Oral Abstract529Assessment of myocardial viability during low-dose dobutamine stress echocardiography by 2D speckle tracking in patients after acute myocardial infarction530Myocardial fibrosis affects left ventricular contractile reserve: noninvasive assessment by cardiac magnetic resonance and stress echo531Additive prognostic value of diastolic dysfunction and coronary flow reserve in non-ischemic dilated cardiomyopathy532Exercise pulmonary hypertension in asymptomatic severe aortic stenosis

# 529 Assessment of myocardial viability during low-dose dobutamine stress echocardiography by 2D speckle tracking in patients after acute myocardial infarction {#article-title-2} Introduction: Low-dose dobutamine stress echocardiography(LDDSE) is useful in assessment of myocardial viability, but involves subjective interpretation of wall motion changes requiring experience. The aim of this study was to assess if use of 2D speckle tracking at rest and during LDDSE may facilitate the prediction of myocardial viability in patients after acute myocardial infarction (AMI). Material and methods: The study group comprised 96patients (65 male, mean age 58±10 years) with first AMI treated with successful primary percutaneous coronary intervention. 7-10 days after AMI, all patients underwent LDDSE with visual assessment of contractile reserve by expert echocardiographer. Subsequently, acquired images were analyzed off-line by echocardiographer in training using 2D speckle tracking. Measurements at baseline and peak of stress protocol included systolic longitudinal strain (SLS), peak longitudinal strain (PLS) and systolic longitudinal strain rate (SLSR). After twelve months each patient underwent control resting transthoracic echocardiography with visual assessment of functional recovery in akinetic/dyskinetic segments at baseline, which was defined as improvement from dyskinesis and akinesis to hypokinesis or normokinesis. Results: At baseline there were 224 segments with akinesis or dyskinesis. 91 (41%) of those segments showed functional recovery after 12months. There were significant differences in mean values of strain between segments with and without functional recovery (P=0.0002 to 0.003). The highest prognostic value for prediction of functional recovery was provided by peak longitudinal strain both at rest (sensitivityof 76%, specificity of 44%, diagnostic accuracy of 61%) and stress (sensitivityof 62%, specificity of 66%, diagnostic accuracy of 64%). However, the diagnostic value of 2D strain analysis was significantly lower than of expert's visual assessment of wall motion abnormalities during LDDSE (sensitivity of 67.12%, specificity of 88.71%, diagnostic accuracy of 77.00%). Conclusions: 2D speckle tracking analysis at rest and during LDDSE canbe helpful in prediction of functional recovery in patients after AMI for inexperienced echocardiographers.The most useful parameter is peak longitudinal strain. # 530 Myocardial fibrosis affects left ventricular contractile reserve: noninvasive assessment by cardiac magnetic resonance and stress echo {#article-title-3} Background: Fibrosis is a common endpoint of many pathological processes affecting the myocardium, influences regional and global left ventricular (LV) function and can be accurately measured with late post-gadolinium myocardial enhancement (LGE) cardiac magnetic resonance. Aim: To assess the value of resting function and contractile reserve evaluated by stress echocardiography in predicting myocardial fibrosis. Methods. We studied 42 patients (32 men; 63±12 years) with idiopathic (n=21) or ischemic (n=21) dilated cardiomyopathy (EF <40% by selection). They underwent, on separate days and within 1 week, stress echo with exercise (n=13), dobutamine (n=28, up to 40 mcg/kg) or dipyridamole (n=1, up to 0.86 mg/kg). By selection, no patient had inducible ischemia with stress echo. We measured LV ejection fraction (EF, Simpson method) and wall motion score index (WMSI) by 2D-echo at rest and peak stress. LGE was semiauthomatically quantified and expressed as left ventricular mass percentage (LGE%). Results: Resting Ejection was 29±7%. LGE score was 13.6±18.2 (range 0-60). WMSI was 2.1±0.3 at rest and 1.9±0.4 at peak stress (p<.0001). LGE was correlated with peak WMSI (r=.6, p<0.01, see figure) and - more weakly - with resting WMSI (r=.47, p=.009), whereas no correlation was detected with resting EF (r=.2, p=ns) or peak EF (r=.1, p=ns). Conclusion: Severity of myocardial fibrosis by LGE correlates with contractile reserve during stress echo in a broad range of myocardial fibrosis in patients with ischemic and non-ischemic dilated cardiomyopathy.[⇓][1] # 531 Additive prognostic value of diastolic dysfunction and coronary flow reserve in non-ischemic dilated cardiomyopathy {#article-title-4} Background: Coronary flow reserve (CFR) on left anterior descending (LAD) can be reduced in non-ischemic dilated cardiomyopathy (DCM). Aim: to assess the additive prognostic value of CFR in LAD and resting severe diastolic dysfunction to identify responders to CRT. Methods. One hundred twenty-nine DCM patients (pts, 87 men, 62±12 years, ejection fraction: 33±7%) underwent dipyridamole (0.84 mg/kg in 6′) stress echo. CFR was defined as the ratio between maximal vasodilation and rest peak diastolic flow velocity in LAD, and diastolic dysfunction as the presence of resting irreversible restrictive transmitral pattern. Results: We divided DCM pts in 4 groups, according to normal (>2, 56 pts) or abnormal (≤2, 73 pts) CFR on LAD and absence (88 pts) or presence (41 pts) of restrictive transmitral pattern. In pts with abnormal CFR on LAD, the additional presence of restrictive patterns was associated to lower ejection fraction at rest (26±5% vs 31±7% p=.007) and at peak stress (30±5% vs 36±8% p=.03) and larger end-systolic volume at rest (149±55 ml vs 185±48, p=.030). During median follow-up of 30 months, 19 deaths, and 33 cardiac adverse events. Abnormal CFR on LAD and diastolic dysfunction were associated with poorer event-free survival (Log Rank: 33.1, p<0.0001, Figure), with additive negative prognostic value in pts with CFR on LAD <2 and the presence of restrictive pattern. Conclusions: In DCM patients with reduced CFR left anterior descending territory during vasodilator stress, the associate presence of restrictive transmitral pattern is an additive independent prognostic marker of ominous outcome.[⇓][2] # 532 Exercise pulmonary hypertension in asymptomatic severe aortic stenosis {#article-title-5} Background: Pulmonary hypertension (PHT) in patients with severe aortic stenosis (AS) is associated with increased morbidity and mortality. Recent studies emphasized the usefulness of exercise stress echocardiography (ESE) in asymptomatic patients with AS. Nevertheless, the additive value of exercise (Ex) PHT in such patients is unexplored. We, therefore, aimed to identify the determinants and impact on outcome of ExPHT in asymptomatic patients with severe AS. Method and results : Asymptomatic patients with severe AS (n=106, aortic valve area 50mmHg and >60mmHg, respectively. Ex PHT was more frequent than resting PHT (55% vs. 6%, p<0.0001). Patients with ExPHT were more frequently male (68% vs. 49%, p=0.035), had significant higher mean aortic gradient (47.4±16 vs. 41.7±12mmHg, p=0.04) and longer diastolic filling time (446±177 vs. 372±126ms, p=0.015) than those without ExPHT. There was no other significant difference between these 2 groups with regard to clinical, demographic and echocardiographic data. ExSPAP was correlated with resting aortic mean pressure gradient and peak aortic velocity (r=0.49 and r=0.48, both p=0.01), with LV diastolic filling time (r=0.54, p=0.003) and the Ex-induced changes in E/Ea ratio (r=-0.53, p=0.007). Multivariate logistic regression analysis showed that only Ex-induced changes in E/Ea ratio (p=0.02, β=-0.8±0.3) and resting peak aortic velocity (p=0.007, β=7±2.5) were independently associated with ExSPAP. ExPHT was associated with reduced cardiac event-free survival (27±7% vs. 53±9%, p=0.02). In multivariate Cox proportional hazard model, the independent predictors of events were resting E/Ea ratio (p=0.01), aortic peak velocity (p<0.0001), indexed left atrium area (p=0.005), LV global longitudinal strain (p=0.04) and ExPHT (hazard ratio=1.9, 95% of confidence interval: 1.1-3.5, p=0.04). In addition, when adding Ex-induced changes in aortic mean pressure gradient to the multivariate model, ExPHT remained an independent predictor of reduced cardiac event-free survival (p=0.033). Conclusion: In asymptomatic patients with severe AS, the main determinants of ExPHT are the severity of AS and the Ex-induced changes in LV filling pressure. ExPHT is associated with 2-fold increased risk of cardiac events. These results strongly support the use of ESE in asymptomatic AS. [1]: #F1 [2]: #F2