Temporary extracorporeal life support: single-centre experience with a new concept.

OBJECTIVES: The combination of veno-arterial extracorporeal membrane oxygenation with a micro-axial flow pump (ECMELLA) is increasingly used for cardiogenic shock (CS) therapy. We report our experience with a novel single-artery access ECMELLA setup with either femoral (2.0) or jugular venous cannulation (2.1), respectively. METHODS: Data from 67 consecutive CS patients treated with ECMELLA 2.0 (n = 56) and 2.1 (n = 11) from December 2020 and December 2022 in a tertiary cardiac center were retrospectively analyzed. RESULTS: The mean age was 60.7 ± 11 years, 56 patients (84%) were male. CS aetiology was acute on chronic heart failure (n = 35, 52%), myocardial infarction (n = 13, 19.5%), postcardiotomy syndrome (n = 16, 24%) and myocarditis (n = 3, 4.5%). Preoperatively 31 patients (46%) were resuscitated, 53 (79%) were on a ventilator and 60 (90%) were on inotropic support. The median vasoactive inotropic score was 32, and the mean arterial lactate was 8.1 mmol/l. In 39 patients (58%), veno-arterial extracorporeal membrane oxygenation was explanted after a median ECMELLA support of 4 days. Myocardial recovery was achieved in 18 patients (27%), transition to a durable left ventricular assist device in 16 (24%). Thirty-three patients (n = 33; 49%) died on support (25 on ECMELLA and 8 on Impella after de-escalation), 9 (13%) of whom were palliated. Axillary access site bleeding occurred in 9 patients (13.5%), upper limb ischaemia requiring surgical revision in 3 (4.5%). Axillary site infection occurred in 6 cases (9%), and perioperative stroke in 10 (15%; 6 hemorrhagic, 4 thromboembolic). CONCLUSIONS: ECMELLA 2.0/2.1 is a feasible and effective therapy for severe CS. The single-artery cannulation technique is associated with a relatively low rate of access-related complications.

Mechanistic assessment and ablation of left ventricular assist device related ventricular tachycardia in patients with severe heart failure.

Aims: Left-ventricular-assist-devices (lvad) are an established treatment for patients with severe heart failure with reduced ejection fraction (HF) and reduce mortality. However, HF patients have significant substrate for ventricular tachycardia (VT) and the lvad itself might be pro-arrhythmogenic. We investigated the mechanism of VT in lvad-patients in relation to the underlying etiology and provide in silico and ex-vivo data for ablation in these HF patients. Methods and Results: We retrospectively analyzed invasive electrophysiological (EP) studies of 17 patients with VT and lvad. The mechanism of VT was determined using electroanatomical, entrainment and activation time mapping. Ischemic cardiomyopathy was present in 70% of patients. VT originated from the lvad region in >30%. 1/6 patients with VT originating from the lvad region had episodes before lvad implantation, while 7/11 patients with VT originating from other regions had episodes before implantation. Number and time of radiofrequency (RF)-ablation lesions were not different between VTs originating from the lvad or other regions. Long-term freedom from VT was 50% upon ablation in patients with VT originating from the lvad region and 64% if ablation was conducted in other regions. To potentially preemptively mitigate lvad related VT in patients undergoing lvad implantation, we obtained in silico derived data and performed ex-vivo experiments targeting ventricular myocardium. Of the tested settings, application of 25 W for 30 s was safe and associated with optimal lesion characteristics. Conclusion: A significant percentage of patients with lvad undergoing VT ablation exhibit arrhythmia originating in close vicinity to the device and recurrence rates are high. Based on in silico and ex-vivo data, we propose individualized RF-ablation in selected patients at risk for/with lvad related VT.

Results of non-elective withdrawal of continuous-flow left ventricular assist devices in selected patients.

BACKGROUND: Protocols have been developed to identify patients for elective withdrawal of continuous-flow left ventricular device (cfLVAD) support. However, little is known about non-elective explantation or decommissioning of cfLVADs. METHODS: A retrospective analysis of all patients who underwent left ventricular assist device (LVAD) explantation or decommissioning at a single center between 2002 and 2021 was performed. RESULTS: Sixty-one patients underwent withdrawal of a cfLVAD (HeartMate II [Abbott] n = 17, HeartMate 3 [Abbott] n = 2, HeartWare HVAD [Medtronic] n = 36, INCOR [Berlin Heart] n = 6). The median follow-up after withdrawal was 1,039 days. The survival at 5 years was 76.1% (95% CI: 64.2%-95.2%). Predictors of worse outcomes in univariate regressive analysis were the duration of heart failure and the age at LVAD implantation. Of the 61 patients, 40 underwent elective withdrawal following a specific protocol. The other twenty-one patients underwent non-elective withdrawal of the cfLVAD because of device infection (n = 12), device thrombosis (n = 6), device malfunction (n = 2) or due to acute intracerebral bleeding (n = 1), also with an excellent survival at 5 years of 81.3%. (95% CI: 63.8-1). The withdrawal was performed in these patients even though they did not fulfill established criteria for successful explantation or decommissioning like clinical stability (n = 21), left ventricular end-diastolic diameter ≤ 55 mm (n = 3), performance of right heart catheterization (n = 6), or pulmonary artery wedge pressure ≤ 15 mm Hg (n = 3). CONCLUSION: Non-elective withdrawal is possible in selected patients after discussion in a team of experienced cardiac surgeons, cardiologists, technicians, and VAD coordinators. The appropriate preoperative assessment before decommissioning or explantation of a cfLVAD warrants further investigation.

State of the Art Review of Surgical Techniques for Microaxial Flow Pump Implantation.

Recently, temporary mechanical circulatory support (tMCS) has been increasingly used for cardiogenic shock therapy. Originally designed as a bail-out option for patients who could not be weaned from cardiopulmonary bypass, the indications for tMCS have been expended and now enable us to support a wide range of patients with various cardiac pathologies. Modern tMCS devices include microaxial flow pumps (mAFP) which are small, versatile systems that can provide both acute cardiac support and cardiac protection for high-risk interventions. In this paper, we review different surgical implantation techniques with modern mAFP as well as specific aspects of preoperative indications and patient evaluation.

Surgical Restoration of Antero-Apical Left Ventricular Aneurysms: Cardiac Computed Tomography for Therapy Planning.

Background: Surgical ventricular restoration (SVR) leads to functional improvement by volume reduction and restoration of left ventricular (LV) geometry. Our purpose was to refine the planning for SVR using cardiac computed tomography (CCT). Methods: The possibility to anticipate the postoperative residual LV volume was assessed using CCT in 205 patients undergoing SVR combined with coronary artery bypass grafting (77%), mitral valve repair/replacement (19%) and LV thrombectomy (19%). The potential of CCT to guide the procedure was evaluated. Additionally, the predictive value of CCT characteristics on survival was addressed. Results: 30-day, 1- and 5-year survival was 92.6, 82.7, and 72.1%, respectively, with a marked reduction of NYHA class III-IV quota after surgery (95.1% vs. 20.5% in the follow-up). Both pre- and postoperative LV end-systolic volume index (LVESVI) were predictive of all defined endpoints according to the following tertiles: preoperative: <74 ml/m2, 74-114 ml/m2 and >114 ml/m2; postoperative: <58 ml/m2, 58-82 ml/m2 and >82 ml/m2. On average, a 50 ml/m2 increase of preoperative LVESVI was associated with a 35% higher hazard of death (p = 0.043). Aneurysms limited to seven antero-apical segments (1-7) were associated with a lower death risk (n = 60, HR 0.52, CI 0.28-0.96, p = 0.038). LVESVI predicted by CCT was found to correlate significantly with effectively achieved LVESVI (r = 0.87 and r = 0.88, respectively, p < 0.0001). Conclusions: CCT-guided SVR can be performed with good mid-term survival and significant improvement in HF severity. CCT-based assessment of achievable postoperative LV volume helps estimate the probability of therapeutic success in individual patients.

Predictive Value of Two-Dimensional Speckle-Tracking Echocardiography in Patients Undergoing Surgical Ventricular Restoration.

Objectives: Parameters of left ventricular (LV) mechanics, obtained from speckle-tracking echocardiography (STE), were found to be of prognostic value in patients with heart failure and those who underwent cardiac surgery. This study aimed to assess the value of STE in patients scheduled to undergo surgical ventricular restoration (SVR). Methods: A total of 158 consecutive patients with baseline STE who underwent SVR due to an LV anteroapical aneurysm were included in the analysis. Preoperative longitudinal STE parameters were evaluated for their association with an outcome, defined as all-cause mortality, LV assist device implantation, or heart transplantation. The echocardiographic follow-up to assess the change in the regional function of the segments remote from the aneurysm was performed in 43 patients at a median of 10 months [interquartile range (IQR): 6-12.7 months] after SVR. Results: During a median follow-up of 5.1 years (IQR: 1.6-8.7 years), events occurred in 68 patients (48%). Less impaired mean basal end-systolic longitudinal strain (BLS) with a cutoff value ≤ -10.1 % demonstrated a strong association with event-free survival, also in patients with an LV shape corresponding to an intermediate shape between aneurysmal and globally akinetic. Initially hypo- or akinetic basal segments with preoperative end-systolic strain ≤ -7.8% showed a greater improvement in wall motion at the short-term follow up. Conclusion: Patients with less impaired preoperative BLS exhibited a better event-free survival after SVR, also those with severe LV remodeling. The preserved preoperative segmental longitudinal strain was associated with a greater improvement in regional wall motion after SVR. BLS assessment may play a predictive role in patients with an LV anteroapical aneurysm who are scheduled to undergo SVR.

Experience with a standardized protocol to predict successful explantation of left ventricular assist devices.

OBJECTIVE: Patients with a continuous-flow left ventricular assist device may show recovery of myocardial function with unloading. Identifying candidates for and predicting clinical and hemodynamic stability after left ventricular assist device explantation remain challenging. METHODS: Retrospective analysis of patients who underwent evaluation for left ventricular assist device explantation following a standardized protocol from January 2016 to March 2020. Patients who met screening criteria underwent echocardiography under "baseline," "minimal net flow," and "pump stop" conditions. If the protocol criteria were met, right heart catheterization with left ventricular assist device stoppage and occlusion of the outflow graft with a balloon catheter were performed. In patients with pulmonary capillary wedge pressure less than 16 mm Hg, explantation was performed under "pump stop" conditions. RESULTS: A total of 544 patients were screened. Of these, 57 (10.5%) underwent a total of 73 echocardiography under "baseline" "minimal net flow" and "pump stop" conditions and 46 underwent left ventricular assist device stoppage and occlusion of the outflow graft with balloon catheter maneuvers. Complications during the procedure were rare. Ultimately, 21 patients (3.9%) underwent explantation. The left ventricular ejection fraction at baseline was 55.5% ± 6.5%. The mean pulmonary capillary wedge pressure was 8.1 ± 2.6 mm Hg and increased to 10.7 ± 2.9 mm Hg under left ventricular assist device stoppage and occlusion of the outflow graft with a balloon catheter. A nonischemic cause of cardiomyopathy was more likely to be found in patients who underwent explantation (20/21 patients [95%], P = .020). The survival 1 year after explantation was 95.2%, with 1 death occurring 222 days after left ventricular assist device explantation. At follow-up (median 24.9 months [interquartile range, 16.4-43.1 months]), patients were in New York Heart Association class 1 (61.9%), 2 (28.6%), and 3 (9.5%). CONCLUSIONS: Our 4-year experience with a standardized protocol for left ventricular assist device explantation showed a low rate of adverse events. If all criteria are met, explantation can be performed safely and with an excellent survival and functional class.

Validity of visual assessment of aortic valve morphology in patients with aortic stenosis using two-dimensional echocardiography.

The diagnostic value of a visual assessment of aortic valve (AV) morphology for grading aortic stenosis (AS) remains unclear. A visual score (VS) for assessing the AV was developed and its reliability with respect to Doppler measurements and the calcium score (ctCS) derived by multislice computed tomography was evaluated. 99 Patients with AS of various severity and 38 patients without AS were included in the analysis. Echocardiographic studies were evaluated using the new VS which includes echogenicity, thickening, localization of lesions and leaflet mobility, with a total score ranging from 0 to 11. The association of VS with ctCS and the severity of AS was analyzed. There was a significant correlation of VS with AV hemodynamic parameters and with ctCS. The cut-off value for the detection of AS of any grade was a VS of 6 (sensitivity 95%, specificity 85% for women; sensitivity 85%, specificity 88% for men). A VS of 9 for women and of 10 for men was able to predict severe AS with a high specificity (96% in women and 94% in men, AUC 0.8 and 0.86, respectively). The same cut-off values were identified for the detection of ctCS of ≥ 1600 AU and ≥ 3000 AU with a specificity of 77% and 82% (AUC 0.69 and 0.81, respectively). Assessment of aortic valve morphology can serve as an additional diagnostic tool for the detection of AS and an estimation of its severity.