An update on the pathophysiology of acute and recurrent pericarditis.

INTRODUCTION: Pericarditis is an inflammatory disease of the pericardium. Progress has been done in recent years in the understanding of its pathophysiology. In particular, preclinical and clinical studies have contributed to increasing our knowledge on the role of interleukin (IL)-1 and NLRP3 (NACHT, leucine-rich repeat, and pyrin domain-containing protein 3) inflammasome. EVIDENCE ACQUISITION: Information for this study has been retrieved in original articles, reviews, systematic reviews, and meta-analyses identified through PubMed using the following search terms (or combination of terms): "pericarditis," "acute pericarditis," "recurrent pericarditis," "idiopathic recurrent acute pericarditis," "autoimmunity," "autoinflammation," "outcomes." Only articles published in English were included. Additional papers identified from the reference list of the retrieved articles were also considered. EVIDENCE SYNTHESIS: Based on current evidence, pericarditis should be considered as an inflammatory reaction to various stimuli, including chemical/physical, infectious, or ischemic ones, with a viral infection being a common etiology. Interaction of pathogens or irritants with toll-like receptor (TLRs) and stimulation of IL-1 receptor by IL-1α and IL-1ß leads to an increased transcription of proinflammatory genes, including those needed for NLRP3 inflammasome assembly. This pathway is confirmed indirectly by the beneficial effect of colchicine (an indirect NLRP3 inflammasome inhibitor) and IL-1 blockers in patients with recurrent pericarditis. More recently, a direct evidence of the NLRP3 inflammasome within the inflamed pericardium has been provided as well. It may, however, occur that self-antigens on the surface of mesothelial cells or microbial peptides may stimulate autoreactive T cells along with B cells producing antiheart antibodies, although less evidence is available on this. CONCLUSIONS: Some uncertainties still remain about the role of neutrophils, neutrophil extracellular traps (NETs), and pericardial interstitial cells in recurrent and constrictive pericarditis. Unraveling these aspects might have a direct impact on the development of novel targeted therapies, especially considering the increasing number of drugs targeting NETs.

Fluorinated steroids are not superior to any treatment to ameliorate the outcome of autoimmune mediated congenital heart block: a systematic review of the literature and meta-analysis.

OBJECTIVES: Fluorinated steroids are largely the therapeutic approach of autoimmune mediated congenital heart block (CHB). We performed a meta-analysis to assess the efficacy of fluorinated steroids for the treatment of CHB. METHODS: Studies evaluating the efficacy of fluorinated steroids versus no treatment in CHB patients were identified in electronic databases. Random-effects model was used to pool odds ratio (OR) (with 95% CI) of live births as the primary outcome. ORs of CHB progression, pacemaker implantation and extranodal disease were the secondary outcome. Subgroup analysis according to CHB grade and study type was performed. RESULTS: Data from nine studies involving 747 patients were analysed. The overall live birth rates were 86.8% and 86.7%, respectively, in the fluorinated steroids exposed foetuses and in the non-exposed ones. Fluorinated steroids did not ameliorate overall survival in CHB (OR 1.02; 95% CI: 0.65-1.61) with any significant statistical heterogeneity between studies (I2 0%, p=0.45). No significant differences for the progression of CHB, the pacing and the presence of extranodal disease were observed. Subgroup analysis revealed a significant protective role of fluorinated steroids for survival in 3rd degree CHB and for pacing in monocentric studies, OR 4.07; 95% CI: 1.10-15.08 and OR 0.15; 95% CI: 0.02-0.99, respectively. CONCLUSIONS: This meta-analysis shows that fluorinated steroids are not superior to any treatment in patients with CHB in terms of live birth, prevention of progression of incomplete CHB, pacemaker implantation and extranodal disease. Thus, considering their side effects, their use in CHB patients should be discouraged.

Myocardial edema in paroxysmal permeability disorders: The paradigm of Clarkson's disease.

PURPOSE: Paroxysmal Permeability Disorders (PPDs) comprise a variety of diseases characterized by recurrent and transitory increase of endothelial permeability. Idiopathic Systemic Capillary Leak Syndrome (ISCLS) is a rare PPD that leads to an abrupt massive shift of fluids and proteins from the intravascular to the interstitial compartment. In some cases, tissue edema may involve the myocardium, but its role in the development of shock has not been elucidated so far. MATERIALS AND METHODS: Assessment of cardiac involvement during ten life-threatening ISCLS episodes admitted to ICU. RESULTS: Transthoracic echocardiographic examination was performed in eight episodes, whereas a poor acoustic window prevented cardiac ultrasound assessment in two episodes. Myocardial edema was detected by echocardiography in eight episodes and marked pericardial effusion in one-episode. Cardiac magnetic resonance showed diffuse myocardial edema in another episode. In one case, myocardial edema caused fulminant left ventricular dysfunction, which required extracorporeal life support. The mean septum thickness was higher during the shock phase compared to the recovery phase [15.5 mm (13.1-21 mm) vs. 9.9 mm (9-11.3 mm), p = .0003]. Myocardial edema resolved within 72 h. CONCLUSIONS: During early phases of ISCLS, myocardial edema commonly occurs and can induce transient myocardial dysfunction, potentially contributing to the pathogenesis of shock.

International collaborative systematic review of controlled clinical trials on pharmacologic treatments for acute pericarditis and its recurrences.

BACKGROUND: Acute pericarditis is common, yet uncertainty persists on its treatment. We thus aimed to conduct a comprehensive systematic review on pharmacologic treatments for acute or recurrent pericarditis. METHODS: Controlled clinical studies were searched in several databases and were included provided they focused on pharmacologic agents for acute pericarditis or its recurrences. Random-effect odds ratios (ORs) were computed for long-term treatment failure, pericarditis recurrence, rehospitalization, and adverse drug effects. RESULTS: From 2,078 citations, 7 studies were finally included (451 patients); but only 3 were randomized trials. Treatment comparisons were as follows: colchicine versus standard therapy (3 studies, 265 patients), steroids versus standard therapy (2 studies, 31 patients), low-dose versus high-dose steroids (1 study, 100 patients), and statins versus standard therapy (1 study, 55 patients). Colchicine was associated with a reduced risk of treatment failure (OR = 0.23 [0.11-0.49]) and recurrent pericarditis (OR = 0.39 [0.20-0.77]), but with a trend toward more adverse effects (OR = 5.27 [0.86-32.16]). Overall, steroids were associated with a trend toward increased risk of recurrent pericarditis (OR = 7.50 [0.62-90.65]). Conversely, low-dose steroids proved superior to high-dose steroids for treatment failure or recurrent pericarditis (OR = 0.29 [0.13-0.66]), rehospitalizations (OR = 0.19 [0.06-0.63]), and adverse effects (OR = 0.07 [0.01-0.54]). Data on statins were inconclusive. CONCLUSIONS: Clinical evidence informing decision-making for the management of acute pericarditis and its recurrences is still limited to few, small, and/or low-quality clinical studies. Notwithstanding such major caveats, available studies routinely using nonsteroidal anti-inflammatory agents in both experimental and control groups suggest a beneficial risk-benefit profile for colchicine and a detrimental one for steroids, especially when used at high dosages.