A prospective cohort study of dynamic cell-free DNA elevation during cardiac surgery with cardiopulmonary bypass.

Cardiac surgery and cardiopulmonary bypass (CPB) are associated with a systemic inflammatory reaction that occasionally induces a life-threatening organ dysfunction caused by the dysregulated host response to the damage-associated molecular patterns (DAMPs). In severe inflammation, cell-free DNA (cfDNA) and histones are released by inflammatory cells and damaged tissue and act as DAMPs. We sought to characterize the changes in circulating cell-free DNA (cfDNA) levels during CPB. Primary outcomes were renal failure, ventilation time (>18 hr), length of stay (LOS) in the intensive care unit (ICU) (>48hr), hospital LOS (>15 days), and death. We looked for associations with blood tests and comparison to standard scores. In a prospective cohort study, we enrolled 71 patients undergoing non-emergent coronary artery bypass grafting. Blood was drawn at baseline, 20 and 40 minutes on CPB, after cross-clamp removal, and 30 minutes after chest closure. cfDNA was measured by our fast fluorescent method. Baseline cfDNA levels [796 (656-1063) ng/ml] increased during surgery, peaked after cross-clamp removal [2403 (1981-3357) ng/ml] and returned to baseline at recovery. The difference in cfDNA from 20 to 40 minutes on CPB (ΔcfDNA 40-20) inversely correlated with peripheral vascular disease (PVD), longer ventilation time, and longer ICU and hospital length of stay (LOS). Receiver operating characteristic (ROC) curve of ΔcfDNA 40-20 for long ICU-LOS (>48hr) was with an area under the curve (AUC) of 0.738 (p = 0.022). ROC AUC of ΔcfDNA 40-20 to long Hospital LOS (>15 days) was 0.787 (p = 0.006). Correction for time on CPB in a multivariate logistic regression model improved ROC-AUC to 0.854 (p = 0.003) and suggests that ΔcfDNA 40-20 is an independent risk factor. To conclude, of measured parameters, including STS and Euroscore, the predictive power of ΔcfDNA 40-20 was the highest. Thus, measurement of ΔcfDNA 40-20 may enable early monitoring of patients at higher risk. Further studies on the mechanism behind the negative association of ΔcfDNA 40-20 with PVD and outcomes are warranted.

Bilateral skeletonized internal mammary versus single-pedicled internal mammary grafting in the elderly.

BACKGROUND: The use of the bilateral internal mammary arteries has been reserved mainly for younger and low risk patients. AIM: To assess the safety and efficacy of BIMA grafting in older patients (> or = 70 years). METHODS: We reviewed the records of all consecutive patients > or = 70 years old who underwent coronary artery bypass surgery with a BIMA graft in our institute over a 2 year period. Demographic data, operative data, perioperative morbidity and mortality were recorded. Findings were compared with a matched-size group of patients who underwent CABG with a left internal mammary artery graft to left anterior descending artery. RESULTS: The study sample included 136 patients, of whom 68 underwent BIMA grafting and 68 LIMA grafting. Baseline demographic and clinical characteristics were similar in the two groups. There was no significant difference in operative mortality between the BIMA and LIMA groups (1.5% vs. 0%, P = 0.3) or in mortality during follow-up at a mean of 16 months (4.4% vs. 2.9%, P = 0.4, respectively). There was no difference between the groups in the incidence of perioperative complications, readmission and reintervention rates during follow-up. Significant between-group differences were noted for mean cardiopulmonary bypass time (93.2 +/- 34.7 min with BIMA vs. 108.8 +/- 40.7 min with LIMA, P = 0.02) and for red blood cell transfusion (1.9 +/- 1.9 vs. 4.3 +/- 2.8 packed cells/patient, P < 0.001). CONCLUSIONS: The performance of mainly arterial revascularization with BIMA grafting in patients 70 years or older is as safe as LIMA grafting, with the added advantage of being a better conduit than saphenous vein graft, requiring fewer blood transfusions, and shorter cardiopulmonary bypass time.