Sex differences in heart transplantation - analysis of the national inpatient sample 2012-2019

INTRODUCTION

Advanced heart failure therapies and heart transplantation (HT) have been underutilized in women. Therefore, we aimed to explore the clinical characteristics and outcomes of HT by sex.

METHODS

We conducted a retrospective analysis of adult discharges from the National Inpatient Sample (NIS) between 2012 and 2019. International Classification of Disease (ICD) procedure codes were used to identify those who underwent HT.

RESULTS

A total of 20,180 HT hospitalizations were identified from 2012-2019. Among them, 28 % were female. Women undergoing HT were younger (mean age 51 vs. 54.5 years, p<0.001). HT hospitalizations among men were more likely to have atrial fibrillation, diabetes, hypertension, renal failure, dyslipidemia, smoking, and ischemic heart disease. HT hospitalizations among women were more likely to have hypothyroidism and valvular heart disease. HT hospitalizations in women were associated with no significant difference in risk of in-hospital mortality (adjusted odds ratio [OR] 0.82; 95 % confidence interval [CI] 0.58-1.16, p=0.271), no significant difference in length of stay or inflation-adjusted cost. Men were more likely to develop acute kidney injury during HT hospitalization (69.2 % vs. 59.7 %, adjusted OR 0.71, 95 % CI 0.61-0.83, p<0.001).

CONCLUSIONS

HT utilization is lower in women. However, most major in-hospital outcomes for HT are similar between the sexes. Further studies are need to explore the causes of lower rates of HT in women.

Evaluation of adjusted international normalized ratio goal in patients with HeartMate 3 left ventricular assist devices

BACKGROUND

The HeartMate3 left ventricular assist device (HM3 LVAD) has shown a low incidence of thrombosis, but bleeding risk is as high as 43%. We aim to describe the impact of lower international normalization ratio (INR) goal on clinical outcomes.

METHODS

In February 2019, our tertiary care institution lowered INR goal in HM3 patients from manufacturer recommendations to 1.8-2.2 and retrospectively analyzed the data. Two cohorts were compared: patients with lower INR goal upon implant (De novo) and those with subsequently lowered INR goal (Adjusted). The Adjusted group also served as its own historical control. Both groups continued aspirin 81 milligrams daily per manufacturer recommendations. The primary outcomes were incidences of bleed and thrombosis events within 12 months. Secondary outcomes included survival free of disabling stroke or reoperation to remove or replace the device and Rosendaal time in therapeutic range (TTR) over 12 months.

RESULTS

Thirty-one patients were evaluated for inclusion with 26 meeting criteria. Within 12 months, incidence of bleeding events was 25% and 28.6% in the De novo and Adjusted groups, respectively. Incidence of thrombotic events within 12 months was 0% in the De novo group and 7.1% in the Adjusted group. Twelve-month survival free of disabling stroke or reoperation to remove or replace the device was higher over 12 months for patients in the De novo group (91.7% vs. 78.6%). Median 12-month TTR was 36%, which was primarily attributable to subtherapeutic deviations.

CONCLUSIONS

A lower INR goal may be safe when initiated De novo following implantation of the HM3. This study informs the need for larger prospective studies.

Bedside ultrasound of the internal jugular vein to assess fluid status and right ventricular function: The POCUS-JVD study

BACKGROUND

Accurate estimation of fluid status is important in the management of heart failure patients, however, the current methods for bedside assessment can be unreliable or impractical for daily use.

METHODS

Non-ventilated patients were enrolled immediately prior to scheduled right heart catheterization (RHC). Using M-mode, IJV maximum (Dmax) and minimum (Dmin) anteroposterior diameters were measured during normal breathing, while supine. Respiratory variation in diameter (RVD) was calculated as [(Dmax - Dmin)/Dmax] in percentage. Collapsibility with sniff maneuver (COS) was assessed. Lastly, inferior vena cava (IVC) was assessed. Pulmonary artery pulsatility index (PAPi) was calculated. Data was obtained by five investigators.

RESULTS

Total 176 patients were enrolled. Mean BMI was 30.5 kg/m2, LVEF 14-69% (range), 38% with LVEF ≤35%. The POCUS of IJV could be performed in all patients in <5 min. Increasing RAP demonstrated progressive increase in IJV and IVC diameters. For high filling pressure (RAP ≥10 mmHg), an IJV Dmax ≥1.2 cm or IJV-RVD < 30% had specificity >70%. Combining the POCUS of IJV to physical examination improved the combined specificity to 97% for RAP ≥10 mmHg. Conversely, a finding of IJV-COS was 88% specific for normal RAP (<10 mmHg). An IJV-RVD <15% is suggested as a cutoff for RAP ≥15 mmHg. The performance of IJV POCUS was comparable to IVC. For RV function assessment, IJV-RVD < 30% had 76% sensitivity and 73% specificity for PAPi <3, while IJV-COS was 80% specific for PAPi ≥3.

CONCLUSION

POCUS of IJV is an easy to perform, specific and reliable method for volume status estimation in daily practice. An IJV-RVD < 30% is suggested for estimation of RAP ≥10 mmHg and PAPi <3.

Covid-19 positive donor utilization for heart transplantation: The new frontier for donor pool expansion

BACKGROUND

Hearts from COVID-19 positive donors (CPD) are being utilized for heart transplantation by some centers; however, this is in the setting of the lack of guidelines or robust evidence. The paucity of evidence is reflected in the recent Organ Procurement and Transplantation Network (OPTN) communication describing CPD utilization as an "unknown risk."

METHODS AND RESULTS

We analyzed the UNOS database for adult heart transplants performed between January 2021 to December 2022, and CPD comprised of a significant percentage of donors, being used in >10% of recipients in some UNOS regions. Between July 2022 and December 2022, 7.9% of heart transplants were with CPD, and in the same period Hepatitis C positive donors accounted for 7.1% and donation after circulatory death (DCD) accounted for 10.3%.

CONCLUSION

If the transplant community comes up with a standardized approach and guidance in using CPD hearts, this could provide an effective donor pool expansion strategy.

Patterns and outcomes of COVID-19 donor utilization for heart transplant

BACKGROUND

The outcomes following COVID-19 positive donor (CPD) utilization for heart transplant are unknown.

METHODS

UNOS database was analyzed for heart transplants performed from the declaration of COVID-19 pandemic until September 30, 2022.

RESULT

Since the onset of pandemic, there were 9876 heart transplants reported. COVID-19 antigen or NAT results were available in 7698 adult donors within 14 days of donation, of which 177 (2.3%) were positive. There was no difference in recipient demographics, including age (COVID positive donor vs. negative: 55 vs. 56 years, p = .2) and BMI. Listing status 1 and 2 were similar in both groups (7% vs. 10% and 48% vs. 49% respectively, p = .4). Durable and temporary mechanical support were similar in both groups pre-transplant (both groups 33%, p = .9). There was no difference in days on the waitlist (median 31 days, p = .9). Simultaneous renal transplant rates were similar (11% vs. 10%, p = .9). CPD utilization has increased since the onset of the pandemic, and the adoption is present across most UNOS regions. Post-transplant, there was no difference in length of stay (median 16 vs. 17 days, p = .9) and acute rejection episodes prior to discharge (3% vs. 8%, p = .1). In survival analysis of 90-day follow up, number of deaths reported were comparable (5% in both groups, p = .9) Follow-up LVEF was comparable (62% vs. 60%, p = .4).

CONCLUSION

Active COVID-19 infection in donors did not affect survival or rejection rates in the short-term post-heart transplant.

The Impact of Adverse Events on Functional Capacity and Quality of Life After HeartWare Ventricular Assist Device Implantation

Left ventricular assist devices (LVADs) improve quality of life (QoL) and functional capacity (FC) for patients with advanced heart failure. The association between adverse events (AEs) and changes in QoL and FC are unknown. Patients treated with the HeartWare ventricular assist device (HVAD) with paired 6-minute walk distance (6MWD, n = 263) and Kansas City Cardiomyopathy Questionnaires (KCCQ, n = 272) at baseline and 24 months in the ENDURANCE and ENDURANCE Supplemental Trial databases were included. Patients were stratified based upon occurrence of clinically significant AEs during the first 24 months of support and analyzed for the mean change in 6MWD and KCCQ. The impact of AE frequency on change in 6MWD and KCCQ from baseline to 24 months was evaluated. Of the AEs examined, only sepsis was associated with an improvement in 6MWD (109 m vs. 16 m, p = 0.002). Patients without improvement in 6MWD test from baseline to 24 months had significantly more AEs than those with FC improvement (p = 0.0002). Adverse events did not affect the KCCQ overall summary score. In this analysis, patients with fewer AEs had greater improvement in FC during the 24-month follow up. The frequency of AEs did not have a significant impact on QoL after LVAD implantation.

Use of Ventricular Assist Devices and Heart Transplantation for Advanced Heart Failure

There are only 2 treatments for the thousands of patients who progress to the most advanced form of heart failure despite the application of guideline-based medical therapy, use of ventricular assist devices and heart transplantation. There has been a great deal of progress in both of these therapies that have led to improved outcomes including significant improvement in survival and functional capacity. Heart transplantation offers the best short- and long-term survival for patients with end-stage heart failure, and the majority of these recipients achieve relatively limitless functional capacity for their age. However, the chronic shortage of available donors limits the number of recipients in the United States to an only 2500 patients/y or only a fraction of potential candidates. The significant improvement in outcomes now possible with durable ventricular assist devices has led to a significant increase in their use, which now exceeds the volume of heart transplants in the United States, with the greatest growth in use for those not considered to be candidates for heart transplantation, previously referred to as destination therapy. This article will review the substantial progress that has taken place for both of these life-saving treatment options, as well as the future directions.

Left ventricular assist device explantation after myocardial recovery

Left ventricular assist device (LVAD) treatment may lead to reverse remodeling in heart failure patients. Selected patients can recover heart function and be eligible for LVAD explantation. Surgical methods for explanting an LVAD have been reported using various surgical accesses and different degrees of retained device material. We report a surgical technique for achieving a complete pump removal, with an emphasis on the technical details of inflow and outflow pump cannula management.

Posterior Reversible Encephalopathy Syndrome after Heart Transplantation: Diagnosis and Immunosuppressive Therapy

Posterior reversible encephalopathy syndrome, an infrequent neurotoxicity associated with the use of tacrolimus, was first described in 1996, as a reversible syndrome manifested by headache, altered mental function, seizures, and visual disturbances. We describe the case of a 37-year-old woman who developed neurologic symptoms consistent with encephalopathy after treatment with tacrolimus, which was prescribed to maintain immunosuppression after orthotopic heart transplantation. This report also discusses the imaging methods used in the diagnosis of posterior reversible encephalopathy and highlights the difficulty of maintaining immunosuppression and managing medication-related adverse effects, while taking into account the risk of acute rejection after transplantation.

Left Ventricular Assist Device as a Bridge to Recovery for Patients With Advanced Heart Failure

BACKGROUND

Left ventricular assist devices (LVADs) have been used as an effective therapeutic option in patients with advanced heart failure, either as a bridge to transplantation, as destination therapy, or in some patients, as a bridge to recovery.

OBJECTIVES

This study evaluated whether patients undergoing an LVAD bridge-to-recovery protocol can achieve cardiac and physical functional capacities equivalent to those of healthy controls.

METHODS

Fifty-eight male patients-18 implanted with a continuous-flow LVAD, 16 patients with LVAD explanted (recovered patients), and 24 heart transplant candidates (HTx)-and 97 healthy controls performed a maximal graded cardiopulmonary exercise test with continuous measurements of respiratory gas exchange and noninvasive (rebreathing) hemodynamic data. Cardiac function was represented by peak exercise cardiac power output (mean arterial blood pressure × cardiac output) and functional capacity by peak exercise O₂ consumption.

RESULTS

All patients demonstrated a significant exertional effort as demonstrated with the mean peak exercise respiratory exchange ratio >1.10. Peak exercise cardiac power output was significantly higher in healthy controls and explanted LVAD patients compared with other patients (healthy 5.35 ± 0.95 W; explanted 3.45 ± 0.72 W; LVAD implanted 2.37 ± 0.68 W; and HTx 1.31 ± 0.31 W; p < 0.05), as was peak O₂ consumption (healthy 36.4 ± 10.3 ml/kg/min; explanted 29.8 ± 5.9 ml/kg/min; implanted 20.5 ± 4.3 ml/kg/min; and HTx 12.0 ± 2.2 ml/kg/min; p < 0.05). In the LVAD explanted group, 38% of the patients achieved peak cardiac power output and 69% achieved peak O₂ consumption within the ranges of healthy controls.

CONCLUSIONS

The authors have shown that a substantial number of patients who recovered sufficiently to allow explantation of their LVAD can even achieve cardiac and physical functional capacities nearly equivalent to those of healthy controls.

The HVAD Left Ventricular Assist Device: Risk Factors for Neurological Events and Risk Mitigation Strategies

OBJECTIVES

The purpose of this study was to determine the risk factors for ischemic in hemorrhage cerebrovascular events in patients supported by the HeartWare ventricular assist device (HVAD).

BACKGROUND

Patients supported with left ventricular assist devices are at risk for both ischemic and hemorrhagic cerebrovascular events.

METHODS

Patients undergoing implantation with a HVAD as part of the bridge-to-transplant trial and subsequent continued access protocol were included. Neurological events (ischemic cerebrovascular accidents [ICVAs] and hemorrhagic cerebrovascular accidents [HCVAs]) were assessed, and the risk factors for these events were evaluated in a multivariable model.

RESULTS

A total of 382 patients were included: 140 bridge-to-transplant patients from the ADVANCE (Evaluation of the HeartWare Left Ventricular Assist Device for the Treatment of Advanced Heart Failure) clinical trial and 242 patients from the continued access protocol. Patients had a mean age of 53.2 years; 71.2% were male, and 68.1% were white. Thirty-eight percent had ischemic heart disease, and the mean duration of support was 422.7 days. The overall prevalence of ICVA was 6.8% (26 of 382); for HCVA, it was 8.4% (32 of 382). Pump design modifications and a protocol-driven change in the antiplatelet therapy reduced the prevalence of ICVA from 6.3% (17 of 272) to 2.7% (3 of 110; p = 0.21) but had a negligible effect on the prevalence of HVCA (8.8% [24 of 272] vs. 6.4% [7 of 110]; p = 0.69). Multivariable predictors of ICVA were aspirin ≤81 mg and atrial fibrillation; predictors of HCVA were mean arterial pressure >90 mm Hg, aspirin ≤81 mg, and an international normalized ratio >3.0. Eight of the 30 participating sites had established improved blood pressure management (IBPM) protocols. Although the prevalence of ICVA for those with and without IBPM protocols was similar (5.3% [6 of 114] vs. 5.2% [14 of 268]; p = 0.99), those with IBPM protocols had a significantly lower prevalence of HCVA (1.8% [2 of 114] vs. 10.8% [29 of 268]; p = 0.0078).

CONCLUSIONS

Anticoagulation, antiplatelet therapy, and blood pressure management affected the prevalence of cerebrovascular events after implantation of the HVAD. Attention to these clinical parameters can have a substantial impact on the occurrence of serious neurological events. (Evaluation of the HeartWare Left Ventricular Assist Device for the Treatment of Advanced Heart Failure [ADVANCE]; NCT00751972).

Heart transplantation in heart failure: The prognostic importance of body mass index at time of surgery and subsequent weight changes

BACKGROUND

Heart transplantation is an important treatment for end-stage chronic heart failure. We studied the effect of body mass index (BMI), and the effect of subsequent weight change, on survival following transplantation in 1902 consecutive patients.

METHODS AND RESULTS

Patients were recruited from: London (n=553), Berlin (N=971) and Boston (N=378). Patients suitable for transplantation due to symptoms, low left ventricular ejection fraction (<or=30%) and peak oxygen consumption (<or=16 ml kg(-1) min(-1)) (N=237) were used as a comparator. In surviving transplanted patients, average duration of follow-up was 80 (SD 34) months. There were 805 deaths. One year survival was 72.7% (95% CI 72.68-72.72) and 5 year survival was 60.96% (61.94-61.99). Baseline BMI did not effect survival either as a continuous variable (hazard ratio (95% CI): 1.02; 0.99-1.04). Weight loss between transplant and 3 months was associated with worse survival (HR (95% CI) 2.6 (1.42-4.74)) compared with those who gained weight. In the reference group, increasing body mass index was related to survival.

CONCLUSIONS

Chronic heart failure patients with very low body weight can be transplanted successfully. The presence of underweight need not be an exclusion criterion for heart transplantation. Underweight patients appear to have a greater benefit from transplantation. Body weight increases after transplantation are not associated with adverse prognosis.

Sensitization following LVAD implantation using leucodepleted blood is not due to HLA antibodies

Implantation of left ventricular assist devices (LVAD) is associated with HLA antibody sensitization. The objective of this study was to determine the specificity of antibodies produced by LVAD recipients using a combination of ELISA, Luminex and microcytotoxicity assays. Fifty-one LVAD patients were studied, from 44 to 838 days post-implantation. No patient developed HLA antibodies, although 24 produced IgG antibodies detectable in both ELISA and Luminex assays. These antibodies manifest as positive reactions with class I and class II wells of the ELISA and also blank wells. In Luminex assays, they produce high MFI readings with the negative control beads. Antibodies were detected 18 to 228 days after implantation. This reactivity was found to be directed against bovine serum albumin (BSA), commonly used to block non-specific binding in ELISA and Luminex assays; absorption of sera with BSA-coated beads completely abrogated reactivity in all solid phase assays, but did not eliminate anti-HLA antibodies in control sera. Ten of the 24 patients have proceeded to transplantation, with a 1-year graft survival of 69%. In conclusion, it appears that implantation of LVADS disrupts immunoregulatory pathways leading to production of anti-albumin antibodies. These can be misinterpreted as anti-HLA antibodies in solid phase assays.

Effect of left ventricular assist device combination therapy on myocardial blood flow in patients with end-stage dilated cardiomyopathy

BACKGROUND

Changes in myocardial blood flow (MBF) and coronary flow reserve (CFR) are independent prognostic risk factors in idiopathic dilated cardiomyopathy (DCM). The aim of this study was to assess the impact of left ventricular unloading using left ventricular assist device (LVAD) combination therapy on resting MBF and CFR in patients with end-stage heart disease.

METHODS

We studied 11 patients with deteriorating end-stage DCM (New York Heart Association Class 4) treated with LVAD support combined with pharmacologic therapy in a recovery program. Absolute MBF was measured using oxygen-15-labeled water (H(2)(15)O) positron emission tomography (PET) at rest during LVAD support and 15 minutes after the LVAD was switched off. Data were corrected for rate pressure product (RPP) when appropriate. Hyperemic MBF (intravenous adenosine, 140 mug/kg . min) was also measured in 6 patients with the LVAD switched off. CFR was calculated as the ratio MBF adenosine/MBF LVAD off (corrected). Data are expressed as mean +/- SD.

RESULTS

At 317 +/- 193 days after device implantation, resting MBF was 0.95 +/- 0.29 (LVAD on) and 1.46 +/- 0.62 (LVAD off, corrected) ml/min . g (p = 0.01). MBF (LVAD on) was comparable with that of 11 age- and gender-matched normal controls (1.09 +/- 0.22 ml/min . g). CFR in the LVAD group was 1.49 +/- 0.99 compared with 3.56 +/- 1.42 in normal controls (p < 0.01).

CONCLUSIONS

During LVAD support, resting MBF (LVAD on) was comparable to MBF in normal controls and increased when the LVAD was switched off. However, CFR was significantly impaired, even though all patients studied showed varying degrees of myocardial recovery. The implications of these findings, particularly in the long term, require further study.