Biological Sex and Its Impact on Clinical Characteristics in Patients Presenting with Myocarditis

Sex-Based Differences in Clinical Characteristics of Patients with Acute Myocarditis: A Cohort Study

BACKGROUND

This study investigated sex differences in acute myocarditis patients during index hospitalization.

METHODS

We included 365 patients with acute myocarditis, hospitalized with continuous monitoring at the intensive care unit from 2000-2023 into the Basel Myocarditis Cohort study. We compared sex differences in clinical presentation, the presenting electrocardiogram, prior medical history, inflammatory and cardiac biomarkers, cardiac imaging, arrhythmia occurrence, and short- to midterm outcomes.

RESULTS

Mean age was 41.3 years, and 26.3% were female. Compared with men, women were older (median 49.7 vs 38.3 years, P < .001) at the time of diagnosis and presented more frequently with dyspnea (41 vs 26%, P = .013) and a higher Killip class (P = .011). In the presenting electrocardiogram, men had a higher occurrence of diffuse ST-elevation (38 vs 9%, P < .001) and PQ-depression (31 vs 20%, P = .042), compared with women. Women had higher N-terminal pro B-type natriuretic peptide levels (1180 vs 387 ng/L, P = .015), lower cardiac troponin T levels (389 vs 726 ng/L, P = .006), and fewer segments with nonischemic late gadolinium enhancement on cardiac magnetic resonance imaging (1 vs 3, P = .005), but similar left ventricular ejection fraction (55 vs 55%, P = .629), compared with men. Overall, hospital stay was longer in women compared with men (7 vs 5 days, P = .018), with a similar length of intensive care unit stay (2.6 vs 2.7 days, P = .922). Women more often developed severe arrhythmia (8.3 vs 2.2%, P = .015) and heart failure during the hospitalization (31.3 vs 16.4%, P = .003).

CONCLUSION

Compared with men, women with acute myocarditis were older at the time of diagnosis, presented more often with heart failure, and had an increased frequency of severe arrhythmia.

The Influence of Biological Sex on Presentation and Outcomes of Acute Myocarditis: A Systematic Review and Meta-Analysis

There is growing evidence of sex-related differences in the epidemiology and pathophysiology of cardiovascular diseases. This is the first systematic review and meta-analysis that aimed to highlight the sex-specific differences in the clinical features and outcomes of acute myocarditis. Electronic searches were performed on Scopus, Embase, and PubMed from inception up to June 2023 to identify studies comparing the clinical features and outcomes of acute myocarditis in males and females. Both qualitative and quantitative summaries were conducted. In this systematic review and meta-analysis of 11 studies involving 34,791 patients presenting with acute myocarditis. Male patients, who comprised 69.8% of the entire pooled population, presented at a markedly younger age (mean difference: -8.99 years; 95% CI: -13.60, -4.38; p=0.0001). They also had significantly lower rates of hypertension, diabetes mellitus, and coronary artery disease compared to female patients (p<0.01). Male patients were more likely to present with ST elevation (RR: 2.57 [1.38, 4.79]; p=0.003) and higher C-reactive protein levels (RR: 3.04 [2.75, 3.34]; p<0.00001) compared to female patients. This review underscores the crucial sex-specific evaluation in acute myocarditis, necessitating tailored approaches in assessment and diagnostic evaluation, and emphasizing the need for additional research in this domain.

Sex differences in myocarditis hospitalizations: Rates, outcomes, and hospital characteristics in the National Readmission Database

Inflammation of the myocardium, or myocarditis, presents with varied severity, from mild to life-threatening such as cardiogenic shock or ventricular tachycardia storm. Existing data on sex-related differences in its presentation and outcomes are scarce. Using the Nationwide Readmission Database (2016-2019), we identified myocarditis hospitalizations and stratified them according to sex to either males or females. Multivariable regression analyses were used to determine the association between sex and myocarditis outcomes. The primary outcome was in-hospital mortality, and the secondary outcomes included sudden cardiac death (SCD), cardiogenic shock (CS), use of mechanical circulatory support (MCS), and 90-day readmissions. We found a total of 12,997 myocarditis hospitalizations, among which 4,884 (37.6 %) were females. Compared to males, females were older (51 ± 15.6 years vs. 41.9 ± 14.8 in males) and more likely to have connective tissue disease, obesity, and a history of coronary artery disease. No differences were noted between the two groups with regards to in-hospital mortality (adjusted odds ratio [aOR] 1.20; confidence interval [CI] 0.93-1.53; P = 0.16), SCD (aOR:1.18; CI 0.84-1.64; P = 0.34), CS (aOR: 1.01; CI 0.85-1.20;P = 0.87), or use of MCS (aOR: 1.07; CI:0.86-1.34; P = 0.56). In terms of interventional procedures, females had lower rates of coronary angiography (aOR: 0.78; CI 0.70-0.88; P < 0.01), however, similar rates of right heart catheterization (aOR 0.93; CI:0.79-1.09; P = 0.36) and myocardial biopsy (aOR: 1.16; CI:0.83-1.62; P = 0.38) compared to males. Additionally, females had a higher risk of 90-day all-cause readmission (aOR: 1.25; CI: 1.16-1.56; P < 0.01) and myocarditis readmission (aOR:1.58; CI 1.02-2.44; P = 0.04). Specific predictors of readmission included essential hypertension, congestive heart failure, malignancy, and peripheral vascular disease. In conclusion, females admitted with myocarditis tend to have similar in-hospital outcomes with males; however, they are at higher risk of readmission within 90 days from hospitalization. Further studies are needed to identify those at higher risk of readmission.

Sex and gender differences in myocarditis and dilated cardiomyopathy: An update

In the past decade there has been a growing interest in understanding sex and gender differences in myocarditis and dilated cardiomyopathy (DCM), and the purpose of this review is to provide an update on this topic including epidemiology, pathogenesis and clinical presentation, diagnosis and management. Recently, many clinical studies have been conducted examining sex differences in myocarditis. Studies consistently report that myocarditis occurs more often in men than women with a sex ratio ranging from 1:2-4 female to male. Studies reveal that DCM also has a sex ratio of around 1:3 women to men and this is also true for familial/genetic forms of DCM. Animal models have demonstrated that DCM develops after myocarditis in susceptible mouse strains and evidence exists for this progress clinically as well. A consistent finding is that myocarditis occurs primarily in men under 50 years of age, but in women after age 50 or post-menopause. In contrast, DCM typically occurs after age 50, although the age that post-myocarditis DCM occurs has not been investigated. In a small study, more men with myocarditis presented with symptoms of chest pain while women presented with dyspnea. Men with myocarditis have been found to have higher levels of heart failure biomarkers soluble ST2, creatine kinase, myoglobin and T helper 17-associated cytokines while women develop a better regulatory immune response. Studies of the pathogenesis of disease have found that Toll-like receptor (TLR)2 and TLR4 signaling pathways play a central role in increasing inflammation during myocarditis and in promoting remodeling and fibrosis that leads to DCM, and all of these pathways are elevated in males. Management of myocarditis follows heart failure guidelines and there are currently no disease-specific therapies. Research on standard heart failure medications reveal important sex differences. Overall, many advances in our understanding of the effect of biologic sex on myocarditis and DCM have occurred over the past decade, but many gaps in our understanding remain. A better understanding of sex and gender effects are needed to develop disease-targeted and individualized medicine approaches in the future.

Prognostic relevance of demographic factors in cardiac magnetic resonance-proven acute myocarditis: A cohort study

Aim

Acute myocarditis (AM) is a heterogeneous condition with variable estimates of survival. Contemporary criteria for the diagnosis of clinically suspected AM enable non-invasive assessment, resulting in greater sensitivity and more representative cohorts. We aimed to describe the demographic characteristics and long-term outcomes of patients with AM diagnosed using non-invasive criteria.

Methods and results

A total of 199 patients with cardiac magnetic resonance (CMR)-confirmed AM were included. The majority (n = 130, 65%) were male, and the average age was 39 ± 16 years. Half of the patients were White (n = 99, 52%), with the remainder from Black and Minority Ethnic (BAME) groups. The most common clinical presentation was chest pain (n = 156, 78%), with smaller numbers presenting with breathlessness (n = 25, 13%) and arrhythmias (n = 18, 9%). Patients admitted with breathlessness were sicker and more often required inotropes, steroids, and renal replacement therapy (p < 0.001, p < 0.001, and p = 0.01, respectively). Over a median follow-up of 53 (IQR 34-76) months, 11 patients (6%) experienced an adverse outcome, defined as a composite of all-cause mortality, resuscitated cardiac arrest, and appropriate implantable cardioverter defibrillator (ICD) therapy. Patients in the arrhythmia group had a worse prognosis, with a nearly sevenfold risk of adverse events [hazard ratio (HR) 6.97; 95% confidence interval (CI) 1.87-26.00, p = 0.004]. Sex and ethnicity were not significantly associated with the outcome.

Conclusion

AM is highly heterogeneous with an overall favourable prognosis. Three-quarters of patients with AM present with chest pain, which is associated with a benign prognosis. AM presenting with life-threatening arrhythmias is associated with a higher risk of adverse events.