Prevalence and Outcomes of Myocarditis in Dengue-Infected Patients Admitted to a Tertiary Care Hospital of Low-Middle Income Country.

BACKGROUND

Myocarditis is a challenging diagnosis due to the heterogeneity of clinical presentations. Myocarditis can present with a mildly raised cardiac enzyme to severe myocarditis leading to congestive heart failure, arrhythmias, cardiogenic shock, and death. It is a predictor of morbidity and mortality in dengue-infected patients. The exact prevalence of dengue myocarditis and its outcomes are unknown in Pakistan.

OBJECTIVES

We aim to study the prevalence and association of myocarditis with the length of stay in the hospital and mortality of dengue-infected patients.

METHODS

A retrospective observational study done at a tertiary care hospital. We reviewed hospital record files of 1008 consecutive patients with dengue viral infection admitted from November 2018 to November 2019.

RESULTS

Out of 1008 dengue-infected patients, 55.4% of patients were older than 35 years and 68.4% were males. Hypertension (HTN) was the most common comorbid condition. The prevalence of myocarditis in hospitalized dengue-infected patients was 4.2%. All (100%) of dengue myocarditis patients had raised cardiac troponin I (cTn-I), 59.5% of patients had at least one electrocardiography (ECG) change, and 24% had reduced ejection fraction (EF) (defined as EF < 55%). On multivariable analysis, patients with raised cTn-I levels (adjusted odds ratios = 5.29; [95% confidence interval (CI): 2.16-12.96]) and abnormal echocardiography (ECHO) [aOR = 4.38; 95% CI: 1.26-15.27)] had a prolonged hospital stay (>3 days). Raised cTn-I levels (aOR = 8.2; [95% CI: 1.83-36.84]) was significantly associated with in-hospital mortality.

CONCLUSIONS

Raised cTn-I is the predictor of length of stay and in-hospital mortality in dengue-infected patients. Atrial fibrillation, diabetes mellitus, hypertension, low serum bicarbonate, high serum creatinine, and any abnormality on echocardiography were associated with adverse outcomes in dengue-infected patients.