Epidemiological Study of Influenza Among Cardiovascular Diseases Patients Hospitalized in Mazandaran Heart Center

Influenza virus is scattered around the world and causes epidemics of varying severity annually. Mortality caused by influenza is more common in cardiovascular patients than in other chronic diseases. Paying attention to this is very important in preventing the disease and its complications in children and adults with cardiovascular diseases. Therefore, this study was conducted with the aim of epidemiological investigation of hospitalized cases caused by influenza in cardiovascular patients and its effect on the health of these patients in Mazandaran Heart Center.

The present study is a cross-sectional descriptive study that was conducted on patients who were admitted to the Mazandaran Heart Center between 2016 and 2018. All patients who were hospitalized with the initial and final diagnosis of influenza and were treated with all flu medicine were included in the study. Since the PCR test was not available for all these patients, as the value of clinical diagnosis was based on symptoms and initial laboratory findings during the epidemic, in addition to PCR-positive cases, cases with clinical diagnosis were also included in the study. All data analysis with SPSS version 16 software was used.

In this study, 113 patients with an average age and standard deviation of 63.3+15 years were included. Among these patients, the highest frequency of history of heart disease was related to congestive heart failure (35.4%) and angioplasty (292%), and the lowest frequency was related to valve replacement 8.0%. Among other underlying diseases, the highest frequency was related to hypertension (65.5%), diabetes mellitus (41.6%), and hyperlipidemia (31.0%), and the lowest frequency was related to thyroid disorders (2.7%). Also, 31.9% of patients had diabetes and hypertension and 16.8% had diabetes and hyperlipidemia. Examining the signs and symptoms of influenza among the patients also showed that the highest frequency related to fever (76.1%), sputum (66.4%), cough (64.6%), shortness of breath (611%) and myalgia (548%) and the lowest frequency was related to diarrhea (5.3%). Only 7% of patients had a recent history of flu vaccination. In the chest radiography report, 25.7% of the patients had increased bronchial marking and 17.7% had evidence of pneumonia. Finally, 82.3% of patients were discharged after complete recovery. Also, only 12 cases (10.6%) of the patients died. Heart failure was the most common underlying disease among deceased patients.

The results of this study revealed that the symptoms of influenza in heart patients are similar to other patients and the type of underlying disease has no effect on the disease presentation and its initial manifestations, but persisting of the symptoms and progression towards severe disease were more common. Most of the deaths were due to heart failure, and this issue highlights the importance of these patients' adherence to the flu vaccine. Unfortunately, the results of the study indicated that this high-risk population had little adherence to influenza and pneumococcal vaccinations.