Predictors and associated clinical outcomes of low cardiac output syndrome following cardiac surgery: insights from the LEVO-CTS trial

Abstract

Background High-risk cardiac surgery is commonly complicated by low cardiac output syndrome (LCOS) which is associated with high mortality. There are limited data derived from multi-center studies with adjudicated endpoints describing factors associated with LCOS and its downstream clinical outcomes. Methods The Levosimendan in Patients with Left Ventricular Systolic Dysfunction Undergoing Cardiac Surgery Requiring Cardiopulmonary Bypass (LEVO-CTS) trial evaluated prophylactic levosimendan versus placebo in patients with a reduced ejection fraction undergoing coronary artery bypass grafting and/or valve surgery. We conducted a pre-specified analysis on LCOS which was characterized by a four-part definition. We constructed a multivariable logistical regression model to evaluate risk factors associated with LCOS and performed Cox proportional hazards modeling to determine the association of LCOS with 90-day mortality. Results A total of 186 (22%) of 849 patients in the LEVO-CTS trial developed LCOS. Factors most associated with a higher adjusted risk of LCOS were pre-operative ejection fraction (OR 1.26; 95% CI: 1.08–1.46 per 5% decrease) and age (OR 1.13; 95% CI: 1.04–1.24 per 5-year increase) whereas isolated CABG surgery (OR 0.44, 95% CI: 0.31–0.64) and levosimendan use (OR 0.65; 95% CI: 0.46–0.92) were associated with a lower risk of LCOS. Patients with LCOS had worse outcomes, including renal replacement therapy at 30-days (10% vs. 1%) and 90-day mortality (16% vs. 3%, adjusted HR of 5.04, 95% CI: 2.66–9.55). Conclusions LCOS is associated with a high risk of post-operative mortality in high risk cardiac surgery.

Postoperative Hyperuricemia—A Risk Factor in Elective Cardiosurgical Patients

“…Independent predictors of increased mortality in patients with LCOS were renal failure (OR 4.3), patient age (OR 1.03) and the need for a reoperative surgical intervention (OR 1.8) [ 51 ]. Further studies should be carried out on the utility of both pre and postoperative hyperuricemia in predicting LCOS, as there is evidence that adjusting the type of cardiac surgery procedure and using inotropes such as levosimendan postoperatively significantly reduce the risk of postoperative LCOS [ 52 ]. Recognizing the patients at risk of this major cardiac surgery complication before the procedure itself or immediately after using a single noninvasive blood biomarker (UA) would have the potential to significantly reduce in-hospital mortality, hospitalization costs, and complication rates.…”

Coronary artery bypass grafting in left ventricular dysfunction: when and how

“…Surgical myocardial revascularization in patients with low ejection fraction carries a significant risk of perioperative mortality and morbidity related to the development of postcardiotomy cardiogenic shock [7 ▪▪ ,8]. Below, we list some medical and temporary mechanical support options that may be considered in the perioperative period.…”

Perioperative Use of Impella 5.0/5.5 in High-Risk Coronary Artery Bypass Grafting

“…Coronary artery bypass grafting for patients with severely reduced cardiac function is challenging because of the high incidence of postoperative low cardiac output syndrome [1]. A study that investigated 55,515 patients in New York State database reported that patients with low ejection fraction had >4 times higher mortality than patients with high ejection fraction [2].…”