4.3 Irrigation system
Baseline characteristics of patients who were ablated with slit-based irrigation (n = 1,291) vs. other catheters (n = 1,829) are summarized in Table 3. Those who were ablated with slit-based irrigation catheter were older (56.65 ± 10.62 vs. 55.10 ± 11.15 years; p < 0.001); had larger LA (41.63 ± 6.18 vs. 40.89 ± 5.93 mm; p = 0.001); lower LAA flow velocity (46.59 ± 21.63 vs. 50.08 ± 21.15 cm/sec; p < 0.001); and higher prevalence of SEC (17.0% vs. 21.5%; p = 0.002) and non-paroxysmal AF (45.5% vs. 37.7%; p < 0.001).
One procedure-related ischemic complication occurred in patients who were ablated with slit-based irrigation (0.08%) whereas 16 events occurred in patients ablated with other catheters (0.87%; p = 0.003; Figure 3A). When classified into three groups, non-irrigation catheters had highest incidence of procedure-related ischemic complication (1.72%) followed by non-slit-based irrigation catheters (0.71%) and slit-based irrigation catheters (0.08%) (p = 0.001; Figure 3B). Slit-based irrigation catheter was also superior in direct comparison with non-slit-based irrigation catheter (0.71% vs. 0.08%; p = 0.009). Incidence of immediate procedure-related ischemic complication (occurring within 3 days of post-RFCA) also differed significantly according to catheter type (Figure 3C, D). Multivariate model revealed that use of slit-based irrigation catheter was the only significant predictor of procedure-related ischemic complication (Table 4).