P143: Validity of Pulse Wave Velocity and Augmentation Index Measurements in Patients with Atrial Fibrillation

Background Individualized weighing of the risk-benefit of anticoagulation is recommended in patients with atrial fibrillation (AF) that have low established risk scores or, conversely, are at increased risk for bleeding 1 . Parameters of arterial stiffness and wave reflection could improve risk stratification, but their use has not been validated in arrhythmia 2–3 . Methods We measured carotid-femoral pulse wave velocity (PWV), central augmentation index (AI) and central pulse pressure (CPP) using the Sphygmo-Cor (AtCor Medical, Sydney, Australia) system in 34 patients (53 to 85 years; 25 males) with AF before and after elective electrical cardioversion. Agreement was assessed using the intraclass correlation coefficient (ICC) and the coefficient of variation, completed with Bland-Altman plots. Results Following cardioversion, mean arterial blood pressure (MAP) and heart rate (HR) decreased significantly by 7 mmHg and 18 bpm respectively. PWV decreased from 11.8 m/s to 10.7 m/s, AI increased from 24% to 29%, and CPP rose from 45 mmHg to 50 mmHg. The decrease in PWV was related to the decrease in MAP (beta = 0.57; R 2 = 0.33; P < 0.001) whereas changes in AI and CPP were related to the decrease in HR (AI: beta = −0.59; R 2 = 0.35; P < 0.001, CPP: beta = −0.52; R 2 = 0.26; P = 0.001). After adjustment for changes in MAP and HR, reliability analysis showed an excellent agreement for PWV (ICC = 0.89; 95%CI: 0.79–0.95) but moderate agreement for AI (ICC = 0.59; 95%CI: 0.17–0.80). Excellent agreement was also found for CPP (ICC = 0.89; 95%CI: 0.78–0.94). Figure 1 A. Scatter plot showing PWV before (PWV t0 ) and after (PWV t1 ) cardioversion. The solid line Is the Ihie of identity, the broken line the regression line for PWV t1 vs PW t0 (Passini & Bablok regression). B. Bland-Altman plot showing the proportional difference (%) between P\) between PWV after (PVW t1 ) and PWV before (PWV t0 ) cardioversion. The solid line represents the mean value ot PWV and the dotted lines mean ± 2 SD. Figure 2 A. Scatter plot showing Al before (Al t0 ) and after (Al t1 ) cardioversion. The solid line is the line of identity, the broken line the regression line for Al t1 vs Al t0 (Passing & Bablok regression). B. Bland-Altman plot showing the proportional difference (%) between Al after (Al t1 ) and Al before (Al t0 ) cardioversion. The solid line represents the mean value of Al and the dotted lines mean ± 2 SD. Conclusions Measurement of PWV and CPP is reliable in patients with AF, as they appear unaffected by the presence of arrhythmia.