Use of Extracorporeal Membrane Oxygenation for Primary Graft Dysfunction After Cardiac Transplantation: Results of an A Priori Ventless Approach.

Primary graft dysfunction (PGD) after cardiac transplantation is a devastating complication with increasing frequency lately in the setting of donation after circulatory death (DCD). Severe PGD is commonly treated with extracorporeal membrane oxygenation (ECMO) using central or peripheral cannulation. We retrospectively reviewed the outcomes of PGD after cardiac transplantation requiring ECMO support at our center from 2015 to 2020, focused on our now preferential approach using peripheral cannulation without a priori venting. During the study period, 255 patients underwent heart transplantation at our center and 26 (10.2%) of them required ECMO for PGD. Of 24 patients cannulated peripherally 19 (79%) were alive at 30 days and 17 (71%) 1 year after transplant; two additional patients underwent central ECMO cannulation due to unfavorable size of femoral vessels and concern for limb ischemia. Successful decannulation with full graft function recovery occurred in 22 of 24 (92%) patients cannulated peripherally. Six of them had an indwelling intra-aortic balloon pump placed before the transplantation. None of the other 18 patients received a ventricular vent. In conclusion, the use of an a priori peripheral and ventless ECMO approach in patients with PGD after heart transplant is an effective strategy associated with high rates of graft recovery and survival.

Exophiala dermatitidis fungal infective endocarditis on prosthetic mitral valve.

Fungal infective endocarditis, although rare, carries a high mortality risk. We present a case of successful multidisciplinary management of Exophiala dermatitidis infective endocarditis in an immunocompetent male with a bio-prosthetic mitral valve. This case highlights the clinical presentation and provides valuable treatment insights into this rare fungal entity. Prompt consideration of fungal pathogens in predisposed patients, expedited detection through non-culture-based tests, and a combined surgical and prolonged antifungal approach are pivotal.

Predicting Hemodynamic Changes During Intra-Aortic Balloon Pump Support With a Longitudinal Evaluation.

The use of intra-aortic balloon pump (IABP) has decreased in recent years due to negative outcome studies in cardiogenic shock complicating acute myocardial infarction, despite its favorable adverse-event profile. Acute hemodynamic response studies have identified potential super-responders with immediate improvements in cardiac index (CI) in heart failure patients. This single-center retrospective study aimed to predict CI and mean arterial pressure (MAP) changes throughout the entire duration of IABP support. The study analyzed 336 patients who received IABP between 2016 and 2022. Linear mixed-effect regression models were used to predict CI and MAP improvement during IABP support. The results showed that CI and MAP increases during the first days of support, and changes during IABP support varied with time and were associated with baseline parameters. Longitudinal CI change was associated with body surface area, baseline CI, baseline pulmonary artery pulsatility index, baseline need for pressors, and diabetes. Longitudinal MAP change was associated with baseline MAP, baseline heart rate, need for pressors, or inotropes. The study recommends considering these parameters when deciding if IABP is the most appropriate form of support for a specific patient. Further prospective studies are needed to validate the findings.

Outcomes of Non-ST-Segment Myocardial Infarction During Chronic Heart Failure and End-Stage Renal Disease.

Non-ST-segment myocardial infarction (NSTEMI) occurs frequently in a growing population of patients with chronic heart failure (HF) and end-stage renal disease (ESRD) but outcomes with invasive management approaches are unknown. We sought to determine in-hospital outcomes with percutaneous coronary intervention (PCI) in comparison with medical management only. The National Inpatient Sample was used to capture hospitalizations in the United States from 2006 to 2019. Admissions for NSTEMI in patients with chronic HF and ESRD were identified by International Classification of Diseases codes. The cohort was divided into those that received PCI or medical management only. In-hospital outcomes were compared by multivariable logistic regression and propensity matching. In 27,433 hospitalizations, 8,004 patients (29%) underwent PCI, and 19,429 (71%) were managed with medications only. PCI was associated with lower adjusted odds of death during hospitalization (adjusted odds ratio 0.59, 95% confidence interval 0.52 to 0.66, p <0.01). This association remained consistent after propensity matching (adjusted odds ratio 0.56, 95% confidence interval 0.49 to 0.64, p <0.01) and was apparent across all subtypes of HF. Patients with PCI had greater duration (5, 3, to 9 vs, 5, 3 to 8 days, p <0.01) and cost of hospitalization ($107,942, 70,230 to $173,182 vs, $44,156, 24,409 to $80,810, p <0.01). In conclusion, patients with HF and ESRD admitted for NSTEMI experienced lower in-hospital mortality with PCI in comparison with medical therapy only. Invasive percutaneous revascularization may be reasonable for appropriately selected patients with HF and ESRD but randomized controlled trials are needed to determine its safety and efficacy in this high-risk population.

Early Outcomes of Adult Heart Transplantation From COVID-19 Infected Donors.

BACKGROUND: There is a paucity of data on heart transplantation (HT) using COVID-19 donors. OBJECTIVES: This study investigated COVID-19 donor use, donor and recipient characteristics, and early post-HT outcomes. METHODS: Between May 2020 and June 2022, study investigators identified 27,862 donors in the United Network for Organ Sharing, with 60,699 COVID-19 nucleic acid amplification testing (NAT) performed before procurement and with available organ disposition. Donors were considered "COVID-19 donors" if they were NAT positive at any time during terminal hospitalization. These donors were subclassified as "active COVID-19" (aCOV) donors if they were NAT positive within 2 days of organ procurement, or "recently resolved COVID-19" (rrCOV) donors if they were NAT positive initially but became NAT negative before procurement. Donors with NAT-positive status >2 days before procurement were considered aCOV unless there was evidence of a subsequent NAT-negative result ≥48 hours after the last NAT-positive result. HT outcomes were compared. RESULTS: During the study period, 1,445 "COVID-19 donors" (COVID-19 NAT positive) were identified; 1,017 of these were aCOV, and 428 were rrCOV. Overall, 309 HTs used COVID-19 donors, and 239 adult HTs from COVID-19 donors (150 aCOV, 89 rrCOV) met study criteria. Compared with non-COV, COVID-19 donors used for adult HT were younger and mostly male (∼80%). Compared with HTs from non-COV donors, recipients of HTs from aCOV donors had increased mortality at 6 months (Cox HR: 1.74; 95% CI: 1.02-2.96; P = 0.043) and 1 year (Cox HR: 1.98; 95% CI: 1.22-3.22; P = 0.006). Recipients of HTs from rrCOV and non-COV donors had similar 6-month and 1-year mortality. Results were similar in propensity-matched cohorts. CONCLUSIONS: In this early analysis, although HTs from aCOV donors had increased mortality at 6 months and 1 year, HTs from rrCOV donors had survival similar to that seen in recipients of HTs from non-COV donors. Continued evaluation and a more nuanced approach to this donor pool are needed.

Escalating and De-escalating Temporary Mechanical Circulatory Support in Cardiogenic Shock: A Scientific Statement From the American Heart Association.

The use of temporary mechanical circulatory support in cardiogenic shock has increased dramatically despite a lack of randomized controlled trials or evidence guiding clinical decision-making. Recommendations from professional societies on temporary mechanical circulatory support escalation and de-escalation are limited. This scientific statement provides pragmatic suggestions on temporary mechanical circulatory support device selection, escalation, and weaning strategies in patients with common cardiogenic shock causes such as acute decompensated heart failure and acute myocardial infarction. The goal of this scientific statement is to serve as a resource for clinicians making temporary mechanical circulatory support management decisions and to propose standardized approaches for their use until more robust randomized clinical data are available.

Effect of pulmonary artery pressure-guided therapy on heart failure readmission in a nationally representative cohort.

AIMS: Pulmonary artery pressure (PAP)-guided therapy in patients with heart failure (HF) using the CardioMEMS (CMM) device, an implantable PAP sensor, has been shown to reduce HF hospitalizations in previous studies. We sought to evaluate the clinical benefit of the CMM device in regard to 30, 90, and 180 day readmission rates in real-world usage. METHODS AND RESULTS: We queried the Nationwide Readmissions Database (NRD) to identify patients who underwent CMM implantation (International Classification of Diseases 9 and 10 codes) between the years 2014 and 2019 and studied their HF readmissions. Moreover, we compared CMM patients and their readmissions with a matched cohort of patients with HF but without CMM. Multivariable Cox regression analysis was performed to adjust for other predictors of readmissions. Prior to matching, we identified 5 326 530 weighted HF patients without CMM and 1842 patients with CMM. After propensity score matching for several patients and hospital-related characteristics, the cohort consisted of 1839 patients with CMM and 1924 with HF without CMM. Before matching, CMM patients were younger (67.0 ± 13.5 years vs. 72.3 ± 14.1 years, P < 0.001), more frequently male (62.7% vs. 51.5%, P < 0.001), with higher rates of prior percutaneous coronary intervention (16.9% vs. 13.2%, P = 0.002), peripheral vascular disease (29.6% vs. 17.8%, P < 0.001), pulmonary circulatory disorder (38.7% vs. 23.2%, P < 0.001), atrial fibrillation (51.2% vs. 45.3%, P = 0.002), prior left ventricular assist device (1.8% vs. 0.2%, P < 0.001), high income (32.2% vs. 16.4%, P < 0.001), and acute kidney disease (43.8% vs. 29.9%, P < 0.001). Readmission rates at 30 days were 17.3% vs. 20.9% for patients with vs. without CMM, respectively, and remained statistically significant after matching (17.3% vs. 21.5%, P = 0.002). The rates of 90 day (29.6% vs. 36.5%, P = 0.002) and 180 day (39.6% vs. 46.6%, P = 0.009) readmissions were lower in the CMM group. In a multivariable regression model, CMM was associated with lower risk of readmissions (hazard ratio 0.75, 95% confidence interval 0.63-0.89, P = 0.001). CONCLUSIONS: The CMM device was associated with reduced HF rehospitalization rates in a nationally representative cohort of HF patients, validating the clinical trial that led to the approval of this device and its utilization in the treatment of HF.

Characteristics and Outcomes of COVID-19 Patients Supported by Venoarterial or Veno-Arterial-Venous Extracorporeal Membrane Oxygenation.

OBJECTIVES: Cardiac injury has been reported in up to 20%-to-30% of patients with COVID-19, and severe disease can lead to cardiopulmonary failure. The role of mechanical circulatory support in these patients remains undetermined. The authors here aimed to determine the characteristics and outcomes of patients with COVID-19 requiring venoarterial extracorporeal membrane oxygenation (VA ECMO) or veno-arterial-venous (VAV) ECMO support. DESIGN AND SETTING: A multicenter, retrospective case series. PARTICIPANTS: The cohort consisted of adult patients (18 years of age and older) with confirmed COVID-19 requiring VA ECMO or VAV ECMO support in the period from March 1, 2020, to April 30, 2021. Outcomes were recorded until July 31, 2021. MEASUREMENTS AND MAIN RESULTS: To show factors related to death during hospitalization, patients were grouped as survivors and nonsurvivors. Kaplan-Meier analysis was used to estimate 90-day in-hospital mortality. Overall, 37 patients from 12 centers comprised the study cohort. The median patient age was 44 years old (interquartile range [IQR], 35-52), and 12 (32%) were female patients. The duration of ECMO support ranged from 2-to-132 days. At the end of the follow-up period, 13 patients (35%) were discharged or transferred alive, and 24 patients (65%) died during the hospitalization. The cumulative in-hospital mortality at 90 days was 64% (95% confidence interval: 47-81). During the time from intubation to VA ECMO or VAV ECMO initiation (1 day [IQR 0-7.5] v 6 days [IQR 2.5-14], p = 0.0383), body mass index (32 [IQR 26-36] v 37 [IQR 33-40], p = 0.009), and baseline C-reactive protein (7.15 v 38.9 mg/dL, p = 0.009) were higher in those who expired. CONCLUSION: Only one-third of the patients with COVID-19 requiring VA ECMO or VAV ECMO survived to discharge. Close monitoring of at-risk patients with early initiation of ECMO with circulatory support may further improve outcomes.

Hospital bed occupancy rate is an independent risk factor for COVID-19 inpatient mortality: a pandemic epicentre cohort study.

INTRODUCTION: COVID-19 first struck New York City in the spring of 2020, resulting in an unprecedented strain on our healthcare system and triggering multiple changes in public health policy governing hospital operations as well as therapeutic approaches to COVID-19. We examined inpatient mortality at our centre throughout the course of the pandemic. METHODS: This is a retrospective chart review of clinical characteristics, treatments and outcome data of all patients admitted with COVID-19 from 1 March 2020 to 28 February 2021. Patients were grouped into 3-month quartiles. Hospital strain was assessed as per cent of occupied beds based on a normal bed capacity of 1491. RESULTS: Inpatient mortality decreased from 25.0% in spring to 10.8% over the course of the year. During this time, use of remdesivir, steroids and anticoagulants increased; use of hydroxychloroquine and other antibiotics decreased. Daily bed occupancy ranged from 62% to 118%. In a multivariate model with all year's data controlling for demographics, comorbidities and acuity of illness, percentage of bed occupancy was associated with increased 30-day in-hospital mortality of patients with COVID-19 (0.7% mortality increase for each 1% increase in bed occupancy; HR 1.007, CI 1.001 to 1.013, p=0.004) CONCLUSION: Inpatient mortality from COVID-19 was associated with bed occupancy. Early reduction in epicentre hospital bed occupancy to accommodate acutely ill and resource-intensive patients should be a critical component in the strategic planning for future pandemics.

A multi-institutional retrospective analysis on impact of RV acute mechanical support timing after LVAD implantation on 1-year mortality and predictors of RV acute mechanical support weaning.

BACKGROUND: There is little insight into which patients can be weaned off right ventricular (RV) acute mechanical circulatory support (AMCS) after left ventricular assist device (LVAD) implantation. We hypothesize that concomitant RV AMCS insertion instead of postoperative implantation will improve 1-year survival and increase the likelihood of RV AMCS weaning. METHODS: A multicenter retrospective database of 826 consecutive patients who received a HeartMate II or HVAD between January 2007 and December 2016 was analyzed. We identified 91 patients who had early RV AMCS on index admission. Cox proportional-hazards model was constructed to identify predictors of 1-year mortality post-RV AMCS implantation and competing risk modeling identified RV AMCS weaning predictors. RESULTS: There were 91 of 826 patients (11%) who required RV AMCS after CF-LVAD implantation with 51 (56%) receiving a concomitant RV AMCS and 40 (44%) implanted with a postoperative RV AMCS during their ICU stay; 48 (53%) patients were weaned from RV AMCS support. Concomitant RV AMCS with CF-LVAD insertion was associated with lower mortality (HR 0.45 [95% CI 0.26-0.80], p = 0.01) in multivariable model (which included age, BMI, angiotensin-converting enzyme inhibitor use, and heart transplantation as a time-varying covariate). In the multivariate competing risk analysis, a TPG < 12 (SHR 2.19 [95% CI 1.02-4.70], p = 0.04) and concomitant RV AMCS insertion (SHR 3.35 [95% CI 1.73-6.48], p < 0.001) were associated with a successful wean. CONCLUSIONS: In patients with RVF after LVAD implantation, concomitant RV AMCS insertion at the time of LVAD was associated with improved 1-year survival and increased chances of RV support weaning compared to postoperative insertion.

Full-Time Cardiac Intensive Care Unit Staffing by Heart Failure Specialists and its Association with Mortality Rates.

BACKGROUND: Cardiac intensive care units (CICUs) serve medically complex patients with multiorgan dysfunction. Whether a CICU that is staffed full time by heart failure (HF) specialists is associated with decreased mortality is unclear. METHODS AND RESULTS: A retrospective review of consecutive CICU admissions from January 1, 2012, to December 31, 2016, was performed. In January 2014, the CICU changed from an open unit staffed by any cardiologist to a closed unit managed by HF specialists. Patients' baseline characteristics were determined, and a multivariate regression analysis was performed to ascertain mortality rates in the CICU. Baseline severity of illness was higher in the closed/HF specialist CICU model (P< 0.001). Death occurred in 101 of 1185 patients admitted to the CICU (8.5%) in the open-unit model and in 139 of 2163 patients (6.4%) admitted to the closed/HF specialist model (absolute risk reduction 2.1%, 95% confidence interval [CI] 0.1-4.0%; P = 0.01). The transition from an open to a closed/HF specialist model was associated with a lower overall CICU mortality rate (odds ratio [OR] 0.63; 95% CI 0.43-0.93). Prespecified interaction with a mechanical circulatory support device and unit model showed that treatment with such a device was associated with lower mortality rates in the closed/HF specialist model of a CICU (OR 0.6; 95% CI 0.18-0.78; P for interaction <0.01). CONCLUSION: Transition to a closed unit model staffed by a dedicated HF specialist is associated with lower CICU mortality rates.

Systems of Care in Cardiogenic Shock.

Outcomes for cardiogenic shock (CS) patients remain relatively poor despite significant advancements in primary percutaneous coronary interventions (PCI) and temporary circulatory support (TCS) technologies. Mortality from CS shows great disparities that seem to reflect large variations in access to care and physician practice patterns. Recent reports of different models to standardize care in CS have shown considerable potential at improving outcomes. The creation of regional, integrated, 3-tiered systems, would facilitate standardized interventions and equitable access to care. Multidisciplinary CS teams at Level I centers would direct care in a hub-and-spoke model through jointly developed protocols and real-time shared decision making. Levels II and III centers would provide early access to life-saving therapies and safe transfer to designated hub centers. In regions with large geographical distances, the implementation of telemedicine-cardiac intensive care unit (CICU) care can be an important resource for the creation of effective systems of care.

A History of Heart Failure Is an Independent Risk Factor for Death in Patients Admitted with Coronavirus 19 Disease.

AIMS: The association between cardiovascular diseases, such as coronary artery disease and hypertension, and worse outcomes in COVID-19 patients has been previously demonstrated. However, the effect of a prior diagnosis of heart failure (HF) with reduced or preserved left ventricular ejection fraction on COVID-19 outcomes has not yet been established. METHODS AND RESULTS: We retrospectively studied all adult patients with COVID-19 admitted to our institution from March 1st to 2nd May 2020. Patients were grouped based on the presence or absence of HF. We used competing events survival models to examine the association between HF and death, need for intubation, or need for dialysis during hospitalization. Of 4043 patients admitted with COVID-19, 335 patients (8.3%) had a prior diagnosis of HF. Patients with HF were older, had lower body mass index, and a significantly higher burden of co-morbidities compared to patients without HF, yet the two groups presented to the hospital with similar clinical severity and similar markers of systemic inflammation. Patients with HF had a higher cumulative in-hospital mortality compared to patients without HF (49.0% vs. 27.2%, p < 0.001) that remained statistically significant (HR = 1.383, p = 0.001) after adjustment for age, body mass index, and comorbidities, as well as after propensity score matching (HR = 1.528, p = 0.001). Notably, no differences in mortality, need for mechanical ventilation, or renal replacement therapy were observed among HF patients with preserved or reduced ejection fraction. CONCLUSIONS: The presence of HF is a risk factor of death, substantially increasing in-hospital mortality in patients admitted with COVID-19.

Prediction of right heart failure after left ventricular assist implantation: external validation of the EUROMACS right-sided heart failure risk score.

AIMS: Prediction of right heart failure (RHF) after left ventricular assist device (LVAD) implant remains a challenge. The EUROMACS right-sided heart failure (EUROMACS-RHF) risk score was proposed as a prediction tool for post-LVAD RHF but lacks from large external validation. The aim of our study was to externally validate the score. METHODS AND RESULTS: From January 2007 to December 2017, 878 continuous-flow LVADs were implanted at three tertiary centres. We calculated the EUROMACS-RHF score in 662 patients with complete data. We evaluated its predictive performance for early RHF defined as either (i) need for short- or long-term right-sided circulatory support, (ii) continuous inotropic support for ≥14 days, or (iii) nitric oxide for ≥48 h post-operatively. Right heart failure occurred in 211 patients (32%). When compared with non-RHF patients, pre-operatively they had higher creatinine, bilirubin, right atrial pressure, and lower INTERMACS class (P < 0.05); length of stay and in-hospital mortality were higher. Area under the ROC curve for RHF prediction of the EUROMACS-RHF score was 0.64 [95% confidence interval (CI) 0.60-0.68]. Reclassification of patients with RHF was significantly better when applying the EUROMACS-RHF risk score on top of previous published scores. Patients in the high-risk category had significantly higher in-hospital and 2-year mortality [hazard ratio: 1.64 (95% CI 1.16-2.32) P = 0.005]. CONCLUSION: In an external cohort, the EUROMACS-RHF had limited discrimination predicting RHF. The clinical utility of this score remains to be determined.

Outflow graft obstruction in patients with the HM 3 LVAD: A percutaneous approach.

BACKGROUND: The use of the HeartMate 3 (HM3) left ventricular assist device (LVAD) is expanding. Despite being associated with lower rates of adverse events and increased survival, outflow graft obstruction (OGO) has been reported in patients with HM3. The incidence and best management of this serious complication remain unclear. METHODS: We describe six cases of HM3 OGO occurring in five patients in our institutional HM3 cohort. Four cases underwent computed tomography angiography and in two percutaneous angiography was directly performed to confirm the diagnosis. In four cases, percutaneous repair of the OG was performed using common interventional cardiology (IC) techniques. RESULTS: Our institutional incidence of OGO was 7% (event rate of 0.05 per patient year); much higher than the previously reported incidence of 1.6%. All cases occurred in the bend relief covered segment. Only two patients had apparent OG twisting, and in two, OGO occurred despite placement of an anti-twist clip at the time of implant. External compression seems to play a role in most cases. Balloon "graftoplasty" and stent deployment via the femoral artery alleviated the obstruction and normalized LVAD flow in all patients who underwent percutaneous repair. The use of self-expanding stents allowed for downsizing of the procedural access site to 10 Fr. No serious procedure-related complications occurred. CONCLUSION: OGO is common in HM3 patients, external compression due to biomaterial accumulated surrounding the OG is a common etiology. Percutaneous repair using standard IC techniques is safe and feasible in cases of compression with or without partial twisting.

Relation of Peripheral Venous Pressure to Central Venous Pressure in Patients With Heart Failure, Heart Transplant, and Left Ventricular Assist Device.

Peripheral venous pressure (PVP) monitoring is a noninvasive method to assess volume status. We investigated the correlation between PVP and central venous pressure (CVP) in heart failure (HF), heart transplant (HTx), and left ventricular assist device (LVAD) patients undergoing right heart catheterization (RHC). A prospective, cross-sectional study examining PVP in 100 patients from October 2018 to January 2020 was conducted. The analysis included patients undergoing RHC admitted for HF, post-HTx monitoring, or LVAD hemodynamic testing. Sixty percent of patients had HF, 30% were HTx patients, and 10% were LVAD patients. The mean PVP was 9.4 ± 5.3 mm Hg, and the mean CVP was 9.2 ± 5.8 mm Hg. The PVP and CVP were found to be highly correlated (r = 0.93, p < 0.00001). High correlation was also noted when broken down by HF (r = 0.93, p < 0.00001), HTx (r = 0.93, p < 0.00001), and LVAD groups (r = 0.94, p < 0.00005). In conclusion, there is a high degree of correlation between PVP and CVP in HF, HTx, and LVAD patients. PVP measurements can be used as a rapid, reliable, noninvasive estimate of volume status in these patient populations.

Feasibility of high-intensity interval training in patients with left ventricular assist devices: a pilot study.

AIMS: Patients with left ventricular assist device (LVAD) suffer from persistent exercise limitation despite improvement of their heart failure syndrome. Exercise training (ET) programmes to improve aerobic capacity have shown modest efficacy. High-intensity interval training (HIIT), as an alternative to moderate continuous training, has not been systematically tested in this population. We examine the feasibility of a short, personalized HIIT programme in patients with LVAD and describe its effects on aerobic capacity and left ventricular remodelling. METHODS AND RESULTS: Patients on durable LVAD support were prospectively enrolled in a 15-session, 5 week HIIT programme. Turndown echocardiogram, Kansas City Cardiomyopathy Questionnaire, and cardiopulmonary exercise test were performed before and after HIIT. Training workloads for each subject were based on pretraining peak cardiopulmonary exercise test work rate (W). Percentage of prescribed training workload completed and adverse events were recorded for each subject. Fifteen subjects were enrolled [10 men, age = 51 (29-71) years, HeartMate II = 12, HeartMate 3 = 3, and time on LVAD = 18 (3-64) months]. Twelve completed post-training testing. HIIT was well tolerated, and 90% (inter-quartile range: 78, 99%) of the prescribed workload (W) was completed with no major adverse events. Improvements were seen in aV̇O2 at ventilatory threshold [7.1 (6.5, 9.1) to 8.5 (7.7, 9.3) mL/kg/min, P = 0.04], work rate at ventilatory threshold [44 (14, 54) to 55 (21, 66) W, P = 0.05], and left ventricular end-diastolic volume [168 (144, 216) to 159 (124, 212) mL, n = 7, P = 0.02]. HIIT had no effect on maximal oxygen consumption (V̇O2peak ) or Kansas City Cardiomyopathy Questionnaire score. CONCLUSIONS: Cardiopulmonary exercise test-guided HIIT is feasible and can improve submaximal aerobic capacity in stable patients with chronic LVAD support. Further studies are needed on its effects on the myocardium and its potential role in cardiac rehabilitation programmes.