Prevalence, Characteristics, and Outcomes of COVID-19-Associated Acute Myocarditis.

BACKGROUND: Acute myocarditis (AM) is thought to be a rare cardiovascular complication of COVID-19, although minimal data are available beyond case reports. We aim to report the prevalence, baseline characteristics, in-hospital management, and outcomes for patients with COVID-19-associated AM on the basis of a retrospective cohort from 23 hospitals in the United States and Europe. METHODS: A total of 112 patients with suspected AM from 56 963 hospitalized patients with COVID-19 were evaluated between February 1, 2020, and April 30, 2021. Inclusion criteria were hospitalization for COVID-19 and a diagnosis of AM on the basis of endomyocardial biopsy or increased troponin level plus typical signs of AM on cardiac magnetic resonance imaging. We identified 97 patients with possible AM, and among them, 54 patients with definite/probable AM supported by endomyocardial biopsy in 17 (31.5%) patients or magnetic resonance imaging in 50 (92.6%). We analyzed patient characteristics, treatments, and outcomes among all COVID-19-associated AM. RESULTS: AM prevalence among hospitalized patients with COVID-19 was 2.4 per 1000 hospitalizations considering definite/probable and 4.1 per 1000 considering also possible AM. The median age of definite/probable cases was 38 years, and 38.9% were female. On admission, chest pain and dyspnea were the most frequent symptoms (55.5% and 53.7%, respectively). Thirty-one cases (57.4%) occurred in the absence of COVID-19-associated pneumonia. Twenty-one (38.9%) had a fulminant presentation requiring inotropic support or temporary mechanical circulatory support. The composite of in-hospital mortality or temporary mechanical circulatory support occurred in 20.4%. At 120 days, estimated mortality was 6.6%, 15.1% in patients with associated pneumonia versus 0% in patients without pneumonia (P=0.044). During hospitalization, left ventricular ejection fraction, assessed by echocardiography, improved from a median of 40% on admission to 55% at discharge (n=47; P<0.0001) similarly in patients with or without pneumonia. Corticosteroids were frequently administered (55.5%). CONCLUSIONS: AM occurrence is estimated between 2.4 and 4.1 out of 1000 patients hospitalized for COVID-19. The majority of AM occurs in the absence of pneumonia and is often complicated by hemodynamic instability. AM is a rare complication in patients hospitalized for COVID-19, with an outcome that differs on the basis of the presence of concomitant pneumonia.

Eosinophilic Myocarditis: Characteristics, Treatment, and Outcomes.

BACKGROUND: Eosinophilic myocarditis (EM) is an acute life-threatening inflammatory disease of the heart. Neither large case series nor clinical trials on this specific myocarditis have been reported. OBJECTIVES: Based on a systematic revision of all published histologically proven cases, this study aimed to describe the clinical presentation, treatment, and outcome of EM. METHODS: The study screened 443 manuscripts in MEDLINE and EMBASE on cases of EM published until June 2017. The authors identified 264 patients and included in the main analysis 179 patients admitted to hospital with histologically proven EM. RESULTS: Median age was 41 years (interquartile range: 27 to 53 years) with similar prevalence in both sexes; pediatric cases (≤16 years of age) accounted for 10.1%. The main symptom at presentation was dyspnea (59.4%), with peripheral eosinophilia observed in 75.9%. Median left ventricular ejection fraction at presentation was 35% (interquartile range: 25% to 50%). The disorders most frequently associated with EM were hypersensitivity and eosinophilic granulomatosis with polyangiitis, which accounted for 34.1% and 12.8% of cases, respectively, whereas idiopathic or undefined forms accounted for 35.7% of cases. Steroids were administered in 77.7% of patients. A temporary mechanical circulatory support (n = 30) was instituted in 16.8% of patients. In-hospital death was 22.3% (n = 40), with the highest occurrence in the hypersensitivity form (36.1%; p = 0.026). CONCLUSIONS: EM has a poor prognosis during the acute phase, despite a publication bias that could have led to an overestimation of mortality. Associated conditions are identified in approximately 65% of cases. Specific trials and multicenter registries are needed to provide evidence-based treatments to improve in-hospital outcome.