A Single Center Analysis Of Correlation Of Heartmate 3 Lvad Flows To Indirect Fick Method Derived By Swan-ganz Catheter

Abstract

Background Heartmate 3 left ventricular assist device (LVAD) has been approved for end stage heart failure patients. The LVAD flows are calculated and are presumed to represent a surrogate for cardiac output (CO). We investigated if cardiac output measured by indirect fick method correlates with the LVAD flows in the peri-operative period to make clinical decisions. Methods This was a single center, retrospective analysis of patients post destination therapy LVAD implantation. LVAD flow (LF) derived from the LVAD was compared to the cardiac output calculated via indirect fick. Patients were also sub-categorized to opening of the aortic valve with use of echocardiogram. Additional data of each patients age, sex, height, weight,intermacs stage, pulmonary artery oxygenation saturation, peripheral arterial oxygenation,heart rate, hemoglobin and hematocrit were also reviewed. The LF, indirect fick CO measurements and opening of aortic valve were all measured within the first 72 hours post LVAD implant Results A total of 27 patients were used in the analysis of this study. The mean indirect fick calculated CO was 5.68 liters per minute (lpm) and the mean LVAD flow (LF) was 4.12lpm. Using Bland-Altman analysis, the fick derived CO systematically over-estimated cardiac output compared to the LVAD PF method (DeltaCO) by 1.56±1.11 L/min (95% CI 1.12 to 2.00,P < 0.001). The difference between the delta CO was not influenced by the flow from the aortic valve with P= 0.56 derived from the overall model. Additional sub-analysis of age, sex, height,weight, a low flow cardiac index of less than 2.2 L/min/m 2, low venous oxygenation, low hemoglobin values did not show statistical correlation of LVAD PF to indirect fick CO. Conclusion There was no significant correlation between the LVAD flow and an indirect fick CO in the first 72 hours post LVAD implant. LVAD flow should not be independently used to make relevant clinical decisions without hemodynamic guidance from swan-ganz catheter. Heartmate 3 left ventricular assist device (LVAD) has been approved for end stage heart failure patients. The LVAD flows are calculated and are presumed to represent a surrogate for cardiac output (CO). We investigated if cardiac output measured by indirect fick method correlates with the LVAD flows in the peri-operative period to make clinical decisions. This was a single center, retrospective analysis of patients post destination therapy LVAD implantation. LVAD flow (LF) derived from the LVAD was compared to the cardiac output calculated via indirect fick. Patients were also sub-categorized to opening of the aortic valve with use of echocardiogram. Additional data of each patients age, sex, height, weight,intermacs stage, pulmonary artery oxygenation saturation, peripheral arterial oxygenation,heart rate, hemoglobin and hematocrit were also reviewed. The LF, indirect fick CO measurements and opening of aortic valve were all measured within the first 72 hours post LVAD implant A total of 27 patients were used in the analysis of this study. The mean indirect fick calculated CO was 5.68 liters per minute (lpm) and the mean LVAD flow (LF) was 4.12lpm. Using Bland-Altman analysis, the fick derived CO systematically over-estimated cardiac output compared to the LVAD PF method (DeltaCO) by 1.56±1.11 L/min (95% CI 1.12 to 2.00,P < 0.001). The difference between the delta CO was not influenced by the flow from the aortic valve with P= 0.56 derived from the overall model. Additional sub-analysis of age, sex, height,weight, a low flow cardiac index of less than 2.2 L/min/m 2, low venous oxygenation, low hemoglobin values did not show statistical correlation of LVAD PF to indirect fick CO. There was no significant correlation between the LVAD flow and an indirect fick CO in the first 72 hours post LVAD implant. LVAD flow should not be independently used to make relevant clinical decisions without hemodynamic guidance from swan-ganz catheter.