RT-PCR Cycle Threshold Values Predicting COVID-19 Cardiac Complications: A Case-control Study

Introduction: COVID-19 causes multiple cardiovascular (CV) complications. As known, Cycle threshold (Ct) value of RT-PCR is inversely related to the viral load, thus it can be used as a predictor of outcomes. We aim to present the risk factors for developing CV events and to investigate whether Ct values, can be used as a predictor of CV events in COVID-19 patients. Methods: This case-control study included 296 confirmed COVID-19 infection hospitalized patients were divided into two groups (n=60 patients cardiac group, them with n=236 non-cardiac group) according to the occurence of CV events. Clinical manifestation, comorbidities, laboratory and radiographic findings were compared between the two groups. In order to assess the link between CV complications and Ct values while controlling for confounders, binary logistic regression was used. The receiver operating characteristic curve analysis was used for estimating the cutoff level of Ct value predicting the occurrence of CV events. Results: Almost 50 % of the patients were male. The mean age was 60.85 19.57 years. Binary logistics regression analysis showed that lower Ct value on admission (OR=0.836, 95% CI 0.753-0.928, p=0.001), higher level of troponin (OR=1.209, 95%CI 1.050-1.392, p=0.008), smoking history (OR=7.336, p<0.001), advanced age (OR= 1.022, 95%CI 1.001-1.044, p=0.039) and male gender (OR=2.742, 95%CI 1.271-5.919, p=0.010) were independent risk factors of CV events in COVID-19 patients . The median Ct value of RT-PCR for all participants was 24.6 (21-28). The Ct-value demonstrated sensitivity of 72%, specificity of 72%, a negative predictive value of 91%, and a positive predictive value of 40% for the prediction of cardiac problems at a cutoff value of 23, according to ROC curve analysis. Conclusion: Our study suggests that <23 Ct-value on the admission of hospitalized COVID-19 patients can predict CV events. As a result, if patients have risk factors for cardiac events and <23 Ct value on admission, they should be evaluated by a competent COVID-19 heart team.