Presentation 1: Non-cardiac Interventions in Patients With High Profile Temporary Transvalvular Pumps
Presented by: Jaime Hernandez-Montfort, MD
Dr Hernandez-Montfort opened by presenting the discussion goals as follows:
- to emphasise the unmet need among high-risk patients with impaired myocardial function requiring non-cardiac interventions
- to review case-based programmatic approaches to patients with impaired myocardial function requiring non-cardiac surgical interventions.
To achieve best possible outcomes, an effective advanced heart disease recovery and replacement programme requires access to an advanced heart failure (HF) specialist, comprehensive therapy with remote monitoring and interdisciplinary teams for cardiogenic shock (CS). As with most cardiac recovery programmes, an interdisciplinary team approach is required to decide the best intervention for the patient. Given that there are multiple mechanical circulatory support (MCS) options available, it is necessary to define the intended transition and haemocompatibility to tailor the device to the patient and optimise the patient’s condition for the next step.
Dr Hernandez-Montfort clarified that determining the next step may require non-cardiogenic profiling.1 He set out the advantages of a temporary MCS device like Impella 5.5, which can offer ambulatory, haemodynamic and end organ stability, assistance with perioperative bleeding, reduced duration in the intensive care unit and lower need for organ replacement.
Dr Hernandez-Montfort provided an example of a non-cardiac case that may require heart support.
The patient was a 66-year-old woman with multiple comorbidities, including hypertension, hyperlipidaemia and coronary artery disease, and presented with bloody diarrhoea, unintentional weight loss and a fall. She experienced refractory shock on noradrenaline, vasopressin and phenylephrine. Her white blood cell count was 18,000/mm3 and lactate was 4.3mmol/l. An echocardiogram showed severe left ventricular (LV) dysfunction with a stress-induced cardiomyopathy pattern, free air and a sigmoid colon mass. Given the colonic perforation with refractory shock, it was decided to proceed with exploratory laparotomy and stabilise the patient upfront with Impella 5.5 with heparin-free purge fluid. After the patient’s conditions resolved, she demonstrated LV remission, normal LV size and normal LV systolic function with an ejection fraction of 55–60%. She underwent rehabilitation before discharge home.
This is one example of a procedure in which the Impella 5.5 was used as a bridge to recovery/replacement by providing cardiac support. Other non-cardiac procedures, such as laparoscopic nephrectomy, cystoscopy and bladder mass resection, lung and liver biopsy and upper and lower endoscopy with biopsy, may benefit from the use of heparin-free Impella support.2
Impella 5.5 is safe and feasible for patients with underlying HF who need to undergo non-cardiac interventions, but more clinical data need to be collected to better understand this patient population and appropriate usage.
Presentation 2: Application of Transvalvular Axial Flow Pumps to Support Advanced Heart Failure Patients Undergoing Abdominal Surgery
Presented by: Nicolas Brozzi, MD
Dr Brozzi shared that more than 10 million major non-cardiac surgical procedures are performed each year in the US and the number of patients with HF is increasing.3 Furthermore, patients presenting with advanced HF and LV dysfunction are facing increased mortality risk during major abdominal surgery. Patients with CS are often not considered appropriate candidates for non-cardiac surgeries. Transvalvular axial flow pumps, such as the Impella 5.0 and 5.5, can offer robust haemodynamic support for these patients with severe LV failure.
Dr Brozzi provided an overview of his study, which was a retrospective review of patients undergoing abdominal surgery under Impella. He collected data on basic demographics, type of abdominal surgery, time on Impella support, transition to other support devices and outcomes, including major complications and mortality. The devices used were Impella CP, 5.0 and 5.5.
Dr Brozzi presented data from four patient cases. All four patients had a long history of cardiomyopathy and were relatively young (aged 22, 26, 32 and 64 years). All were receiving inotropic treatment and were readmitted in CS. Three patients received an intra-aortic balloon pump in an attempt to stabilise them, and all four were transitioned onto the Impella device. The surgeries performed were one nephrectomy, two sleeve gastrostomies and one cholecystectomy. Two patients required transitional support; one required extracorporeal membrane oxygenation (ECMO), but then proceeded to Society for Cardiovascular Angiography and Interventions (SCAI) SHOCK Stage E before eventually being transplanted. Another patient proceeded to HeartMate 3 because they could not be weaned off Impella. There were three successful transplants in total.
Dr Brozzi set out the surgical and anaesthetic considerations that were taken into account in each case. The procedures were conducted under cardiac anaesthesia with invasive monitoring via a left arterial line, Swan-Ganz catheter and transoesophageal echocardiogram to optimise patient management intraoperatively. The procedures involved cardiac surgeons remaining on stand-by , along with ECMO, in the operating room during device implantation. Systemic heparin was discontinued 4–6 h prior to surgery and the patients were administered bicarbonate purge solution at the time of transition to Impella and throughout the course of Impella support until 12–24 h after surgery. Systemic heparin was restarted postoperatively if there was no evidence of bleeding.
Dr Brozzi concluded that his initial experience of using Impella for patients requiring haemodynamic support for advanced HF CS was satisfactory, with 75% (n=3) of his patients successfully transplanted. He made the point that implantable LV assist devices have set a precedence for this strategy in non-cardiac operations and the adoption of alternative anticoagulation strategies in the perioperative period do not affect Impella performance. Dr Brozzi closed his presentation by acknowledging that this is just the beginning, and further research is required.
Presentation 3: Benefits of Bariatric Surgery and Rapid Weight Loss on Cardiac Health
Presented by: Raul Rosenthal, MD
Dr Rosenthal’s presentation provided an outline of the benefits of bariatric surgery and rapid and durable weight loss on cardiac health. Due to its particular anatomical location and its proximity to the coronary arteries, pericardial fat is linked to coronary pathology (e.g. coronary atherosclerosis).4
Dr Rosenthal obtained a linear measurement of pericardial fat thickness from 113 patients 1.07 years before and 1.3 years after undergoing bariatric surgery. Measurements were performed on CT examinations that were reformatted into the sagittal plane. Measurements before and after bariatric surgery were compared and related to the risk of developing coronary artery disease (CAD) by the Framingham Heart Study parameters and predictors of CHD at 10 years.5 The patients had a mean (±SD) age of 56 ± 14 years and had commodities associated with CAD, including diabetes type 2 and hypertension. The results demonstrated a significant decrease in pericardial fat thickness after the bariatric procedure (from 5.64 ± 1.90 to 4.68 ± 4.68 mm after bariatric surgery; p=0.0001). This benefit translated into a decreased risk of CAD after procedure (12.43% versus 10.25%) with a reduction in RR of 17.43%.
Dr Rosenthal’s study also showed improvements in ventricular conduction after reduction in pericardial fat triggered by rapid weight loss in patients with severe obesity undergoing bariatric interventions. This was investigated by a retrospective review of ECG changes. Dr Rosenthal compared changes in pericardial fat thickness and ECG components before and after bariatric surgery. The results showed that as pericardial fat decreased after surgery, both the QT interval (401.93 ± 32.31 versus 389.00 ± 35.62 ms before and after bariatric surgery, respectively; p=0.017) and QTc interval (438.74 ± 29.01 versus 426.88 ± 25.39 ms before and after bariatric surgery, respectively; p=0.006) improved in this patient population.
In his study, Dr Rosenthal also looked at LV ejection fraction (LVEF) by conducting a retrospective review of echocardiographic changes in systolic function in patients with obesity who underwent bariatric surgery at his institution. LVEF before bariatric surgery was compared to that 12 months after surgery when maximum weight loss occurs, and patients with preoperative HF were compared to those without preoperative HF. Results showed that bariatric surgery and rapid and durable weight loss improved LVEF after 12 months in patients with severe obesity and HF: LVEF in patients without and with HF was 59.90 ± 7.58% and 38.79 ± 13.26%, respectively, before bariatric surgery (p=0.001), compared with 59.88 ± 7.85% and 48.47± 14.57%, respectively, after bariatric surgery (p=0.0001). In addition, Dr Rosenthal examined the cardiac geometry and found that weight loss following bariatric surgery resulted in improved heart ventricular function and structure. Most of the patients with obesity presented with significant concentric remodelling before surgery and improved to normal geometry of chambers after bariatric surgery.
Dr Rosenthal found there was an improvement in LV mass index and ventricular contractility in patients with obesity following rapid weight loss after bariatric surgery: LV fractional shortening improved from 31.05 ± 8.82% before to 36.34 ± 8.21% after surgery (p=0.007); posterior wall thickness improved from 1.16 ± 0.23 mm before to 1.04 ± 0.22 mm after surgery (p=0.01); and the LV mass index improved from 101.3 ± 38.3 g/m2 before to 86.70 ± 26.6 g/m2 after surgery (p=0.005).
Dr Rosenthal explained that obesity and excessive visceral adiposity have been considered key mediators in metabolic and cardiovascular diseases. His study aimed to report the changes in interatrial fat after bariatric surgery and its effect on the risk of developing new-onset AF using CT and ECG parameters. The results showed a decrease in interatrial fat formation following rapid weight loss after bariatric surgery (3.93 ± 1.38 versus 2.97 ± 0.97 mm before and after bariatric surgery, respectively; p=0.001) that was associated with a lowering of the risk of new-onset AF in patients with severe obesity (9.08 ± 10.04% versus 7.48 ± 8.74% before and after bariatric surgery, respectively; p=0.341). Dr Rosenthal concluded that obesity and excess visceral adiposity are risk factors for AF and bariatric surgery decreases interatrial fat thickness in patients with obesity, resulting in a lower risk for new-onset AF.
Dr Rosenthal also conducted a retrospective analysis of the US National (Nationwide) Inpatient Sample (NIS) database to assess whether rapid and durable weight loss had an impact on hospital admissions in patients with diastolic HF and severe obesity.6 The results showed that in this retrospective case-control study of a large, representative national sample of patients with severe obesity, bariatric surgery was associated with significantly reduced hospitalisations for diastolic HF when adjusted for baseline cardiovascular disease risk factors. Bariatric surgery was also found to reduce the incidence of diastolic HF in high-risk patients with hypertension and CAD.
Panel Discussion
Dr Anderson opened the discussion by expressing his appreciation of the extension of the therapeutic indications of MCS devices as highlighted in the presentations. He queried whether there is need for any legitimate concern of infection risk associated with the introduction of a foreign body, like the Impella device, into a patient with sepsis. He asked the experts to comment on the associated infection risks of a contaminated device, including endocarditis, wound infection, persistent bacteraemia and abdominal sepsis, during non-cardiac procedures.
Dr Hernandez-Montfort replied that in his experience, a procedure like exploratory laparotomy is an extreme case and would be rare. The patient would be on prophylactic antibiotics prior to procedure and support would not persist for longer than 1 or 2 weeks. In his opinion, the risks need to be weighed up and the potential outcomes of potential recovery versus death thoroughly discussed with the patient and their family to arrive at a shared decision. In his practice to date, surveillance cultures have all come back negative.
Dr Reddy clarified that in his practice, an abdominal procedure would only be performed with multidisciplinary team agreement. Because the Impella is only a temporary device and not permanent, in his practice he does not staple it in place, which means the graft can be removed in entirety with little risk of wound sepsis. Dr Reddy added that the lack of need for heparin systemically or in the pump has made a positive difference too, and he now only uses heparin subcutaneously.
Dr Anderson next asked the experts how they decide between an Impella CP implantation percutaneously versus surgical cutdown procedure.
Dr Brozzi responded by stating that an Impella 5.0 or 5.5 will provide more support for the high-risk patient with decompensated HF. He offered an extreme example of one patient with small artery anatomy and a BMI of 52 kg/m2 for whom his team had to use Impella CP, which proved sufficient to support the patient through the non-cardiac surgery.
Dr Hernandez-Montfort replied that in his practice he uses the Impella 5.5 to prepare patients with LV unloading for further transition, such as additional profiling, remission, recovery or replacement.
Dr Reddy emphasised it is important to get the patient ambulatory, which can be achieved with Impella 5.5. In his practice, he also uses Impella 5.5 to provide the patient with maximum support upfront. Dr Anderson agreed with these positions and confirmed it makes sense to use the most powerful pump for all these reasons.
Dr Anderson expressed his intrigue with the use of Impella to change phenotypes and achieve rapid weight loss after bariatric surgery. He enquired whether patients who need bariatric surgery can go on to receive guideline-directed medical therapy, LVAD or heart transplant.
Dr Brozzi reminded us that these patients are high-risk end-stage HF patients with INTERMACS profile 2 and 3, so they will all eventually need either LVAD or heart transplant. However, in actual practice only 30% of the patients who need bariatric surgery in order to receive the next therapy actually receive bariatric surgery and were subsequently successful in transplantation. According to his analysis of the Nationwide Inpatient Sample database of 7 million hospitalisations in 2018, one million patients had reported BMI and 3,000 patients with BMI >35 kg/m2 were admitted with end-stage HF or CS. Therefore, this is evidence that there is a significant number of patients whose care may be being neglected, and this presents an opportunity to address these patients’ needs. Dr Brozzi continued that this opportunity will bring challenges, but nonetheless the initial experience is encouraging. For example, patient adherence to therapies and dietary restrictions after bariatric surgery is required if the patient is to have the prospect of a transplant.
Dr Anderson reflected that the Impella pumps are highly haemocompatible, but wondered whether the experts had experienced any post-procedural issues with anticoagulation or bleeding complications.
Dr Hernandez-Montfort confirmed that he has not experienced any anticoagulation problems save one case of haemolysis that was due to device malposition. His centre has seen positive results with bicarbonate-based solution as the Impella purge solution. He explained that to mitigate the risk of deep vein thrombosis, he sometimes administers prophylactic subcutaneous heparin or low-molecular-weight heparin. However, he clarified that in his clinical practice he has not experienced any incidents of pump or device thrombosis. He confirmed that he has also successfully removed the device without the need for heparin.
The question was asked whether the patients undergoing bariatric surgery had mostly been inpatients, elective admissions or placements?
Dr Hernandez-Montfort confirmed that all his patients to date have been inpatients and there have been no elective indications.
Dr Brozzi confirmed that in his practice all patients undergoing bariatric surgery have also been non-elective inpatients. However, he clarified that we are still at the early stages of this approach.
Dr Gopalan explained that in his centre they have performed Impella support in outpatients who required elective bariatric surgery but who are considered high-risk with LVEF <25%. He presented the case example of a 60-year-old man who had non-revascularisable CAD with low ejection fraction and a BMI of 41 kg/m2 who could not undergo transplant due to his high BMI. After outpatient discussion, the patient was brought actively into hospital for preparation 2 days prior to undergoing high-risk bariatric surgery. He was found to have low cardiac output with a cardiac index of 1.8. The patient was supported with inotropes before an elective placement of Impella 5.5 via axillary insertion for LV unloading and to reduce the ischaemic burden. This patient successfully survived surgery and was discharged 4 days later without the need for anticoagulation but with bicarbonate-based purge solution during Impella. During surgery, the patient experienced a non-sustained ventricular tachycardia and hypertension but did not require any significant escalation of care as a result of the protective nature of preparation prior to surgery with Impella.
Dr Anderson wrapped up the discussion by thanking the panellists and stating the importance of collecting the data and collectively analysing it to potentially expand the indications of Impella for non-cardiac surgery. He looks forward to hearing about these data and the application of acute LV unloading in non-cardiac procedures at next year’s A-CURE symposium.