Heart Transplantation in a Patient With a Heterotopic Percutaneous Tricuspid Valve Prosthesis: A Case Report.

The bicaval transcatheter prosthesis (TricValve) allows the treatment of cava reflux in patients with severe tricuspid regurgitation and high surgical risk. It consists of the implantation of 2 self-expanding valves in both vena cava without directly approaching the native tricuspid valve. Heart transplantation in this setting may require some modifications compared with the conventional bicaval technique. We describe the clinical case of a 69-year-old woman with a background of rheumatic mitral valve disease who required a mitral valve replacement a few decades before. Ongoing clinical deterioration with biventricular dysfunction and severe tricuspid regurgitation was treated with a percutaneous bicaval heterotopic self-expanding valve system, with no clinical benefit. The patient underwent an elective heart transplantation. For the surgical approach, venous cannulation was performed percutaneously for both the right internal jugular and right femoral vein. Due to the impossibility of extracting percutaneous caval valves, the biatrial technique was selected for heart implantation. The postoperative course was difficult, but the patient was successfully discharged home 2 months postoperatively. She remains in good clinical condition with normal heart function 1 year after the transplant. To our knowledge, this is the first report describing a heart transplant in a patient with a bicaval transcatheter prosthesis.

Heart Transplantation and Thromboembolic Risk In Patients With Percutaneous Aortic Valve Prosthesis and Left Ventricular Assist Device: A Case Report.

Transcatheter aortic valve replacements have become a good option for patients with aortic valve disease and high surgical risk. Thromboembolism is reported as a relatively common complication of Transcatheter aortic valve replacement. This risk may be increased in patients who have left ventricular assist devices, as valve motion is drastically reduced. We present the case of a 65-year-old man with a history of alcoholism and valvular cardiomyopathy (severe chronic aortic insufficiency) with severe left ventricular dysfunction. Improvement in ventricular function followed the cessation of alcohol consumption, but still in poor clinical condition. Due to his high surgical risk, it was decided to implant a percutaneous aortic valve to treat the valve deficiency. Two months later, he suffered from a first episode of embolic stroke, which he successfully recovered. Despite the treatment, his clinical status did not improve (INTERMACS 3-4), and he was referred for heart transplantation. A left ventricular assist device was implanted as a bridge to the transplant. While on the waiting list, he suffered from other 3 episodes of stroke, 2 of them requiring mechanical thrombectomy. Finally, his transplant was performed with a favorable postoperative clinical course. Heart transplantation may be feasible in patients with multiple intracardiac devices in left chambers, although we must be aware of the increased thromboembolic risk, especially when used in combination.

Development of a Novel Prediction Model for Red Blood Cell Transfusion Risk in Cardiac Surgery.

BACKGROUND: Cardiac surgery is a complex and invasive procedure that often requires blood transfusions to replace the blood lost during surgery. Blood products are a scarce and expensive resource. Therefore, it is essential to develop a standardized approach to determine the need for blood transfusions in cardiac surgery. The main objective of our study is to develop a simple prediction model for determining the risk of red blood cell transfusion in cardiac surgery. METHODS: Retrospective cohorts of adult patients who underwent cardiac surgery between 2017 and 2019 were studied to identify hypothetical predictors of blood transfusion. Finally, a multivariable logistic regression model was developed to predict the risk of transfusion in cardiac surgery using the AUC and the Hosmer-Lemeshow goodness-of-fit test. RESULTS: We included 1234 patients who underwent cardiac surgery. Of the entire cohort, 875 patients underwent a cardiac procedure 69.4% [CI 95% (66.8%; 72.0%)]; 119 patients 9.6% [CI 95% (8.1%; 11.4%)] underwent a combined procedure, and 258 patients 20.9% [CI 95% (18.7; 23.2)] underwent other cardiac procedures. The median perioperative hemoglobin was 13.0 mg/dL IQR (11.7; 14.2). The factors associated with the risk of transfusion were age > 60 years OR 1.37 CI 95% (1.02; 1.83); sex female OR 1.67 CI 95% (1.24; 2.24); BMI > 30 OR 1.46 (1.10; 1.93); perioperative hemoglobin < 14 OR 2.11 to 51.41 and combined surgery OR 3.97 CI 95% (2.19; 7.17). The final model shows an AUC of 80.9% for the transfusion risk prediction [IC 95% (78.5-83.3%)]; p < 0.001]. CONCLUSIONS: We have developed a model with good discriminatory ability, which is more parsimonious and efficient than other models.

Donor-specific circulating cell free DNA as a noninvasive biomarker of graft injury in heart transplantation.

BACKGROUND: Considerable effort has been exerted to develop noninvasive diagnostic biomarkers that might replace or reduce the need to perform endomyocardial biopsies. In this context, graft DNA circulating on transplant recipients has been proposed as a potential biomarker of organ rejection or cellular graft injury. METHODS: We propose a digital PCR (dPCR) method based on the amplification of ten specific InDels sufficiently sensitive to detect small amounts of specific donor circulating DNA diluted on the host cell free DNA (cfDNA). We obtained 23 informative mismatches from 30 host and donor organ biopsy pairs. RESULTS: Patients without heart-related complications showed a high increase in the specific genomic marker levels during the first 24 h after transplantation that dropped to the basal levels on days 3-4 post-surgery. In contrast, patients with complications presented a significantly lagged decay pattern from day one after transplantation. A specific donor cfDNA increase was detected in one patient two days before rejection diagnosis, diminishing the basal levels after successful immunotherapy. A cfDNA increase was also observed during graft injury due to heart damage. CONCLUSION: These results suggest that cfDNA monitoring of transplanted patients may be a useful tool to detect and probably anticipate graft rejection.

The morphologically right and left ventricles cannot be distinguished by their coronary arterial pattern.

OBJECTIVES: The morphologically right and left ventricles are distinguished from each other based on their internal anatomical features, because their external (epicardial) surfaces do not appear to have any distinguishing mark for such ventricular identification. Nevertheless, ventricular identification based on epicardial characteristics, if these were possible, would be interesting to surgeons, because this would enable them to identify each ventricle rapidly upon opening the chest. This made us curious as to whether or not the two ventricles may be distinguished based on their epicardial coronary arterial patterns, because this is the most obvious epicardial ventricular feature. METHODS: This idea led us to formulate the following 2 hypotheses: (i) The morphologically left ventricle is always the one that receives the higher number of the marginal arteries as compared to the morphologically right ventricle. (ii) Only the morphologically left ventricle receives the diagonal arteries from the anterior and posterior interventricular arteries. These hypotheses were tested in this anatomical observational study by examination of 98 normal and 398 congenitally malformed formaldehyde-preserved hearts encompassing most malformations, including rare ones and hearts in which 1 ventricle is hypoplastic. RESULTS: These examinations show that both hypotheses are false. CONCLUSIONS: The two ventricles cannot be distinguished from each other based on the number of marginal arteries that they receive or which one receives diagonal arteries; both ventricles may receive diagonal arteries from either or both interventricular arteries.

A simple surgical technique to prevent atrial reentrant tachycardia in surgery for congenital heart disease†.

OBJECTIVES: To present and test a simple surgical technique that may prevent atrial reentrant tachycardia following surgery for congenital heart disease. This arrhythmia is one of the commonest long-term complications of such a surgery. It may occur many years (even decades) after the operation. It is usually explained as a late consequence of right atriotomy, which is an inherent component of many operations for congenital heart disease. Right atriotomy results in a long scar on the right atrial myocardium. This scar, as any scar, is a barrier to electrical conduction, and macro-reentrant circuits may form around it, causing reentrant tachycardia. However, this mechanism may be counterchecked and neutralized by our proposed method, which prevents reentrant circuits around right atriotomy scars. METHODS: The proposed method is implemented after termination of cardiopulmonary bypass and tying the venous purse-strings. It consists of constructing a full-thickness suture line on the intact right atrial wall from the inferior vena cava (IVC) (a natural conduction barrier) to the atriotomy incision. This suture line is made to cross the venous cannulation sites if these are on the atrial myocardium (rather than being directly on the venae cavae). Thus, the IVC, atriotomy and cannulation sites are connected to each other in series by a full-thickness suture line on the atrial wall. If this suture line becomes a conduction barrier, it would prevent reentrant circuits around right atrial scars. This was tested in 13 adults by electroanatomical mapping. All 13 patients had previously undergone right atriotomy for atrial septal defect closure: 8 of them with the addition of the proposed preventive suture line (treatment group) and 5 without (control group). RESULTS: In all 13 cases, the atriotomy scar was identified as a barrier to electrical conduction with electrophysiological evidence of fibrosis (scarring). In the 8 patients with the proposed suture line, this had also become a scar and a complete conduction barrier. In the 5 patients without this suture line, there was free electrical conduction between the IVC and atriotomy scar. CONCLUSIONS: The proposed suture line becomes a scar and conduction barrier. Therefore, it would prevent reentrant circuits around atrial scars and their consequent arrhythmias.

Surgical technique for heart transplantation: a strategy for congenital heart disease.

The standard techniques for orthotopic heart transplantation often require certain adjustments when the procedure is carried out for complex congenital heart disease. This is because of both the unusual anatomy and possible distortions caused by previous surgery. Such technical adjustments have been described in various published reports over the years. Those reports, when combined, do cover the full spectrum of the technical difficulties that may be encountered, whether the defects are in their original form or altered by surgery, such that no cardiac malformation or distortion would prohibit transplantation. However, those reports are comprehensive only when combined. None of the individual reports addresses all the possible technical challenges. Consequently, the available information is somewhat fragmented. In addition, the generic aspect of the described technical strategies is not always given the emphasis that it deserves. Indeed, occasionally a technique may be presented as a specific solution for a specific malformation, without necessarily pointing out that the same technique may be applied to other hearts with different overall pathologies but which share that specific malformation. The aim of this review article was to combine all the available published information in one article in a manner that constructs a simple but comprehensive and generic system of decision-making that may be applied to any heart in order to determine the exact technical adjustments needed for transplantation in each case. Such a strategy is possible for two reasons. First, only a few anatomical sites are technically significant, namely the points of anastomosis between the donor's organ and the recipient. The rest of the intracardiac morphology does not affect the operation and may be ignored. Second, each of those anatomical sites can present difficulties in only a few ways, and each of those few difficulties has a well-described and published solution already. Therefore, the exact technical adjustments required in each case may be worked out by the sequential assessment of the anastomotic sites alone.

Criopreservación cardíaca a temperatura subcero: estudio de la función sistólica y diastólica / Cardiac cryopreservation at subzero temperatures: study of systolic and diastolic function

Introducción. Estudiamos las alteraciones producidas en la función sistólica y diastólica del ventrículo izquierdo tras aplicar un protocolo de criopreservación a temperatura subcero sobre corazón de conejo aislado, utilizando como agente crioprotector el polietilenglicol de PM 4.000 al 5 por ciento. Material y método. Usamos el CP-16 como solución crioprotectora en el corazón explantado en tres fases: inducción, almacenamiento y recalentamiento. Tras 60 min a -1,6 °C y recalentado a 2,7 °C/min, el corazón se conecta al sistema Langendorff y se perfunde por vía anterógrada con solución de Krebs-Henseleit. Analizamos los parámetros sistólicos y diastólicos antes y después de la criopreservación, estableciendo un estudio estadístico comparativo. Resultados. Tras la criopreservación encontramos un aumento estadísticamente significativo (p < 0,05) de los valores de la presión pico y desarrollada de ventrículo izquierdo con desplazamiento de la curva de función ventricular hacia arriba y la izquierda, lo que indica una mejora de la función sistólica. Sin embargo, en la función diastólica se observó un empeoramiento, con un aumento estadísticamente significativo (p < 0,05) de la rigidez media, descenso de la rigidez diferencial con p < 0,05 y desplazamiento hacia arriba y la izquierda de la curva diastólica de presión-volumen. Conclusiones. Según nuestros resultados concluimos que: a) el polietilengliol de PM 4000 al 5 por ciento mantiene la viabilidad biológica del corazón durante el protocolo de criopreservación a temperatura subcero, y b) tras la criopreservación se produce un empeoramiento de la función diastólica de ventrículo izquierdo con mejoría de la función sistólica (AU)