Results
A total of 132 AF patients with mild renal dysfunction were included in this study. Table 1 summarizes the clinical characteristics at baseline during the initial admission. Among all the patients, 66.7% were men (n = 88), and 54.5% (n = 72) were diagnosed with paroxysmal AF. The mean age was 62.8±0.7 years. The baseline CHA2DS2-VASc score was 1.7±0.1.
The median duration between the two admissions was 11 months (IQR: 6-22 months). The CHA2DS2-VASc score was 0.2±0.0. The mean eGFR at readmission was significantly increased compared with the eGFR at baseline before the index RFCA procedure (81.5±1.1 vs. 78.0±0.7 ml/min/1.73 m², P < 0.01), as shown in Figure 1. After all patients underwent successful CPVI, 94 (71.2%) patients showed paroxysmal atrial arrhythmia and the remaining 38 (28.8%) showed persistent atrial arrhythmia when readmitted due to recurrence.
Among the 4 groups classified based on patterns of arrhythmia change, the difference in eGFR was statistically significant (P = 0.03), as shown in Figure 2. Figure 3 shows that patients with recurrence of paroxysmal atrial arrhythmia had better renal function outcomes regardless of whether they initially had paroxysmal or persistent AF (P < 0.001 and P = 0.004, respectively).
In the univariate Cox regression, the CHA2DS2-VASc score, left atrial diameter (LAD) and recurrent atrial arrhythmia type were significantly associated with changes in eGFR. Although not a significant factor in the univariate Cox regression, baseline age was still included in the multivariate analysis because age has always been a strong risk factor for renal dysfunction. As shown in Table 2, after adjusting for baseline age and the CHA2DS2-VASc score, LAD and recurrent atrial arrhythmia type, the multivariate Cox regression showed that a lower CHA2DS2-VASc score (hazard ratio [HR]: 0.416, 95% confidence interval [CI]: 0.235-0.735,P = 0.003) and paroxysmal recurrent atrial arrhythmia (HR: 2.965, 95% CI: 1.604-5.483, P = 0.001) were associated with better renal function.