Dynamic trend of lung fluid movement during exercise in heart failure: From lung imaging to alveolar-capillary membrane function.

BACKGROUND: In chronic heart failure (HF), exercise-induced increase in pulmonary capillary pressure may cause an increase of pulmonary congestion, or the development of pulmonary oedema. We sought to assess in HF patients the exercise-induced intra-thoracic fluid movements, by measuring plasma brain natriuretic peptide (BNP), lung comets and lung diffusion for carbon monoxide (DLCO) and nitric oxide (DLNO), as markers of hemodynamic load changes, interstitial space and alveolar-capillary membrane fluids, respectively. METHODS AND RESULTS: Twenty-four reduced ejection fraction HF patients underwent BNP, lung comets and DLCO/DLNO measurements before, at peak and 1 h after the end of a maximal cardiopulmonary exercise test. BNP significantly increased at peak from 549 (328-841) to 691 (382-1207, p < 0.0001) pg/mL and almost completely returned to baseline value 1 h after exercise. Comets number increased at peak from 9.4 ± 8.2 to 24.3 ± 16.7, returning to baseline (9.7 ± 7.4) after 1 h (p < 0.0001). DLCO did not change significantly at peak (from 18.01 ± 4.72 to 18.22 ± 4.73 mL/min/mmHg), but was significantly reduced at 1 h (16.97 ± 4.26 mL/min/mmHg) compared to both baseline (p = 0.0211) and peak (p = 0.0174). DLNO showed a not significant trend toward lower values 1 h post-exercise. CONCLUSIONS: Moderate/severe HF patients have a 2-step intra-thoracic fluid movement with exercise: the first during active exercise, from the vascular space toward the interstitial space, as confirmed by comets increase, without any effect on diffusion, and the second, during recovery, toward the alveolar-capillary membrane, clearing the interstitial space but worsening gas diffusion.

[Recent advances on the studies of the platelet's inhibition and aggregation. State of the art of new P2Y12 antagonists]. / Recenti progressi nello studio dell'attivazione e dell'aggregazione delle piastrine.

The interaction of ADP with its platelet receptor P2Y12 plays a crucial role in platelet activation and thrombogenesis. This article reviews the pharmacology and clinical trials of specific antagonists of P2Y12. Clopidogrel is a thienopyridine with proven antithrombotic efficacy, but it has some important drawbacks: i) it is a pro-drug that needs to be metabolized to its active metabolite; ii) it has a delayed onset and offset of action; iii) there is high inter-individual variability in pharmacological response. Prasugrel is also a thienopyridine, with faster onset of action and more uniform inhibition of platelet function compared to clopidogrel, accounting for lower incidence of ischemic events in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) and higher incidence of both non-CABG (Coronary Artery Bypass Grafting) related bleeding complications. Two direct and reversible P2Y12 antagonists, cangrelor and ticagrelor, are characterized by rapid onset and reversal of platelet inhibition. Cangrelor did not prove superior to clopidogrel in preventing thrombotic events in patients undergoing PCI. Ticagrelor proved to be superior to clopidogrel in preventing major adverse cardiac events in ACS patients, but was, like prasugrel, was associated with higher frequency of non-CABG-related bleeding complications. A shorter period of drug discontinuation before surgery was necessary in ticagrelor-treated patients compared to clopidogrel-treated patients to limit the severity of post-surgical bleeding.