INTERMACS Profile Does Not Predict Required Flow Rate of CF-LVAD at Discharge

Purpose Recent studies involving partial-support ventricular assist device (VADs) have suggested INTERMACS Profiles may be used as a means of identifying patients with less severe heart failure who require lower flow rates. We explore which preoperative factors are predictive of continuous-flow left VAD (CF-LVAD) flow requirements at discharge. Methods Retrospective review of 206 patients who underwent primary implantation of CF-LVAD from May 2013 through August 2017 at our center and survived to discharge. We performed step-wise multiple linear regression analysis on preoperative factors to identify factors that predicted CF-LVAD flow rates at the time of discharge. Results Of the 206 patients in our study, 27 (13.1%) were INTERMACS Profile 1, 53 (25.7%) were Profile 2, 95 (46.1%) were Profile 3, 14 were Profile 4, and 17 (6.8%) were Profile 5-7. Mean flow rates at discharge were 5.3±1.3, 5.3±1.6, 4.9±1.3, 5.3±1.2, and 5.8±1.0 L/min, respectively. Linear regression analysis showed INTERMACS Profile was not correlated with LVAD flow (p=0.73). Age (Regression Coefficient [RC] = -0.03, p=0.009), body surface area (BSA; RC = 0.23, p=0.03), creatinine (RC = 0.40, p=0.02) and mean right atrial pressure (RC = 0.05, p=0.02) were significantly correlated with higher flow rates (Table). Conclusion INTERMACS Profile was not a predictor of required flow rates for patients on CF-LVAD support at the time of discharge. Younger age, higher BSA, and preoperative creatinine and mean right atrial pressure predicted greater flow requirements. Further studies are warranted to devise predictive models of CF-LVAD flow requirements.