Candidacy for heart transplantation in adult congenital heart disease patients: a cohort study

Objective

The object of the present study is to evaluate factors precluding heart transplantation (HTx) in adult congenital heart disease patients (ACHD) with end-stage heart failure (HF) referred for HTx evaluation.

Methods

This retrospective cohort study enrolled consecutive ACHD patients considered for HTx in our institution between 2014 and 2020 and patients receiving HTx between 2001 and 2013. HTx refusal due to poor candidacy status for excess risk of mortality after transplantation, served as the main study outcome.

Results

Between 2014 and 2020, 46 ACHD patients were evaluated for HTx, 14 ACHD patients underwent HTx between 2001 and 2013. We compared clinical, anatomical and demographic data of 41 patients suitable for transplantation (including both listed/transplanted patients, not yet listed because too well and patients who chose to refuse transplantation) with 15 patients refused after screening (excluding 4 patients with ongoing screening). Risk factors for refusal were: multiple high risk features (odds ratio [OR]: 3.6; 95% confidence interval [CI]: 1.1 to 12.9; p 0.048); anatomical factors (OR: 14.5; 95% CI: 3.1 to 68.4; p 0.001), out-of-center ACHD/HTx program referral (OR: 5.3; 95% CI: 1.5 to 19.0; p 0.01). HTx refusal identifies a high risk ACHD patient subgroup (hazard ratio for overall mortality: 3.1; 95% CI: 1.1 to 8.3; p 0.02).

Conclusions

In our study risk factors for refusal from HTx are adverse anatomical features, multiple conventional HTx high risk factors and out-of-center referral. ACHD patients refused from HTx present shorter time to death. Efforts to increase HTx candidacy are strongly necessary for this growing population.

Funding Acknowledgement

Type of funding sources: None.

Enhanced detection of terrestrial gamma-ray flashes by AGILE

At the end of March 2015 the onboard software configuration of the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite was modified in order to disable the veto signal of the anticoincidence shield for the minicalorimeter instrument. The motivation for such a change was the understanding that the dead time induced by the anticoincidence prevented the detection of a large fraction of Terrestrial Gamma-Ray Flashes (TGFs). The configuration change was highly successful resulting in an increase of one order of magnitude in TGF detection rate. As expected, the largest fraction of the new events has short duration (<100 μs), and part of them has simultaneous association with lightning sferics detected by the World Wide Lightning Location Network. The new configuration provides the largest TGF detection rate surface density (TGFs/km²/yr) to date, opening prospects for improved correlation studies with lightning and atmospheric parameters on short spatial and temporal scales along the equatorial region.

Terrestrial gamma-ray flashes as powerful particle accelerators

Strong electric discharges associated with thunderstorms can produce terrestrial gamma-ray flashes (TGFs), i.e., intense bursts of x rays and γ rays lasting a few milliseconds or less. We present in this Letter new TGF timing and spectral data based on the observations of the Italian Space Agency AGILE satellite. We determine that the TGF emission above 10 MeV has a significant power-law spectral component reaching energies up to 100 MeV. These results challenge TGF theoretical models based on runaway electron acceleration. The TGF discharge electric field accelerates particles over the large distances for which maximal voltages of hundreds of megavolts can be established. The combination of huge potentials and large electric fields in TGFs can efficiently accelerate particles in large numbers, and we reconsider here the photon spectrum and the neutron production by photonuclear reactions in the atmosphere.

Gamma-ray localization of terrestrial gamma-ray flashes

Terrestrial gamma-ray flashes (TGFs) are very short bursts of high-energy photons and electrons originating in Earth's atmosphere. We present here a localization study of TGFs carried out at gamma-ray energies above 20 MeV based on an innovative event selection method. We use the AGILE satellite Silicon Tracker data that for the first time have been correlated with TGFs detected by the AGILE Mini-Calorimeter. We detect 8 TGFs with gamma-ray photons of energies above 20 MeV localized by the AGILE gamma-ray imager with an accuracy of ∼5-10° at 50 MeV. Remarkably, all TGF-associated gamma rays are compatible with a terrestrial production site closer to the subsatellite point than 400 km. Considering that our gamma rays reach the AGILE satellite at 540 km altitude with limited scattering or attenuation, our measurements provide the first precise direct localization of TGFs from space.

Effect of short-term treatment with bezafibrate on plasma fibrinogen, fibrinopeptide A, platelet activation and blood filterability in atherosclerotic hyperfibrinogenemic patients

The effect of bezafibrate (BZF) on plasma fibrinogen levels has been studied in 62 patients with atherosclerotic vasculopathy and hyperfibrinogenemia (643 +/- 15 (SEM) mg/dl). In a preliminary study, 15-30 days of BZF therapy (400-600 mg/day) normalized fibrinogen values in 16 subjects were compared to 16 controls. The effect was rapid and dose-dependent, and discontinuation in 6 patients who could not complete the study was followed by a rebound increase. A controlled study with 400 mg/day in the other 24 patients for 15 days showed that BZF lowered fibrinogen, PF4, blood filterability and platelet aggregating thresholds to the normal range. BTG and FpA decreased significantly compared to the placebo group (12 and 12 patients randomly distributed) without any variation in potentially biassing hematologic values (WBC, PLTS, Ht, lipids and plasma glucose). BZF may be of value in chronic treatment of hyperfibrinogenemia in atherosclerotic patients with a view to improving the haemorheologic pattern and, hence, reducing activation of the coagulation pathway.