Patient characteristics and surgical variables associated with intraoperative reduced right ventricular function.

Objective: Perioperative right ventricular function is a significant predictor of patient outcomes after cardiac surgery. This prospective study aimed to identify perioperative factors associated with reduced intraoperative right ventricular function.

Methods: Right ventricular function was assessed at the beginning and end of surgery by standardized transesophageal echocardiographic measurements, including tricuspid annular plane systolic excursion, peak systolic longitudinal right ventricular strain, and fractional area change, in 109 adult patients undergoing cardiac surgery at Cleveland Clinic. Associations between right ventricular function and 33 patient characteristics and perioperative factors were analyzed by random forest machine learning. The relative importance of each variable in predicting right ventricular function at the end of surgery was determined.

Results: Longer aortic clamp duration and lower baseline right ventricular function were highly important variables for predicting worse right ventricular function measured by tricuspid annular plane systolic excursion, right ventricular strain, and fractional area change at the end of surgery. For example, right ventricular function after longer aortic clamp times of 100-120 minutes was worse (median [Q1, Q3] tricuspid annular plane systolic excursion 1.0 [0.9, 1.1] cm) compared with right ventricular function after shorter aortic clamp times of 50 to 70 minutes (tricuspid annular plane systolic excursion 1.5 [1.3, 1.7]; P = .001). Right ventricular strain at the end of surgery was reduced in patients with worse baseline right ventricular function compared with those with higher baseline right ventricular function (end of surgery right ventricular strain in lowest quartile -13.7 [-16.6, -12.4]% vs highest quartile -17.7 [-18.6, -15.3]% of baseline right ventricular function; P = .043).

Conclusions: Intraoperative decline in right ventricular function is associated with longer aortic clamp time and worse baseline right ventricular function. Efforts to optimize these factors, including better myocardial protection strategies, may improve perioperative right ventricular function.