Comparative effects of angiotensin receptor blockade and ACE inhibition on the fibrinolytic and inflammatory responses to cardiopulmonary bypass.

ABSTRACT

The effects of angiotensin-converting enzyme (ACE) inhibition and angiotensin II type 1 receptor blockade (ARB) on fibrinolysis and inflammation after cardiopulmonary bypass (CPB) are uncertain. This study tested the hypothesis that ACE inhibition enhances fibrinolysis and inflammation to a greater extent than ARB in patients undergoing CPB. One week to 5 days before surgery, patients were randomized to ramipril 5 mg/day, candesartan 16 mg/day, or placebo. ACE inhibition increased intraoperative bradykinin and tissue-type plasminogen activator (t-PA ) concentrations as compared to AR B. Both ACE inhibition and AR B decreased the need for plasma transfusion relative to placebo, but only ACE inhibition decreased the duration of hospital stay. Neither ACE inhibition nor AR B significantly affected concentrations of plasminogen activator inhibitor-1 (PAI -1), interleukin (IL )-6, IL -8, or IL -10. ACE inhibition enhanced intraoperative fibrinolysis without increasing the likelihood of red-cell transfusion. By contrast, neither ACE inhibition nor ARB affected the inflammatory response. ACE inhibitors and ARBs may be safely continued until the day of surgery.