FACTORS THAT PREDICT THE USE OF POSITIVE INOTROPIC DRUG SUPPORT AFTERCARDIAC-VALVE SURGERY

Left ventricular dysfunction is common after cardiac surgery and is of ten treated with positive inotropic drugs (PIDs). We hypothesized that the use of PIDs after cardiac valve surgery would have significant as sociations with the valvular pathophysiology and surgical procedure, a nd unlike the case for patients undergoing coronary artery surgery, wo uld be unrelated to duration of cardiopulmonary bypass (CPB) or of aor tic clamping. One hundred forty-nine consenting patients undergoing ca rdiac valve surgery were studied. Patients with hepatic or renal failu re, or New York Heart Association class TV cardiac symptoms, were excl uded. Patients were considered to have received PIDs if they received an infusion of amrinone, dobutamine, epinephrine, or dopamine (greater than or equal to 5 mu g.kg(-1).min(-1)). PIDs were received by 78 pat ients (52%). In a univariate model, older age, history of congestive h eart failure, decreasing left ventricular ejection fraction, longer du rations of CPB, and concurrent coronary artery surgery significantly i ncreased the likelihood of PID support. There was also significant var iation by anesthesiologist in the administration of PTDs. The specific diseased valve and valvular stenosis or insufficiency did not influen ce the likelihood of receiving PID support. In a multivariable model, age, history of congestive heart failure, decreasing left ventricular ejection fraction, and anesthesiologist were significantly associated with the likelihood of PID support, but duration of CPB and concurrent coronary artery surgery were not. In conclusion, patient age and vent ricular function, as well as physician preferences, predicted the need for inotropic drug support; however, neither the specific valvular le sion, nor duration of CPB were strongly predictive in a multivariable model. Implications: We evaluated factors related to use of positive i notropic drugs after cardiac valve surgery. The likelihood of a patien t receiving these drugs increases with advancing age and with more sev ere preoperative left ventricular dysfunction, but was not influenced by the specific diseased valve or the duration of cardiopulmonary bypa ss.