Spencer, Philip J.

ABSTRACT Background Addition of left heart catheterization (LHC) to exercise protocols allows for a unique focus on parameters of systolic and diastolic responses to increased activity in patients with left ventricular assist device (LVAD) support. Methods A retrospective review was conducted of all consecutive adult patients who underwent LHC with exercise for any indication from June 2017 to June 2023. For all patients, the relationship between exercise and parameters of LV systolic and diastolic response was assessed. Patients were divided into two cohorts based on the indication for testing: hemodynamic optimization (Optim, n = 5) or weaning consideration (Wean, n = 3). Results Eight patients (88% male, median age 57 years (IQR 44, 65)) were included. LVEF was 45% (IQR 45, 56) in Wean and 25% (IQR 20, 42) in Optim. LV systolic work index (LVSWI) increased more rapidly over levels of exercise in Wean vs. Optim (slope 46.3 vs. −0.625; p = 0.044) and LVSWI rose more quickly at lower levels of LV end diastolic pressure (LVEDP) in Wean vs. Optim (slope 219.5 vs. −2.008; p = 0.0026). Pulse power index was higher in Wean patients at baseline (0.046 (IQR 0.04, 0.07) vs. 0.016 (IQR 0.001, 0.04); p = 0.14) and peak exercise (0.12 (IQR 0.12, 0.12) vs. 0.06 (IQR 0.03, 0.1); p = 0.29). Conclusions Patients with favorable remodeling on LVAD support have significantly improved LV systolic and diastolic responses to exercise and a trend of higher systemic pulsatility. Improving our understanding of LV‐LVAD interactions with activity may aid in future efforts to improve exercise tolerance through speed modulation.

A 40 year old woman who underwent combined heart-lung transplant for familial severe pulmonary hypertension experienced episodes of nonsustained ventricular tachycardia followed by sudden ventricular fibrillation arrest 8 days after transplant. Postarrest investigations revealed left lower lobe herniation into the right lower hemithorax, prompting emergent reoperation, and hernia reduction. Arrhythmias resolved following reduction of the herniated lung and facilitated rapid weaning from vasopressor and ventilatory support. To our knowledge, this is the first reported case of cardiac arrest due to lung herniation after combined heart-lung transplantation. Herein, we describe this rare presentation and offer insights and management strategies for the cardiac intensivist.

Abstract Introduction Cardiopulmonary exercise testing (CPET) parameters such as peak VO2 ≤ 14ml/kg/min, percentage predicted peak VO2 (ppVO2) ≤ 50% and ventilation equivalent of carbon dioxide (Ve/VCO2) >35 l/min/l/min are recommended thresholds to list for isolated heart transplant. There is minimal data on clinical events after listing to guide clinical management or priority in organ allocation. Purpose To assess the effect of peak VO2, ppVO2, Ve/VCO2 on clinical events after listing for isolated heart transplant. Methods In a single centre retrospective study, we identified patients who were status 6 or status 2 prior to 2018 at time of listing for isolated heart transplant between 2007 and 2021. Clinical data were collected by chart review. Primary outcome of progressive heart failure was defined as death or upgrade in transplant priority status (new inotropes or mechanical circulatory support). Comparison was made between peak VO2 strata (> 14 vs ≤ 14 ml/kg/min), ppVO2 strata (> 50% vs 40-50% vs <40%) and Ve/VCO2 strata (<35 vs >35 l/min/l/min). Secondary outcome was time dependent survival after listing for heart transplant. Results We identified 141 patients of which 133 underwent CPET and follow up was available for 130 who were included in the analysis. Median age was 53 years (interquartile range 41-59 years), 29.1% of patients were female. Median peak VO2 was 14.0 ml/kg/min (11.2-15.7), ppVO2 was 44% (36-52), Ve/VCO2 slope was 34.0 (31.0-37.0) and RER was 1.1 (1.1-1.2). 87 patients had progressive heart failure consisting of 34 deaths and 83 patients having upgrade in priority status. There was a significant difference in risk of progressive heart failure comparing peak VO2 strata (Figure 1) (freedom from event at one year 71.4% with peak VO2 > 14 vs 46.5% with peak VO2 ≤ 14, p=0.00061) and ppVO2 strata (Figure 2) (freedom from event at one year 75.0% with ppVO2 >50% vs 61.2% with ppVO2 40-50% vs 42.6% with ppVO2 <40%, p=0.0015). There was no significant difference with Ve/VCO2 strata (freedom from event at one year 59.8% with Ve/VCO2 <34 vs 54.9% with Ve/VCO2 >34, p=0.52). There were 34 deaths before transplant and 23 deaths after transplant. 87 patients underwent transplant. In a time dependent survival analysis, age, gender and ppVO2<50% (HR 1.65 (0.87-3.12)) were not significant predictors of mortality. Both early transplant (defined as < 1 year after listing, HR 0.14 (0.06-0.34) and late transplant (defined as > 1 year after listing, HR 0.16 (0.08-0.32)) were significant predictors of lower mortality whilst Ve/VCO2>35 (HR 2.09 (1.19-3.68)) was a significant predictor of higher mortality. Conclusions Peak VO2 and ppVO2 stratify risk of progressive heart failure in ambulatory patients awaiting isolated heart transplant. However, Ve/VCO2 is a predictor of significantly higher mortality. These findings should affect clinical management and transplant priority status; and influence revision of future guidelines.Freedom from event by peak VO2 strataFreedom from event by ppVO2 strata

ABSTRACTBackgroundEvolving trends in organ procurement and technological innovation prompted an investigation into recent trends, indications, and outcomes following combined heart–lung transplantation (HLTx).MethodsThe United Network for Organ Sharing database was queried for all adult (≥18 years) HLTx performed between July 1, 2013 and June 30, 2023. Patients with previous transplants were excluded. The primary endpoint was the effect of donor, recipient, and transplantation characteristics on 1‐ and 5‐year survival. Secondary analyses included a comparison of HLTx at high‐ and low‐volume centers, an assessment of HLTx following donation after circulatory death (DCD), and an evaluation of HLTx volume over time. Cox proportional‐hazards models were used to assess factors associated with mortality. Temporal trends were evaluated with linear regression.ResultsAfter exclusions, 319 patients were analyzed, of whom 5 (1.6%) were DCD. HLTx volume increased from 2013 to 2023 (p < 0.001). One‐ and 5‐year survival following HLTx was 84.0% and 59.5%, respectively. One‐year survival was higher for patients undergoing HLTx at a high‐volume center (88.3% vs. 77.9%; p = 0.012). After risk adjustment, extracorporeal membrane oxygenation support 72 h posttransplant and predischarge dialysis were associated with increased 1‐year mortality (HR = 3.19, 95% CI = 1.86–5.49 and HR = 3.47, 95% CI = 2.17–5.54, respectively) and 5‐year mortality (HR = 2.901, 95% CI = 1.679–5.011 and HR = 3.327, 95% CI = 2.085–5.311, respectively), but HLTx at a high‐volume center was not associated with either.ConclusionsHLTx volume has resurged, with DCD HLTx emerging as a viable procurement strategy. Factors associated with 1‐ and 5‐year survival may be used to guide postoperative management following HLTx.

Axillary artery intra-aortic balloon pump (axIABP) placement has been implemented as a bridging solution before heart transplantation. This study evaluates complications associated with axIABP support and describes an approach to minimize adverse events. We previously described a percutaneous approach for axIABP placement. However, patients receiving axIABP between September 1, 2017, and September 26, 2019 (n = 32) demonstrated a high rate of balloon pump malfunction (8/32; 25%) and other complications (totaling 15/32; 47%). Sixty-four patients were sequentially treated under a revised protocol. Compared to the initial cohort, no significant differences in demographics were noted. A significant reduction in rate of balloon malfunction (8/32, 25% vs. 1/64, 2%; p < 0.001) and total complications (15/32, 47% vs. 10/64, 16%; p = 0.0025) during the period of support were noted after intervention. Subsequent analysis of total complications per device size (40 vs. ≤ 34 ml balloon) revealed significantly reduced complications in patients with smaller devices (40% vs. 13%, respectively; p = 0.0022). This study provides guidelines to limit complications in patients supported with axIABP, facilitating a protracted period of bridging support.

The purpose of this study was to evaluate left ventricular (LV) unloading strategies in patients supported with peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO). A retrospective review was conducted of all consecutive patients requiring VA-ECMO support for any indication, who underwent novel LV unloading strategies with either direct left atrial venoarterial (LAVA) cannulation or pulmonary artery venoarterial (PAVA) venting, in comparison to Impella and intra-aortic balloon pump (IABP). The primary outcome was successful bridge to transplant, LV assist device, or myocardial recovery. Forty-six patients (63% male, mean age 52.8 ± 17.6 years) were included. Fourteen patients (30%) underwent novel unloading with either LAVA or PAVA, 11 patients (24%) underwent IABP placement, and 21 patients (46%) underwent Impella insertion. In the novel LV unloading cohort, 10 patients (71%) survived to hospital discharge. Four patients (29%) were weaned from ECMO and eight patients (57%) underwent cardiac transplantation. Although a trend favoring cannula-based unloading for the primary outcome was noted, the cohort was too small for statistical significance (79% LAVA/PAVA, 57% Impella, 45% IABP; p = 0.21). However, probability of survival was greater in the LAVA/PAVA cohort compared to Impella and IABP (p < 0.05). Thus, we demonstrate the efficacy of LA and PA cannulation as an alternative LV unloading strategy for patients supported with peripheral VA-ECMO.

AbstractBackgroundGastrointestinal bleeding (GIB) in patients with continuous flow left ventricular assist devices (CF‐LVADs) is often related to GI angiodysplasia (GIAD). We previously reported data on VEGF inhibition with IV bevacizumab in the treatment of LVAD‐associated GIAD bleeding, and now present follow‐up data on patients treated with IV bevacizumab and/or low‐dose oral pazopanib.MethodsAll consecutive adult patients with LVAD‐associated GIB from GIAD treated with bevacizumab or pazopanib, from July 20, 2017 to June 22, 2022, were included in the analysis. Data on hospitalizations, GI endoscopic procedures, and blood transfusions were obtained from first admission for GIB up to a median of 35.7 months following treatment initiation (range 1.3–59.8 months).ResultsEleven patients (91% male, mean 69.5 ± 8.9 years) were included. Eight patients (73%) received IV bevacizumab, two patients (18%) received oral pazopanib, and one patient (9%) received bevacizumab followed by pazopanib therapy. We observed a significantly decreased number of annualized hospitalizations for GIB (median difference − 2.87, p = 0.002), blood transfusions (median difference − 20.9, p = 0.01), and endoscopies (median difference − 6.95, p = 0.007) in patients pre‐ and post‐anti‐angiogenic therapy (bevacizumab and/or pazopanib). Similarly, a significant improvement in these clinical outcomes was noted in the bevacizumab group with decreased annualized hospitalizations (median difference − 2.75, p = 0.014), blood transfusions (median difference − 24.5, p = 0.047), and number of endoscopies (median differences −6.88, p = 0.006).ConclusionAnti‐angiogenic therapy with IV bevacizumab and/or low‐dose oral pazopanib appears to provide benefits in patients with LVAD‐associated GIB with reduced hospitalizations, blood transfusions, and need for GI endoscopic procedures.

Combined heart-lung transplant (HTLx) is the most durable treatment available for end-stage heart and lung failure. Many patients are unable to receive combined organs due to organ availability and allocation policies prioritizing separate heart or lung transplantation. While an average of 45 HTLxs have been performed per year in the United States half the listed patients do not receive organs. Recently, donation after circulatory death (DCD) utilizing normothermic regional perfusion (NRP) has been utilized for heart allografts with excellent results, and here, we present a case utilizing mobile NRP to procure a heart and lung block from a circulatory death donor and successful implantation for a recipient in a separate center.

Mechanical circulatory support is increasingly being used as bridge-to-transplant and destination therapy in patients with advanced heart failure. Technologic improvements have led to increased patient survival and quality of life, but infection remains one of the leading adverse events following ventricular assist device (VAD) implantation. Infections can be classified as VAD-specific, VAD-related, and non-VAD infections. Risk of VAD-specific infections, such as driveline, pump pocket, and pump infections, remains for the duration of implantation. While adverse events are typically most common early (within 90 days of implantation), device-specific infection (primarily driveline) is a notable exception. No diminishment over time is seen, with event rates of 0.16 events per patient-year in both the early and late periods postimplantation. Management of VAD-specific infections requires aggressive treatment and chronic suppressive antimicrobial therapy is indicated when there is concern for seeding of the device. While surgical intervention/hardware removal is often necessary in prosthesis-related infections, this is not so easily accomplished with VADs. This review outlines the current state of infections in patients supported with VAD therapy and discusses future directions, including possibilities with fully implantable devices and novel approaches to treatment.