In this presentation, Yasir Abu-Omar, MD, FRCS, Dphil, discusses options for mechanical support and device considerations for patients in cardiogenic shock.
Thank you. My name is Yasser Abu. Jamal cardiac surgeon. Director of cardiothoracic transplantation. Mechanical support here at university hospitals. Today. My talk will focus on the options of mechanical circulatory support for patients in cardiogenic shock. Have no disclosures. I'll start by presenting a clinical case that we have recently encountered here over 25 Presenting three days following a Cesarean section. She presents with respiratory failure box here. The normal lactic acid and an X ray demonstrated severe pullman. As shown here she was profoundly hypoxic party and was into it intensive care of no chair have fought kind of actually right Following his 2nd heart transplant while being integrated. She sustained pea arrest um quickly returned to normal circulation. Mm She remains and gas it six. An echo demonstrated all eight very soon. Should not shown here. I'll come back this case nature. This is a classical definition of card. It actually systems historic blood pressure less than monument battery, responding to fluid administration. It is shown to be secondary to cardiac dysfunction associated with signs of heart fusion. The narcotic index of less than 2.2 and pulmonary capillary wedge pressure. Do you? The society for cardiovascular angiography and interventions. The efforts toward the more uniform courage commission. And the classification scheme displayed Based on this new definition. There are five categories risk pretty shocked too. Extreme cardiogenic shock labeled as A to E. In the figure here identifying the free shock stages dissolved and appealing as it may reduce motel prevent progression to cardiogenic shock. Through the shooting at strategies it is important that treatment is directed towards the cause of the cardiogenic shock and former co therapy with the use of water troops in the intensive care unit setting is usually started prior to consideration of mechanical circulatory support which these are the most commonly available temporary mechanical support devices used today and it's played here. Yeah, variable features in terms of right or left ventricular unloading. We will discuss these in further detail but principle these devices are you as a bridge other two recovery or two we need to therapy such as ventricular assist device, an endurable fashion or heart transplantation. So the ideal mechanical circulatory support device should be imminently available with rapid insertion and provides adequate e more dynamic support and my guard protection should have a low rate of complication namely hemorrhage, ischemia, embolism, Humala Asus and infection and with optimal timing and optimal serve food and prevention of device complications. The best outcomes are achieved and the principal goal here is to preserve end organ function and provide a bridge to recovery. Long term therapy. Yeah. The intra aortic balloon pump is the most frequently used device. It is usually inserted through the femoral artery using a selling technique And has been in use since the 1960s. It provides a counter pulsation therapy by inflating in die yesterday and by augmenting the diastolic pressure. It improves coronary perfusion and myocardial oxygen delivery. It's deflation. Pre sisterly serves to reduce the after load, thus reducing myocardial oxygen demand in recent years. The intra aortic balloon pump is being inserted through the auxiliary route when prolonged support is anticipated. For example, in patients waiting for heart transplant. This allows ambulance nation of these patients and minimizes the risk associated. There are several indications for the use of the intro to balloon pump, the shock, post cardiogenic shock following cardiac surgery and failure to win from cardiopulmonary bypass, as well as for primary graft dysfunction following heart transplantation. Other indications include unstable angina refractory to pharmacological therapy, patients developing mechanical complications from my current function and can be used as a junked of therapy in complicated cases for PC. It is also used for prophylaxis in patients with critical coronary disease awaiting surgery or further revascularization and also in patients with intractable ventricular arrhythmias and refractory heart failure. There are several contraindications for the use of intra aortic balloon pumps and the most important ones are significantly decreased vegetation, the presence so particular section and severe peripheral vascular disease. The outcomes regarding the use of intra aortic balloon pumps has been a subject of controversy for several years, particularly since the publication, the intra aortic balloon pump in shock randomized trial which demonstrated no difference in outcomes specifically mortality at 30 days. In patients with acute myocardial infarction and cardiogenic shock where the balloon pump was used or not. This resulted in the downgrading of the use of intra aortic balloon pump in the international guidelines and has also resulted in a significant reduction in its use worldwide. In turn, this has led to increased use of other intravascular temporary mechanical support with devices. The impeller is a trans valvular continuous micro axial flow device designed to propel blood from the left ventricle into the water. The setting of cardiogenic shock, it serves to unload the left ventricle. It reduces the left ventricular end diastolic pressure. In turn, it improves the mean arterial pressure and reduces myocardial oxygen consumption. Several devices are available from the impeller range. The most frequently used devices For insertion burn continuously through the femoral artery or the 2.5 on CPP The five and 5.5. Our devices are inserted surgically following the exposure of the axillary artery and as to moses of vascular graft. The device is then inserted under echocardiogram fix and fluoroscope guidance. It is highly effective in patients with single ventricle failure. It also serves as event during ECMO support. There are several contraindications for the use of the name paella, uh, which includes the severe stenosis or mechanical aortic valve. As this requires assertion through the welcome to the left ventricle mm. The presence of left ventricular thrombosis, patients with severe peripheral arterial disease and those with intra cardi actions. The safety and feasibility of the use of propeller has been reported in large registries, the largest trials reported here have all failed to demonstrate any mortality difference between the use of impeller and intra aortic balloon pump in patients with cardiogenic A more recent matched pair mortality analysis, uh vim pela treated versus intra aortic balloon pump treated courage. Election patients confirmed the lack of mortality benefit With the impeller device at 30 days. And of note severe or life threatening bleeds and peripheral vascular complications were observed more frequently with the imperative extracorporeal membrane oxygenation provides robust by ventricular support for patients encouraging shock and those in respiratory failure. Since its first description In the 1970s by Hill and colleagues, it has evolved greatly over the following decades. It's, you see worldwide, year on year, continues to increase dramatically. ECMO. Its simplest form involves the use of a blood pump which is usually centrifugal and the membrane oxygenate er and the heat exchanger. It provides excellent short term circulatory support for patients with ventricular failure. It has several advantages that are being readily available and its ease of insertion in the intensive care unit at the bedside. It's a very useful strategy in patients with cardiogenic shock as well as those it caught it arrest catania's cancelation in those patients can be performed at the bedside while cardiopulmonary bypass continues. ECMO can be divided brought into two types of material and we have been sick. The material is used mainly to support patients in cardiogenic shock or those in cardio respiratory failure, venus venus is reserved for patients with isolated respiratory dysfunction or failure. It is further subdivided into central or peripheral depending on the calculation. Central calculation involves cancelation directly in the heart of the great vessels and peripheral usually involves calculation no peripheral artery or and vain. V. A. ECMO can be used in many scenarios, including patients who have had a witness to rest in the form of E. C. P. R. Those following failure to win from cardiopulmonary bypass with the hope for recovery. Those with cardiogenic shock with without end organ dysfunction. Where this serves as a bridge to decision or recovery and also allows for stabilization of patients prior to more definitive therapy. In the form of durable left ventricular assist support or transplantation. It is also used in the support of patients having undergone transplant with primary graft dysfunction. Well, there are several advantages of uh ECMO support encouraging shock. It tends to increase the after load of the left ventricle and therefore increases the left ventricular and diastolic pressure. In some cases there is required the compression of the left ventricle using an adjunctive device such as left ventricular vent or insertion of an impeller differential cyanosis or how liquid syndrome can develop where there is a retrograde flow through peripheral V. A. ECMO. And where there is native cardiac output resulting in a mixing zone and potential the oxygenated blood in the proximal aorta resulting in differential cyanosis contraindications to the use of ECMO I displayed here. They're all relative the decisions are usually made by a specialist multidisciplinary team. Well, those are the uncontrolled hemorrhage. Uh those with difficulty to calculate or refuse and those with irreversible cardiac dysfunction, patients at extremes of age and with established multi organ failure usually have very poor prognosis. Several complications have been reported that includes hemorrhage, thrombosis and embolism limb ischemia, which can be mitigated by the use of distal re perfusion line attached to the arterial cannula as displayed here. Other complications include sepsis Humala sis and thrombosis opinion one of the limitations of dogma was that patients are bed bound. Um And while this has been the practice for many years it is now routine to mobilize patients both V. V. And V. A. ECMO in highly specialist centers as a ECMO devices continue to evolve. We now have the cardio health device which is this portable ECMO machine that allows transport of patients with these. It also allows ECMO teams to travel to community hospitals to retrieve patients back to centers of excellence. After placing them on ECMO using this device, Further evolution in the development of extracorporeal support involves E. C. P. All programs that continue to emerge and expand following the publication of the arrest randomized trial, reporting substantial benefits. Mm Certain subgroup of patients who suffer at a hospital cardiac arrest that is witnessed and with a shock kable rhythm. We have locally instituted protocol and workflows as well as staff training and have commenced our program. Other devices include the tandem heart which is an axial flow pump with its inflow inserted for cutaneous lee via the femoral vein into the right atrium and then transept lee into the left atrium and it pumps centrifugal e Up to five L per minute through an outflow cannula inserted, perky dangerously through the femoral artery. The main limitation of the tandem heart is it requires the technical expertise of transept all access which seems to have limited its widespread use. The impala copy is similar to the impeller that supports the right side and it's implanted continuously through the the femoral vein and all the way up into the pulmonary artery. Its in flow is from the I. V. C. And outflow into the pulmonary artery, thus providing significant support for the right ventricle. Another device available for right ventricular support is the protect dual which is dual lumen cannula placed via the internal jugular vein and supports the right ventricle by drainage from the right atrium and re infusion of blood into the pulmonary artery. This uses a tandem hot or central central mag centrifugal pumps for RV support. There is limited data available on the use of these devices in terms of patient outcomes. Back to the clinical case discussed at the beginning at university hospitals we have multidisciplinary shock team That is available 24/7 where patients encouraging a shock or discussed and then informed planned decision made for further management. The decision of the multi discipline routine must proceed with peripheral Vi attack. Move for this patient which was inserted uneventfully at the bedside on the intensive care unit with peripheral re perfusion line. Two prevent limb ischemia. She made excellent progress over the ensuing few days and was able to be excavated. Unfortunately unfortunately she developed acute pulmonary oedema and required re intubation. Well there was some LV ejection. She clearly had high left ventricular end diastolic pressure. We therefore proceeded with implementation of Pallor 5.5 Device which is demonstrated here which is inserted through the writings artery artery all the way into the left ventricle which prevents which provides adequate decompression. The patient made excellent progress uh And with continuing improvement in are we function and pulmonary function. The ECMO was weaned and she was excavated and the impeller was left in place for a few days. During that period the patient was assist for advanced therapies including heart transplantation and L. VOD. However, she made adequate recovery to allow removal of the intel a at the bedside and she made an excellent recovery overall This patient presented an acute cardiogenic shock. 2nd it's right ventricular cardiomyopathy. She required ECMO insertion immediately and was transplanted within three days of admission and is now back to normal life. The use of mechanical circulatory support in cardiac shock continues to increase and evolve for many patients with different ideologies device selection is in general guarded by human dynamic support needs as well as the operators and institutional experience and divides specific uh complication rates and risks. There is no substitute to multidisciplinary team, decision making, and we proud of having very effective shock team here at university hospitals that involves all of the following, including interventional cardiology, heart failure physicians, critical care nursing, emergency medicine and cardiac surgery. Such an approach shows the best outcome for our patients. Thank you for your attention.
