West Nile Virus as a Trigger for Cardiovascular Diseases: A Meta–summary of Case Reports

Background The West Nile virus (WNV) is a widespread, mosquito–borne flavivirus that poses a significant public health issue in endemic regions. In a small fraction of cases (less than 1%), the virus invades the central nervous system, leading to a serious condition known as West Nile neuroinvasive disease (WNND). This can manifest as encephalitis (50–71%), meningitis (15–35%), or acute flaccid paralysis (3–19%). WNV has been recently described as a possible trigger of cardiovascular diseases (CVDs). Methods We searched for case reports published in Pubmed, Google Scholar and EMBASE from 2009 to 2023. In the present meta–summary, 8 case reports describing patients who experienced CVDs following an WNV infection were included. Results A total of 8 patients with diagnosed CVDs triggered by WNV were examined. The median age was 67.29 (interquartile range, IQR: 53–70) years and 87.5% were male. 6 of 8 (75%) patients had altered mental status due to neurological involvement of the infection. Comorbidities were present in 5 patients (62.5%). Left ventricular ejection fraction was impaired in 5 patients (62.5%). 4 of 8 patients (50%) had arrhythmias, with 3 of them having a normal ejection fraction. Only the female patient failed to recover her ejection fraction and was implanted with a cardiac resynchronization therapy device. Data on the length of hospital stay and the day of onset of cardiac complications are not available for all patients. Sudden cardiac death was reported in one patient (12.5%). Discussion: Currently, very few cases of WNV–associated CVDs have been reported. Cardiac arrhythmias are a frequent complication in critically ill patients. However, specific arrhythmias in WNV have not been reported. It‘s still unclear whether the heart damage in WNV–associated myocarditis is caused by an indirect immune reaction to the virus or by the virus directly invading heart cells and causing inflammation. Direct viral involvement of the myocardium could be explained by a greater viral aggressiveness in penetrating cells, which might also explain why patients with frequent cardiovascular involvement also more frequently have neurological involvement. Furthermore, being male and having an advanced age are other common factors in patients with CVDs. Conclusions CVDs due to WNV have been associated with myocarditis and arrhythmias in particular, among elderly patients, males, and those with neurological impairment.