Naoto Fukunaga1, Roberto Vanin Pinto Ribeiro1, Myriam Lafreniere-Roula1, Cedric Manlhiot1, Mitesh V Badiwala1, Vivek Rao2. 1. Division of Cardiovascular Surgery, Peter Munk Cardiac Centre, Toronto General Hospital, University of Toronto, University Health Network, 200 Elizabeth Street, Toronto, ON, Canada. 2. Division of Cardiovascular Surgery, Peter Munk Cardiac Centre, Toronto General Hospital, University of Toronto, University Health Network, 200 Elizabeth Street, Toronto, ON, Canada. Electronic address: vivek.rao@uhn.ca.
Abstract
BACKGROUND: The interactive relationship between left ventricular ejection fraction (LVEF) and LV size in predicting perioperative outcomes following cardiac surgery has not been clarified. METHODS: We reviewed all patients who underwent cardiac surgery between 2010 and 2016 with either preserved LVEF (> 60%, n = 5685) or severely reduced LVEF (< 20%, n = 143). LV size was categorized by using either LV end-diastolic/systolic diameter and/or a qualitative assessment as follows; normal < 4cm, mildly enlarged 4.1 - 5.4cm, moderately enlarged 5.5 - 6.5cm and severely enlarged > 6.5cm. Using propensity score analysis, we matched patients with LVEF < 20% (n = 143) in a 3:1 ratio to patients with LVEF > 60% (n = 429). RESULTS: There were significant differences in mortality, major morbidity and operative mortality (MMOM) and prolonged length of stay (pLOS) between patients with LVEF < 20% and LVEF > 60%. In patients with LVEF < 20%, there were no significant differences in outcomes between those with LV size < 5.4cm and > 5.5cm. In patients undergoing isolated coronary artery bypass grafting (CABG), LV size predicted MMOM (OR 5.5 [2.0 - 15.7] (p < 0.001) and pLOS (3.4 [1.2 - 10.3] (p = 0.026), respectively. CONCLUSIONS: LVEF is more important than LV size in predicting outcomes following cardiac surgery. However, in patients undergoing isolated CABG, LV size has an interactive effect with LVEF and can potentially aid the decision-making process. Risk adjustment models employing only LVEF may be inaccurate, particularly with respect to isolated CABG procedures.
BACKGROUND: The interactive relationship between left ventricular ejection fraction (LVEF) and LV size in predicting perioperative outcomes following cardiac surgery has not been clarified. METHODS: We reviewed all patients who underwent cardiac surgery between 2010 and 2016 with either preserved LVEF (> 60%, n = 5685) or severely reduced LVEF (< 20%, n = 143). LV size was categorized by using either LV end-diastolic/systolic diameter and/or a qualitative assessment as follows; normal < 4cm, mildly enlarged 4.1 - 5.4cm, moderately enlarged 5.5 - 6.5cm and severely enlarged > 6.5cm. Using propensity score analysis, we matched patients with LVEF < 20% (n = 143) in a 3:1 ratio to patients with LVEF > 60% (n = 429). RESULTS: There were significant differences in mortality, major morbidity and operative mortality (MMOM) and prolonged length of stay (pLOS) between patients with LVEF < 20% and LVEF > 60%. In patients with LVEF < 20%, there were no significant differences in outcomes between those with LV size < 5.4cm and > 5.5cm. In patients undergoing isolated coronary artery bypass grafting (CABG), LV size predicted MMOM (OR 5.5 [2.0 - 15.7] (p < 0.001) and pLOS (3.4 [1.2 - 10.3] (p = 0.026), respectively. CONCLUSIONS: LVEF is more important than LV size in predicting outcomes following cardiac surgery. However, in patients undergoing isolated CABG, LV size has an interactive effect with LVEF and can potentially aid the decision-making process. Risk adjustment models employing only LVEF may be inaccurate, particularly with respect to isolated CABG procedures.