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This activity reviews the indications and contraindications of intra-aortic balloon pump in patients with cardiogenic shock secondary to various cardiac conditions, including myocardial infarction and subsequent mechanical complications. It covers the structure of the IABP device and its hemodynamic effects, the complications related to IABP use, and, most importantly, how an interprofessional team approach in caring for patients with cardiogenic shock requiring IABP support can help improve the clinical outcomes. Objectives: Review the anatomic and physiologic effects of the intra-aortic balloon pump. Review the indications for the intra-aortic balloon pump procedure. Review the technique of intraaortic balloon pump placement. Outline strategies for interprofessional communication to help make timely decisions about escalation or deescalation of care consistent with the patient's goals of care and the long-term prognosis with an intra-aortic balloon pump. Access free multiple choice questions on this topic.

Patients with the clinical and biochemical signs and symptoms of hypoperfusion secondary to cardiac failure or cardiac arrest carry high short-term mortality.[1] Various mechanical circulatory devices have been developed to mitigate the adverse outcomes of cardiogenic shock until treating the underlying cause. To date, four types of mechanical circulatory support devices exist that include Intra-aortic balloon pump (IABP), non-IABP ventricular circulatory assist devices, extracorporeal membrane oxygenation devices, and non-percutaneous ventricular assist devices. Intra-aortic balloon pump is the simplest, cost-effective, easy to implant and explant in the coronary catheterization laboratory by an interventional cardiologist and can effectively be managed in an intensive care unit by an intensivist.[2] Although IABP has a modest hemodynamic beneficial effect compared with novel, advanced mechanical circulatory support devices, it has a better safety profile, relative simplicity to use, and the beneficial cardiovascular physiological impact. These features make IABP a frequently used circulatory support device in patients requiring hemodynamic support either in cardiogenic shock or at risk of hemodynamic decompensation during a high-risk coronary intervention. However, currently available evidence related to the use of IABP is in constant flux. Therefore, it is important to review the safety and efficacy of IABP in various clinical conditions and appraise the health care providers of current evidence-based literature related to IABP. This article reviews the physiological and hemodynamic effects of IABP on the cardiovascular system as well as the safety and efficacy of its use in various cardiovascular clinical conditions.

The Benchmark Registry reports an incidence of 2.6% for major complications (major complications include severe limb ischemia, severe bleeding, balloon leak, or death due to IABP insertion or failure) with 21.2% in-hospital mortality, and only 0.05 % of in-hospital mortality was directly attributable to IABP.[15] Complications of the IABP in 5495 patients with acute myocardial infarction reported in the Benchmark registry are:[16] All Complications 8.1% Major complication 2.7% Minor complication 5.4% Bleeding Complication Any access site bleeding 4.3% Severe access site bleeding 1.4% Transfusion 1.4% Vascular Complications and Limb Ischemia Any limb ischemia 2.3% Visceral ischemia 0.1% Major limb ischemia (loss of pulse, loss of sensation, or abnormal temperature or pallor limb necessitating intervention, arterial repair or amputation) 0.5% Amputation 0.1% Vascular surgery 0.7% Deep venous thrombosis 0.1% Superficial vein thrombosis 0.1% Infection 0.1% Stroke 0.1% IABP Related Mortality 0.05% Others IABP leak 0.8% Poor inflation 0.6% Difficult insertion of IABP 0.1% Poor augmentation 1.1% Independent risk factors for major complications identified in the Benchmark Registry were female gender, peripheral vascular disease, body surface area less than 1.65 m, and age greater than or equal to 75 years. However, additional risk factors leading to ischemic vascular complications are the duration of IABP support, catheter size, diabetes, and cardiac index less than 2.2 L/min/m. Diabetes and hypertension are known risk factors of developing peripheral arterial disease and may indirectly predispose to risk of vascular complication due to a higher prevalence of PAD in this group of patients.[17][18][19][20] In the IABP SHOCK II Trial, researchers observed no significantly higher risk of complication in the IABP group as compared with the control group. Various complication observed in IABP vs control group are as follows: Major bleeding risk (3.3 % in IABP group vs 4.4 % in control group, p value = 0.51) Peripheral ischemia complications (3.3 % in IABP group vs 4.4 % in control group, p value = 0.51) Sepsis (3.3 % in IABP group vs 4.4 % in control group, p value = 0.51) Stroke (0.7% in IABP vs 1.7% in control, P = 0.28)

Although IABP has a less significant impact on the hemodynamic improvement, its physiological effect of offloading the left ventricle during active ischemic heart disease, especially in hypotensive patients with reduced cardiac output, results in decreased myocardial oxygen demand, and thus, indirectly assist compromised left ventricle to enhance the cardiac output. New short-term mechanical circulatory support devices demonstrate significantly improved hemodynamic support as compared with IABP. However, studies observed no mortality benefit, and a higher rate of bleeding and incidence of an ischemic limb is noted with these new MCS devices compared with IABP. Although the use of IABP is declining over time; nevertheless, IABP is still the most widely used cardiac assist device encompassing a wide array of indications ranging from prophylactic use during high-risk percutaneous or surgical intervention to the cardiogenic shock needing hemodynamic stabilization. Despite its widespread use in various clinical conditions, except for the guidelines available for the utility of IABP in ST-segment elevation MI, there are no specific guidelines by the American College of Cardiology/American Heart Association available to guide initiation of IABP in various other clinical conditions. Further studies are warranted to devise stringent criteria and protocol to assist physicians in decision-making related to the timing of initiation and weaning of IABP and to identify the patient group with cardiogenic shock who will benefit the most from IABP therapy.

Although IABP has a less significant impact on the hemodynamic improvement, its physiological effect of offloading the left ventricle during active ischemic heart disease, especially in hypotensive patients with reduced cardiac output, results in decreased myocardial oxygen demand, and thus, indirectly assist compromised left ventricle to enhance the cardiac output. New short-term mechanical circulatory support devices demonstrate significantly improved hemodynamic support as compared with IABP. However, studies observed no mortality benefit, and a higher rate of bleeding and incidence of an ischemic limb is noted with these new MCS devices compared with IABP. Although the use of IABP is declining over time; nevertheless, IABP is still the most widely used cardiac assist device encompassing a wide array of indications ranging from prophylactic use during high-risk percutaneous or surgical intervention to the cardiogenic shock needing hemodynamic stabilization. Despite its widespread use in various clinical conditions, except for the guidelines available for the utility of IABP in ST-segment elevation MI, there are no specific guidelines by the American College of Cardiology/American Heart Association available to guide initiation of IABP in various other clinical conditions. Further studies are warranted to devise stringent criteria and protocol to assist physicians in decision-making related to the timing of initiation and weaning of IABP and to identify the patient group with cardiogenic shock who will benefit the most from IABP therapy. Cardiogenic shock is a time-sensitive clinical condition that carries a high early mortality rate despite the implementation of advanced treatment strategies, including the early use of percutaneous coronary intervention, medical therapy, hemodynamic support with medications, and mechanical support devices.[56] Early diagnosis and application of interprofessional collaboration in the management of cardiogenic shock are vital to improving clinical outcomes in terms of mortality. Jacob et al. proposed an interprofessional cardiogenic shock team model to ensure prompt diagnosis of cardiogenic shock and the underlying etiology. This approach can enhance the survival outcomes through timely utilization of medical therapies adjunct to supportive therapies and, if possible, earlier revascularization. Implementation of a plan for escalation of hemodynamic support with IABP or the newer advanced mechanical support devices such as left-side heart pump systems in those patients with severe hemodynamic collapse deemed to require a mechanical support device that can ensure high cardiac output.II[57]

Cardiogenic shock is a time-sensitive clinical condition that carries a high early mortality rate despite the implementation of advanced treatment strategies, including the early use of percutaneous coronary intervention, medical therapy, hemodynamic support with medications, and mechanical support devices.[56] Early diagnosis and application of interprofessional collaboration in the management of cardiogenic shock are vital to improving clinical outcomes in terms of mortality. Jacob et al. proposed an interprofessional cardiogenic shock team model to ensure prompt diagnosis of cardiogenic shock and the underlying etiology. This approach can enhance the survival outcomes through timely utilization of medical therapies adjunct to supportive therapies and, if possible, earlier revascularization. Implementation of a plan for escalation of hemodynamic support with IABP or the newer advanced mechanical support devices such as left-side heart pump systems in those patients with severe hemodynamic collapse deemed to require a mechanical support device that can ensure high cardiac output.II[57] Patients with cardiogenic shock requiring hemodynamic support are critically ill and necessitate intensive care by an interprofessional team that includes the emergency department, critical care intensivist, interventional cardiologist, advanced heart failure specialist, cardiothoracic surgeon depending upon the underlying clinical condition causing cardiogenic shock. These causes can include mitral valve regurgitation due to papillary muscle rupture or ventricular septum defect as a result of myocardial infarction necessitating surgical repair, telemetry units, 24-hour intensive care nurse certified to manage IABP, 24-hour certified nursing assistant to perform frequent monitoring of vitals and peripheral pulses, and the 24-hour pharmacist to assist in the selection of the appropriate dose of the medications and identify and manage the drug interactions. The decision to initiate an IABP support is usually at the discretion of the interventional cardiologist and the advanced heart failure specialist after taking into consideration the short term and long term prognosis, goals of the care, age, and other comorbidities of the patient that may have an impact on the clinical outcomes.

Patients with cardiogenic shock requiring hemodynamic support are critically ill and necessitate intensive care by an interprofessional team that includes the emergency department, critical care intensivist, interventional cardiologist, advanced heart failure specialist, cardiothoracic surgeon depending upon the underlying clinical condition causing cardiogenic shock. These causes can include mitral valve regurgitation due to papillary muscle rupture or ventricular septum defect as a result of myocardial infarction necessitating surgical repair, telemetry units, 24-hour intensive care nurse certified to manage IABP, 24-hour certified nursing assistant to perform frequent monitoring of vitals and peripheral pulses, and the 24-hour pharmacist to assist in the selection of the appropriate dose of the medications and identify and manage the drug interactions. The decision to initiate an IABP support is usually at the discretion of the interventional cardiologist and the advanced heart failure specialist after taking into consideration the short term and long term prognosis, goals of the care, age, and other comorbidities of the patient that may have an impact on the clinical outcomes. Although the SHOCK II study fails to demonstrate short-term and long-term mortality benefits with IABP therapy adjunctive to PCI in ST-elevation MI complicated by CS as compared to a medical therapy group, it may be secondary to extensive damage to the heart muscle tissue not able to sustain the cardiac function for an increased period of time despite IABP support. In such patients, IABP may be an option as temporizing hemodynamic support to bridge to the durable mechanical assistance device or heart transplantation. Therefore, early consultation with an interprofessional cardiogenic shock team, including an interventional cardiologist and advanced heart failure specialist, before or at the time of IABP insertion may prove beneficial to devise a plan of care about urgent revascularization. Such a plan can ensure the adequacy of the hemodynamic support and contemplate a long-term plan of care to improve survival outcomes. The interventional cardiologist's role is the decision-making about the initiation of mechanical support devices and placement of the IABP and or other percutaneous mechanical support devices and revascularization for acute myocardial infarction. Advanced heart failure cardiologist evaluation is essential to assess for the requirement of durable ventricular assist devices or heart transplantation, and, if needed, can coordinate for listing the patient for durable VAD and heart transplantation. Additionally, heart failure specialists can provide further recommendations about treatment options for patients with decompensated heart failure complicated by cardiogenic shock. Further, the cardiothoracic surgery team should be promptly involved in patient care if mechanical complications of myocardial infarction, i.e., severe mitral regurgitation due to papillary muscle rupture or ventricle septal rupture, is diagnosed and require urgent surgical repair. Furthermore, the role of intensivist is imperative in care as patients with cardiogenic shock secondary to myocardial infarction usually experience multi-organ failure, and require intensive care interventions to prevent and treat multi-organ dysfunction and manage the critically ill patients requiring mechanical ventilator support, and prevent and treat malnutrition, delirium, pressure ulcers, and thromboembolism.[58] The intensive care unit physician plays the role of a coordinating physician and serves the responsibilities of diagnosis, triage, activation of subspecialties and additional team members, and medical management of the cardiogenic shock patients with multi-organ failure. Moreover, an intensivist has a vital role in ensuring the adequate functioning of the IABP and continuous monitoring for early identification of the device-related complication and its management. Intensivist and interventional cardiologists must be cognizant of the patient's goals of care consistently throughout the care. In conditions of refractory cardiogenic shock with an inappropriate response to medical therapy, revascularization, inotropes/vasopressors and IABP support, and further escalation of care to heart transplantation or permanent ventricular assist device is not a goal or deemed futile, and an interprofessional team approach can assist in the transition of care to end of life care/comfort care. In such a condition, consultation of the palliative care/hospice care team to provide comfort care is warranted.

Patients with cardiogenic shock dependent on IABP support require certified/accredited intensive care unit nurses to monitor the hemodynamics of the patient. Therefore and to ensure adequate augmentation with IABP. Vitals should be observed frequently over the day, and any adverse change in hemodynamics should be reported to the intensivist immediately. Patients with IABP catheter inserted in the femoral artery need bedrest with as minimal as possible movement of the lower extremity to avoid displacement of the intra-aortic balloon from its recommended position. Bending of leg and movement of the patient can lead to migration of balloon proximal to the origin of the subclavian artery and can result in vascular complications including compromise of blood supply to the left upper extremity and stroke. Migration of the balloon below the origin of the renal artery can result in renal injury. Patients with IABP in place are at risk of developing bacteremia and sepsis. Therefore, sepsis workup should be initiated promptly if the patient developed fever, leukocytosis, or other signs of infection, and, if clinically warranted, empiric antibiotic therapy should commence. Another significant complication of IABP is the thrombosis or thromboembolic phenomena. To reduce the risk of thrombosis, the patients requiring IABP are usually anticoagulated unless there is a pre-existing contraindication to anticoagulation. These patients should be monitored closely for bleeding complications, and hemoglobin/hematocrit should be monitored closely. Daily chest X-ray should be obtained to confirm the position of the IABP catheter tip. The carina may be the best landmark to confirm the positioning of the IABP catheter tip, and the IAPB catheter tip 2 cm above the carina results in adequate positioning of the IABP in 95.3% of the patients (1.5 to 3.5 cm distal to the origin of the Left subclavian artery).[59] Daily monitoring of hemoglobin/hematocrit, platelet count, serum creatinine is advised. Adequate anticoagulation management requires collaborative efforts of ICU pharmacist, nurses, and the physician to monitor for activated clotting times and an early sign of the bleeding complication. [Level 5]

The interprofessional team should closely monitor vital signs to ensure adequate augmentation with IABP. In patients with hypotension/hemodynamic instability despite being on IABP, urgent troubleshooting should be considered that includes evaluation of adequate timing of balloon inflation and deflation to assess the positioning of the intra-aortic balloon by fluoroscopy and imaging studies checking for kinking of tubings and functioning of gas supply apparatus. If no problem is detected, then alternate possibilities may be considered that include dehydration, sepsis, or overt hemodynamic collapse due to severe myocardial depression. If the patient develops a fever, a broad differential diagnosis should be considered that includes but is not limited to sepsis, thrombosis, or thromboembolic phenomena related to IABP catheter/balloon, pressure ulcers, pneumonia/atelectasis, or drug reaction. Monitor for hemorrhagic complications. Frequent neurological exams to monitor for cerebrovascular complications (stroke) and to monitor for delirium are needed. Helium gas leaks secondary to balloon rupture or malfunction can lead to acute embolic stroke. In case of a suspicion of gas leak from the balloon, the patient should be placed in a Trendelenburg position, and IABP should be switched off with termination of gas supply. Frequent monitoring of peripheral arterial pulses is imperative to promptly identify the vascular complications secondary to IABP and manage them accordingly.