title: The acute effect of IABP-induced pulsatility on coronary vascular resistance and graft flow in critical ill patients during ECMO.
abstract: OBJECTIVE
  The combination of the two cardiac support mechanisms of intra-aortic balloon pumping (IABP) and non-pulsatile circulatory extracorporeal membrane oxygenation (ECMO) has been confirmed to improve efficacy of the cardiac support as a whole. However, reports on benefits of diastolic augmentation on coronary vascular bed and graft flowmetry during concomitant use of IABP and ECMO are lacking. The aim of this study was to evaluate the acute impact of IABP support on coronary vascular resistance (CVR) and coronary bypass flows (CBF) in high-risk patients with peripheral ECMO following coronary artery bypass grafting (CABG).
  
  
  METHODS
  In eight emergency CABG patients (mean age=67.8±1.9 years; gender: six male and two female; EF=25.5±2.4%) requiring mechanical circulatory support with ECMO hemodynamic parameters, CVR, CBF, diastolic filling index (DFI), graft flow reserve (GFR), and pulsatility index (PI) were analyzed with and without diastolic augmentation using a transit time flowmeter.
  
  
  RESULTS
  The addition of IABP to ECMO decreased CVR significantly by 6.5%±1.9% compared to baseline with ECMO alone (1.62±0.2 versus 1.78±0.2; P<0.0045). Accordingly, significant higher mean CBF were found during IABP assist, resulting in a 21.6%±2.6% increase (60.7±8.7 mL/min with versus 51.3±7.4 mL/min without IABP; P<0.0001). IABP also significantly increased DFI by 9.8±0.9% (73.2%±1.4% with versus 66.7%±1.3% without IABP; P<0.0001). GFR was recruited during IABP in all grafts (GFR>1). There were no statistically significant differences in PI with and without IABP assistance (2.6±0.1 versus 2.5±0.2).
  
  
  CONCLUSIONS
  IABP-induced pulsatility significantly improves diastolic filling index and mean coronary bypass graft flows by lowering coronary vascular resistance during non-pulsatile peripheral ECMO. The combination of ECMO with IABP may provide more optimal myocardial oxygen conditions resulting in an improved efficacy of the cardiac support as a whole in critical ill patients with postcardiotomy myocardial dysfunction following CABG.
authors.affiliation: Department of Cardiothoracic Surgery, Cologne University Heart Centre, Cologne, Germany. navid.madershahian@web.de
authors.forename: N
authors.initials: N
authors.lastname: Madershahian
authors.forename: J
authors.initials: J
authors.lastname: Wippermann
authors.forename: O
authors.initials: O
authors.lastname: Liakopoulos
authors.forename: T
authors.initials: T
authors.lastname: Wittwer
authors.forename: E
authors.initials: E
authors.lastname: Kuhn
authors.forename: F
authors.initials: F
authors.lastname: Er
authors.forename: U
authors.initials: U
authors.lastname: Hoppe
authors.forename: T
authors.initials: T
authors.lastname: Wahlers
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D003324:Coronary Artery Disease / Q000503:physiopathology / Q000601:surgery*; D003326:Coronary Circulation; D016638:Critical Illness; D015199:Extracorporeal Membrane Oxygenation; D005260:Female; D005858:Germany; D006801:Humans; D007423:Intra-Aortic Balloon Pumping; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D011446:Prospective Studies; D011673:Pulsatile Flow; D020127:Recovery of Function; D013997:Time Factors; D016896:Treatment Outcome; D014655:Vascular Resistance