Pulmonary vascular resistance index during coronary artery bypass surgery with aprotinin

Low pulmonary vascular resistance index (PVRI) reflects favorable redundant pulmonary circulation following coronary artery bypass grafting with cardiopulmonary bypass surgery (CPB). This randomized study investigated whether aprotinin given in different modalities impacts PVRI after coronary artery bypass grafting. A total of 40 patients undergoing coronary artery bypass grafting were randomized to four groups according to aprotinin dose: (1) high dose, (2) early low dose, (3) late low dose, and (4) without aprotinin. Oxygenation index, pulmonary shunt, alveolar-arterial oxygen gradient and PVRI were determined. PVRI was calculated as the transpulmonary pressure gradient divided by cardiac index multiplied by 80. The results showed that PVRI remained relative low in all patients provided aprotinin regardless of treatment dosage; PVRI increased at 4h after restarting ventilation after CPB in patients without aprotinin as compared with aprotinin (266 +/- 137, 266 +/- 115, 244 +/- 86 vs. 386 +/- 121, dynes-s-cm(-5), respectively, p=.047). Elevated postoperative PVRI was predictive for patients without aprotinin (AUC 0.668; SE 0.40; p<.0001; CI 0.590-0.746). There were no statistical differences in oxygenation index, pulmonary shunt or alveolar-arterial oxygen gradient between the groups. In conclusion, aprotinin maintains a low PVRI in elective patients with healthy lungs during CPB. We suggest that aprotinin maintains pulmonary arterial endothelial integrity.