Intra-aortic baloon pumps what, who, why why why? Daniel Lovric Fellow, CVICU Auckland City Hospital Auckland Region ICU Study Day 30th October 2014

IABP – What is it? Mechanical hemodynamic support device Two principal parts

How does it work?

Theoretical benefits – Two basic principles

Physiological effects Hanlon-Pena et al, AJCC 2011

Reduction in LV workload

Schreuder et al, Ann Thorac Surg 2005 Commencement of IABP pulsation Reduction in left ventricular pressure Reduction in left ventricular stroke work Increase in left ventricular stroke volume

Augmented coronary flow Conficting evidence Inflation of the balloon diastolic pressure and diastolic perfusion pressure gradient (Port, JACC 1984; Williams, Circ 1982) Animals with normal systemic blood pressure myocardial oxigen consumption, no change in coronary flow (Kern, Am Heart J 1999) Coronary flow measurements pre-stenotic flow (MacDonald, Am J Cardiol 1987; Kern, Circ 1991) post-stenotic flow (MacDonald, Am J Cardiol 1987; Gewirtz, Am J Cardiol 1982) Angina symptoms (Folland, Circ 1991) “Artificial myoconservation” (Ohman, Circ 1994) stimulation of collateral circulation (Ohman, Circ 1994; Fuchs, Circ 1983) stimulation of collateral circulation (Ohman, Circ 1994; Fuchs, Circ 1983)

Augmented coronary flow Laplace’s Law Deflation of the balloon end-diastolic pressure wall stress myocardial oxygen demand

How it begun – Kantrowitz described the principle of counterpulsation 1962 – Moulopoulos (Cleveland Clinic) described the modern intra-aortic counterpulsation device - carbon dioxide - R wave timing 1971 – Krakauer & Kantrowitz describe series of 30 pts in cardiogenic shock 2° to STEMI treated with IABP - 25 of 30 pts achieved hemodynamic stabilisation and reversal of shock Moulopoulos et al, Am Heart J 1962; Goldberg et al, NEJM 1999; Antman et al, Circulation 2008 Buckley et al, Circ 1973; Housman et al, JAMA 1973; Bergman et al, A. Th. Surg 1980; Subramanian et al, Circ – Successful use of IABP in weaning of cardio- pulmonary bypass published by two different groups 1980 – Development of percutaneous catheter introduction

... and took hold 1959 – Kantrowitz described the principle of counterpulsation 1962 – Moulopoulos (Cleveland Clinic) described the modern intra-aortic counterpulsation device - carbon dioxide - R wave timing 1986 – 1997 overall ~20% of patients received IABP suport for cardiogenic shock due to MI 1997 – 42% of patients Moulopoulos et al, Am Heart J 1962; Goldberg et al, NEJM 1999; Antman et al, Circulation 2008 Buckley et al, Circ 1973; Housman et al, JAMA 1973; Bergman et al, A. Th. Surg 1980; Subramanian et al, Circ 1980

Randomized trials IABP in STEMI

Analysis of trials IABP in STEMI Sjauw et al. EHJ 2009

Analysis of trials IABP in STEMI with cardiogenic shock Sjauw et al. EHJ 2009

IABP SHOCK II Trial Thiele et al. NEJM 2012

In cardiac surgery Ranucci et al. Crit Care Med 2013 Vent. wean Discharge

In high-risk PCI – BCIS-1 Perera et al. JAMA 2010, Circ 2013 P=0.03

Indications What’s left? Fotopoulos et al. Heart 1999; Ferguson et al, JACC 2001

Contraindications

Positioning 3-4mm metalic density Should be ~2 cm below the origin of left subclavian artery 2cm bellow the top of aortic knob 2nd – 3rd intercostal space anteriorly

Positioning Should be ~2 cm below the origin of left subclavian artery Kim et al, Anesth Analg cm above carina 1-2cm above PAC

Positioning Should be ~2 cm below the origin of left subclavian artery

IABP Timing Determines periods of inflation and deflation during cardiac cycle Criticaly important for achieving beneficial hemodynamic effects Newer systems can adjust timing completely automatically

Conventional Timing Studied and used in practice since the beginning of IABC Both inflation and deflation occur within diastole Deflation Timed at onset of systole Should occur before ejection Isovolumetric contraction phase Deflation Timed at onset of systole Should occur before ejection Isovolumetric contraction phase Inflation Timed to commence immediately prior or at the time of AV closure (dictrotic notch) Inflation Timed to commence immediately prior or at the time of AV closure (dictrotic notch)

Timing Errors Early inflation before AV closure LV forced to eject against inflated balloon, premature closure of AV Afterload Oxygen demand Stroke volume to 20% Aortic regurgitation may appear Trost et al, Am J Cardiol 2006

Timing Errors Late inflation after dicrotic notch – AV closure Augmentation Trost et al, Am J Cardiol 2006

Timing Errors Early deflation Before end of diastole, loss of sharp V diastolic pressure trace Augmentation May promote retrograde arterial flow from the coronaries and carotids Trost et al, Am J Cardiol 2006

Timing Errors Late deflation After begining of systole during ejection phase End-diastolic pressure Afterload Oxygen demand LV workload Trost et al, Am J Cardiol 2006

Real-time Timing R wave deflation Hanlon-Pena et al, AJCC 2011 Deflation occurs in early systole Safe when ≥50% of IABP volume is removed before the start of ejection 2-part potential effect Delayed opening of AV brings prolongation of isovolumetric contraction Length of ejection and stroke volume increased more than in conventional Delayed opening of AV brings prolongation of isovolumetric contraction Length of ejection and stroke volume increased more than in conventional Preferred method when arrhythmia is present

Complications During insertion Unable to pass the catheter up the aorta Arterial dissection or rupture Retroperitoneal bleeding or damage to adjacent structures

Complications During use Distal limb ischemia Poor supply to LSCA/renal arteries/mesenteric arteries Balloon rupture and gas embolism Thromboembolism Haemolysis & Thrombocytopenia

Complications On removal Inability to remove the catheter Bleeding Embolism Pseudoaneurysm AV fistula

Final thoughts

Thank you...