Improvements in early interventions after acute myocardial infarction (AMI), notably, the increased use of timely reperfusion therapy, have increased survival dramatically in recent decades. Despite this, maladaptive ventricular remodelling and subsequent heart failure (HF) following AMI remain a significant clinical challenge, particularly because several pre-clinical strategies to attenuate remodelling have failed to translate into clinical practice. Monocytes and macrophages, pleiotropic cells of the innate immune system, are integral in both the initial inflammatory response to injury and subsequent wound healing in many tissues, including the heart. However, maladaptive immune cell behaviour contributes to ventricular remodelling in mouse models, prompting experimental efforts to modulate the immune response to prevent the development of HF. Seminal work in macrophage biology defined macrophages as monocyte-derived cells that are comprised of two populations, pro-inflammatory M1 macrophages and reparative M2 macrophages, and initial investigations into cardiac macrophage populations following AMI suggested they aligned well to this model. However, more recent data, in the heart and other tissues, demonstrate remarkable heterogeneity and plasticity in macrophage development, phenotype, and function. These recent insights into macrophage biology may explain the failure of non-specific immunosuppressive strategies and offer novel opportunities for therapeutic targeting to prevent HF following AMI. Here, we summarize the traditional monocyte-macrophage paradigm, experimental evidence for the significance of these cells in HF after AMI, and the potential relevance of emerging evidence that refutes canonical models of monocyte and macrophage biology.

Background Idiopathic recurrent pericarditis (IRP) is an orphan disease that carries significant morbidity, partly driven by corticosteroid dependence. Innate immune modulators, colchicine and anti‐interleukin‐1 agents, pioneered in monogenic autoinflammatory diseases, have demonstrated remarkable efficacy in trials, suggesting that autoinflammation may contribute to IRP. This study characterizes the phenotype of patients with IRP and monogenic autoinflammatory diseases, and establishes whether autoinflammatory disease genes are associated with IRP. Methods and Results We retrospectively analyzed the medical records of patients with IRP (n=136) and monogenic autoinflammatory diseases (n=1910) attending a national center (London, UK) between 2000 and 2021. We examined 4 genes ( MEFV, MVK, NLRP3, TNFRSF1A ) by next‐generation sequencing in 128 patients with IRP and compared the frequency of rare deleterious variants to controls obtained from the Genome Aggregation Database. In this cohort of patients with IRP, corticosteroid dependence was common (39/136, 28.7%) and was associated with chronic pain (adjusted odds ratio 2.8 [95% CI, 1.3–6.5], P =0.012). IRP frequently manifested with systemic inflammation (raised C‐reactive protein [121/136, 89.0%] and extrapericardial effusions [68/136, 50.0%]). Pericarditis was observed in all examined monogenic autoinflammatory diseases (0.4%–3.7% of cases). Rare deleterious MEFV variants were more frequent in IRP than in ancestry‐matched controls (allele frequency 9/200 versus 2932/129 200, P =0.040). Conclusions Pericarditis is a feature of interleukin‐1 driven monogenic autoinflammatory diseases and IRP is associated with variants in MEFV , a gene involved in interleukin‐1β processing. We also found that corticosteroid dependence in IRP is associated with chronic noninflammatory pain. Together these data implicate autoinflammation in IRP and support reducing reliance on corticosteroids in its management.

Objectives The systemic autoinflammatory diseases are rare conditions, to date data on COVID-19 infection and vaccination safety are scarce. Agents targeting innate immune pathways have transformed management of affected patients, and their outcomes are of wider interest given the role of inflammation in both viral clearance and severe COVID-19 disease. We surveyed patients with systemic autoinflammatory disease on biologic therapy to determine the prevalence and outcomes of COVID-19 infection and to gather early safety data on vaccination. Methods Electronic medical records of 248 patients with systemic autoinflammatory disease on biologic therapy at a national centre were reviewed. Patients were then surveyed in clinic or using a web-based survey. Results In the cohort of 248 patients, no deaths were recorded. 175 survey responses were received. Among the respondents, 27 reported suspected COVID-19 infection, of which 14 were confirmed by testing (8.0%). Two patients required admission due to dehydration. No patient required respiratory support or intensive care. 138 doses of COVID-19 vaccine had been administered to 130 patients. Side effects were reported following 71/138 (51.4%) administrations and were consistent with a flare of the underlying disease in 26/138 (18.8%) instances. No serious adverse events or hospital admissions were reported following vaccination. Conclusions These data, including the largest published series of patients on anti-Interleukin-1/6 biologics to receive any adenoviral vector or mRNA vaccine, show no serious early concerns regarding vaccination and will provide an urgently needed resource to inform decision making of these patients and their clinicians.