We describe the steps for the percutaneous implantation of the intra-aortic balloon pump (IABP), a mechanical circulatory support device. It acts by counterpulsation, inflating at the onset of diastole, augmenting diastolic aortic pressure and improving coronary blood flow and systemic perfusion, and deflating before systole, reducing left ventricular afterload.
Cardiogenic shock remains one of the most challenging clinical syndromes in modern medicine. Mechanical support is being increasingly used in the management of cardiogenic shock. Intra-aortic balloon pump (IABP) is one of the earliest and most widely used types of mechanical circulatory support. The device acts by external counterpulsation and uses systolic unloading and diastolic augmentation of aortic pressure to improve hemodynamics. Although IABP provides less hemodynamic support when compared with newer mechanical circulatory support devices, it can still be the mechanical support device of choice in appropriate situations because of its relative simplicity of insertion and removal, need for smaller size vascular access and better safety profile. In this review, we discuss the equipment, procedural and technical aspects, hemodynamic effects, indications, evidence, current status and recent advances in the use of IABP in cardiogenic shock.
Cardiogenic shock is a clinical condition characterized by decreased end organ perfusion due to severe cardiac dysfunction. The most widely accepted definition of cardiogenic shock is based on the Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock trial (SHOCK)1 and Intra-aortic Balloon Support for Myocardial Infarction with Cardiogenic Shock (IABP-SHOCK-II) trial2 and includes the following parameters:
1. Systolic blood pressure <90 mm Hg for ≥30 min or vasopressor and/or mechanical support to maintain SBP ≥90 mm Hg
2. Evidence of end-organ hypoperfusion (urine output <30 mL/h or cool extremities)
3. Hemodynamic criteria: cardiac index ≤2.2 L/min/m2 and pulmonary capillary wedge pressure ≥15 mm Hg
Acute myocardial infarction (AMI) is the most common cause of cardiogenic shock accounting for approximately 30% of cases3. Despite advances in the treatment of patients with AMI with early invasive revascularization, the mortality of cardiogenic shock remains high4. The mechanism of diastolic augmentation showing improvement in coronary perfusion and decreased left ventricular work was first demonstrated in 19585. Subsequently, in 1962 the first experimental prototype of IABP was developed6. Six years later, Kantrowitz et al.7 presented the first clinical experience of IABP use in four patients with AMI and cardiogenic shock unresponsive to medical therapy.
The IABP's mechanism of action involves inflation of the balloon during diastole and deflation during systole. This results in two important hemodynamic consequences: When the balloon inflates in diastole, the blood in the aorta is displaced proximally towards the aortic root thereby increasing coronary blood flow. When the balloon deflates in systole, it causes a vacuum or suction effect decreasing afterload and augmenting cardiac output8. The hemodynamic changes caused by IABP are listed below9 (Table 1):
1.Increase in aortic diastolic pressure
2.Decrease in systolic blood pressure
3.Increase in mean arterial pressure
4.Decrease in pulmonary capillary wedge pressure
5.Increase in cardiac output by ~20%
6.Increase in coronary blood flow10
The major indications of IABP are cardiogenic shock (due to AMI and other causes like ischemic and non-ischemic cardiomyopathy, myocarditis), mechanical complications of AMI like ventricular septal defect or severe mitral regurgitation, mechanical support during high risk percutaneous coronary interventions11, as a bridge to coronary artery bypass surgery in patients with critical CAD, inability to wean off cardiopulmonary bypass and as a bridge to decision or advanced therapies like left ventricular assist devices (LVAD) or cardiac transplantation in end stage heart failure12,13,14,15. Contraindications to use of IABP include moderate or severe aortic regurgitation which can worsen with counterpulsation, severe peripheral vascular disease which would preclude optimal arterial access and placement of the device and aortic pathologies like dissection12,15.
The IABP device consists of a console to control the unit and a vascular catheter with the balloon.
The console includes the following four components:
a) Monitor unit which helps to process and determine a trigger signal for the balloon. The signal can be either electrocardiographic (ECG) triggering or pressure signal triggering;
b) Control unit: Processes the trigger signal and activates the gas valve to help with inflation or deflation;
c) A gas cylinder that contains helium. Carbon dioxide is an alternative but is less preferred than helium. Helium has a lower density and provides better balloon inflation characteristics with more rapid inflation and deflation16;
d) A valve unit which helps with gas delivery.
The IABP (balloon) catheter is a 7-8.5 F vascular catheter with distance markings. The catheter has a polyethylene balloon mounted at the tip. The balloon size can vary from 20-50 mL. The ideal balloon has a length to cover from the left subclavian artery to the celiac artery take off, the inflated diameter measuring 90 to 95% of that of the descending aorta. The most commonly used balloon size in adult patients (height 5'4″/162 cm to 6'/182 cm) is 40 mL. A 50 mL balloon is used for patients >6'/182 cm and 34 cm balloon for 5'/152 cm to 5'4″/162 cm tall patients12,17 (Table 2).
This protocol follows the guidelines of institutional human research ethics committee.
1. Pre-insertion preparation
NOTE: The IABP is preferably inserted in the cardiac catheterization lab under fluoroscopic guidance. Bedside placement can be considered in very critical clinical situations.
2. Insertion of the IABP
3. Switching on and setting up the IABP
4. Assessment of the patient after placement of IABP
5. Removal of IABP
Despite being used for many decades now, the evidence on IABP use has been controversial. Routine use of IABP in patients with AMI and cardiogenic shock is not recommended. The previous guidelines of the American Heart Association/American College of Cardiology (AHA/ACC) and the European Society of Cardiology (ESC) strongly recommended the use of the IABP in patients with AMI-associated cardiogenic shock (Class I B and Class I C) on the basis of pathophysiological considerations, non-randomized trials and registry data. However, the AHA/ACC in 2013 downgraded the use of IABP to class II A, primarily based on the results of the IABP Shock II trial13. The ESC STEMI Guidelines 2017 recommended no routine IABP counterpulsation but the guidelines state that IABP may be considered for haemodynamic support in selected patients as those with severe mitral insufficiency or ventricular septal defect14. The ESC NSTE-ACS 2020 guidelines discourage form routine use of IABP in patients with CS (class IIIB) but recommend IABP in ACS-related mechanical complications (class IIA)20.
The IABP Shock II trial2, randomized 600 patients with acute MI complicated by cardiogenic shock to either IABP or no IABP. At 30 days, there were no differences in outcomes, including length of stay in the intensive care unit, renal function, rates of major bleeding, peripheral ischemic complications, sepsis, or stroke. There was no difference in mortality at long-term follow-up of 12 months and 6.2 years21.The major limitations of the trial were – the timing of insertion of IABP was not controlled (86.6% were inserted post PCI). A lower mortality rate compared to other studies precludes application of this study to severe cardiogenic shock. Subsequent meta-analyses have showed that there is no convincing randomized data to support the routine use of IABP in AMI related cardiogenic shock22.
However, several recent studies have shown that there is still some utility for the use of IABP. A meta-analysis of 9212 patients investigated the utility of the IABP when implanted preoperatively in patients undergoing coronary bypass graft surgery. The results support the use of IABP in this clinical setting, with a 4% relative risk reduction of mortality. Also, the risk of MI, renal failure, intensive care, and hospital length of stay were reduced with IABP23. Interestingly, with the increasing use of advanced heart failure therapies, IABP is being increasingly used in combination with extracorporeal membrane oxygenation and was associated with better survival in a recent meta-analysis24.
Structure | Hemodynamic effect |
Aorta | ↓systolic pressure, ↑diastolic pressure |
Left ventricle | ↓systolic pressure, ↓end-diastolic pressure, ↓volume, ↓wall tension |
Heart | ↓afterload, ↓preload, ↑cardiac output |
Coronaries | ↑/unchanged coronary blood flow |
Table 1: Hemodynamic effects of IABP
Company | Product | Catheter size (F) | Sheath size (F) | Balloon size (ml) |
Balton | IABC Balloon | 7.5, 8 | 7.5, 8 | 20, 25, 30, 34, 40, 50 |
Getinge | Cardiosave IABP | 7, 7.5, 8 | 7.5,8 | 25, 30, 34, 40, 50 |
Getinge | CS300 IABP | 7, 7.5, 8 | 7.5,8 | 25, 30, 34, 40, 50 |
Getinge | Linear | 7.5 | 7.5 | 25, 34, 40 |
Getinge | Mega | 7.5, 8 | 7.5, 8 | 30, 40, 50 |
Getinge | Sensation | 7 | 7 | 34,40 |
Getinge | Sensation Plus | 7.5, 8 | 7.5,8 | 40,50 |
Teleflex | Arrow AC3 Optimus Intra-Aortic Balloon Pump | 7, 7.5, 8 | 8,8.5 | 30,40,50 |
Teleflex | Arrow RediGuard IAB Catheters | 7,8 | 8,8.5 | 30,40,50 |
Teleflex | Arrow Ultra 8 Fiber-Optic IAB Catheters | 8,8.5 | 8,8.5 | 30,40,50 |
Teleflex | Arrow Ultra 8 Fluid-Filled IAB Catheters | 8 | 8 | 30,40 |
Teleflex | Arrow UltraFlex 7.5 IAB Catheters | 7.5, 8 | 8,8.5 | 30,40,50 |
Table 2: Comparison of catheter and sheath sizes across different IABP manufacturers33
Problem | Probable cause | Solution |
Console alarm – “check IABP Catheter” | Kink in tubing | Relieve kink |
Incomplete unfolding of balloon membrane | Manually inflate and deflate balloon | |
A part of the balloon is in the sheath | Check balloon position | |
Rapid Gas Loss or Leak in IABP Circuit | Possible rupture | Check tubing for blood |
If there is no blood in the tubing, double check the connections | ||
Weak left radial pulse or left arm ischemia. | Left subclavian artery occlusion | Check position of IABP |
Low urine output or hematuria | Renal artery occlusion | Check position of IABP |
Excessive bleeding from insertion site | Difficult arterial access, multiple sticks | Apply firm pressure while ensuring distal flow |
Limb ischemia | Arterial access site issues, peripheral vascular disease | Consider removing the IABP. Consider alternate access |
Blood noted in catheter tubing | Balloon rupture | Stop the IABP and remove the catheter immediately |
Arterial dissection | Improper advancement of the guidewire with subsequent insertion of the IABP into a false lumen | Remove IABP |
Table 3: Troubleshooting of potential device malfunction and major patient complications from IABP
Figure 1: Hemodynamic waveform with IABP and appropriate timing of IABP augmentation Please click here to view a larger version of this figure.
Mechanical circulatory support is a rapidly evolving field. Even with the arrival of newer support devices, IABP remains the most widely used and simplest to deploy mechanical circulatory support device available currently25. In this article we describe in detail, the procedure for percutaneous insertion of IABP, the indications, evidence, troubleshooting and complications. Despite conflicting evidence regarding the use of IABP in AMI-related cardiogenic shock, it remains the most widely used form of mechanical support. In addition to use in AMI related cardiogenic shock IABP is also used in coronary artery bypass surgery and as a bridge to advanced heart failure therapies like LVAD or cardiac transplant.
Insertion of the IABP is straightforward and the technique can be rapidly deployed either at bedside or preferably in the cardiac catheterization laboratory where fluoroscopic guidance can be used to confirm positioning. We recommend using ultrasound guidance to obtain arterial access to improve first pass success and better safety profile26. The IABP wire can either be backloaded (advancing the balloon and wire together as a unit) or over the wire as mentioned above. However, in patients with known peripheral vascular disease, we recommend the "over the wire" method. This helps confirm whether it is possible to navigate the IABP catheter through a narrow or tortuous vasculature. In patients with risk factors for limb ischemia, sheathless insertion technique can be considered which reduces the risk of ischemic complications secondary to the vascular sheath27.
IABP is now being increasingly used in patients with end stage heart failure as a bridge to decision or advanced heart failure therapies like LVAD or cardiac transplant. A large study looking at the use of IABP in 1342 patients showed that IABP utilization increased over three fold since the 2018 cardiac transplant allocation change28. Since these patients often require mechanical support for a prolonged period of time, IABP insertion through the axillary artery can be considered. The axillary approach is well tolerated and permits ambulation and reduces the risk of infection in those requiring prolonged mechanical support. This overcomes the major limitation of the femoral approach which restricts ambulation and thereby promoting deconditioning in this tenuous patient population29. Newer devices which operate on the same principles as an IABP like the intravascular ventricular assist system (iVAS) are currently being studied which allow the patient to be discharged home with a temporary mechanical support device30.
Complications from IABP most commonly result from difficult arterial access, malposition and patient risk factors like peripheral vascular disease. Due to the endovascular nature of the device, the most common complications are primarily related to vascular injury. Other complications include cerebrovascular accident, thrombocytopenia, insertion site bleeding, aortic dissection, spinal cord ischemia, blood stream infections, balloon rupture and gas embolism11,27,31,32. Troubleshooting of the device and the common complications are summarized in Table 3.
The authors have nothing to disclose.
None
IABP catheter and console | Getinge | Sensation Plus | |
Micropuncture Introducer Set | Cook Medical | G48006 | |
Sterile drapes | Haylard | ||
Ultrasound | GE | ||
Lidocaine | Pfizer |