Risk factors, resource use, and cost of postoperative low cardiac output syndrome.

OBJECTIVE: Low cardiac output syndrome complicates recovery after cardiac surgery. We examined the incidence and risk factors for low cardiac output syndrome and its association with postoperative mortality, morbidity, resource use, and cost. METHODS: This cross-sectional retrospective observational study examined patients having cardiac surgery captured in the Premier Healthcare Database. Low cardiac output syndrome was defined as the requirement for postoperative mechanical circulatory support and/or hemodynamic instability requiring prolonged inotropic support. Incidence, risk factors, and association of low cardiac output syndrome with postoperative outcomes, including mortality, hospital and intensive care unit length of stay, hospital readmission, and cost at 30 days, 90 days, and 6 months, were examined. RESULTS: Among 59,810 patients from 164 hospitals having cardiac surgery between July 1, 2012, and June 30, 2014, low cardiac output syndrome developed in 6067 (10.1%) patients. Patients presenting in cardiogenic shock or systolic (± diastolic) heart failure were at greatest risk. Risk-adjusted in-hospital mortality was 12-fold greater with low cardiac output syndrome (odds ratio, 12.0; 95% confidence interval, 10.6-13.5). Risk-adjusted hospital costs (2019$; median [Q1, Q3]) were $64,041 [21,439] in patients who developed low cardiac output syndrome versus $48,086 [16,098] without; P < .001. Increased costs were driven by longer risk-adjusted hospital stay (10.1 [4.5] vs 8.5 [3.8] days); P < .001, intensive care unit (5.5 [2.5] vs 3.3 [1.5] days; P < .001) stay, and all-cause 30-day adjusted hospital readmission rates (mean [SD] 16.6 [8.2]% vs 13.9 [7.2]%; P < .001). CONCLUSIONS: Cardiac surgical patients who develop postoperative low cardiac output syndrome suffer greater mortality and have greater resource use, health care costs, and all-cause readmission, which informs perioperative decision making, and impacts hospital performance metrics and federal priority to reduce health care costs.

Levosimendan in patients with reduced left ventricular function undergoing isolated coronary or valve surgery.

OBJECTIVE: In the Levosimendan in Patients with Left Ventricular Systolic Dysfunction Undergoing Cardiac Surgery Requiring Cardiopulmonary Bypass (LEVO-CTS) trial, no differences in clinical outcomes were observed between levosimendan and placebo in a broad population of patients undergoing cardiac surgery. In previous studies, the benefits of levosimendan were most clearly evident in patients undergoing isolated coronary artery bypass grafting (CABG) surgery. In a prespecified analysis of LEVO-CTS, we compared treatment-related outcomes and costs across types of cardiac surgical procedures. METHODS: Overall, 563 (66.4%) patients underwent isolated CABG, 97 (11.4%) isolated valve, and 188 (22.2%) combined CABG/valve surgery. Outcomes included the co-primary 4-component composite (30-day mortality, 30-day renal replacement, 5-day myocardial infarction, or 5-day mechanical circulatory support), the 2-component composite (30-day mortality or 5-day mechanical circulatory support), 90-day mortality, low cardiac output syndrome (LCOS), and 30-day medical costs. RESULTS: The 4- and 2-component outcomes were not significantly different with levosimendan and placebo in patients undergoing CABG (15.2% vs 19.3% and 7.8% vs 10.4%), valve (49.0% vs 33.3% and 22.4% vs 2.1%), or combined procedures (39.6% vs 35.9% and 24.0% vs 19.6%). Ninety-day mortality was lower with levosimendan in isolated CABG (2.1% vs 7.9%; hazard ratio [HR], 0.26; 95% confidence interval [CI], 0.11-0.64), but not significantly different in valve (8.3% vs 2.0%; HR, 4.10; 95% CI, 0.46-36.72) or combined procedures (10.4% vs 7.6%; HR, 1.39; 95% CI, 0.53-3.64; interaction P = .011). LCOS (12.0% vs 22.1%; odds ratio, 0.48; 95% CI, 0.30-0.76; interaction P = .118) was significantly lower in levosimendan-treated patients undergoing isolated CABG. Excluding study drug costs, median and mean 30-day costs were $53,707 and $65,852 for levosimendan and $54,636 and $67,122 for placebo, with a 30-day mean difference (levosimendan - placebo) of -$1270 (bootstrap 95% CI, -$8722 to $6165). CONCLUSIONS: Levosimendan was associated with lower 90-day mortality and LCOS in patients undergoing isolated CABG, but not in those undergoing isolated valve or combined CABG/valve procedures.