Christian Schreiber

Improvements in Transcatheter Aortic Valve Implantation Outcomes in Lower Surgical Risk Patients : A Glimpse Into the Future

OBJECTIVES The purpose of this study was to investigate the evolution of patient selection criteria for transcatheter aortic valve implantation (TAVI) and its impact on clinical outcomes. BACKGROUND Anecdotal evidence suggests that patient selection for TAVI is shifting toward lower surgical risk patients. The extent of this shift and its impact on clinical outcomes, however, are currently unknown. METHODS We conducted a single-center study that subcategorized TAVI patients into quartiles (Q1 to Q4) defined by enrollment date. These subgroups were subsequently examined for differences in baseline characteristics and 30-day and 6-month mortality rate. The relationship between quartiles and mortality rate was examined using unadjusted and adjusted (for baseline characteristics) Cox proportional hazard models. RESULTS Each quartile included 105 patients (n = 420). Compared with Q4 patients, Q1 patients had higher logistic EuroSCORES (25.4 ± 16.1% vs. 17.8 ± 12.0%, p < 0.001), higher Society of Thoracic Surgeons scores (7.1 ± 5.5% vs. 4.8 ± 2.6%, p > 0.001), and higher median N-terminal pro-B-type natriuretic peptide levels (3,495 vs. 1,730 ng/dl, p < 0.046). From Q1 to Q4, the crude 30-day and 6-month mortality rate decreased significantly from 11.4% to 3.8% (unadjusted hazard ratio [HR]: 0.33; 95% confidence interval [CI]: 0.11 to 1.01; p = 0.053) and from 23.5% to 12.4% (unadjusted HR: 0.49; 95 CI: 0.25 to 0.95; p = 0.07), respectively. After adjustment for baseline characteristics, there were no significant differences between Q1 and Q4 in 30-day mortality rate (adjusted HR ratio: 0.29; 95% CI: 0.08 to 1.08; p = 0.07) and 6-month mortality rate (HR: 0.67; 95% CI: 0.25 to 1.77; p = 0.42). CONCLUSIONS The results of this study demonstrate an important paradigm shift toward the selection of lower surgical risk patients for TAVI. Significantly better clinical outcomes can be expected in lower than in higher surgical risk patients undergoing TAVI.

Transcatheter aortic valve implantation for failing surgical aortic bioprosthetic valve: from concept to clinical application and evaluation (part 1).

With an aging population, improvement in life expectancy, and significant increase in the use of bioprosthetic valves, structural valve deterioration will become more and more prevalent. The operative mortality for an elective redo aortic valve surgery is reported to range from 2% to 7%, but this percentage can increase to more than 30% in high-risk and nonelective patients. Because transcatheter aortic valve (TAV)-in-surgical aortic valve (SAV) implantation represents a minimally invasive alternative to conventional redo surgery, it may prove to be safer and just as effective as redo surgery. Of course, prospective comparisons with a large number of patients and long-term follow-up are required to confirm these potential advantages. It is axiomatic that knowledge of the basic construction and dimensions, radiographic identification, and potential failure modes of SAV bioprostheses is fundamental in understanding key principles involved in TAV-in-SAV implantation. The goals of this paper are: 1) to review the classification, physical characteristics, and potential failure modes of surgical bioprosthetic aortic valves; and 2) to discuss patient selection and procedural techniques relevant to TAV-in-SAV implantation.

Results of percutaneous and transapical transcatheter aortic valve implantation performed by a surgical team.

OBJECTIVE Transcatheter aortic valve implantation has been performed by several groups, most of them either specializing on the transapical (surgeons) or the percutaneous femoral transarterial approach (cardiologists). We achieved both transapical and percutaneous transcatheter valve implantation by a surgical team in a hybrid suite. METHODS Since June 2007, 137 patients (n=78 female, mean age 81+/-7 years) underwent transcatheter aortic valve implantation (n=109 transfemoral, n=3 via subclavian artery, n=2 directly through ascending aorta, n=23 transapical) with the CoreValve (n=114) or the Edwards Sapien (n=23) prosthesis. RESULTS Thirty-day mortality was 12.4% in this patient cohort. One hundred and eight patients (78.8%) are alive at a mean follow-up of 97+/-82 days. Pacemaker implantation due to postoperative AV block was performed in 27 patients (19.7%), and 7 patients (5.1%) sustained neurological events. Patients improved in NYHA class (from 3.1+/-0.3 to 1.9+/-0.5, p<0.001) and in self-assessed health state (from 55+/-17% to 68+/-16%, p<0.001) at one-month follow-up. Echocardiographic assessment revealed excellent hemodynamic function of the prostheses with a mean aortic gradient (MAG) of 11.9+/-4.4 mmHg and an effective orifice area (EOA) of 1.6+/-0.4 cm(2) at discharge and a MAG of 11.0+/-4.2 mmHg and an EOA of 1.6+/-0.3 cm(2) at six months FU. CONCLUSIONS Transcatheter aortic valve implantation has become an alternative technique for the treatment of aortic stenosis with reasonable short- and mid-term results at our institution. With the opportunity to treat aortic stenosis by conventional surgical valve replacement and transapical and percutaneous transcatheter procedures, the technique of lowest risk for the individual patient can be chosen and performed by one team.

Platelets contribute to postnatal occlusion of the ductus arteriosus

The ductus arteriosus (DA) is a fetal shunt vessel between the pulmonary artery and the aorta that closes promptly after birth. Failure of postnatal DA closure is a major cause of morbidity and mortality particularly in preterm neonates. The events leading to DA closure are incompletely understood. Here we show that platelets have an essential role in DA closure. Using intravital microscopy of neonatal mice, we observed that platelets are recruited to the luminal aspect of the DA during closure. DA closure is impaired in neonates with malfunctioning platelet adhesion or aggregation or with defective platelet biogenesis. Defective DA closure resulted in a left-to-right shunt with increased pulmonary perfusion, pulmonary vascular remodeling and right ventricular hypertrophy. Our findings indicate that platelets are crucial for DA closure by promoting thrombotic sealing of the constricted DA and by supporting luminal remodeling. A retrospective clinical study revealed that thrombocytopenia is an independent predictor for failure of DA closure in preterm human newborns, indicating that platelets are likely to contribute to DA closure in humans.

Transcatheter Aortic Valve Implantation through the Ascending Aorta: An Alternative Option for No-Access Patients

Retrograde transcatheter aortic valve implantation (TAVI) was successfully performed in an 80-year-old woman who had critical aortic stenosis but had no conventional access available because of severe calcifications of the femoral, iliac, and subclavian arteries. The TAVI procedure was performed with the CoreValve ReValving System. The currently available results obtained with TAVI show that such approaches provide significant clinical improvement in patients with severe aortic stenosis and unacceptable risk or contraindications for surgery. The ascending aorta approach might help to expand the implantation possibilities for those patients for whom the typical access sites are not available.

First successful aortic valve implantation with the CoreValve ReValving System via right subclavian artery access: a case report.

We successfully implanted a bioprosthetic aortic valve via the right subclavian artery within the framework of the CoreValve transapical aortic valve replacement (TAVR) ReValving (CoreValve, Irvine, CA, USA) clinical trial on November 20, 2007, at the Clinic for Cardiovascular Surgery at the German Heart Center Munich, Technical University Munich. The self-expanding aortic valve prosthesis is primarily designed for retrograde delivery across the aortic valve. The described approach via the right subclavian artery was performed because of severe peripheral vascular disease of the femoral and iliac arteries, as well as the left subclavian artery, and because a transapical delivery system was not available at the time of surgery.

Exercise capacity, quality of life, and daily activity in the long-term follow-up of patients with univentricular heart and total cavopulmonary connection.

AIMS Patients with congenital heart disease usually show diminished exercise capacity and quality of life. However, there is only little information about daily activity, a marker for lifestyle, exercise capacity, and the prevention of arteriosclerosis. This study investigated exercise capacity, quality of life, daily activity, and their interaction with univentricular heart physiology after total cavopulmonary connection (TCPC). METHODS AND RESULTS Fifty-seven patients (18 females, 39 males, age 8-52 years) after TCPC (lateral tunnel 28, extra-cardiac conduit 29) who underwent surgery during 1994-2001 were examined in our institution. They performed a symptom-limited cardiopulmonary exercise test. Those patients 14 years of age and older filled in the health-related quality-of-life questionnaire SF-36, and those who were 8-13 years of age, the CF-87. Daily activity parameters were obtained by using a triaxial accelerometer over the next three consecutive days. Exercise capacity was severely reduced after TCPC (25.0 mL/min/kg corresponding to 59.7% of age- and sex-related reference values). Daily activity was within the recommendations of the United Kingdom Expert Consensus Group (> or =60 min, > or =3 metabolic equivalent, > or =5 days/week) in 72% of the investigated patients. It was reduced in older patients (Spearman r = - 0.506, P < 0.001) and patients with a lower peak oxygen uptake (Spearman r = 0.432, P = 0.001). In children <14 years, mental health was related to daily activity. CONCLUSION Despite their diminished exercise capacity, patients after TCPC show a fairly normal activity pattern. However, their activity depends not only on age, but also on exercise capacity, which, in contrast to healthy people, decreases already from early adolescence on.

Scimitar Syndrome A European Congenital Heart Surgeons Association (ECHSA) Multicentric Study

Background— Scimitar syndrome is a rare congenital heart disease. To evaluate the surgical results, we embarked on the European Congenital Heart Surgeons Association (ECHSA) multicentric study. Methods and Results— From January 1997 to December 2007, we collected data on 68 patients who underwent surgery for scimitar syndrome. Primary outcomes included hospital mortality and the efficacy of repair at follow-up. Median age at surgery was 1.4 years (interquartile range, 0.46 to 7.92 years). Forty-four patients (64%) presented with symptoms. Surgical repair included intraatrial baffle in 38 patients (56%; group 1) and reimplantation of the scimitar vein onto the left atrium in 21 patients (31%; group 2). Eight patients underwent right pneumectomy, and 1 had a right lower lobe lobectomy (group 3). Four patients died in hospital (5.9%; 1 patient in group 1, 2.6%; 3 patients in group 3, 33%). Median follow-up time was 4.5 years. There were 2 late deaths (3.1%) resulting from severe pulmonary arterial hypertension. Freedom from scimitar drainage stenosis at 13 years was 83.8% in group 1 and 85.8% in group 2. Four patients in group 1 were reoperated, and 3 patients (2 in group 1 [6%] and 1 in group 2 [4.8%]) required balloon dilation/stenting for scimitar drainage stenosis. Conclusions— The surgical treatment of this rare syndrome is safe and effective. The majority of patients were asymptomatic at the follow-up control. There were a relatively high incidence of residual scimitar drainage stenosis that is similar between the 2 reported corrective surgical techniques used. # Clinical Perspective {#article-title-44}Background— Scimitar syndrome is a rare congenital heart disease. To evaluate the surgical results, we embarked on the European Congenital Heart Surgeons Association (ECHSA) multicentric study. Methods and Results— From January 1997 to December 2007, we collected data on 68 patients who underwent surgery for scimitar syndrome. Primary outcomes included hospital mortality and the efficacy of repair at follow-up. Median age at surgery was 1.4 years (interquartile range, 0.46 to 7.92 years). Forty-four patients (64%) presented with symptoms. Surgical repair included intraatrial baffle in 38 patients (56%; group 1) and reimplantation of the scimitar vein onto the left atrium in 21 patients (31%; group 2). Eight patients underwent right pneumectomy, and 1 had a right lower lobe lobectomy (group 3). Four patients died in hospital (5.9%; 1 patient in group 1, 2.6%; 3 patients in group 3, 33%). Median follow-up time was 4.5 years. There were 2 late deaths (3.1%) resulting from severe pulmonary arterial hypertension. Freedom from scimitar drainage stenosis at 13 years was 83.8% in group 1 and 85.8% in group 2. Four patients in group 1 were reoperated, and 3 patients (2 in group 1 [6%] and 1 in group 2 [4.8%]) required balloon dilation/stenting for scimitar drainage stenosis. Conclusions— The surgical treatment of this rare syndrome is safe and effective. The majority of patients were asymptomatic at the follow-up control. There were a relatively high incidence of residual scimitar drainage stenosis that is similar between the 2 reported corrective surgical techniques used.

The blood sparing effect and the safety of aprotinin compared to tranexamic acid in paediatric cardiac surgery.

OBJECTIVE Recently, the safety of aprotinin administration during open-heart surgery has been debated. The aim of the study was to compare the blood sparing effect and the side effects of aprotinin and tranexamic acid in paediatric cardiac surgery patients. METHODS Perioperative data of 199 consecutive patients weighing less than 20kg undergoing open-heart cardiac surgery were prospectively collected between September 2005 and June 2006. During the first 5 months, 85 patients received aprotinin (group A); in the next 5 months, 114 patients were treated with tranexamic acid (group T). Except for antifibrinolytic therapy, the anaesthesiological and surgical protocols remained unchanged. Postoperative complications and in-hospital and 1-year mortality were considered as outcome parameters. RESULTS The descriptive parameters and the intraoperative parameters were well comparable in the two groups. The blood loss was significantly lower in group A compared to group T at 6h [55 (35-82.5) vs 70 (45-100)ml, p=0.031], but not at 12 and 24h after operation. The incidence [9 (11%) vs 25 (22%), p=0.035] and the amount of red blood cell transfusion during the first 24h after surgery were also significantly lower in group A (0.1+/-0.4 vs 0.3+/-0.6 unit, p=0.036). There were significantly less rethoracotomies in group A [2 (2.4%) vs 11 (9.6%), p=0.039]. We found no difference in the incidence of the postoperative complications and in-hospital and 1-year mortality. There was a tendency for a higher incidence of seizures in group T [4 (3.5%) vs 0 (0%), p=0.14]. CONCLUSIONS Aprotinin administration bears no additional risks compared to tranexamic acid and it has a stronger blood sparing effect in paediatric cardiac surgery. There were fewer rethoracotomies and less postoperative red blood cell transfusion in patients who received aprotinin.

Quality of life among patients undergoing transcatheter aortic valve implantation

BACKGROUND Transcatheter aortic valve implantation (TAVI) has been introduced to offer a new treatment option for patients who are not eligible for conventional aortic valve replacement. Especially in this subset of patients, the expected improvement of quality of life (QoL) after valve implantation will be critical for decision-making for TAVI. METHODS We performed a prospective analysis of 99 patients (41 male) aged 82 years (range 57-94 years) who underwent TAVI. For assessment of QoL, the Short Form 36 Health Survey Questionnaire was used preoperatively and 3 months after TAVI. RESULTS Thirty-day mortality rate was 10.1%. The Short Form 36 Health Survey Questionnaire scores for physical functioning (34.7 +/- 2.8 vs 48.5 +/- 3.4, P < .001), bodily pain (61.7 +/- 3.1 vs 73.2 +/- 2.9, P < .01), general health (47.1 +/- 1.9 vs 54.1 +/- 2.3, P < .01), and vitality (37 +/- 2.8 vs 46.1 +/- 2.7, P < .01) increased significantly 3 months after TAVI compared with preoperative scores. No significant changes were found for role-physical (21.7 +/- 4.1 vs 31.1 +/- 5.1, P < .08), social functioning (74.6 +/- 3.4 vs 74.6 +/- 3.1, P = 1), and mental health (63 +/- 2.9 vs 67.4 +/- 2.2, P = .17) 3 months after TAVI. Only the score for role-emotional (69.3 +/- 5.6 vs 51.7 +/- 6, P = .02) decreased significantly 3 months after TAVI compared with the preoperative score. Corresponding to these results, the physical health summarized score (31.2 +/- 1.2 vs 38.6 +/- 1.6, P < .001) was significantly increased 3 months after TAVI compared with the preoperative score, whereas the mental health summarized score (48.5 +/- 1.8 vs 47.3 +/- 1.7, P = .5) showed no changes. CONCLUSION In patients who are not eligible for conventional aortic valve replacement, TAVI leads to a considerable QoL improvement within 3 months after valve implantation.