3.1 Patient characteristics
Baseline patient characteristics are shown in Table 1. The mean age was 83.2±4.7 years in group Y and 92.1±1.9 years in group N (p <0.0001). Preoperative pacemaker implantation was slightly higher in group N than in group Y (17.3% vs. 5.9%). The other patient characteristics did not differ significantly between the two groups. The Society of Thoracic Surgery (STS) risk score was 7.7% in group Y and 8.4% in group N.