Impact of right ventricular dysfunction after MitraClip treatment as a bridge to heart transplantation: insights from the MitraBridge registry

Background

MitraClip treatment has been recently proposed as a “bridge strategy” solution for advanced heart failure (HF) patients with significant functional mitral regurgitation (MR), who are potential candidates or are waiting for cardiac replacement therapy (LVAD or heart transplantation, HTx). In this clinical scenario, left-ventricular-related right ventricular dysfunction (RVD) represents an important prognostic factor.

Purpose

Our study aimed to investigate the possible prognostic implication of RVD in advanced HF patients treated with MitraClip as a bridge to HTx strategy.

Methods

RVD was assessed using the relationship between tricuspid annular peak systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP). All patients from the MitraBridge registry for whom these two echocardiographic parameters were available, were included in the study. A cut-off value of TAPSE/PASP ratio <0.36 was used to defined RVD, as previously reported. The primary outcome was a composite end-point of all-cause death or rehospitalization for HF at 2-year. For patients who underwent LVAD implantation or HTx, follow-up data were censored at the time of those events.

Results

A total of 80 patients were included in the study. The median TAPSE/PASP ratio was 0.35 (25th-75th: 0.27–0.46), with 43 (54%) patients having a TAPSE/PASP ratio <0.36 (RVD group). The latter had a prevalent MR ischemic etiology (49% vs 38%), with a more frequent history of percutaneous coronary intervention (46.5% vs 22%, p=0.02). Except for TAPSE (15.7±3.6 mm vs 19.2±3.7 mm, p=0.001) and PASP (61±14 mmHg vs 39.5±9.5 mmHg, p<0.001), the other echocardiographic characteristics were similar between the two study groups (overall mean left ventricular ejection fraction 26.9±8%, median left ventricular end-diastolic volume index 120.7, 25th-75th: 102.2–146.5 mL/m2). After a median follow-up time of 508 (25th-75th: 160–899) days, elective HTx occurred in 12 patients (7 from the RVD group), while LVAD implantation was performed in 13 patients (7 from the RVD group). The primary outcome occurred in 30 patients (38%) with a 2-year Kaplan-Meier estimate of freedom from the composite end-point of 41%. At univariate (HR 1.3 95% CI 0.6–2.8, p=0.451) and multivariate (HR 1.6 CI 0.7–3.8, p=0.249) Cox-regression analysis, TAPSE/PASP ratio <0.36 was not identified as an independent predictor of primary outcome. Indeed, at follow-up echocardiographic control (median time 252, 25th-75th: 122–365 days), a significant improvement in TAPSE/PASP ratio was observed in the RVD group (baseline median TAPSE/PASP ratio 0.27, 25th-75th: 0.22–0.32 vs follow-up median TAPSE/PASP ratio 0.37, 25th-75th: 0.28–0.47, p<0.001).

Conclusion

In advanced HF patients with functional MR, MitraClip treatment could prevent or ameliorate left-ventricular-related RVD, allowing safe access to HTx or LVAD.

Funding Acknowledgement

Type of funding sources: None.

Implementation of a Rooftop Farm Integrated With a Teaching Kitchen and Preventive Food Pantry in a Hospital Setting

Safety-net hospitals serving populations with disproportionately high levels of poverty, food insecurity, and chronic disease can utilize innovative strategies to improve the health and environment of their communities. Boston Medical Center in Boston, Massachusetts, constructed an on-site rooftop farm to provide fresh produce for the hospital's preventive food pantry, teaching kitchen, cafeterias, and inpatient meal services. This novel model can be replicated by other organizations aiming to alleviate food insecurity, encourage healthy eating, and promote environmental sustainability.

Prediction of high on-treatment platelet reactivity in clopidogrel-treated patients with acute coronary syndromes

BACKGROUND

About 40% of clopidogrel-treated patients display high platelet reactivity (HPR). Alternative treatments of HPR patients, identified by platelet function tests, failed to improve their clinical outcomes in large randomized clinical trials. A more appealing alternative would be to identify HPR patients a priori, based on the presence/absence of demographic, clinical and genetic factors that affect PR. Due to the complexity and multiplicity of these factors, traditional statistical methods (TSMs) fail to identify a priori HPR patients accurately. The objective was to test whether Artificial Neural Networks (ANNs) or other Machine Learning Systems (MLSs), which use algorithms to extract model-like 'structure' information from a given set of data, accurately predict platelet reactivity (PR) in clopidogrel-treated patients.

METHODS

A complete set of fifty-nine demographic, clinical, genetic data was available of 603 patients with acute coronary syndromes enrolled in the prospective GEPRESS study, which showed that HPR after 1month of clopidogrel treatment independently predicted adverse cardiovascular events in patients with Syntax Score >14. Data were analysed by MLSs and TSMs. ANNs identified more variables associated PR at 1month, compared to TSMs.

RESULTS

ANNs overall accuracy in predicting PR, although superior to other MLSs was 63% (95% CI 59-66). PR phenotype changed in both directions in 35% of patients across the 3 time points tested (before PCI, at hospital discharge and at 1month).

CONCLUSIONS

Despite their ability to analyse very complex non-linear phenomena, ANNs or MLS were unable to predict PR accurately, likely because PR is a highly unstable phenotype.

[Atheroembolic renal disease]

Atheroembolic renal disease can be defined as renal failure due to occlusion of the renal arterioles by cholesterol crystal emboli usually dislodged from ulcerated atherosclerotic plaques of the aorta. Atheroembolic renal disease is part of multisystem disease, since the embolization usually involves other organ systems such as the gastrointestinal system, central nervous system, and lower extremities. The kidney is frequently involved because of the proximity of the renal arteries to the abdominal aorta, where erosion of atheromatous plaques is most likely to occur. Embolization may occur spontaneously or after angiographic procedures, vascular surgery, and anticoagulation. In the last decade, atheroembolic renal disease has become a recognizable cause of renal disease. An ante-mortem diagnosis of the disease is possible in a significant proportion of cases as long as the level of diagnostic suspicion is high. The disease can severely affect kidney and patient survival. Although no specific treatment has been proven efficacious, use of statins may be justifiable and such therapy would be a reasonable choice for future treatment trials.

A novel 19F-NMR method for the investigation of the antioxidant capacity of biomolecules and biofluids

A new assay for the measurement of the antioxidant capacity of biomolecules by high resolution 19F-NMR spectroscopy is presented here. This method is based on the use of trifluoroacetanilidic detectors, namely trifluoroacetanilide, N-(4-hydroxyphenyl)-trifluoroacetamide and 2-hydroxy-4-trifluoroacetamidobenzoic acid. Upon hydroxyl radical attack, such fluorinated detectors yield trifluoroacetamide and trifluoroacetic acid that can be quantitatively determined by 19F-NMR spectroscopy. Trifluoroacetamide was found to be a reliable reporter of hydroxyl radical attack on the fluorinated detectors, whereas N-(4-hydroxyphenyl)-trifluoroacetamide was found to be the most sensitive detector amongst the ones considered. Therefore, N-(4-hydroxyphenyl)-trifluoroacetamide has been used in competition experiments to assess the antioxidant capacity of a number of low and high molecular weight antioxidants. The antioxidant capacity of a given compound has been scaled in terms of an adimensional parameter, kF, that represents the ratio between the scavenger abilities of the fluorinated detector and the competitor. kF values obtained for low-molecular-mass compounds fall in the range 0.17 < kF < 1.5 and are in good agreement with second order rate constants (k2OH) for the reaction of the antioxidant with hydroxyl radicals. The kF value for serum albumin is much larger (46.9) than that predicted from the reported k2OH value. This finding supports the view that the protein can very effectively scavenge hydroxyl radicals as well as secondary radicals. Human blood serum showed that its antioxidant capacity is even higher than that shown by aqueous solutions of albumin at physiologic concentration suggesting a further contribution from other macromolecular serum components.