Lethal heparin-induced thrombocytopenia after transfemoral aortic valve implantation

SIN FINANCIACIÓN

Incidence and clinical impact of infective endocarditis after transcatheter aortic valve implantation

The aim of this study is to describe the characteristics of infective endocarditis (IE) after transcatheter aortic valve implantation (TAVI). This study was performed using the GAMES database, a national prospective registry of consecutive patients with IE in 26 Spanish hospitals. Of the 739 cases of IE diagnosed during the study, 1.3% were post-TAVI IE, and these 10 cases, contributed by five centres, represented 1.1% of the 952 TAVIs performed. Mean age was 80 years. All valves were implanted transfemorally. IE appeared a median of 139 days after implantation. The mean age-adjusted Charlson comorbidity index was 5.45. Chronic kidney disease was frequent (five patients), as were atrial fibrillation (five patients), chronic obstructive pulmonary disease (four patients), and ischaemic heart disease (four patients). Six patients presented aortic valve involvement, and four only mitral valve involvement; the latter group had a higher percentage of prosthetic mitral valves (0% vs. 50%). Vegetations were found in seven cases, and four presented embolism. One patient underwent surgery. Five patients died during follow-up: two of these patients died during the admission in which the valve was implanted. Conclusions: IE is a rare but severe complication after TAVI which affects about 1% of patients and entails a relatively high mortality rate. IE occurred during the first year in nine of the 10 patients.

Genomics to elucidate the molecular basis of calcific aortic valve disease

Le rétrécissement valvulaire aortique (RVA) est causé par une calcification et une fibrose progressive de la valve aortique. Le risque de développer la maladie augmente avec l’âge. À cause de l’augmentation de l’espérance de vie, le RVA est devenu un problème de santé publique. Le RVA est fatal en absence de traitement médical. Actuellement, la chirurgie est le seul traitement pour le stade sévère de la maladie, mais près de 50% des individus avec RVA n’y sont pas éligibles, principalement due à la présence de comorbidités. Plusieurs processus biologiques ont été associés à la maladie, mais les voies moléculaires spécifiques et les gènes impliqués dans le développement et la progression du RVA ne sont pas connus. Il est donc urgent de découvrir les gènes de susceptibilité pour le RVA afin d’identifier les personnes à risque ainsi que les biomarqueurs et les cibles thérapeutiques pouvant mener au développement de médicaments pour inverser ou limiter la progression de la maladie. L’objectif de cette thèse de doctorat était d’identifier la base moléculaire du RVA. Des approches modernes en génomique, incluant l’étude de gènes candidats et le criblage génomique par association (GWAS), ont été réalisées à l’aide de collections d’ADN provenant d’un grand nombre de patients bien caractérisés pour le RVA. Des études complémentaires en transciptomique ont comparé le profil d’expression global des gènes entre des valves calcifiées et non-calcifiées à l’aide de biopuces à ADN et de séquençage de l’ARN. Une première étude a identifié des variations dans le gène NOTCH1 et suggère pour la première fois la présence d’un polymorphisme commun dans ce gène conférant une susceptibilité au RVA. La deuxième étude a combiné par méta-analyse deux GWAS de patients provenant de la ville de Québec et Paris (France) aux données transcriptomiques. Cette étude de génomique intégrative a confirmé le rôle de RUNX2 dans le RVA et a permis l’identification d’un nouveau gène de susceptibilité, CACNA1C. Les troisième et quatrième études sur l’expression des gènes ont permis de mieux comprendre les bases moléculaires de la calcification des valves aortiques bicuspides et ainsi d’identifier de nouvelles cibles thérapeutiques pour le RVA. Les données générées par ce projet sont la base de futures découvertes importantes qui permettront d’améliorer les options de traitement et la qualité de vie des patients atteints du RVA.

Le remplacement valvulaire aortique chez le jeune adulte

Chez le jeune adulte, le substitut valvulaire aortique idéal demeure inconnu. La prothèse mécanique est durable. Cependant, elle requiert une anticoagulation à vie. De récentes études ont démontré un excès de mortalité à long terme chez les patients après un remplacement valvulaire aortique (RVA) mécanique. D’autres part, plusieurs patientes sont en âge de procréer lorsqu’une chirurgie est indiquée. La grossesse chez les patientes porteuses de RVA mécanique est à risque d’évènements thromboemboliques. Dans ce contexte, ces derniers sont mieux prévenus par la warfarine comparativement à l’héparine chez les patientes enceintes porteuses de prothèses mécaniques. Cependant, la warfarine est associée à des malformations fœtales. Les prothèses biologiques évitent l’anticoagulation. Par contre, la dégénérescence structurelle de la prothèse est plus rapide chez les patients jeunes, ce qui les expose à un haut risque de réintervention. L’objectif de ce mémoire est d’étudier les issues à long terme suivant un RVA chez le jeune adulte. Deux études ont été réalisées dans le cadre de ce travail. La première avait pour objectif de déterminer la survie et les complications à long terme dans une population de jeunes adultes ayant subi un RVA mécanique isolé. La survie de ce groupe de patient est inférieure à celle de la population générale québécoise appariée pour l’âge et le sexe. De plus, il existe un risque faible, mais constant à long terme de dysfonction de la prothèse et de réopération dans cette population. La deuxième étude a pour objectif de déterminer les complications cardiaques, maternelles et fœtales durant la grossesse chez des patientes porteuses de RVA mécanique ou biologique. Les résultats obtenus démontrent que la grossesse chez ces patientes est associée à un risque de complications maternelles et cardiaques significatives, et ce surtout chez les patientes porteuses d’une prothèse mécanique.

Caracterización de los pacientes críticos ventilados en la Fundación Santa Fe de Bogotá 2009 a 2013

Objetivo: Caracterizar a los pacientes que recibieron ventilación mecánica en las unidades de cuidado intensivo (UCI) de la Fundación Santa Fe de Bogotá entre los años 2009 y 2013. Metodología: Se analizó una cohorte retrospectiva de los pacientes en UCI que requirieron soporte ventilatorio mecánico al ingreso a la unidad independientemente de la causa. Resultados: La media de edad de los pacientes fue 63,83 años; el diagnóstico más frecuente de ingreso fue revascularización miocárdica, seguido por neumonía y recambio valvular aórtico; en el 43% de los casos la causa de la falla fue el estado postoperatorio. Los modos ventilatorios más frecuentemente utilizados fueron SIMV (27,5%) y ventilación asistida controlada (26,12%). El 50% de los pacientes fueron ventilados con PEEP < 6 cmH2O. La mortalidad bruta fue del 15%. 22% de los pacientes tuvieron estancia prolongada en UCI. Se aplicó protocolo de retiro de ventilación mecánica en el 77% de los pacientes. La duración de la ventilación mecánica es mayor a medida que aumenta la edad del paciente entre los 60 y los 80 años. La mortalidad es cercana al 50% alrededor de los 50 años y mayor a 80% después de los 80 años. El soporte ventilatorio por cinco o más días aumentó la mortalidad a 80% o más. Discusión y Conclusiones: Estos resultados son comparables a los encontrados en estudios previos. Este estudio puede ser considerado como el primer paso para generar un registro adecuado de la ventilación de la mecánica de las unidades de cuidado intensivo del país.

Clinical experience with the ATS 3f Enable® Sutureless Bioprosthesis

The ATS 3f Enable® Bioprosthesis is a self-expanding valve with a tubular design that allows for decreased leaflet stress and preservation of aortic sinuses. We report the midterm results of a prospective, multicenter clinical study evaluating the safety and efficacy of this stented bioprosthesis in patients undergoing isolated aortic valve replacement with or without concomitant procedures.

Outcome in adult patients after arterial switch operation for transposition of the great arteries

BACKGROUND: The arterial switch operation (ASO) is currently the treatment of choice in neonates with transposition of the great arteries (TGA). The outcome in childhood is encouraging but only limited data for long-term outcome into adulthood exist. METHODS AND RESULTS: We studied 145 adult patients (age>16, median 25years) with ASO followed at our institution. Three patients died in adulthood (mortality 2.4/1000-patient-years). Most patients were asymptomatic and had normal left ventricular function. Coronary lesions requiring interventions were rare (3 patients) and in most patients related to previous surgery. There were no acute coronary syndromes. Aortic root dilatation was frequent (56% patients) but rarely significant (>45mm in 3 patients, maximal-diameter 49mm) and appeared not to be progressive. There were no acute aortic events and no patient required elective aortic root surgery. Progressive neo-aortic-valve dysfunction was not observed in our cohort and only 1 patient required neo-aortic-valve replacement. Many patients (42.1%), however, had significant residual lesions or required reintervention in adulthood. Right ventricular outflow tract lesions or dysfunction of the neo-pulmonary-valve were frequent and 8 patients (6%) required neo-pulmonary-valve replacement. Cardiac interventions during childhood (OR 3.0, 95% CI 1.7-5.4, P<0.0001) were strong predictors of outcome (cardiac intervention/significant residual lesion/death) in adulthood. CONCLUSIONS: Adult patients with previous ASO remain free of acute coronary or aortic complications and have low mortality. However, a large proportion of patients require re-interventions or present with significant right sided lesions. Life-long cardiac follow-up is, therefore, warranted. Periodic noninvasive surveillance for coronary complications appears to be safe in adult ASO patients.

Acute hyponatremia after cardioplegia by histidine-tryptophane-ketoglutarate - a retrospective study

Background Hyponatremia is the most common electrolyte disorder in hospitalized patients and is known to be associated with increased mortality. The administration of antegrade single-shot, up to two liters, histidine-tryptophane-ketoglutarate (HTK) solution for adequate electromechanical cardiac arrest and myocardial preservation during minimally invasive aortic valve replacement (MIAVR) is a standard procedure. We aimed to determine the impact of HTK infusion on electrolyte and acid–base balance. Methods In this retrospective analysis we reviewed data on patient characteristics, type of surgery, arterial blood gas analysis during surgery and intra-/postoperative laboratory results of patients receiving surgery for MIAVR at a large tertiary care university hospital. Results A total of 25 patients were included in the study. All patients were normonatremic at start of surgery. All patients developed hyponatremia after administration of HTK solution with a significant drop of serum sodium of 15 mmol/L (p < 0.01). Measured osmolality did not change during all times of surgery compared to start of surgery (p = 0.28 – p = 0.79), indicating isotonic hyponatremia. After administration of HTK solution pH fell significantly due to development of metabolic acidosis. Conclusions Acute hyponatremia during cardioplegia with HTK solution is isotonic and should probably not be corrected without presence of hypotonicity as confirmed by measurement of serum osmolality.

Benefits of cardiac surgery in octogenarians--a postoperative quality of life assessment

OBJECTIVE: Assessment of postoperative quality of life in patients over 80 years after cardiac surgery including coronary artery bypass grafting (CABG), aortic valve replacement (AVR) and combined procedures. METHODS: Quality of life of n=136 patients over 80 years at operation (82.3+/-2.1 years), undergoing isolated CABG in 61 patients (45%), isolated AVR in 34 patients (25%) and a combination of CABG and AVR in 41 patients (30%) between January 1999 and December 2003 was reviewed. Preoperatively 66.2% presented in NYHA-class III/IV or CCS-class III/IV. Mean ejection fraction (EF) was 59.5%+/-14.0 (range 25-90%). Quality of life assessment was performed via a Seattle Angina Questionnaire. Follow-up was 100% complete for a total of 890 days (69-1853 days). RESULTS: Five-year survival was 70% for the CABG group, 75% for the AVR group and 65% for the CABG/AVR group. Quality of life was remarkable in all of the three groups after surgery. Overall 97 patients (81%) were not or little disabled in their daily activity. One hundred and twelve patients (93%) were free or considerably less symptomatic. Seventy-eight patients or 65% reported to be very satisfied with their current quality of life and 112 patients (93%) felt very reassured to have continuous full access to medical treatment despite of their advanced age. CONCLUSIONS: A remarkable quality of life and important improvement in the functional status after cardiac surgery in patients over 80 paired with a satisfactory medium-term survival justify early intervention for heart disease in this age group. Therefore, referral practice for patients over 80 years for heart surgery should be handled liberally.

Novel emboli protection system during cardiac surgery: a multi-center, randomized, clinical trial.

BACKGROUND Stroke is a major cause of morbidity and mortality during open-heart surgery. Up to 60% of intraoperative cerebral events are emboli induced. This randomized, controlled, multicenter trial is the first human study evaluating the safety and efficacy of a novel aortic cannula producing simultaneous forward flow and backward suction for extracting solid and gaseous emboli from the ascending aorta and aortic arch upon their intraoperative release. METHODS Sixty-six patients (25 females; 68±10 years) undergoing elective aortic valve replacement surgery, with or without coronary artery bypass graft surgery, were randomized to the use of the CardioGard (CardioGard Medical, Or-Yehuda, Israel) Emboli Protection cannula ("treatment") or a standard ("control") aortic cannula. The primary endpoint was the volume of new brain lesions measured by diffusion-weighted magnetic resonance imaging (DW-MRI), performed preoperatively and postoperatively. Device safety was investigated by comparisons of complications rate, namely neurologic events, stroke, renal insufficiency and death. RESULTS Of 66 patients (34 in the treatment group), 51 completed the presurgery and postsurgery MRI (27 in the treatment group). The volume of new brain lesion for the treatment group was (mean±standard error of the mean) 44.00±64.00 versus 126.56±28.74 mm3 in the control group (p=0.004). Of the treatment group, 41% demonstrated new postoperative lesions versus 66% in the control group (p=0.03). The complication rate was comparable in both groups. CONCLUSIONS The CardioGard cannula is safe and efficient in use during open-heart surgery. Efficacy was demonstrated by the removal of a substantial amount of emboli, a significant reduction in the volume of new brain lesions, and the percentage of patients experiencing new brain lesions.

Komplikationen beim kathetergestützten Aortenklappenersatz nach transfemoralem Zugang

Hintergund Seit mehr als 10 Jahren wird der kathetergestützte Aortenklappenersatz (Transkatheter-Aortenklappenimplantation, „transcatheter aortic valve implantation“, TAVI) durchgeführt. Bereits in der Anfangsphase haben sich eingriffstypische Komplikationen nach transfemoralem Zugang herauskristallisiert. Ziel der Arbeit Beispielhaft wird anhand von 4 Sektionsfällen beschrieben, wie die Indikationsstellung zur TAVI und die Vermeidbarkeit der Komplikation zu prüfen ist. Material und Methoden Bei einer 86-jährigen Frau war es im Rahmen eines Repositionsversuchs des Implantats zu einem Abriss der rechten Beckengefäße gekommen. Bei einer 82-jährigen Frau war es während der Intervention zu einem Einriss des Aortenklappenrings mit Perikardtamponade gekommen. Eine 89-jährige Frau erlitt während der Intervention eine gedeckte Aortenverletzung und war während der anschließenden operativen Versorgung des Defekts verstorben. Im vierten Fall war bei einer 83 Jahre alt gewordenen Patientin im Rahmen des transfemoralen Klappenersatzes die Positionierung der Klappe misslungen, und ventrikelwärts entwickelte sich eine Embolisation der entfalteten Klappe. Es wurde eine zweite gleichartige Klappe positioniert, die in der Aorta hielt. Ergebnisse Die Indikationsstellung zur TAVI war in den 4 Fällen der multimorbiden Patientinnen gerechtfertigt. Die Komplikationen waren sehr unterschiedlich und die Gefäßverletzungen in 2 Fällen aufgrund der begonnenen Operationen nicht mehr zu prüfen. Schlussfolgerungen Die Versorgung einer Komplikation ist beim indikationsgerechten Patientenkollektiv aufgrund der Multimorbidität extrem schwierig und mit zahlreichen weiteren Komplikationen behaftet. Schlüsselwörter Herzklappenerkrankungen – Herzklappenprothese – Minimalinvasive Verfahren – Behandlungsfehler – Inoperabilität

Long-Term Clinical and Imaging Follow-Up After Reinforced Pulmonary Autograft Ross Procedure.

The Ross operation remains a controversially discussed procedure when performed in the full root technique because concern exists regarding late dilatation of the pulmonary autograft and regurgitation of the neo-aortic valve. In 2008, we published our short-term experience when using external reinforcement of the autograft, which was inserted into a prosthetic Dacron graft. This detail was thought to prevent neoaortic root dilatation. Since 2006, 22 adult patients have undergone a Ross procedure using this technique. Indications were aortic regurgitation (n = 2), aortic stenosis (n = 15), and combined aortic stenosis and insufficiency (n = 5). A bicuspid aortic valve was present in 10 patients. Prior balloon valvuloplasty had been performed in seven patients. No early or late deaths occurred in this small series. One patient required aortic valve replacement early postoperatively, but freedom from late reoperation is 100% in the 21 remaining patients. Echocardiography confirmed the absence of more than trivial aortic insufficiency in 15 patients after a mean of 70 months (range, 14 to 108 months). No autograft dilatation was observed during follow-up and all patients are in New York Heart Association Class I. Autograft reinforcement is a simple and reproducible technical adjunct that may be especially useful in situations known for late autograft dilatation, namely, bicuspid aortic valve, predominant aortic insufficiency, and ascending aortic enlargement. The mid- to long-term results are encouraging because no late aortic root enlargement has been observed and the autograft valve is well functioning in all cases.

Correlation of Calcification on Excised Aortic Valves by Micro-Computed Tomography with Severity of Aortic Stenosis

Background and aim of the study: The quantification of incidentally found aortic valve calcification on computed tomography (CT) is not performed routinely, as data relating to the accuracy of aortic valve calcium for estimating the severity of aortic stenosis (AS) is neither consistent nor validated. As aortic valve calcium quantification by CT is confounded by wall and coronary ostial calcification, as well as motion artifact, the ex-vivo micro-computed tomography (micro-CT) of stenotic aortic valves allows a precise measurement of the amounts of calcium present. The study aim, using excised aortic valves from patients with confirmed AS, was to determine if the amount of calcium on micro-CT correlated with the severity of AS. Methods: Each of 35 aortic valves that had been excised from patients during surgical valve replacement were examined using micro-CT imaging. The amount of calcium present was determined by absolute and proportional values of calcium volume in the specimen. Subsequently, the correlation between calcium volume and preoperative mean aortic valve gradient (MAVG), peak transaortic velocity (V-max), and aortic valve area (AVA) on echocardiography, was evaluated. Results: The mean calcium volume across all valves was 603.2 +/- 398.5 mm(3), and the mean ratio of calcium volume to total valve volume was 0.36 +/- 0.16. The mean aortic valve gradient correlated positively with both calcium volume and ratio (r = 0.72, p <0.001). V-max also correlated positively with the calcium volume and ratio (r = 0.69 and 0.76 respectively; p <0.001). A logarithmic curvilinear model proved to be the best fit to the correlation. A calcium volume of 480 mm(3) showed sensitivity and specificity of 0.76 and 0.83, respectively, for a diagnosis of severe AS, while a calcium ratio of 0.37 yielded sensitivity and specificity of 0.82 and 0.94, respectively. Conclusion: A radiological estimation of calcium amount by volume, and its proportion to the total valve volume, were shown to serve as good predictive parameters for severe AS. An estimation of the calcium volume may serve as a complementary measure for determining the severity of AS when aortic valve calcification is identified on CT imaging. The Journal of Heart Valve Disease 2012;21:320-327

Aortic and Tricuspid Endocarditis in Hemodialysis Patient with Systemic and Pulmonary Embolism

This is a case report of a 43-year-old Caucasian male with end-stage renal disease being treated with hemodialysis and infective endocarditis in the aortic and tricuspid valves. The clinical presentation was dominated by neurologic impairment with cerebral embolism and hemorrhagic components. A thoracoabdominal computerized tomography scan revealed septic pulmonary embolus. The patient underwent empirical antibiotherapy with ceftriaxone, gentamicin and vancomycin, and the therapy was changed to flucloxacilin and gentamicin after the isolation of S. aureus in blood cultures. The multidisciplinary team determined that the patient should undergo valve replacement after the stabilization of the intracranial hemorrhage; however, on the 8th day of hospitalization, the patient entered cardiac arrest due to a massive septic pulmonary embolism and died. Despite the risk of aggravation of the hemorrhagic cerebral lesion, early surgical intervention should be considered in high-risk patients.