Association between ethnicity and degree of improvement in cardiac function following initiation of sacubitril/valsartan

AIMS

The aim of this study was to determine the degree of short-term improvement in left ventricular ejection fraction (LVEF), haemodynamics, NT-proBNP and quality of life following initiation of sacubitril/valsartan in black patients when compared with white patients.

METHODS

This was a retrospective, observational, single-centre, hypothesis-generating study of patients with symptomatic heart failure and reduced ejection fraction (HFrEF) treated with guideline recommended therapy, who were transitioned from an ACE inhibitor (ACE-I) or angiotensin receptor blocker (ARB) to sacubitril/valsartan.

RESULTS

Our analysis included 83 patients (mean age 57 years) with echocardiography performed before and after transition from ACE-I/ARB to sacubitril/valsartan, after excluding patients with concomitant Cardiac resynchronization therapy implantation. Overall, sacubitril/valsartan was associated with LVEF improvement from 28.8% ± 0.7 to 32.0% ± 1.1% (P = 0.0002), but no reverse remodelling was observed. The association with LVEF improvement was only observed in white patients (n = 46, P = 0.0006), but not in black patients (n = 37, P = 0.1728), and appeared to be associated with reduced blood pressure (baseline vs. 2-week blood pressure 116.5 ± 13.9 vs. 109.4 ± 14.3 mmHg, respectively, in white patients, P = 0.0449). Fifteen patients (18.1%) became ineligible for primary prevention Implantable cardioverter defibrillator implantation.

CONCLUSION

Sacubitril/valsartan was associated with improved LVEF, NT-proBNP concentrations and quality of life in patients with symptomatic HFrEF on guideline recommended therapy. However, in our cohort, improvement of LVEF and quality of life might be attenuated in black patients, which warrants further investigation.

Intracellular pH-sensing using core/shell silica nanoparticles

An in-depth understanding of biochemical processes occurring within biological systems is key for early diagnosis of disease and identification of appropriate treatments. Nanobiophotonics offers huge potential benefits for intracellular diagnostics and therapeutics. Intracellular sensing using fluorescent nanoparticles is a potentially useful tool for real-time, in vivo monitoring of important cellular analytes. This work is focused on synthesis of optical chemical nanosensors for the quantitative analysis of pH inside living cells. The structure of the nanosensor comprises a biofriendly silica matrix with co-encapsulated Texas Red, acting as a reference dye, and pH-sensitive fluorescein isothiocyanate enabling ratiometric quantitative environmental detection. In order to obtain silica-based nanoparticles -70 nm in size, a modified sol-gel-based Stöber method was employed. The potential of these nanosensors for intracellular pH monitoring is demonstrated inside a live human embryonic kidney cell line whereby a significant change in fluorescence is observed when the cell pH is switched from acidic to basic. High loading efficiencies of nanoparticles into the cells is seen, with little effect on cell morphology even following extended nanoparticle exposure (up to 72 h). Nanoparticle incubation time and the fast response of the nanosensor (-2 s) make it a very powerful tool in monitoring the processes occurring within the cytosol.