Longitudinal Arrhythmic Risk Assessment Based on Ejection Fraction in Patients with Recent-Onset Nonischemic Dilated Cardiomyopathy.

BACKGROUND: Practice guidelines suggest the use of implantable cardioverter-defibrillators in patients with left ventricular ejection fractions (LVEF) ≤ 35% despite 3 to 6 months of guideline-directed medical therapy (GDMT). It remains unclear whether this strategy is appropriate for patients with dilated cardiomyopathy (DCM), who can experience reverse ventricular remodeling for up to 24 months after the initiation of GDMT. The aim of this study was to assess the longitudinal dynamic relationship between LVEF ≤ 35% and arrhythmic risk in patients with recent-onset nonischemic DCM on GDMT. METHODS: A retrospective analysis was conducted among patients with recent-onset DCM (≤6 months) and recent initiation of GDMT (≤3 months) consecutively enrolled in a longitudinal registry. Risk for major ventricular arrhythmic events or sudden cardiac death was assessed in relationship to LVEF ≤ 35% at enrollment and 6 and 24 months after initiation of GDMT. RESULTS: Five hundred forty-four patients met the inclusion criteria. LVEF ≤ 35% identified patients with increased risk for major ventricular arrhythmic events or sudden cardiac death starting from 24 months after initiation of GDMT (hazard ratio, 2.126; 95% CI, 1.065-4.245; P = .03). However, LVEF ≤ 35% at presentation or 6 months after enrollment did not have prognostic significance. Sixty-seven percent of 131 patients with LVEF ≤ 35% at 6 months after initiation of GDMT had improved LVEFs (to >35%) by 24 months. This late LVEF improvement correlated with lower arrhythmic risk (P = .012) and was preceded by a reduction of LV dimensions in the first 6 months of GDMT. CONCLUSIONS: In patients with DCM, the present findings suggest that risk stratification for major ventricular arrhythmic events or sudden cardiac death on the basis of LVEF ≤ 35% is effective after 2 years of GDMT, but not after 6 months. In selected patients with DCM, it would be appropriate to wait 24 months before primary prevention ICD implantation.

Global Right Heart Assessment with Speckle-Tracking Imaging Improves the Risk Prediction of a Validated Scoring System in Pulmonary Arterial Hypertension.

BACKGROUND: Right ventricular (RV) function and right atrial (RA) remodeling are major determinants of outcome in pulmonary arterial hypertension (PAH). Strain echocardiography is emerging as a valuable approach for the study of RV and RA function. We sought to assess the incremental prognostic value of serial combined speckle-tracking examination of right chambers in newly diagnosed therapy-naïve PAH patients. METHODS: The study endpoint was a composite of all-cause mortality, hospitalizations due to worsening PAH, and initiation of parenteral prostanoids. Patients were assessed at baseline and at first revaluation after initiation of treatment. Right ventricular free-wall longitudinal strain (FWLS) and RA peak atrial longitudinal strain (PALS) were used as measures of RV and RA function. RESULTS: Eighty-three patients were included. Mean RV-FWLS and RA-PALS were -13.9% ± 6.1% and 23.1% ± 11.4%. The best performing prognostic score among the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension, French Pulmonary Hypertension Registry, and Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL) scores was the REVEAL (area under the curve = 0.79, P < .001). With the identified cutoffs, both RV-FWLS (hazard ratio for RV-FWLS < -13.2% = 0.366; 95% CI, 0.159-0.842; P = .018) and RA-PALS (hazard ratio for RA-PALS > 20% = 0.399; 95% CI, 0.176-0.905; P = .028) were independently associated with the primary outcome after correction for the REVEAL score. The combined assessment of RV-FWLS and RA-PALS in addition to the REVEAL score determined a net improvement in prediction of 0.439 (95% CI, 0.070-0.888, P = .04). At 5 months (interquartile range, 4-8) of follow-up, RV-FWLS and RA-PALS improved significantly only in patients free from the primary outcome (P < .001 and P = .001, respectively). CONCLUSIONS: The combined assessment of RV-FWLS and RA-PALS determined an improvement in outcome prediction of validated prognostic risk scores and should be considered within the multiparametric evaluation of patients with PAH.

Assessment of EtQxBox complexation in solution by steady-state and time-resolved fluorescence spectroscopy.

Reliable chemical sensors with high selectivity and sensitivity toward specific target molecules require rational synthesis of receptors, in-depth characterization of their complexation abilities and highly efficient transduction of the molecular recognition event. Here we report a steady-state and time-resolved fluorescence investigation of EtQxBox, a fluorescent conformationally blocked quinoxaline-based cavitand, aimed at assessing its selectivity toward aromatic versus non-aromatic analytes in solution. Fluorescence quenching of the EtQxBox in acetone is observed at increasing concentration of both aromatic (i.e. benzonitrile) and aliphatic (i.e. acetonitrile) compounds. The combination with fluorescence lifetime measurements permits to discriminate the predominantly static quenching of the aromatic analyte, due to non-fluorescent host-guest complex formation, from the mostly dynamic quenching of the non-aromatic compound, resulting from aspecific diffusive collisions between the fluorophore and the quencher. The equilibrium association constants for both the complexes have been estimated using Stern-Volmer model.