Cardiovascular Risk Score and Pulmonary Gas Exchange in COVID-19 Patients Show No Correlation

Abstract

Background: COVID-19 induces robust systemic inflammation. Patients with cardiovascular disease (CVD) are at an increased risk of death. However, much effort is being spent to identify possible predictors of negative outcomes in order to have a more specific clinical setting. CVD scores are a useful tool in evaluating risk of cardiovascular events. Aim: We evaluated oxygenation and characteristics in COVID-19 patients according to cardiovascular risk stratification performed using the Framingham risk score (FRS) for cardiovascular disease. Materials and methods: We evaluated 155 COVID-19 patients (110 males and 45 females, aged 67.43 ± 14.72 years). All patients underwent a complete physical examination, chest imaging, laboratory tests and blood gas analysis at the time of diagnosis. Seventeen patients died (10 males and 7 females, aged 74.71 ± 7.23 years) while the remaining 138 patients (100 males and 38 females, aged 66.07 ± 15.16 years) were alive at discharge. Results: Deceased patients have an increased FRS compared to those that survived (27.37 ± 5.03 vs. 21.33 ± 9.49, p < 0.05). Compared to survivors, the deceased group presents with a significant increase in white blood cells (p < 0.05) and D-dimers (p < 0.05). There was no difference in pCO2, SO2, and in alveolar arteriolar oxygen difference (A-aDO2). On the contrary, in deceased patients there was an increased pO2 (p < 0.05) and a decreased ratio between oxygen inspired and pO2 (P/F; p < 0.05). FRS shows a negative correlation to P/F (r = 0.42, p < 0.05) in the deceased while no correlation was found in the survivors. No other correlation has been found with blood gas parameters or in the inflammation parameters evaluated in the two groups. Discussion: CVD may be considered as a major risk factor for death in COVID-19 patients. The increased risk relates to a reduced lung capacity but it is not related to blood gas values. Similarly, CV risk score results are independent from the inflammatory status of the patients.