Correlation Between Cardiac Autonomic Dysfunction and Severity of Coronary Artery Lesions in Patients With Chronic Coronary Syndrome.

Background Autonomic dysfunction is associated with adverse outcomes in patients with coronary artery disease. Cardiac autonomic dysfunction parameters such as heart rate variability (HRV) and heart rate recovery (HRR) have been studied individually and have been linked to the presence or likelihood of coronary artery disease. In this study, the cardiac autonomic function was assessed in terms of HRR and HRV. In addition, the association of these parameters with the severity of coronary artery lesions was studied. Methodology A total of 100 patients aged more than 18 years who had complaints of typical angina were enrolled in this study. These patients had to undergo the treadmill test for HRR and 24-hour Holter monitoring for HRV. These patients then underwent invasive coronary angiography, and the severity of the lesions was described as single vessel or two/three (multivessel) involvement. The lesions were also grouped as lesions with <70% stenosis and ≥70% stenosis. The association between the severity of the lesions and autonomic dysfunction was studied. Results HRR and HRV values were associated with patients with more severe disease. Multivariate regression analysis showed that abnormal HRV was associated with more severe disease; however, abnormal HRR was not directly associated with lesion severity. These autonomic parameters had a negative correlation with the SYNTAX Score. Conclusions Our results showed that autonomic dysfunction was associated with more severe coronary artery disease in patients with chronic coronary syndrome. We observed a negative correlation between HRR1 and HRV with the severity of coronary artery disease. Hence, we may try to incorporate these parameters in screening patients with a low likelihood of CAD. Future studies may be planned to see any improvement in cardiac autonomic function after revascularization and its association with outcome.