Impact of cardiac surgery using cardiopulmonary bypass on course of chronic lymphatic leukemia: a case-control study

BACKGROUND: Chronic lymphatic leukemia (CLL) is a common disease among elderly individuals. The number of older patients undergoing operations with cardiopulmonary bypass (CPB) is increasing. The aim of the present study was to evaluate the impact of cardiac surgery using CPB on the long-term course of CLL. METHODS: From 1992 to 2000, a total of 28 patients with CLL underwent heart surgery using CPB at our institution (group I). These patients were compared with 25 patients from the CLL register who were retrospectively matched with regard to preoperative administration of chemotherapy, Binet classification, age, and sex (group II). A time-point was selected for each patient in group II so that the variables for the two groups corresponded in relation to the time of operation of the patients in group I. Midterm follow-up data in both groups were analyzed. RESULTS: There were no differences between groups regarding matched variables. The mean follow-up time was similar in both groups (2.6 +/- 2.2 vs 2.3 +/- 1.3 years, p > 0.5). The 30-day mortality in group I was 14.3%. The mean stay in the intensive care unit was 4.2 +/- 7.5 days; the median number of units of packed red blood cells transfused was three (range 0 to 17). Compared with group II, in group I significantly fewer patients (11 vs 17, p = 0.049) required chemotherapy significantly later (1.98 +/- 2.06 vs 0.84 +/- 1.18 years, p = 0.018). During follow-up, no difference was found between groups regarding severe infections (10 vs 14, p = 0.14). Despite postoperative mortality in group I, the long-term mortality was similar in both groups (p = 0.3). CONCLUSIONS: Cardiac surgery using CPB did not have a negative impact on the natural course of CLL. Moreover, this procedure seems to be associated with a decrease in the number of postoperative chemotherapy administrations and with an increase of chemotherapy-free survival time. Although CLL may be a risk factor in the early postoperative period, it is not a contraindication for cardiac surgery using CPB.