Disparities in donor heart acceptance between the USA and Europe: clinical implications.

BACKGROUND AND AIMS: Given limited evidence and lack of consensus on donor acceptance for heart transplant (HT), selection practices vary widely across HT centres in the USA. Similar variation likely exists on a broader scale-across countries and HT systems-but remains largely unexplored. This study characterized differences in heart donor populations and selection practices between the USA and Eurotransplant-a consortium of eight European countries-and their implications for system-wide outcomes. METHODS: Characteristics of adult reported heart donors and their utilization (the percentage of reported donors accepted for HT) were compared between Eurotransplant (n = 8714) and the USA (n = 60 882) from 2010 to 2020. Predictors of donor acceptance were identified using multivariable logistic regression. Additional analyses estimated the impact of achieving Eurotransplant-level utilization in the USA amongst donors of matched quality, using probability of acceptance as a marker of quality. RESULTS: Eurotransplant reported donors were older with more cardiovascular risk factors but with higher utilization than in the USA (70% vs. 44%). Donor age, smoking history, and diabetes mellitus predicted non-acceptance in the USA and, by a lesser magnitude, in Eurotransplant; donor obesity and hypertension predicted non-acceptance in the USA only. Achieving Eurotransplant-level utilization amongst the top 30%-50% of donors (by quality) would produce an additional 506-930 US HTs annually. CONCLUSIONS: Eurotransplant countries exhibit more liberal donor heart acceptance practices than the USA. Adopting similar acceptance practices could help alleviate the scarcity of donor hearts and reduce waitlist morbidity in the USA.

Recurrent HeartMate 3 Right Ventricular Assist Device Stoppages in a Biventricular Assist Device Carrier.

A 44-year-old female patient with chemotherapy-induced cardiomyopathy presented with acute cardiogenic shock requiring ECMO support. Multiple failed weaning trials from temporary mechanical circulatory assistance prompted a transition to staged durable biventricular support. Her course was complicated with recurrent RVAD stoppages. The initial event was treated with pump exchange, while for the subsequent RVAD standstill, we employed a device wash-out and reimplantation strategy. A brief period of circulatory arrest was employed to explore the right-sided cardiac chambers using a single-use bronchoscope.

Three-month outcomes after the implantation of two HeartMate 3 devices in total artificial heart configuration.

BACKGROUND: Total artificial heart (TAH) implantation is a rarely performed procedure. Contrarily, left ventricular assist device (VAD) implantation is rather common in many centers. As transplantation is quantitatively limited cardiac replacement with artificial hearts is a viable alternative in the treatment of severe biventricular heart failure. An alternative to TAH is the implantation of two VADs in a TAH configuration. We hereby present the first multi-center study on 3-months outcomes of patients treated by cardiectomy and placement of two HeartMate 3s in a TAH configuration. METHODS: We retrospectively investigated a cohort of 15 patients that underwent HM3-TAH-implantation at three international institutions. Follow-up was 3 months after implantation. Baseline, intra- and postoperative parameters as well as survival data and adverse events were collected. RESULTS: A total of 1089 days on HM3-TAH were observed. Thirty-day survival after HM3-TAH implantation was 53% (8/15) and three month survival was 40% (6/15). The longest duration on device was 274 days. Causes of death were multi-organ failure, sepsis, and neurological adverse events. No technical complications were documented. Two patients remained on the device. Four patients (26%) were successfully bridged to transplantation. CONCLUSIONS: The implantation of two HeartMate 3s in a TAH configuration is a last resort and off-label concept in cases of extreme biventricular heart failure. In a diligently selected patient cohort, HM3-TAH implantation is a feasible method to increase the chance of survival in a severely ill patient cohort and successfully bridge patients to heart transplantation that would otherwise have died.

Transendocardial CD34+ Cell Therapy Improves Local Mechanical Dyssynchrony in Patients With Nonischemic Dilated Cardiomyopathy.

We investigated the effects of cell therapy on local mechanical dyssynchrony (LMD) in patients with nonischemic dilated cardiomyopathy (NICM). We analyzed electromechanical data of 30 NICM patients undergoing CD34+ cell transplantation. All patients underwent bone marrow stimulation; CD34+ cells were collected by apheresis and injected transendocardially. At baseline and at 6 months after therapy, we performed electromechanical mapping and measured unipolar voltage (UV) and LMD at cell injection sites. LMD was defined as a temporal difference between global and segmental peak systolic displacement normalized to the average duration of the RR interval. Favorable clinical response was defined as increase in the left ventricular ejection fraction (LVEF) ≥5% between baseline and 6 months. Using paired electromechanical point-by-point analysis, we were able to identify 233 sites of CD34+ cell injections in 30 patients. We found no overall differences in local UV between baseline and 6 months (10.7 ± 4.1 mV vs 10.0 ± 3.6 mV, P = 0.42). In contrast, LMD decreased significantly (17 ± 17% at baseline vs 13 ± 12% at 6 months, P = 0.00007). Favorable clinical response at 6 months was found in 19 (63%) patients (group A), and 11 (37%) patients did not respond to cell therapy (group B). At baseline, the two groups did not differ in age, gender, LVEF, or N terminal-pro brain natriuretic peptide (NT-proBNP) levels. Similarly, we found no differences in baseline UV (9.5 ± 2.9 mV in group A vs 8.6 ± 2.4 mV in group B, P = 0.41) or LMD at cell injection sites (17 ± 19% vs 16 ± 14%, P = 0.64). In contrast, at 6 months, we found higher UV in group A (10.0 ± 3.1 mV vs 7.4 ± 1.9 mV in group B, P = 0.04). Furthermore, when compared with group B, patients in group A displayed a significantly lower LMD (11 ± 12% vs 16 ± 10%, P = 0.002). Thus, it appears that favorable clinical effects of cell therapy in NICM patients may be associated with a decrease of LMD at cell injection sites.

Left Ventricular Pseudoaneurysm: Unexpected Finding in a Patient Who Presented With Bacterial Endophthalmitis.

A large left ventricular pseudoaneurysm was discovered in a patient who presented with bacterial endophthalmitis 1 year after medically treated Staphylococcus aureus mitral valve endocarditis. After medical therapy, the patient underwent cardiac surgery uneventfully. We present a rare finding of a pseudoaneurysm complicated with a very late ocular septic event. (Level of Difficulty: Advanced.).

Heart re-transplantation in Eurotransplant.

Internationally 3% of the donor hearts are distributed to re-transplant patients. In Eurotransplant, only patients with a primary graft dysfunction (PGD) within 1 week after heart transplantation (HTX) are indicated for high urgency listing. The aim of this study is to provide evidence for the discussion on whether these patients should still be allocated with priority. All consecutive HTX performed in the period 1981-2015 were included. Multivariate Cox' model was built including: donor and recipient age and gender, ischaemia time, recipient diagnose, urgency status and era. The study population included 18 490 HTX, of these 463 (2.6%) were repeat transplants. The major indications for re-HTX were cardiac allograft vasculopathy (CAV) (50%), PGD (26%) and acute rejection (21%). In a multivariate model, compared with first HTX hazards ratio and 95% confidence interval for repeat HTX were 2.27 (1.83-2.82) for PGD, 2.24 (1.76-2.85) for acute rejection and 1.22 (1.00-1.48) for CAV (P < 0.0001). Outcome after cardiac re-HTX strongly depends on the indication for re-HTX with acceptable outcomes for CAV. In contrast, just 47.5% of all hearts transplanted in patients who were re-transplanted for PGD still functioned at 1-month post-transplant. Alternative options like VA-ECMO should be first offered before opting for acute re-transplantation.

New graft sizing rings for aortic valve reimplantation procedures.

OBJECTIVES: The objective was to design sizing rings that would enable proper sizing of the graft in reimplantation procedures and to perform leaflet repair before graft implantation. METHODS: The rings were designed in Autodesk Fusion 360 (San Rafael, CA, USA) and 3D printed using a commercial online 3D printing service. We designed incomplete rings with a low profile and complete rings with a high profile. The complete rings are best suited for reimplantation procedures, whereas low profile C rings are intended for isolated aortic valve repair, where the ascending aorta is not transected. The rings come in sizes corresponding to Vascutek Gelweave graft sizes (Vascutek Terumo, Renfrewshire, Scotland). The ring internal diameters are 5% larger than the designated ring sizes and account for the 5% stretch of the grafts when pressurized. Blades of the rings are placed at 20° intervals. The slits between the blades are designed in such a way that the commissural U-sutures, when put in place and under tension, will lock the ring in position. RESULTS: The rings were successfully used in 10 of our latest reimplantation procedures. After dissection of the aortic root, the commissures were suspended with U-stitches and then the ring was seated onto them. Complete leaflet repair with plication to achieve adequate effective height was then performed, followed by graft implantation. No additional leaflet repair was needed. CONCLUSIONS: The newly designed sizing rings enable proper sizing of the graft in reimplantation procedures and enable complete leaflet repair before graft implantation.

LVAD as a Bridge to Heart Transplantation in a Patient with Left Ventricular Noncompaction Cardiomyopathy and Advanced Heart Failure.

Left ventricular noncompaction cardiomyopathy (LVNC) is a rare hereditary cardiomyopathy characterized by the formation of an outer compacted and inner noncompacted layer of the myocardium. The latter is characterized by prominent trabeculations and deep intertrabecular recesses and is functionally inferior to the compacted myocardium. As there is no specific treatment for patients with LVNC who develop heart failure, the management of these patients is limited and many patients progress to advanced stages of the disease. For LVNC patients with advanced heart failure, the data regarding the use of mechanical circulatory support are scarce. We report a case of a 29-year-old patient with LVNC and advanced refractory heart failure, who was successfully bridged to heart transplantation using a long-term continuous-flow left ventricular assist device.

Effects of transendocardial CD34+ cell transplantation in patients with ischemic cardiomyopathy.

BACKGROUND: We investigated the effects of transendocardial CD34(+) cell transplantation in patients with ischemic cardiomyopathy. METHODS AND RESULTS: In a prospective crossover study, we enrolled 33 patients with ischemic cardiomyopathy with New York Heart Association class III and left ventricular ejection fraction <40%. In phase 1, patients were treated with medical therapy for 6 months. Thereafter, all patients underwent transendocardial CD34(+) cell transplantation. Peripheral blood CD34(+) cells were mobilized by granulocyte colony stimulating factor, collected via apheresis, and injected transendocardially in the areas of hibernating myocardium. Patients were followed up for 6 months after the procedure (phase 2). Two patients died during phase 1 and none during phase 2. The remaining 31 patients were 85% men, aged 57±6 years. In phase 1, we found no change in left ventricular ejection fraction (from 25.2±6.2% to 27.1±6.6%; P=0.23), N-terminal pro B-type natriuretic peptide (from 3322±3411 to 3672±5165 pg/mL; P=0.75) or 6-minute walk distance (from 373±68 to 411±116 m; P=0.17). In contrast, in phase 2 there was an improvement in left ventricular ejection fraction (from 27.1±6.6% to 34.9±10.9%; P=0.001), increase in 6-minute walk distance (from 411±116 to 496±113 m; P=0.001), and a decrease in N-terminal pro B-type natriuretic peptide (from 3672±5165 to 1488±1847 pg/mL; P=0.04). The average number of injected CD34(+) cells was 90.6±7.5×10(6). Higher doses of CD34(+) cells and a more diffuse distribution of transendocardial cell injections were associated with better clinical response. CONCLUSIONS: Transendocardial CD34(+) cell transplantation may be associated with improved left ventricular function, decreased N-terminal pro B-type natriuretic peptide levels, and better exercise capacity in patients with ischemic cardiomyopathy. These effects seem to be particularly pronounced in patients receiving diffusely distributed cell injections and high-dose cell therapy. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01350310.

Understanding coronary artery bypass transit time flow curves: role of bypass graft compliance.

OBJECTIVES: Low mean bypass graft flow (Q) and high pulsatility index (PI) measured by the transit time flow measurement method are not specific for anastomotic stenosis, but occur with competitive flow and poor coronary run-off. We hypothesized that graft compliance is responsible for these changes and that flow measured at the proximal end of the coronary bypass can be viewed as a sum of the graft capacitive flow and flow that passes through the distal anastomosis. METHODS: Transit time flow measurements (TTFMs) of 15 left internal thoracic artery (LITA) to LAD bypass grafts and 10 saphenous vein grafts (SVGs) to either the right coronary artery (RCA) or posterior descending artery (PDA) were analysed. The TTFM was performed on the proximal and distal end of the graft, and proximally with distal occlusion of the graft. Low mean bypass graft flow PI and diastolic filling (DF) measured distally and proximally were compared, and graft compliance was estimated. RESULTS: Diastolic filling was higher distally in every single case (LITA-LAD: distal DF 76 ± 12% vs proximal 66 ± 13%, P = 0.005; SVG-RCA/PDA: distal 72 ± 15% vs proximal 63 ± 12%, P = 0.018). There were no significant differences in Q and PI. Subtracting the distal from the proximal flow gave a result identical to the proximal TTFM in distally occluded grafts, confirming the presence of graft capacitive flow. Graft compliance estimated from the flow of distally occluded grafts was 0.99 ± 0.47 µl/mmHg for LITA grafts and 0.78 ± 0.42 µl/mmHg for SVG grafts. CONCLUSIONS: The study confirmed that the TTFM measured at the proximal end of the coronary bypass could be viewed as a sum of graft capacitive flow and the flow that passes through the distal anastomosis. Graft capacitive flow increases the systolic and decreases the diastolic TTFM when measured at the proximal end of the graft. It explains the higher DF when the TTFM is measured at the distal end of the graft and the increase in the PI at the proximal end when Q decreases. As the influence of graft capacitive flow on the PI in low Q can be eliminated by performing the TTFM at the distal end of the graft, we believe that the value of PI is clinically irrelevant.

Thymic fat pad flap to cover the left internal thoracic artery graft.

With a skeletonized harvesting technique of the left internal thoracic artery (LITA), opening of the pleural space during dissection can usually be avoided. However, due to the bulging of the ventilated lungs, the LITA graft comes to lie immediately below the sternum at the end of the procedure, which makes it vulnerable to injury in case of a reoperation. The authors present a simple technique to move the skeletonized LITA graft away from the undersurface of the sternum, by using a thymic fat pad flap (TFP).

Use of a totally artificial heart for a complex postinfarction ventricular septal defect.

The incidence of cardiac rupture complicating myocardial infarction has declined since the introduction of thrombolytic therapy. Despite the advances in the management of myocardial infarction, cardiac rupture remains an important cause of death among infarction-related fatalities. We discuss a patient who presented to our hospital with myocardial infarction and who subsequently developed a complex ventricular septal rupture, for which surgical repair was not feasible. Implantation of a CardioWest Total Artificial Heart (SynCardia Systems) allowed for immediate hemodynamic stabilization and served as a bridge to transplantation.

Intraoperative left subclavian artery occlusion with left hand ischaemia and steal syndrome in the left internal thoracic artery.

We present a case of a 62-year old man with a left main stenosis, left coronary artery dominance, normal ejection fraction and no valvular pathology, and status post right carotid artery stenting, who was scheduled for elective coronary revascularization. We performed off-pump coronary revascularization, anastomosing the left internal thoracic artery to the left anterior descending artery, and three separate saphenous vein grafts to the intermediate artery and the first and second obtuse marginals, respectively. Proximally, the right internal thoracic artery was used as the inflow for all three venous grafts due to a heavily calcified ascending aorta. During the construction of the distal anastomoses to the obtuse marginals, the arterial pressure in the left radial artery suddenly dropped. The left hand was found to be pale and pulseless. A femoral artery catheter was placed for pressure monitoring and the anastomoses were completed as planned. Intraoperative transit-time graft flow measurement showed a reversed flow in the left internal thoracic artery. Postoperatively, angiography was performed showing a subtotal stenosis of the proximal left subclavian artery. The artery was dilated and stented. The postoperative course was uneventful and the patient was discharged on the 12th postoperative day.

Xiphoid lower-sternotomy approach for multivessel revascularization of the left internal mammary artery to the left anterior descending artery and right internal mammary artery inflow to the other vessels.

BACKGROUND: We describe the technical details and the preliminary results of a new surgical approach for multivessel disease that involves using a lower T sternotomy, grafting of the left internal mammary artery (LIMA) to the left anterior descending coronary artery (LAD) and use of the right internal mammary artery (RIMA) as inflow to the other vessels. OPERATIVE TECHNIQUE: The sternotomy was made from the xiphoid up to the fourth intercostal space and then was continued transversally (T incision). The LIMA was harvested for a length of approximately 8 cm, with preservation of the distal part. The vein was simultaneously taken from the leg. The RIMA was dissected for a length of approximately 5 cm, and the distal part was occluded. Then, 3 mg/kg heparin was given. The anastomosis between the vein and the RIMA was performed. The distal venous anastomoses were done either singly or sequentially. The anterior or posterior route was chosen according to the patient's anatomy. The LIMA was then anastomosed to the LAD. One drain was placed. The sternum was closed with 4 wires, 2 for the T incision and 2 for the sternum. RESULTS: Between September and December 2008, 9 patients underwent their operations with this technique. The mean age was 60 years (range, 55-68 years). The mean number of grafts was 2.8. The mean hospital stay was 5.2 days. Operative mortality was 0%. All patients were reevaluated with 16-slice multislice computed tomography, and all grafts were patent. At the 3-month follow-up, all patients were alive and free of symptoms. CONCLUSION: This minimally invasive technique is a useful alternative for complete revascularization. The sternal mammary supply and the upper part of the sternum are preserved.