Association of CHA2DS2 VASC score with mechanical prosthetic valve thrombusis

Abstract

Despite the high durability of mechanical valves and their use in young people, the risk of thromboembolism in these types of valves is high, and the patient must receive anticoagulant drugs forever. The CHA2DS2-VASc criterion estimates the risk of thromboembolism in patients with non-valvular atrial fibrillation (NVAF). Previous studies have investigated the clinical application and importance of this score in acute coronary syndromes. However, limited studies are available on the association of CHA2DS2-VASc criteria with prosthetic valve thrombosis. Due to the lack of sufficient studies in this regard, in this study, the relationship between the CHA2DS2-VASc criterion and the occurrence of artificial valve thrombosis was investigated. Methods: In this study, which was a case-control study, all patients with artificial metal valve replacement who underwent transesophageal echocardiography (TEE) between 1396 and 1400 at Shahid Madani Hospital Center in Tabriz were included in the study. Based on TEE findings, patients were divided into two groups with PVT and control group (without PVT). The CHA2DS2-VASc score of each patient was calculated using the clinical data obtained from the hospital admission record. The average dose of warfarin in the last one year, as well as the average of at least 3 INR test results of the patients in the last year (to evaluate the patient's adherence to the drug), as well as the number of years since the valve replacement operation in the two groups, were recorded using regression tests. Several variables were included in the final analysis of patients and their confounding effect was controlled. Results: During 4 years, 104 patients had artificial valve thrombosis. Among these patients, 82 patients (78%) did not have an INR within the therapeutic range, in other words, they did not take warfarin regularly, so they were excluded from the study. 22 patients with artificial valve thrombus with INR in the therapeutic range and 78 patients with artificial valve thrombus were examined. The most frequent location of thrombus was on the artificial mitral valve, which was in 10 patients (45.45%). The average CHA2DS2VASC score of the patients as a whole was 2.58 (±1.65), which was 2.68 (±1.63) in the group with thrombosis and 2.23 (±1.72) in the group without thrombosis. These opinions were not significantly different from each other (pvalue = 0.23). The subthreshold level for the predictive power of the CHA2DS2VASC criterion for artificial valve thrombus was found to be 0.417 (95% confidence interval 0.558 to 0.276) and this predictive power was not significant (P<0.05). ). Multivariate analysis by removing the confounding effect of patients' INR and EF showed that there was no significant relationship between CHA2DS2VASC criteria and artificial valve thrombosis (p = 0.248).