Novel insights into short-term troponin remeasurement and long-term cardiac function and structure following fulminant myocarditis

TL;DR

This study finds that delayed normalization of troponin levels in patients with fulminant myocarditis is linked to worse long-term heart function and structure.

Contribution

The study identifies elevated troponin levels at 30 days post-discharge as a novel predictor of long-term cardiac deterioration in fulminant myocarditis patients.

Findings

Patients with normal troponin levels at 30 days had better left ventricular function and structure over time.

Elevated troponin at 30 days was strongly associated with higher incidence of secondary composite endpoints.

Multivariable analysis confirmed troponin normalization as an independent predictor of cardiac outcomes.

Abstract

Elevated serum high-sensitivity cardiac troponin (hs-cTn) levels are commonly observed in patients with fulminant myocarditis (FM) after the acute phase. This study aims to evaluate the relationship between elevated hs-cTnI levels at 30-day post-discharge and long-term cardiac structure and function.

This study is a retrospective cohort study that selected FM patients hospitalized at Tongji Hospital in Wuhan from April 2016 to December 2022. All patients underwent serial monitoring of hs-cTnI levels. Patients were stratified into two groups based on hs-cTnI levels at 30 days post-discharge: the normal hs-cTnI (N-cTnI) group and the high hs-cTnI (H-cTnI) group. Left ventricular (LV) function and structure were assessed using 2-dimensional volume and speckle tracking strain echocardiography. Measurements were obtained at admission, discharge, and 6 months, 12 months, and annually thereafter post-discharge.

Among 95 patients with analysable echocardiographic data (median age: 33 years; 42.11 % male), the N-cTnI group demonstrated significantly higher proportions of patients meeting cardiac function criteria during follow-up compared to the H-cTnI group: LV ejection fraction (LVEF) > 50 % (95 % vs. 72 %; P = 0.003), global longitudinal strain (GLS) > 16 % (68 % vs. 36 %; P = 0.002), and LV end-diastolic dimension < 5 cm (86 % vs. 65 %; P = 0.020). Given that the primary composite endpoint occurred in only 5 patients, statistical analyses focused on secondary composite endpoints. The incidence of secondary composite endpoints was significantly higher in the H-cTnI group than in the N-cTnI group (61.91 % vs. 16.98 %; P < 0.001). Multivariable Cox regression identified elevated hs-cTnI at 30 days post-discharge (HR: 5.365; 95 % CI: 1.876–15.344; P = 0.002) and LV-GLS at discharge (HR: 0.844; 95 % CI: 0.732–0.974; P = 0.021) as independent predictors of secondary composite endpoints.

Delayed normalization of hs-cTnI after 30 days post-discharge may predict long-term deterioration of cardiac function and structural remodeling in patients with FM.

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