0110: Exercise stress echocardiography in secondary mitral regurgitation: impact of pulmonary hypertension

BackgroundSecondary mitral regurgitation (MR) is a serious and frequent complication of dilated cardiomyopathy and/or coronary artery disease. The impact of exerxise pulmonary hypertension (ExPHT) on outcome in patients with secondary MR is unknown.Method and resultsAll patients with secondary MR, sinus rhythms, narrow QRS (<120ms) and referred for exercise stress echocardiography with quantifiable exercise systolic pulmonary arterial pressure (SPAP), were included in this study (n=159, 65±11 years, 66% of male). Resting and ExPHT were defined as a systolic pulmonary arterial pressure (SPAP) >50mmHg and >60mmHg, respectively. ExPHT was more frequent than resting PHT (40% vs. 13%, p<0.0001). There was no significant difference between patients with or without ExPHT regarding demographic and clinical data, as well as medication. Using multiple linear regression, exercise SPAP was determined by resting SPAP (β=0.94±0.1, p<0.0001), exercise MR severity (β=0.58±0.1, p<0.0001), and resting e’-wave velocity (β=–1.3±0.4, p=0.004). During a mean follow-up of 35±11 months, 60 major adverse cardiovascular events occured. The incidence of combined cardiac event was significantly higher in patients with ExPHT as compared to those without ExPHT (2-year: 11±3 vs. 28±6%; 4-year: 20±5 vs. 40±7%, p<0.0001). Similarly, patients with ExPHT demonstrated significantly reduced survival (2-year: 88±4 vs. 99±1%; 4-year: 62±8% vs. 94±2%, p<0.0001). In multivariate Cox proportional Hazard model, after adjustment for age, sex, left ventricular volumes, both resting and exercise diastolic function and resting MR severity, ExPHT remains significantly associated with high risk of combined cardiac event (Hazard ratio=3.7, 95% of CI: 1.9-7.2, p<0.0001).ConclusionIn patients with secondary MR, ExPHT may be frequent and mainly determined by resting SPAP, LV diastolic burden markers and exercise MR severity. ExPHT is a powerful predictor of poor outcome and is associated with a 3.7-fold increase in risk of cardiac event. These results further highlight the usefulness of exercise stress echocardiography for the management and the risk stratification of these patients

124 Does Resting Left Ventricular Longitudinal Function may predict Exercise Pulmonary Hypertension in Organic Mitral Regurgitation?

IntroductionExercise pulmonary hypertension (PHT) can develop in patients with organic mitral regurgitation (OMR), even when resting pulmonary arterial pressure (PAP) is normal. However, systolic PAP is not always available during stress echocardiography. The purpose of this study was to identify resting echocardiographic predictors of exercise PHT in OMR.Method and resultsResting and exercise transthoracic echocardiography including Doppler and tissue Doppler imaging (TDI) quantification were performed in 66 consecutive patients (61±15 years, 55% of male) with moderate to severe OMR. LV longitudinal and filling functions were quantified by peak and time-to-peak velocities (TP) using TDI for Ea- and Sa-wave. PAP was derived from transtricuspid pressure gradient and was available during exercise in 52 patients (79%). Systolic PAP significantly increased during exercise (from 31±10 to 54±17mmHg, p<0.01) and exercise PHT (exercise PAP ≥60mmHg) was observed in 24 patients (46%). Patients with exercise PHT were significantly older (69±11 vs. 59±15 yrs, p=0.004) and had higher resting PAP (36±9 vs. 27±7mmHg, p=0.0004), higher septal E/Ea ratio (16±6 vs. 13±4, p=0.03), slower TP-Sa (127±27 vs. 153±30ms, p=0.002) and TP-Ea (456±48 vs. 483±50ms, p=0.03) and lower septal Ea velocity (6.4±2 vs. 7.4±3cm/s, p=0.01). Exercise PAP was correlated with age (r=0.39, p=0.004), resting TP-Sa (r=0.42, p=0.002) and septal E/Ea ratio (r=0.28, p=0.04). On multivariate analysis, after adjustment for age, sex and septal E/Ea ratio, the independent predictors of exercise PHT were resting systolic PAP (Odds-ratio (OR) =1.25, 95%CI: 1.05-1.4, p=0.003) and TPSa (OR=1.04, 95%CI: 1.01-1.1, p=0.03).ConclusionThis study shows that resting impaired LV longitudinal function is associated with exercise PHT in patients with OMR. The presence of resting subclinical LV dysfunction could play an important role in PHT

Detection and clinical usefulness of a biphasic response during exercise echocardiography early after myocardial infarction

OBJECTIVES The aim of this study was to determine the accuracy of exercise echocardiography (EE) for detecting infarct-related artery (IRA) stenosis and predicting functional recovery early after acute myocardial infarction (AMI). BACKGROUND Dobutamine stress echocardiography is widely used for identifying jeopardized myocardium. The clinical usefulness of a biphasic response detected during EE has never been investigated. METHODS A total of 114 consecutive patients with a first AMI and greater than or equal to2 dyssynergic segments in the infarct-related territory underwent semi-supine continuous EE 6 +/- 2 days after AMI. Quantitative coronary angiography was performed in all patients after EE. A follow-up echocardiogram was obtained one month later. RESULTS Ninety-seven patients had significant (greater than or equal to50%) IRA stenosis, and 26 had multivessel disease. Residual ischemia was identified in 77 patients (biphasic response in 62 and worsening response in 15). The sensitivity and specificity of ischemia during EE for predicting IRA stenosis were 75% and 76%, respectively. The sensitivity of a biphasic response was higher than the sensitivity of a worsening response (61% vs. 14%, p < 0.0001). Wall motion abnormalities induced in other vascular territories were specific (97%) and moderately sensitive (62%) for the detection of multivessel disease. Functional recovery was observed in 75 patients. Two independent variables predicted contractile recovery: contractile reserve during EE (p < 0.0001) and elective angioplasty of the IRA (p = 0.002). A biphasic response, but not sustained improvement, predicted reversible dysfunction (73% vs. 9%, p < 0.0001). CONCLUSIONS A biphasic response can be detected during exercise. Exercise echocardiography is an accurate tool for detecting IRA stenosis and predicting functional improvement early after AMI

Is global left ventricular afterload has an impact on left atrial function in patients with aortic stenosis?

IntroductionIn aortic stenosis (AS), global left ventricular (LV) afterload is evaluated using valvulo-arterial impedance (Zva) and has been recently associated with LV dysfunction and patient outcome. Left atrial (LA) enlargement is a surrogate marker of diastolic burden and a predictor of outcome. Whether LA function might be affected by elevated global LV afterload has never been examined. The aim of this study was thus undertaken to investigate the impact of Zva on LA volume and function in severe AS.Method and resultsTissue Doppler imaging and 2D transthoracic echocardiography including measurements of LV and LA function and AS assessment was performed in 39 consecutive patients (63% of male, 70±13 years) with an aortic valve area < 1cm2. Zva was calculated by dividing the estimated LV systolic pressure (systolic arterial pressure + aortic mean transvalvular gradient) by the LV stroke volume index. Patients were studied in 2 groups according to Zva (median = 4.7ml/mmHg/m2). Although patients with Zva ≥ 4.7 had higher LV mass (178±47 vs. 143±33 g/m2, p=0.03), there was no significant difference between the 2 groups regarding LV volume and function. By contrast, patients with a Zva ≥ 4.7 had lower LA ejection fraction (42±13 vs. 53±10%, p=0.02), LA passive function (18±8 vs. 26±10%, p=0.03) and LA conduit volume (19±21 vs. 47±24ml, p=0.0012) compared to those with a low Zva. Late annular diastolic velocity (Aa) was significantly lower in patients with a Zva ≥ 4.7 (7.1±3 vs. 9.2±3 cm/s, p=0.04), suggesting impaired LA active function. There are significant correlations between Zva and Aa (r=−0.62, p=0.0002), LA ejection fraction (r=−0.41, p=0.018), LA passive (r=−0.39, p=0.03) and LA conduit volume (r=−0.71, p<0.0001).ConclusionIn patients with severe AS, global LV afterload had significant impact on LA ejection fraction and on LA active, passive and conduit functions. Further studies are needed to evaluate the prognostic impact of LA dysfunction in AS

The role of ischemic mitral regurgitation in the pathogenesis of acute pulmonary edema

BACKGROUND: Acute mitral regurgitation may cause pulmonary edema, but the pathogenetic role of chronic ischemic mitral regurgitation, a dynamic condition, has not yet been characterized. METHODS: We prospectively studied 28 patients (mean [+/-SD] age, 65+/-11 years) with acute pulmonary edema and left ventricular systolic dysfunction and 46 patients without a history of acute pulmonary edema. The two groups were matched for all baseline characteristics. Patients underwent quantitative Doppler echocardiography during exercise. Exercise-induced changes in the left ventricular volume, the ejection fraction, the mitral regurgitant volume, the effective regurgitant orifice area, and the transtricuspid pressure gradient were compared in patients with and without acute pulmonary edema. RESULTS: The two groups had similar clinical and baseline echocardiographic characteristics. They also had similar exercise-induced changes in heart rate, systolic blood pressure, and left ventricular volumes. In the univariate analysis, patients with recent pulmonary edema had a much higher increase than did the patients without pulmonary edema in mitral regurgitant volume (26+/-14 ml vs. 5+/-14 ml, P<0.001), the effective regurgitant orifice area (16+/-10 mm(sup 2) vs. 2+/-9 mm(sup 2), P<0.001), and the transtricuspid pressure gradient (29+/-10 mm Hg vs. 13+/-11 mm Hg, P<0.001). In the multivariate analysis, exercise-induced changes in the effective regurgitant orifice area (P<0.001), in the transtricuspid pressure gradient (P=0.001), and in the left ventricular ejection fraction (P=0.02) were independently associated with a history of recent pulmonary edema. CONCLUSIONS: In patients with left ventricular systolic dysfunction, acute pulmonary edema is associated with the dynamic changes in ischemic mitral regurgitation and the resulting increase in pulmonary vascular pressure