The Impact of Ipsilateral Implantable Cardioverter Defibrillator in Axillary Intra-Aortic Balloon Pump Support as Bridge to Heart Transplantation.

BACKGROUND: The axillary artery (AX) access for intra-aortic balloon pump (IABP) as a bridge to heart transplant (HT) allows mobility while awaiting a suitable donor. As end-stage heart failure patients often have an implantable cardioverter defibrillator (ICD) on the left side, the left AX approach may be avoided due to the perception of difficult access and proximity of two devices. We aimed to evaluate the outcomes of patients bridged to HT with a left-sided AX IABP with or without ipsilateral ICDs. METHODS: We retrospectively reviewed HT candidates at our institution supported by left-sided axillary IABP from November 2019 to February 2024, dividing them into two groups based on the presence (Group ICD, n = 48) or absence (Group No-ICD, N = 19) of an ipsilateral left-sided ICD. The exposure time was defined as the time from skin incision to the beginning of anastomoses of a Dacron graft. RESULTS: Technical success was achieved in 100% of the cohort, with median exposure times for AX access similar between groups (ICD, 12 [7.8, 18.2] vs. No ICD, 11 [7, 19] min; p = 0.75). The rate of procedural adverse events, such as significant access site bleeding and ipsilateral limb ischemia, did not significantly differ between both groups. Device malfunction rates were comparable (ICD, 29.2% vs. No ICD, 15.8%; p = 0.35). Posttransplant, in-hospital mortality, severe primary graft dysfunction, and stroke rates were comparable in both groups. CONCLUSION: The presence of an ipsilateral left-sided ICD does not adversely impact the procedural efficacy, complication rates, or posttransplant outcomes of left-sided AX IABP insertion in HT candidates.

Machine learning-based model development for predicting risk factors of prolonged intra-aortic balloon pump therapy in patients with coronary artery bypass grafting.

Machine learning algorithms are frequently used to clinical risk prediction. Our study was designed to predict risk factors of prolonged intra-aortic balloon pump (IABP) use in patients with coronary artery bypass grafting (CABG) through developing machine learning-based models. Patients who received perioperative IABP therapy were divided into two groups based on their length of IABP implantation longer than the 75th percentile for the whole cohort: normal (≤ 10 days) and prolonged (> 10 days) groups. Seven machine learning-based models were created and evaluated, and then the Shapley Additive exPlanations (SHAP) method was employed to further illustrate the influence of the features on model. In our study, a total of 143 patients were included, comprising 56 cases (38.16%) in the prolonged group. The logistic regression model was considered the final prediction model according to its most excellent performance. Furthermore, feature important analysis identified left ventricular end-systolic or diastolic diameter, preoperative IABP use, diabetes, and cardiac troponin T as the top five risk variables for prolonged IABP implantation in patients. The SHAP analysis further explained the features attributed to the model. Machine learning models were successfully developed and used to predict risk variables of prolonged IABP implantation in patients with CABG. This may help early identification for prolonged IABP use and initiate clinical interventions.

Volume-Outcome Relationships for Intra-Aortic Balloon Pump in Acute Myocardial Infarction.

BACKGROUND: Acute myocardial infarction (AMI) is a major scenario for the use of an intra-aortic balloon pump (IABP), particularly when complicated by cardiogenic shock, although the utilization of mechanical circulatory support devices varies widely per hospital. We evaluated the relationship, at the hospital level, between the volume of IABP use and mortality in AMI.Methods and Results: Using a Japanese nationwide administrative database, 26,490 patients with AMI undergoing primary percutaneous coronary intervention (PCI) from 154 hospitals were included in this study. The primary endpoint was the observed-to-predicted in-hospital mortality ratio. Predicted mortality per patient was calculated using baseline variables and averaged for each hospital. The associations among PCI volume for AMI, observed and predicted in-hospital mortality, and observed and predicted IABP use were assessed per hospital. Of 26,490 patients, 2,959 (11.2%) were treated with IABP and 1,283 (4.8%) died during hospitalization. The annualized number of uses of IABP per hospital in AMI was 4.5. In lower-volume primary PCI centers, IABP was more likely to be underused than expected, and the observed-to-predicted in-hospital mortality ratio was higher than in higher-volume centers. CONCLUSIONS: A lower annual number of IABP use was associated with an increased mortality risk at the hospital level, suggesting that IABP use can be an institutional quality indicator in the setting of AMI.

Is preoperative IABP insertion significantly reducing postoperative complication in augmented high-risk coronary artery bypass grafting patients?

BACKGROUND: The aim of this study was to determine whether pre-operative intra-aortic balloon pump (IABP) insertion improves surgical outcomes in high-risk coronary artery bypass grafting (CABG) patients. METHODS: Patients with a EuroSCORE II greater than 1.2% who underwent CABG from 2009 to 2016 were included in the study, while those who utilized intra-operative or post-operative IABP were excluded. The analysis included a total of 2907 patients, with 377 patients undergoing preoperative IABP insertion (EuroSCORE II > 5.018%) and 1198 patients in the non-IABP group before matching; after propensity score matching (PSM), both groups consisted of a matched cohort of 250 patients. RESULTS: 30-day mortality events occurred in 9 (3.6%) non-IABP group and in 12 (4.8%) IABP patients (OR: 1.33 95%CI: 0.52-3.58). Kaplan-Meier survival curve analysis showed no significant differences between the two groups in mortality up to one year after the operation (p = 0.72). On multivariate analysis, IABP usage among the PSM patients was associated with lower 30-day mortality (OR: 0.28, 95%CI: 0.07-0.92, P-value = 0.043), 90-day mortality (OR: 0.26, 95%CI: 0.08-0.78, P-value = 0.022) and reduced risk of developing severe respiratory disorders (OR: 0.10, 95%CI:0.01-0.50, P-value = 0.011). CONCLUSION: Pre-operative IABP use in high-risk patients reduces 30- and 90-day mortality rates, along with a notable decrease in rates of severe respiratory disorders.

Unloading in cardiogenic shock: the rationale and current evidence.

PURPOSE OF REVIEW: Discussing the rationale and current evidence for left ventricular unloading in cardiogenic shock. RECENT FINDINGS: Microaxial flow pumps (MFP) and intra-aortic balloon pumps (IABP) augment cardiac output while simultaneously unloading the left ventricle (e.g. reducing left ventricular pressure), thereby targeting a key mechanism of cardiogenic shock. A recent randomized trial has shown a mortality reduction with MFP in selected patients with cardiogenic shock, strengthening the rationale for this strategy, although the evidence for the IABP is so far neutral. MFP/IABP can also be used concomitantly with veno-arterial extracorporeal membrane oxygenation (va-ECMO) to alleviate the va-ECMO-related increase in left ventricular afterload, to facilitate weaning and ultimately to improve myocardial recovery and prognosis of affected patients. However, the use of MFP/IABP in this indication solely relies on retrospective data, which need to be interpreted with caution, especially as these strategies are associated with more complications. Currently ongoing randomized trials will help to further clarify the role of left ventricular unloading in patients on va-ECMO. SUMMARY: Left ventricular unloading addresses a key mechanism of cardiogenic shock, with strong evidence to support MFP use in selected patients, but further randomized controlled trials are required to clarify the role of different devices/strategies for the overall shock population.

Spontaneous intercostal artery bleeding occurring simultaneously in numerous vessels during antithrombotic therapy with mechanical circulatory support: a case report.

BACKGROUND: Intercostal artery bleeding often occurs in a single vessel; in rare cases, it can occur in numerous vessels, making it more difficult to manage. CASE PRESENTATION: A 63-year-old Japanese man was admitted to the emergency department owing to sudden chest and back pain, dizziness, and nausea. Emergency coronary angiography revealed myocardial infarction secondary to right coronary artery occlusion. After intra-aortic balloon pumping, percutaneous coronary intervention was performed in the right coronary artery. At 12 hours following percutaneous coronary intervention, the patient developed new-onset left anterior chest pain and hypotension. Contrast-enhanced computed tomography revealed 15 sites of contrast extravasation within a massive left extrapleural hematoma. Emergency angiography revealed contrast leakage in the left 6th to 11th intercostal arteries; hence, transcatheter arterial embolization was performed. At 2 days after transcatheter arterial embolization, his blood pressure subsequently decreased, and contrast-enhanced computed tomography revealed the re-enlargement of extrapleural hematoma with multiple sites of contrast extravasation. Emergency surgery was performed owing to persistent bleeding. No active arterial hemorrhage was observed intraoperatively. Bleeding was observed in various areas of the chest wall, and an oxidized cellulose membrane was applied following ablation and hemostasis. The postoperative course was uneventful. CONCLUSION: We report a case of spontaneous intercostal artery bleeding occurring simultaneously in numerous vessels during antithrombotic therapy with mechanical circulatory support that was difficult to manage. As bleeding from numerous vessels may occur during antithrombotic therapy, even without trauma, appropriate treatments, such as transcatheter arterial embolization and surgery, should be selected in patients with such cases.

Impact of Left Ventricular Unloading on Outcome of Heart Transplant Bridging With Extracorporeal Membrane Oxygenation Support in New Allocation Policy.

BACKGROUND: The new heart allocation policy places veno-arterial extracorporeal membrane oxygenation (VA-ECMO)-supported heart transplant (HT) candidates at the highest priority status. Despite increasing evidence supporting left ventricular (LV) unloading during VA-ECMO, the effect of LV unloading on transplant outcomes following bridging to HT with VA-ECMO remains unknown. METHODS AND RESULTS: From October 18, 2018 to March 21, 2023, 624 patients on VA-ECMO at the time of HT were identified in the United Network for Organ Sharing database and were divided into 2 groups: VA-ECMO alone (N=384) versus VA-ECMO with LV unloading (N=240). Subanalysis was performed in the LV unloading group: Impella (N=106) versus intra-aortic balloon pump (N=134). Recipient age was younger in the VA-ECMO alone group (48 versus 53 years, P=0.018), as was donor age (VA-ECMO alone, 29 years versus LV unloading, 32 years, P=0.041). One-year survival was comparable between groups (VA-ECMO alone, 88.0±1.8% versus LV unloading, 90.4±2.1%; P=0.92). Multivariable Cox hazard model showed LV unloading was not associated with posttransplant mortality after HT (hazard ratio, 0.92; P=0.70). Different LV unloading methods had similar 1-year survival (intra-aortic balloon pump, 89.2±3.0% versus Impella, 92.4±2.8%; P=0.65). Posttransplant survival was comparable between different Impella versions (Impella 2.5, versus Impella CP, versus Impella 5.0, versus Impella 5.5). CONCLUSIONS: Under the current allocation policy, LV unloading did not impact waitlist outcome and posttransplant survival in patients bridged to HT with VA-ECMO, nor did mode of LV unloading. This highlights the importance of a tailored approach in HT candidates on VA-ECMO, where routine LV unloading may not be universally necessary.

Angiographic Characteristics and Clinical Outcomes in Patients With Chronic Kidney Disease Undergoing Impella-Supported High-Risk Percutaneous Coronary Intervention: Insights From the cVAD PROTECT III Study.

BACKGROUND: Prior studies have found that patients with chronic kidney disease (CKD) have worse outcomes following percutaneous coronary intervention (PCI). There are no data about patients with advanced CKD undergoing Impella-supported high-risk PCI. We, therefore, aimed to evaluate angiographic characteristics and clinical outcomes in patients with CKD who received Impella-supported high-risk PCI as part of the catheter-based ventricular assist device PROTECT III study (A Prospective, Multi-Center, Randomized Controlled Trial of the IMPELLA RECOVER LP 2.5 System Versus Intra Aortic Balloon Pump [IABP] in Patients Undergoing Non Emergent High Risk PCI). METHODS: Patients enrolled in the PROTECT III study were analyzed according to their baseline estimated glomerular filtration rate (eGFR). The primary outcome was 90-day major adverse cardiovascular and cerebrovascular events (the composite of all-cause death, myocardial infarction, stroke/transient ischemic attack, and repeat revascularization). RESULTS: Of 1237 enrolled patients, 1052 patients with complete eGFR baseline assessment were evaluated: 586 with eGFR ≥60 mL/min per 1.73 m2, 190 with eGFR ≥45 to <60, 105 with eGFR ≥30 to <45, and 171 with eGFR <30 or on dialysis. Patients with lower eGFR (all groups with eGFR <60) were more frequently females and had a higher prevalence of hypertension, diabetes, anemia, and peripheral artery disease. The baseline Synergy Between PCI With Taxus and Cardiac Surgery score was similar between groups (28.2±12.6 for all groups). Patients with lower eGFR were more likely to have severe coronary calcifications and higher usage of atherectomy. There were no differences in individual PCI-related coronary complications between groups, but the rates of overall PCI complications were less frequent among patients with lower eGFR. Major adverse cardiovascular and cerebrovascular events at 90 days and 1-year mortality were significantly higher among patients with eGFR <30 mL/min per 1.73 m2 or on dialysis. CONCLUSIONS: Patients with advanced CKD undergoing Impella-assisted high-risk PCI tend to have higher baseline comorbidities, severe coronary calcification, and higher atherectomy usage, yet CKD was not associated with a higher rate of immediate PCI-related complications. However, 90-day major adverse cardiovascular and cerebrovascular events and 1-year mortality were significantly higher among patients with eGFR<30 mL/min per 1.73 m2 or on dialysis. Future studies of strategies to improve intermediate and long-term outcomes of these high-risk patients are warranted. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04136392.

Characterizing Adaptive Changes and Patient Survival After 2018 Donor Allocation Restructuring: A UNOS Database Analysis.

PURPOSE: We sought to characterize adaptive changes to the revised United Network for Organ Sharing donor heart allocation policy and estimate long-term survival trends for heart transplant (HTx) recipients. METHODS: Patients listed for HTx between October 17, 2013 and September 30, 2021 were identified from the United Network for Organ Sharing database, and stratified into pre- and postpolicy revision groups. Subanalyses were performed to examine trends in device utilization for extracorporeal membranous oxygenation (ECMO), durable left ventricular assist device (LVAD), intra-aortic balloon pump (IABP), microaxial support (Impella), and no mechanical circulatory support (non-MCS). Survival data post-HTx were fitted to parametric distributions and extrapolated to 5 years. RESULTS: We identified 27,523 HTx waitlist candidates during the study period, most of whom (n = 16,376) were waitlisted in the prepolicy change period. Overall, 19,554 patients underwent HTx during the study period (pre: 12,037 and post: 7517). Listings increased after the policy change for ECMO ( P < 0.01), Impella ( P < 0.01), and IABP ( P < 0.01) patients. Listings for LVAD ( P < 0.01) and non-MCS ( P < 0.01) patients decreased. HTx increased for ECMO ( P < 0.01), Impella ( P < 0.01), and IABP ( P < 0.01) patients after the policy change and decreased for LVAD ( P < 0.01) and non-MCS ( P < 0.01) patients. Waitlist survival increased for the overall ( P < 0.01), ECMO ( P < 0.01), IABP ( P < 0.01), and non-MCS ( P < 0.01) groups. Waitlist survival did not differ for the LVAD ( P = 0.8) and Impella ( P = 0.1) groups. Post-transplant survival decreased for the overall ( P < 0.01), LVAD ( P < 0.01), and non-MCS ( P < 0.01) populations. CONCLUSIONS: Allocation policy revisions have contributed to greater utilization of ECMO, Impella, and IABP, decreased utilization of LVADs and non-MCS, increased waitlist survival, and decreased post-HTx survival.

Impact of right ventricular dysfunction on outcomes in patients requiring intra-aortic balloon pump placement: A retrospective nationwide analysis (2016-2020).

Right ventricular dysfunction (RVD) continues to be a significant contributor to both mortality and morbidity, posing a significant challenge in the management of patients undergoing evaluation for mechanical circulatory support (MCS). Currently, there is a paucity of data regarding outcomes in this subset of patients. We analyzed the National Inpatient Sample database (NIS) to identify adult hospitalizations who underwent intra-aortic balloon pump (IABP) placement with or without co-existence of RVD. Multivariate logistic regression, and linear regression analyses were used to compare outcomes, and adjust for possible confounders. Out of 126,985 hospitalizations who underwent IABP placement, 1,475 (1.2%) had RVD. Patients with RVD who received an IABP had higher adjusted odds of inpatient mortality (Adjusted odds ratio [aOR]: 2.33, 95% confidence interval [CI]: 1.7-3.2, p<0.001) than those without co-existing RVD. Hospitalized patients who underwent IABP placement with RVD had higher adjusted odds of worse hospitalization outcomes in general. Conducting additional prospective studies and clinical trials with an emphasis on further subcategorization of patients with RVD is crucial for determining optimal management strategies for these patients.

Percutaneous Microaxial Ventricular Assist Device Versus Intra-Aortic Balloon Pump for Nonacute Myocardial Infarction Cardiogenic Shock.

BACKGROUND: Evidence on the comparative outcomes following percutaneous microaxial ventricular assist devices (pVAD) versus intra-aortic balloon pump for nonacute myocardial infarction cardiogenic shock is limited. METHODS AND RESULTS: We included 704 and 2140 Medicare fee-for-service beneficiaries aged 65 to 99 years treated with pVAD and intra-aortic balloon pump, respectively, for nonacute myocardial infarction cardiogenic shock from 2016 to 2020. Patients treated using pVAD compared with those treated using intra-aortic balloon pump were more likely to be concurrently treated with mechanical ventilation, renal replacement therapy, and blood transfusions. We computed propensity scores for undergoing pVAD using patient- and hospital-level factors and performed a matching weight analysis. The use of pVAD was associated with higher 30-day mortality (adjusted odds ratio, 1.92 [95% CI, 1.59-2.33]) but not associated with in-hospital bleeding (adjusted odds ratio, 1.00 [95% CI, 0.81-1.24]), stroke (adjusted odds ratio, 0.91 [95% CI, 0.56-1.47]), sepsis (OR, 0.91 [95% CI, 0.64-1.28]), and length of hospital stay (adjusted mean difference, +0.4 days [95% CI, -1.4 to +2.3]). A quasi-experimental instrumental variable analysis using the cross-sectional institutional practice preferences showed similar patterns, though not statistically significant (adjusted odds ratio, 1.38; 95% CI, 0.28-6.89). CONCLUSIONS: Our investigation using the national sample of Medicare beneficiaries showed that the use of pVAD compared with intra-aortic balloon pump was associated with higher mortality in patients with nonacute myocardial infarction cardiogenic shock. Providers should be cautious about the use of pVAD for nonacute myocardial infarction cardiogenic shock, while adequately powered high-quality randomized controlled trials are warranted to determine the clinical effects of pVAD.

Evaluating the Use of Unfractionated Heparin with Intra-Aortic Balloon Counterpulsation.

BACKGROUND: Evidence supporting anticoagulation with unfractionated heparin (UFH) in patients with an intra-aortic balloon pump (IABP) to prevent limb ischaemia remains limited, while bleeding risks remain high. Monitoring heparin in this setting with anti-factor Xa (anti-Xa) is not previously described. OBJECTIVES: The study objective is to describe the incidence of thromboembolic and bleeding events with the use of UFH in patients with an IABP utilising monitoring with both anti-Xa and activated partial thromboplastin time (aPTT). METHODS: This is a retrospective study of adults who received an IABP and UFH for ≥24 hours. Electronic medical records were reviewed for pertinent data. The primary outcome was the incidence of limb ischaemia during IABP. Secondary outcomes included myocardial infarction, thrombus on IABP, or stroke. Exploratory outcomes included any venous thromboembolism and bleeding events. RESULTS: Of 159 patients, 88% received an IABP for cardiogenic shock and median duration of IABP support was 118 hours (interquartile range, 67-196). Limb ischaemia occurred in four of 159 patients (2.5%). Strokes occurred in 3.8% of the cohort, and bleeding events occurred in 33%. Despite anticoagulation use in all patients, 11% experienced a venous thromboembolism, with most identified upon asymptomatic screening with concern for heparin-induced thrombocytopenia. We found no differences in outcomes that occurred with a hybrid anti-Xa and aPTT versus aPTT monitoring alone. CONCLUSIONS: We observed a high rate of thrombotic and bleeding complications with the use of UFH in patients with an IABP. Use of anti-Xa versus aPTT for monitoring was not associated with complications. These data suggest safer anticoagulation strategies are needed in this setting.

Mechanical Circulatory Support in Cardiogenic Shock: Uses in the Emergency Setting.

Cardiogenic shock is a lethal condition with significant morbidity, characterized by myocardial insults leading to low cardiac output and ensuing systemic hypoperfusion. While mortality rates remain high, we have improved upon our recognition and definition of cardiogenic shock, now with an emphasis on defining stages of shock to help guide effective treatment strategies with either pharmacologic or mechanical circulatory support. In this review, the authors summarize these stages as well as discuss indications, function, selection, and troubleshooting of the various temporary mechanical circulatory support devices.