Temporal deformation pattern in acute and late phases of ST-elevation myocardial infarction: incremental value of longitudinal post-systolic strain to assess myocardial viability.

BACKGROUND: Identification of transmural extent and degree of non-viability after ST-segment elevation myocardial infarction (STEMI) is clinically important. The objective of the present study was to assess the regional mechanics and temporal deformation patterns using speckle tracking echocardiography (STE) in acute and later phases of STEMI to predict myocardial damage in these patients. METHODS AND RESULTS: Ninety-eight patients with first STEMI underwent both echocardiography and cardiac magnetic resonance imaging in acute phase and at 6 months follow-up with 2D STE-derived measurements of peak longitudinal strain (PLS), Pre-STretch index (PST) and post-systolic deformation index (PSI). For each segment, late gadolinium enhancement (LGE) was defined as transmural (LGE >66 %) or non-transmural (<66 %). Global deformation values were significantly correlated with LVEFCMR and infarct size at both visits. A significantly lower value of segmental PLS and higher PSI and PST in necrotic segments were observed comparatively to control, adjacent and remote segments. The best parameters to predict transmural extent in acute phase were PSI with a cutoff value of 8 % (AUC: 0.84) and PLS with a cutoff value of -13 % (AUC: 0.86). PST showed high specificity, but poor sensitivity in predicting transmural extent. More importantly, the addition of PSI and PST to PLS in acute phase was associated with improved prediction of viability at 6 months (integrated discrimination improvement 2.5 % p < 0.01; net reclassification improvement 27 %; p < 0.01). CONCLUSIONS: All systolic deformation values separated transmural from non-transmural scarring. PLS combined with additional information relative to post-systolic deformation appears to be the most informative parameters to predict the transmural extent of MI in the early and late phases of MI. CLINICAL TRIAL REGISTRATION: http://clinicaltrials.gov/show/NCT01109225 ; NCT01109225.

AV nodal reentrant tachycardia or AV reentrant tachycardia using a concealed bypass tract-related adverse events.

OBJECTIVES: To jointly study paroxysmal supraventricular tachycardia (SVT)-related adverse events (AE) and ablation-related complications, with specific emphasis on the predictors of SVT-related AE as well as their significance by investigating their association with long-term mortality. METHODS: 1770 patients were included, aged 6 to 97, with either atrioventricular nodal reentrant tachycardia (AVNRT) or orthodromic atrioventricular reciprocal tachycardia (AVRT) mediated by concealed accessory pathway, consecutively referred for SVT work-up in a tertiary care center. RESULTS: SVT-related AE were identified in 339 patients (19%). Major AEs were identified in 23 patients (1%; 15 cardiac arrests or ventricular arrhythmias requiring cardioversion and 8 hemodynamic collapses). Other AE were related to syncope (n=236), acute coronary syndrome (n=57) and heart failure/rhythmic cardiomyopathy (n=21). In multivariable analysis, higher age, heart disease and requirement of isoproterenol to induce SVT were independently associated with a higher risk for SVT-related AE. During follow-up (2.8±3.0years), death occurred more frequently in patients with SVT-related AE, especially in patients with major adverse events (p<0.001). In multivariable analysis, major SVT-related AE remained significantly associated with occurrence of death (HR=6.72, IC=(2.58-17.52), p<0.001) independently of age and presence of underlying heart disease. Major SVT-related AE in the whole population referred for SVT were more frequent than immediate major ablation complications in patients undergoing SVT ablation (5/1186 vs. 23/1770, p=0.02). CONCLUSIONS: SVT-related AE are independent predictors of mortality and are more frequent than immediate major ablation complications in patients undergoing SVT ablation. The present findings support systematically performing SVT ablation in patients with SVT-related adverse events.