional resting and stress echocardiographic parameters of AS severity (AVA(Proj): r = -0.78 vs. other parameters: r = 0.46 to 0.56). In the whole group (N = 55), 18 (33%) patients had an AVA(Proj) >1.0 cm(2), being consistent with the presence of pseudo severe AS. The AVA(Proj) was also superior to traditional parameters of stenosis severity for predicting outcomes (hazard ratio: 1.32/0.1 cm(2) decrease in AVA(Proj)). In patients with PLFLG AS, the measurement of AVA(proj) derived from stress echocardiography is helpful to determine the actual severity of the stenosis and predict risk of adverse events.

Usefulness of the valvuloarterial impedance to predict adverse outcome in asymptomatic aortic stenosis.

OBJECTIVES: This study was designed to examine the prognostic value of valvuloarterial impedance (Z(va)) in patients with aortic stenosis (AS). BACKGROUND: We previously showed that the Z(va) is superior to standard indexes of AS severity in estimating the global hemodynamic load faced by the left ventricle (LV) and predicting the occurrence of LV dysfunction. This index is calculated by dividing the estimated LV systolic pressure (systolic arterial pressure + mean transvalvular gradient) by the stroke volume indexed for the body surface area. METHODS: We retrospectively analyzed the clinical and echocardiographic data of 544 consecutive patients having at least moderate AS (aortic jet velocity > or =2.5 m.s(-1)) and no symptoms at baseline. The primary end point for this study was the overall mortality regardless of the realization of aortic valve replacement (AVR). RESULTS: Four-year survival was significantly (p < 0.001) lower in the patients with a baseline Z(va) > or =4.5 mm Hg x ml(-1) x m(2) (65 +/- 5%) compared with those with Z(va) between 3.5 and 4.5 mm Hg x ml(-1) x m(2) (78 +/- 4%) and those with Z(va) < or =3.5 mm Hg x ml(-1) x m(2) (88 +/- 3%). The risk of mortality was increased by 2.76-fold in patients with Z(va) > or =4.5 mm Hg x ml(-1) x m(2) and by 2.30-fold in those with a Z(va) between 3.5 and 4.5 mm Hg x ml(-1) x m(2) after adjusting for other risk factors and type of treatment (surgical vs. medical). CONCLUSIONS: Increased Z(va) is a marker of excessive LV hemodynamic load, and a value >3.5 successfully identifies patients with a poor outcome. These findings suggest that beyond standard indexes of stenosis severity, the consideration of Z(va) may be useful to improve risk stratification and clinical decision making in patients with AS.