P5423Exercise oscillatory ventilation improves the performance of prognosis scores currently used for heart failure

Background and aim

Several prognostic risk scores are available for heart failure with reduced ejection fraction (HFrEF), and are used, together with other criteria, to help decide the ideal timing for listing candidates for a heart transplant. The detection of an oscillatory ventilatory pattern (OVP) during cardiopulmonary exercise testing (CPET) has been associated with more advanced HF and a worse prognosis, but was not considered in the development of all the current risk scores. We evaluated whether OVP adds significant prognostic information to four contemporary HF scores.

Methods

Single-centre retrospective cohort study of consecutive HFrEF patients undergoing CPET for functional and prognostic assessment from October 1996 till May 2018. The Heart Failure Survival Score (HFSS), Seattle Heart Failure Model (SHFM), Meta-analysis Global Group in Chronic Heart Failure (MAGGIC) and Metabolic Exercise Cardiac Kidney Index (MECKI) were obtained in each patient. Cox model was fit with time to death or urgent transplant (whichever came first within 2 years) as the dependent variable and OVP and respective HF score as the independent variables. We further assessed the added discriminative power by performing ROC curve comparisons.

Results

We studied 387 patients, median age 58 (IQR 49; 65) years, and 77% were male. The most common HFrEF aetiology was ischemic heart disease (54%). Median peak oxygen consumption was 15,7 mL/kg/min (IQR 12,8; 20,0). OVP was present in 150 (39%) patients. Over the 2-year follow-up period, 48 patients died, and 52 underwent heart transplantation (of which 25 were urgent). HFSS showed the weakest (c-statistic 0,625; 95% [CI] 0,54–0,71) and MECKI score the strongest (c-statistic 0,819; 95% [CI] 0,76–0,88) discriminatory ability. Contrasting with NTproBNP value, the presence of OVP predicted the study endpoint independently of the HF prognosis score used (see table). Adding the occurrence of OVP to the HFSS and the MAGGIC scores significantly improved their prognostic performance (see Table).

Conclusion

An OVP is a common finding in HFrEF patients undergoing CPET, and adds prognostic information to contemporary HF prognosis scores. Systematic evaluation of this easily available criterion may assist the decision on the appropriate timing for heart transplantation listing.

P1474Simpsons Triplane versus Biplane for left ventricle ejection fraction after myocardial infarction

Introduction

Simpson's biplane (SBP) ignores the apical long-axis plane. It is estimated that 40% of myocardial infarction (MI)-related segmental abnormalities are located in this plane. The real-time triplane (RT3P) overcomes this issue, allowing to obtain all apical views simultaneously, at the same cardiac cycle. This method could be a more precise and reliable alternative to SBP in ejection fraction (EF) quantification in this setting.

Purpose

The authors aimed to compare EF assessed by two quantification methods, SBP and RT3P, using quantitative three-dimensional echocardiography (3DE) as the reference method, in patients with MI.

Methods

We have prospectively gathered data from 52 adult patients, which had recent or past history of MI. Exclusion criteria were the presence of atrial fibrillation, unknown coronary anatomy, significant valvular disease, left branch block, ventricular pacing and poor definition of endocardial borders.

Estimation of EF by SBP, RT3P and 3DE was performed in all patients and gathered by two experienced operators. The two operators were blinded for the coronary angiography results before volume quantification. They were also blinded for their own measurements, as well as for the other operator's measurements.

Spearman's correlation and linear regression were performed for correlation analysis. Bland-Altman plot was used for agreement assessment among the different methods. Interobserver agreement was assessed by Cohen's kappa.

Results

Patient characteristics are shown in table 1. EF calculation was feasible in all patients.

There were excellent correlations between EF measured by SBP vs 3DE and RT3P vs 3DE (r=0.813 and r=0.9 respectively).

Test of equality between two correlation coefficients confirmed that EF by RT3P method is significantly more correlated with the reference method, compared with EF by SBP (p=0.004).

We have also performed a further analysis to study this results in special subsets. In anterior MI subset, EF by RT3P correlated by 0.909 with 3DE, versus 0.826 from EF by SBP (p=0.019). In inferior MI subset, EF by RT3P correlated by 0.779 with the reference method, versus 0.706 from EF by SBP (p=0.246).

Fig 1 Correlation and Bland-Altman plot

Conclusions

Estimation of EF using SBP and RT3P methods by experienced operators strongly correlate with EF determined by 3DE. The RT3P method showed the strongest correlation between the two methods, which may point to its usefulness in the evaluation of EF in patients with anterior wall motion abnormalities after myocardial infarction.

Selective Bond Excision in Nitroimidazoles by Electron Transfer Experiments

We have performed comprehensive charge-transfer experiments yielding negative ion formation in collisions of fast neutral potassium atoms with nitroimidazole and methylated derivative molecules. The anionic pattern reveals that in the unimolecular decomposition of the precursor parent anion, single and multiple bond cleavages are attained. Selective excision of hydrogen atoms from the N1 position in 4-nitroimidazole (4NI) is completely blocked upon methylation in 1-methyl-4-nitroimidazole (1m4NI) and 1-methyl-5-nitroimidazole (1m5NI). Additionally, only 4NI and 2-nitroimidazole (2NI) are efficient in selectively producing neutral ^•OH and NO^• radicals in contrast to 1m4NI and 1m5NI. These findings present a novel experimental evidence of selective chemical bond breaking by just tuning the proper collision energy in atom-molecule collision experiments. The present work contributes to the current need of pinpointing a class of charge-transfer collisions that exhibit selective reactivity of the kind demonstrated here, extending to tailored chemical control for different applications such as tumor radiation therapy through nitroimidazole-based radiosensitization.

Electronic structure and VUV photoabsorption measurements of thiophene

The absolute photoabsorption cross sections for thiophene in the 5.0-10.7 eV range were measured using synchrotron radiation. New theoretical calculations performed at the time-dependent density functional theory level were used to qualitatively interpret the recorded photoabsorption spectrum. The calculations facilitated a re-analysis of the observed vibronic and Rydberg structures in the photoabsorption spectrum. Here a number of features have been re-assigned, while a number of other features have been assigned for the first time. This represents the most comprehensive and self-consistent assignment of the thiophene high-resolution photoabsorption spectrum to date.

Targeted Theranostic Nanoparticles for Brain Tumor Treatment

The poor prognosis and rapid recurrence of glioblastoma (GB) are associated to its fast-growing process and invasive nature, which make difficult the complete removal of the cancer infiltrated tissues. Additionally, GB heterogeneity within and between patients demands a patient-focused method of treatment. Thus, the implementation of nanotechnology is an attractive approach considering all anatomic issues of GB, since it will potentially improve brain drug distribution, due to the interaction between the blood⁻brain barrier and nanoparticles (NPs). In recent years, theranostic techniques have also been proposed and regarded as promising. NPs are advantageous for this application, due to their respective size, easy surface modification and versatility to integrate multiple functional components in one system. The design of nanoparticles focused on therapeutic and diagnostic applications has increased exponentially for the treatment of cancer. This dual approach helps to understand the location of the tumor tissue, the biodistribution of nanoparticles, the progress and efficacy of the treatment, and is highly useful for personalized medicine-based therapeutic interventions. To improve theranostic approaches, different active strategies can be used to modulate the surface of the nanotheranostic particle, including surface markers, proteins, drugs or genes, and take advantage of the characteristics of the microenvironment using stimuli responsive triggers. This review focuses on the different strategies to improve the GB treatment, describing some cell surface markers and their ligands, and reports some strategies, and their efficacy, used in the current research.