Prognostic value of visual and quantitative CMR regional myocardial function in patients with suspected myocarditis

Sports behaviour and adherence to sports and exercise recommendations in patients with myocarditis

Aim

In the clinical setting of acute myocarditis, existing guidelines recommend refraining from moderate-intensity to high-intensity sports for 3-6 months, yet the extent to which these recommendations are implemented by clinicians and followed by patients remains unclear.

Methods

From January 2020 to December 2023, consecutive patients with myocarditis according to European Society of Cardiology criteria were prospectively enrolled. Myocarditis was categorised into acute, subacute and non-acute myocarditis. Patients completed a sports questionnaire and sports behaviour was categorised into no sports (NSP), recreational (REC) or competitive sports (COMP).

Results

A total of 165 patients with myocarditis (mean age 50±17 years, 35% women) completed the questionnaire. Overall 73 (44%) patients received sports counselling. A total of 44 (72%) patients engaged in sports (REC+COMP) with acute or subacute myocarditis, received sports counselling with 38 (87%) adhering. Overall COMP patients (all male) received more counselling (11/11; 100%) compared with REC (53/105; 50%) and NSP (9/49; 18%). Of 39 women in the REC group, 14 (36%) received recommendations, whereas of 66 men 39 (59%) received recommendations (p<0.001). Of all patients engaged in sports, 55% received recommendations. Self-reported adherence to recommendations was significantly lower in COMP (73%) compared with REC (92%, p<0.001).

Conclusion

Although only half of the myocarditis patients received counselling regarding sports activity, adherence to these recommendations was generally high but varied by activity level. Women received fewer recommendations overall compared with men. While competitive athletes were counselled more frequently than recreational athletes, they were less likely to adhere to the recommendations.

Prognostic Implications of Clinical and Imaging Diagnostic Criteria for Myocarditis

BACKGROUND

The European Society of Cardiology (ESC), the American College of Cardiology, the American Heart Association, and expert consensus documents provide different diagnostic criteria for myocarditis. Their overlap and prognostic value have never been compared.

OBJECTIVES

This study aims to assess and compare the predictive value of ESC criteria for clinically suspected myocarditis, updated Lake-Louise criteria (LLC), American Heart Association criteria for probable acute myocarditis (pAM), and expert consensus criteria for acute myocarditis (AM) and complicated myocarditis (CM).

METHODS

Patients with a clinical suspicion of myocarditis referred for cardiac magnetic resonance were enrolled at 2 centers. Those with any prior cardiomyopathy were excluded. The association of composite outcome events (heart failure hospitalization, recurrent myocarditis, sustained ventricular tachycardia, or death) with ESC diagnostic criteria, LLC, pAM, AM, and CM were compared.

RESULTS

Among 1,557 consecutive patients referred for cardiac magnetic resonance with possible myocarditis, 1,050 (62.6% male; 48.9 ± 16.8 years of age) were without an alternative diagnosis. Of those, 938 (89.3%) met ESC criteria for clinically suspected myocarditis, 299 (28.5%) LLC, and 356 (33.9%), 216 (20.6%), and 77 (7.3%) pAM, AM, and CM, respectively. Adverse events occurred in 161 patients (15.3%) during a median follow-up of 3.4 years. The highest annualized event rates (6.6%) were observed in patients meeting LLC, whereas negative ESC criteria indicated excellent prognosis (0.7% annualized event rate). Among all myocarditis definitions, ESC criteria and LLC were the strongest multivariable outcome predictors and had independent and incremental prognostic value (HRadjusted: 3.87; 95% CI: 1.22-12.2; P = 0.021, and HRadjusted: 2.53; 95% CI: 1.83-3.49; P < 0.001, respectively) when adjusted for clinical characteristics.

CONCLUSIONS

In a real-world cohort of patients with possible myocarditis, diagnosis was reached in most patients using ESC criteria whereas only approximately one-quarter of patients reached a diagnosis with LLC. The independent prognostic value of ESC-criteria and LLC highlights the complementary role of clinical and CMR-based findings in the diagnosis and risk stratification of myocarditis.