[ANMCO/SIC Consensus document on the management of myocarditis]

Global, Regional, and National Burden of Myocarditis in 204 Countries and Territories From 1990 to 2019: Updated Systematic Analysis

BACKGROUND

Myocarditis is characterized by high disability and mortality, and imposes a severe burden on population health globally. However, the latest global magnitude and secular trend of myocarditis burden have not been reported.

OBJECTIVE

This study aimed to delineate the epidemiological characteristics of myocarditis burden globally for optimizing targeted prevention and research.

METHODS

Based on the Global Burden of Disease Study 2019, the myocarditis burden from 1990 to 2019 was modeled using the Cause of Death Ensemble tool, DisMod-MR, and spatiotemporal Gaussian regression. We depicted the epidemiology and trends of myocarditis by sex, age, year, region, and sociodemographic index (SDI). R program version 4.2.1 (R Project for Statistical Computing) was applied for all statistical analyses, and a 2-sided P-value of <.05 was considered statistically significant.

RESULTS

The number of incident cases (1,268,000) and deaths (32,450) associated with myocarditis in 2019 increased by over 1.6 times compared with the values in 1990 globally. On the other hand, the age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) decreased slightly from 1990 to 2019. The disability-adjusted life years (DALYs) decreased slightly in the past 3 decades, while the age-standardized DALY rate (ASDR) decreased greatly from 18.29 per 100,000 person-years in 1990 to 12.81 per 100,000 person-years in 2019. High SDI regions always showed a more significant ASIR. The ASIR slightly decreased in all SDI regions between 1990 and 2019. Middle SDI regions had the highest ASMR and ASDR in 2019. Low SDI regions had the lowest ASMR and ASDR in 2019. The age-standardized rates (ASRs) of myocarditis were higher among males than among females from 1990 to 2019 globally. All ASRs among both sexes had a downward trend, except for the ASMR among males, which showed a stable trend, and females had a more significant decrease in the ASDR than males. Senior citizens had high incident cases and deaths among both sexes in 2019. The peak numbers of DALYs for both sexes were noted in the under 1 age group in 2019. At the national level, the estimated annual percentage changes in the ASRs had significant negative correlations with the baseline ASRs in 1990.

CONCLUSIONS

Globally, the number of incident cases and deaths associated with myocarditis have increased significantly. On the other hand, the ASRs of myocarditis showed decreasing trends from 1990 to 2019. Males consistently showed higher ASRs of myocarditis than females from 1990 to 2019 globally. Senior citizens gradually predominated in terms of myocarditis burden. Policymakers should establish targeted control strategies based on gender, region, age, and SDI; strengthen aging-related health research; and take notice of the changes in the epidemic characteristics of myocarditis.

Left Ventricular Mass with Delayed Enhancement as a Predictor of Major Events in Patients with Myocarditis with Preserved Ejection Fraction

Background: Cardiac Magnetic Resonance (CMR) has a key role in subjects presenting with acute myocarditis, independent from left ventricular ejection fraction; it is widely used as a non-invasive imaging test for both diagnostic and prognostic purposes. However, poor data is available about the CMR-derived prognostic parameters of acute myocarditis with preserved ejection fraction (AMpEF). The aim of this study was to investigate the role of CMR in predicting outcomes in patients followed up for AMpEF, using a composite endpoint of all-cause mortality and hospitalization for heart failure (HF). Methods: We retrospectively enrolled 61 patients with diagnosed AMpEF. All patients underwent biohumoral, echocardiographic and CMR evaluation in the acute phase. Myocarditis was confirmed by Lake–Louis criteria assessed on CMR images. Mean follow-up was 4.8 ± 0.6 years during which a composite endpoint of all-cause mortality and hospitalization for HF was investigated. Results: The population was fairly homogeneous regarding baseline clinical features. In particular, no significant differences in age and main cardiovascular risk factors were found between patients with and without events at follow-up. Seven patients met the endpoint. They had significantly higher levels of circulating neutrophils in the acute phase (76 ± 7% vs. 61 ± 11%, p = 0.014) and a higher amount of left ventricular mass with delayed enhancement (DE-LVM, 18 (14–29.5) vs. 12 (8–16) g, p = 0.028). At Cox univariate analysis, DE-LVM was the only significant predictor of endpoint, regardless of the site of inflammation. Conclusions: DE-LVM can predict the composite endpoint of all-cause mortality and hospitalization for HF in a population of patients with AMpEF, representing a new added tool for prognostic stratification.