Abstract 18664: Left Ventricular End-Diastolic Pressure is a Predictor of Survival in Patients Undergoing Coronary Artery Bypass Graft Surgery with Left Ventricular Dysfunction

Abstract

There is an association between depressed left ventricular ejection fraction (ejection fraction < 35%; LVEF) and increased mortality in patients undergoing coronary artery bypass graft (CABG). There are a few studies suggesting that elevated pre-operative left ventricular end-diastolic pressure (LVEDP) is an independent predictor of operative mortality for patients undergoing CABG, and could be a greater risk than LVEF < 35%. It is unclear if LVEDP is a better predictor of long-term survival than LVEF in patients undergoing CABG. We hypothesized that LVEDP may add further prognostic value than LVEF alone. We studied 6790 consecutive patients from 2004-2011 undergoing isolated CABG at our institution. Patients were divided into four groups based on LVEF and LVEDP: Group 1 (LVEF≥35%, LVEDP<18mmHg), Group 2 (LVEF<35%, LVEDP<18mmHg), Group 3 (LVEF≥35%, LVEDP≥18mmHg), and Group 4 (LVEF<35%, LVEDP≥18mmHg). The 4 groups had similar pre-operative characteristics of age, history of stoke, renal failure, peripheral vascular disease (PVD), hypertension, and hyperlipidemia. Patients with a low LVEF (Groups 2 and 4) had a higher incidence of chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), smoking and history of myocardial infarction (p<0.001). The Kaplan-Meier survival curves identified that the groups with preserved LVEF had improved long-term survival compared to groups with depressed LVEF (p<0.001). As well, there was no significant correlation between elevated LVEDP and decreased survival in patients with a preserved LVEF (Group 1 versus Group 3, p=0.84). However, in patients with depressed LVEF<35%, an elevated LVEDP was associated with worse long-term survival when compared to patients with an LVEDP<18mmHg (Group 2 versus Group 4, p<0.001). The independent predictors of death by Cox proportional hazards modeling were: LVEF<35%, advanced age, COPD, PVD, dialysis dependent renal failure, and CHF (p<0.001); while elevated LVEDP≥18mmHg was not significant. We conclude that elevated LVEDP≥18mmHg is not an independent risk factor for mortality in patients undergoing isolated CABG; however, in patients with depressed LVEF<35%, an elevated LVEDP further prognosticates a significant decrease in long-term survival.