Divergent prognostic roles and risk determinants of myocardial injury in SFTS and HFRS

BACKGROUND: This study explored the role of myocardial injury in the prognostic assessment of severe fever with thrombocytopenia syndrome (SFTS) and hemorrhagic fever with renal syndrome (HFRS) patients, and analyzed its risk factors. METHODS: A retrospective study included 188 SFTS and 101 HFRS patients (2020-2024) from two hospitals. Epidemiological, clinical, and laboratory data were dynamically recorded and statistically analyzed. RESULTS: SFTS patients were older (65.35 ± 11.04 vs. 53.26 ± 14.66 years) and had more females (56.90% vs. 26.70%, both P < 0.001). HFRS was more likely to present early symptoms (myalgia, fatigue/anorexia, abdominal pain, diarrhea, vomiting, skin petechiae/ecchymosis, headache; all P ≤ 0.040). SFTS mortality (19.70%, 37/188) was significantly higher than HFRS (4.00%, 4/101, P < 0.001). Both groups had elevated myocardial markers (ALT, AST, CK, CK-MB, cTn, LDH, α-HBDH): HFRS had higher levels during days 3-7 (which then decreased), while SFTS levels increased and exceeded those of HFRS during days 8-14. SFTS patients with myocardial injury had higher mortality (29.10% vs. 11.80%, P = 0.003), but HFRS showed no mortality difference between those with and without myocardial injury (P = 0.952). Myocardial injury risk factors emerged in both groups during days 3-7, increased during days 8-14, peaking on day 10 (SFTS) and days 6/12/13 (HFRS). CONCLUSION: SFTS has a higher mortality rate. Myocardial injury is common and early in both groups: HFRS patients show rapid recovery, while SFTS patients experience worsening injury associated with death. Early intervention targeting risk factors is key to reducing mortality.