High premature atrial complex loads indicate a high central aortic pressure index in young low-risk patients

Objectives: To elucidate the relation between premature atrial complex (PAC) loads and aortic stiffness in the low-risk young population. Methods: We enrolled 200 consecutive patients (< 50 years old; 95 men; mean age, 36 ± 10 years) who received a 24-h ambulatory electrocardiography (ECG) examination for palpitation. Aortic stiffness and two aortic pressure indices - augmentation (AG) and the augmentation index (AIx) - were measured, and atherosclerosis risk factors were evaluated. Patients with < 2 risk factors were defined as the low-risk group. Results: Twenty-three patients (12%) had high PAC loads. Age (p = 0.037), AG (p = 0.022), and AIx (p = 0.008) were significantly higher in these patients. Gender, risk factors, and drug history were not associated with high PAC loads. A multivariate analysis showed high PAC loads (p = 0.036, OR 1.09, 95% CI. 1.01-1.18) was an independent factor associated with AIx. In the low-risk group, 19 (14%) patients had high PAC loads. Age (p = 0.042), AG (p = 0.012), and AIx (p = 0.002) were significantly higher in patients with high PAC loads. A multivariate analysis showed high PAC loads (p = 0.021, OR 1.23, 95% CI. 1.03-1.41) was an independent factor associated with AIx in low-risk patients. Conclusion: High PAC loads were significantly associated with increased central aortic pressure indices in young subjects, especially in the low-risk subgroup. High PAC loads might be a surrogate marker of central aortic stiffness in a low-risk group.