The Association Between Cardio-Ankle Vascular Index and Primary Idiopathic Complete Atrioventricular Block in an Elderly Population

Disruption of the endothelial glycocalyx layer is associated with idiopathic complete atrioventricular block in the elderly population: An observational pilot study

Idiopathic atrioventricular block (iCAVB) is the most common reason for the need for a permanent pacemaker in the elderly population. The fibrotic process that occurs in the conduction system of the heart with aging is the main pathogenesis in the development of iCAVB. However, the processes that trigger the development of iCAVB in the elderly population have not been fully elucidated. In this study, we aimed to reveal the possible relationship between the endothelial glycocalyx (EG) layer and idiopathic complete atrioventricular block. A group of 68 consecutive patients who developed iCAVB and a group of 68 healthy subjects matched for age, sex, and cardiovascular risk factors were included in the study. The groups were compared for clinical, laboratory, and levels of Syndecan-1 (SDC1), an EG layer marker. In the study, SDC1 levels were found to be significantly higher in the iCAVB group compared to the control group (23.7 ± 7.5 vs 16.7 ± 5.2; p = 0.009). In multivariable regression analysis, SDC1 was determined as an independent potential predictor for iCAVB (OR: 1.200; 95% CI: 1.119-1.287; p < 0.001). In the receiver operating characteristic curve analysis, SDC1 predicted iCAVB with 74% sensitivity and 72% specificity at the best cut-off value of 18.5 ng/mL (area under the curve: 0.777; confidence interval: 0.698-0.856; p < 0.001). Disruption of the endothelial glycolic layer may be one of the main triggering factors for the process leading to iCAVB.

Cardio-ankle brachial index is associated with prolonged Tp-e interval in patients with arterial hypertension

AIM

The cardio-ankle vascular index (CAVI) is a marker of arterial stiffness, and elevated CAVI values have been reported to be associated with an increased risk of cardiovascular mortality and cardiac arrhythmia. This study aimed to evaluate the relationship between Tp-e interval and CAVI, which is associated with cardiac arrhythmia on electrocardiography (ECG).

METHOD

The study included patients with hypertension whose blood pressure values were taken under control with optimal medical treatment. Arterial stiffness and CAVI were measured using the vascular scanning system VaSera VS-1000. The patients were divided into two groups as CAVI<9 and CAVI≥9. Ventricular repolarization markers QT and QTc intervals, Tp-e interval, and Tp-e/QT and Tp-e/QTc ratios were measured using 12‑lead ECG.

RESULTS

Tp-e interval (78.7 ± 10.3 vs. 63.6 ± 9.1, p < 0.001), Tp-e/QT ratio (0.018 ± 0.02 vs. 0.015 ± 0.02, p < 0.001), and Tp-e/QTc ratio (0.17 ± 0.02 vs. 0.14 ± 0.04, p = 0.025) were statistically significantly higher in the CAVI≥9 group compared to the CAVI<9 group. In the prediction of patients in the CAVI≥9 group, Tp-e interval had an area under the curve value of 0.862 (0.784-0.940, p < 0.001) at the cut-off point of >72.5 msec, indicating a statistically significant result. Left CAVI and right CAVI were found to be significantly correlated with Tp-e interval (r = -0.650, p < 0.001 and r = -0.663, p < 0.001, respectively).

CONCLUSION

We found that elevated CAVI values were associated and positively correlated with prolonged Tp-e interval values in patients with hypertension. Patients with elevated CAVI values should be followed up closely to prevent cardiac arrhythmic events.

Increased whole blood viscosity is associated with primary idiopathic complete atrioventricular block and poor clinical outcomes in these patients

BACKGROUND

Complete atrioventricular block is most commonly caused by age-related degeneration and fibrosis in the cardiac conduction system and is called primary idiopathic complete atrioventricular (iCAVB). Although many factors affect this situation, which increases with age in the cardiac conduction system, the relationship between whole blood viscosity (WBV) and iCAVB has not been clarified until now. In this study, we aim to reveal the relationship between iCAVB and WBV.

METHODS AND RESULTS

141 patients with dual-chamber permanent pacemaker implanted for iCAVB and 140 age- and sex-matched subjects were included in this study. The WBV values of the study groups were compared in both high shear rate (HSR) and low shear rate (LSR). Both WBV at HSR and WBV at LSR were significantly higher in the iCAVB group compared to the control group (16.11 [15.14-16.89] vs 14.40 [13.62-15.58]; 39.82 [17.43-55.23] vs 1.38 [-13.14-26.73]; p < 0.001, respectively). The patient population was followed up for an median of 38 months for all-cause mortality. Higher mortality rates were found in higher WBV at HSR and WBV at LSR (p < 0.001,for both).

CONCLUSIONS

In this study, WBV was found to be an independent predictor for iCAVB, and in these patients WBV was associated with poor clinical outcomes.