Results
During the study period, 2978 cases of cardiac surgery were performed in
our institution, of which 707 cases were identified as isolated CABG
(687 cases (97.2%) were off- pump). Of these, 94 cases were
>80 years old at the time of surgery. Table 1 shows the
pre-operative characteristics of the 613 cases in the young group and 94
cases in the old group. The old group showed a higher proportion of
females, smaller body size and lower frequencies of diabetes,
dyslipidemia and smoking history compared to the young group. The older
group displayed lower renal function and higher frequency of anemia
compared to the young group. Euroscore II and Clinical Frailty Scale
were significantly higher in the old group than in the young group. The
old group displayed a higher frequency of left main trunk disease than
the young group, but pre-operative echocardiographic findings were
broadly comparable. Table 2 shows the operative results. The old group
had a shorter operative time, lower frequency in the usage of right
internal thoracic arteries (ITAs), and a greater frequency of
transfusion than the young group. The number of distal anastomoses was
identical between groups. Cardiopulmonary bypass was used for 3.3% of
cases in the young group, whereas all cases in the old group were
treated using OPCAB, as intended. Graft patency rate was 97.0% in the
young group and 96.2% in the old group. Post-operative hospitalization
was longer in the old group, but ventilator time and stay in the
intensive care unit were comparable between groups. Eighty of 94 old
patients (85.1%) were discharged to home. Fourteen patients were
transferred to another hospital, with 13 for further rehabilitation, and
1 for treatment of cerebral infarction. Operative/in-hospital death
rates were very low in both groups (young group, 0.5%; old group, 0%).
The old group required temporary post-operative hemodialysis and
suffered atrial fibrillation more frequently than the young group, but
no significant differences were seen in other morbidities, including
re-intubation, re-exploration, mediastinitis or cerebral infarction.
The collection rate for follow-up data was 100%, with a mean follow-up
of 1318 days (range, 40–4309 days). Figure 1 shows the survival curve
for all-cause death. Actual 1-, 3-, and 5-year survival rates were
92.1%, 81.2% and 68.3%, respectively. Twenty-eight deaths occurred
during the observational period. Leading causes of late death were
infection, including pneumonia (n=7). Other causes of death were heart
failure in 5 cases, neurological and natural death (death from old age)
in 4 cases each, cancer in 3 cases and renal failure in 2 cases.