Ina Carolin Ennker

Aortic valve replacement in octogenarians: identification of high-risk patients §

OBJECTIVE This study identifies high-risk octogenarians for surgical aortic valve replacement (AVR) because with the current advances in transcatheter valve therapy, a definition of patient selection criteria is essential. METHODS Between 1996 and 2006, 493 consecutive octogenarians with symptomatic aortic stenosis underwent AVR with and without (51%) concomitant coronary artery bypass grafting (CABG). To identify high-risk patient groups, risk factors of 6-month mortality were determined using multivariable logistic regression. RESULTS The 30-day mortality rate was 8.4% and it increased up to 15.2% until 6 months after AVR. Independent risk factors of 6-month mortality were patients older than 84 years (odds ratio (OR): 2.2 (1.29-3.61)), left ventricular ejection fraction <60% (OR: 2.5 (1.35-4.61)), body mass index (BMI) <24 (OR: 2.0 (1.22-3.36)), creatinine (OR: 1.6 (1.04-2.53)) and blood glucose (OR: 1.01 (1.001-1.009)). High-risk groups were patients older than 84 years with an ejection fraction <60% (6-month mortality 28%) and patients younger than 84 years with an ejection fraction <60% and a BMI <24 (6-month mortality 23.2%). These high-risk groups comprised 37% of the patient population. After isolated AVR, the 30-day mortality and survival at 1 and 5 years was 11.6%, 69% and 35% in this high-risk group, respectively. In octogenarians with an STS score >10 and an EuroScore >20, the 30-day mortality and survival at 1 year was 10.5% and 80%, 11.6% and 77%, respectively. CONCLUSIONS In most octogenarians, AVR is a safe and beneficial procedure. In high-risk octogenarians, identified by STS score >10, EuroScore >20 and by simple three risk factors (age >84 years, ejection fraction <60% and BMI <24), the mortality after surgical AVR was no different from the currently reported outcome after transcatheter AVI.

Impact of valve prosthesis-patient mismatch estimated by echocardiographic-determined effective orifice area on long-term outcome after aortic valve replacement

BACKGROUND The impact of valve prosthesis-patient mismatch on long-term outcome after aortic valve replacement estimated by various variables such as projected indexed effective orifice area and internal geometric orifice area obtained from in vivo or in vitro published data is still controversial. METHODS The effective orifice area was measured by echocardiography in 533 patients. The mean age of the patients was 71 +/- 9 years; mean follow-up time was 4.7 +/- 2.2 years. The impact of severe (indexed effective orifice area <or=0.6 cm(2)/m(2)) and moderate mismatch (0.6 cm(2)/m(2) < indexed effective orifice area <or=0.85 cm(2)/m(2)) on survival was evaluated by Cox regression. RESULTS Severe mismatch (hazard ratio: 1.9 [1.08-3.21]) was a significant predictor of survival time after adjustment for age, left ventricular ejection fraction, atrial fibrillation, New York Heart Association class, serum creatinine, and hemoglobin level. The 5- and 7-year survival rates were 71% +/- 4% and 54% +/- 8% for patients with severe mismatch and 83% +/- 4% and 80% +/- 8% for patients with mild mismatch, respectively. The correlation between projected and measured indexed effective orifice area was of medium strength (r = 0.49), and the frequency of observed mismatch depended linearly on the projected indexed effective orifice area. Although projected indexed effective orifice area and indexed internal geometric orifice area were significant predictors of severe mismatch, the sensitivity and specificity for severe prosthesis-patient mismatch were only 75% and 52%, using an optimal threshold of projected indexed effective orifice area defined by the Youden index. CONCLUSIONS Severe prosthesis-patient mismatch estimated by effective orifice area measured within 10 days was an independent risk factor of survival time. Projected indexed effective orifice area determined at surgery does not sufficiently predict mismatch.

The impact of gelatin-resorcinol glue on aortic tissue: A histomorphologic evaluation

PURPOSE Although gelatin-resorcinol-formaldehyde glue has been used to treat acute aortic dissections for some time, concerns about formaldehydes mutagenicity and carcinogenicity made it imperative to develop a new glue compound. Gelatin-dialdehyde glue was produced by omitting the formaldehyde component and replacing it with two less toxic aldehydes, glutaraldehyde and glyoxal. This study evaluated the histomorphologic effects of the new glue through in vivo use on the aortic tissue of domestic pigs. METHODS Each animals infrarenal aorta was glued around an implanted prosthesis. Histomorphologic evaluation was performed after operation after 1 and 4 weeks. RESULTS The results demonstrated that the clinically observed tanning effect can be attributed primarily to the disintegration of the fiber texture, specifically collagenous, as well as smooth muscle fibers, and to the reciprocal alterations of the proteoglycan interstitial substance in the aortic wall. Macroscopic, microscopic, and electron microscopic analysis of the gluing process revealed an adequate healing process without any morphologically significant difference between formaldehyde and formaldehyde-free gelatin-resorcinol glue. CONCLUSIONS Gelatin-dialdehyde glue is able to produce the same effects in the area of the aortic wall as the substantially more toxic gelatin-resorcinol-formaldehyde glue and thus could be recommended for clinical trials for treating acute aortic dissections thus far yielding excellent initial results.

Formaldehyde-free collagen glue in experimental lung gluing

Because of the well-known limitations of the adhesive strength of fibrin glue, it is imperative to develop a stronger glue with acceptable biocompatibility. This was accomplished by removing the formaldehyde component from gelatin-resorcinol-formaldehyde glue and replacing it by two less toxic aldehydes--pentanedial and ethanedial. To evaluate the adhesive strength of this new glue, GR-DIAL, lung incisions in rabbit hybrids were glued together. Each group (n = 5) was examined histologically after 2 days and 1, 2, and 4 weeks. The glue disintegrated gradually with good bioresorption when the incision was closed with a thin layer of glue. The healing process was favorable, indicating good biocompatibility. Therefore, GR-DIAL glue is capable of enhancing the use of surgical glues in the field of thoracic surgery by enabling surgeons to close larger parenchymal lesions than with fibrin glue.

Impact of Gender on Outcome After Coronary Artery Bypass Surgery

Following recent studies concerning the increased risk of coronary artery bypass surgery for women, the impact of sex is still a controversial issue. Between 1996 and 2006, 9,527 men and 3,079 women underwent isolated coronary artery bypass in our institute. To adjust for dissimilarities in preoperative risk profiles, propensity score-based matching was applied. Before adjustment, clinical outcomes in terms of operative mortality, arrhythmias, intensive care unit stay, and maximum creatine kinase-MB levels were significantly different for men and women. After balancing the preoperative characteristics, including height, no significant differences in clinical outcomes were observed. However, there was decreased use of internal mammary artery, less total arterial revascularization, and increasing creatine kinase-MB levels with decreasing height. This study supports the theory that female sex per se does not increase operative risk, but shorter height, which is more common in women, affects the outcome, probably due to technical difficulties in shorter patients with smaller internal mammary arteries and coronary vessels. Thus women may especially benefit from sequential arterial grafting.

Ten-Year Experience With Stentless Aortic Valves: Full-Root Versus Subcoronary Implantation

BACKGROUND We compared the midterm outcome after aortic valve replacement with the Freestyle stentless bioprosthesis for the full-root or subcoronary implantation technique, while adjusting for patient and disease characteristics by a propensity score. METHODS Between 1996 and 2005, 1,014 patients underwent aortic valve replacement with the stentless Medtronic Freestyle bioprosthesis, 168 using full-root technique. Based on a saturated propensity score, 148 matched pairs were created. Mean age of the 296 patients was 73 +/- 3 years. Mean follow-up time was 32 +/- 30 months (maximum, 116 months). RESULTS Operative mortality was 4.7% and 2.7% (p = 0.36) in the full-root and subcoronary groups, respectively. Freedom from reoperation, prosthetic valve endocarditis, major bleeding, and thromboembolism after 9 years was 98% +/- 1% and 90% +/- 7% (p = 0.38), 95% +/- 3% and 92% +/- 7% (p = 0.76), 72% +/- 21% and 98% +/- 2% (p = 0.12), and 75% +/- 8% and 84% +/- 7% (p = 0.28), for full-root and subcoronary groups, respectively. Survival rates after 9 years were 34% +/- 24% and 33% +/- 11% (p = 0.46), for the full-root and subcoronary groups, respectively. Patients in the full-root group received larger valve sizes (p = 0.03), and the mean transprosthetic gradients at discharge were significantly lower for each valve size. Nevertheless, during follow-up, peak gradients decreased to a greater extent in patients presenting high peak gradients (>36 mm Hg) at discharge. CONCLUSIONS As risk-adjusted comparison of both implantation techniques did not reveal any differences regarding operative and midterm outcomes, full-root replacement can be liberally performed in patients with small aortic roots, annuloaortic ectasia, or requiring replacement of ascending aorta.

Kurz- und Langzeitergebnisse des Aortenklappenersatzes bei 80- und über 80-Jährigen

Hintergrund: Das durchschnittliche Alter der am Herzen operierten Patienten nimmt mit zunehmenden Anteil älterer Menschen an der Gesamtbevölkerung zu. Wir haben in unserem Patientengut die Kurz- und Langzeitergebnisse des isolierten oder mit koronarer Bypassoperation kombinierten Aortenklappenersatzes in der neunten Lebensdekade untersucht. Patienten und Methode: Zwischen dem 1.1.1995 und dem 31.12.1999 wurden 126 Patienten (93 Frauen, 33 Männer, 80–89 Jahre alt, 82,8 ± 2,4 Jahre) einem Aortenklappenersatz unterzogen. Bei 64 Patienten wurde ein isolierter Klappenersatz vorgenommen (Gruppe A), 62 erhielten zusätzlich eine Myokardrevaskularisation (Gruppe B). Ergebnisse: Die 30-Tage-Letalität betrug bei isoliertem Klappenersatz 6,3% und bei Kombinationseingriffen 14,5%. Die Nachbeobachtungszeit lag zwischen 3 und 63 Monaten (32 ± 16). Reoperationen wegen Prothesendysfunktion oder -endokarditis wurden nicht beobachtet. Nur ein Patient aus der Gruppe A hatte nach 3 Jahren eine Blutungskomplikation aufgrund der Therapie mit Phenprocoumon. Von den 15 Todesfällen während der Nachbeobachtungsphase waren sieben (47%) kardial bedingt und zwei (13%) Folge eines Schlaganfalls. Die Überlebensrate betrug bei Patienten der Gruppe A nach 1 Jahr 89%, nach 2 Jahren 85% und nach 3 Jahren 77%. Für die Gruppe B waren die entsprechenden Zahlen 76%, 72% und 70%. Die Freiheitsrate von Pflegebedürftigkeit war beim isolierten Aortenklappenersatz nach 1 Jahr 100%, nach 2 Jahren 98%, nach 3 Jahren 95% und bei Kombinationseingriffen 100%, 93% und 90%. Die Freiheitsrate von erneuten kardialen Beschwerden (Angina pectoris, Dyspnoe) war in der Gruppe A nach 1 Jahr 93%, nach 2 Jahren 91%, nach 3 Jahren 85% und in der Gruppe B 84%, 77% sowie 71%. Die Freiheitsrate von erneuter stationärer Behandlung aus kardialen Gründen war in der Gruppe A nach 1 Jahr 96%, nach 2 Jahren 96%, nach 3 Jahren 94% und in der Gruppe B 88%, 81% sowie 75%. Schlussfolgerung: Der Aortenklappenersatz ist bei Patienten in der neunten Lebensdekade im Vergleich zu jüngeren Patienten mit einer deutlich erhöhten Letalität und Morbidität verbunden. Berücksichtigt man jedoch die schlechte Prognose der konservativen Therapie klinisch manifester Aortenvitien, so weisen unsere Daten darauf hin, dass auch im hohen Alter der funktionelle Status und die Lebenserwartung durch den Klappenersatz positiv beeinflusst werden können.Background: Due to demographic changes in average life expectancy the age of patients undergoing cardiac surgery is increasing as well. We have reviewed the short- and long-term outcome in patients over 80 years of age after aortic valve replacement with or without concomitant coronary grafting. Patients and Methods: From 1.1.1995 until 31.12.1999, 126 patients (93 women, 33 men between 80 and 89 years, 82.8 ± 2.4) underwent aortic valve replacement. 64 patients (group A) received isolated valve replacement, 62 (group B) underwent myocardial revascularization as well. Results: The 30-day hospital mortality rate was 6.3% for group A and 14.5% for group B. The follow-up time ranged between 3 and 63 months (32 ± 16). None of the patients had to be reoperated for prosthetic valve dysfunction or endocarditis. Bleeding complications due to anticoagulation therapy were observed by one patient from group A 3 years after the operation. Of the 15 deaths during the follow-up period seven (47%) were cardiac in nature and two (13%) related to stroke. Actuarial survival rates for group A were 89%, 85% and 77% at 1, 2 and 3 years, and for group B 76%, 72% and 70%. Permanent nursing care was not required 1 year after the operation by 100% of patients in group A (2 years: 98%, 3 years 95%) and by 100% of patients in group B (2 years: 93%, 3 years: 90%). At an interval of 1 year after the operation 96% of patients in group A had not been hospitalized as a result of cardiac disorders (2 years: 96%, 3 years: 94%). The rates for group B were 88%, 81% and 75%. Conclusion: Compared with younger age groups, aortic valve replacements in patients 80 years of age and older is associated with a distinctly increased mortality and morbidity. However, our data suggest that considering the poor prognosis of conservative therapy of symptomatic aortic valve disease, functional status as well as life expectancy in this age group seem to be positively influenced by aortic valve replacement.

Effect of surgeon on transprosthetic gradients after aortic valve replacement with Freestyle® stentless bioprosthesis and its consequences: A follow-up study in 587 patients

BackgroundThe implantation of stentless valves is technically demanding and the outcome may depend on the performance of surgeons. We studied systematically the role of surgeons and other possible determinants for mid-term survival, postoperative gradients and Quality of Life (QoL) after aortic valve replacement (AVR) with Freestyle® stentless bioprostheses.MethodsBetween 1996 and 2003, 587 patients (mean 75 years) underwent AVR with stentless Medtronic Freestyle® bioprostheses. Follow-up was 99% complete. Determinants of morbidity, mortality, survival time and QoL were evaluated by multiple, time-related, regression analysis. Risk models were built for all sections of the Nottingham Health Profile (NHP): energy, pain, emotional reaction, sleep, social isolation and physical mobilityResultsActuarial freedom from aortic valve re-operation, structural valve deterioration, non-structural valve dysfunction, prosthetic valve endocarditis and thromboembolic events at 6 years were 95.9 ± 2.1%, 100%, 98.7 ± 0.5%, 97.0 ± 1.5%, 79.6 ± 4.3%, respectively. The actuarial freedom from bleeding events at 6 years was 93.1 ± 1.9%. Estimated survival at 6 years was similar to the age-matched German population (61.4 ± 3.8 %). Predictors of survival time were: diabetes mellitus, atrial fibrillation, peripheral vascular disease, renal dysfunction, female gender > 80 years and patients < 165 cm with BMI < 24. Predictive models showed characteristic profiles and good discriminative powers (c-indexes > 0.7) for each of the 6 QoL sections. Early transvalvular gradients were identified as independent risk factors for impaired physical mobility (c-index 0.77, p < 0.002). A saturated propensity score identified besides patient related factors (e.g. preoperative gradients, ejection fraction, haematological factors) indexed geometric orifice area, subcoronary implantation technique and individual surgeons as predictors of high gradients.ConclusionIn addition to the valve size (in relation to body size), subcoronary technique (versus total root) and various patient-related factors the risk of elevated gradients after stentless valve implantation depends, considerably on the individual surgeon.Although there was no effect on survival time and most aspects of QoL, higher postoperative transvalvular gradients affect physical mobility after AVR.

Midterm outcome after aortic root replacement with stentless porcine bioprostheses

OBJECTIVE Midterm clinical outcome was evaluated after aortic root replacement with Freestyle® stentless aortic root bioprostheses. METHODS Between April 1996 and December 2007, 301 patients underwent aortic valve replacement with stentless Medtronic Freestyle® bioprostheses in full-root technique at a single center. Concomitant coronary artery bypass grafting (CABG) was required in 96 patients (32%). In 94 patients (31%), the ascending aorta was replaced. The mean age was 71.6 ± 9.1 (range: 36-89) years. Follow-up was closed in October 2008, 99% complete and encompassed 916 patient-years. RESULTS Overall mortality within 30 days was 5%. A total of 62 patients died during the follow-up period. Overall survival at 5 and 9 years was 74 ± 4% and 53 ± 6%, respectively. Re-operations were required in three patients: in one patient due to structural valve deterioration, and in two patients due to prosthetic valve endocarditis. Non-structural dysfunctions were not observed. In eight patients, prosthetic valve endocarditis occurred, in most of them (N = 6) during the first year after surgery. Rate of freedom from re-operation, structural valve deterioration, prosthetic valve endocarditis, thrombo-embolic and major bleeding events at 9 years was 94 ± 6%, 94 ± 6%, 94 ± 3%, 87 ± 5%, and 95 ± 2%, respectively. The linearized rates of late adverse events in percent per patient-year were 0.35, 0.12, 0.83, 1.7, and 0.7, respectively, for re-operation, structural valve deterioration, prosthetic valve endocarditis, thrombo-embolic and major bleeding events. A little less than a quarter (22%) of the patients required anticoagulation therapy. CONCLUSIONS Aortic root replacement with the stentless Freestyle® bioprosthesis provided a respectable short-term mortality, optimal valve durability and acceptable rates of valve-related complications within 9 years.

Short term outcomes of total arterial coronary revascularization in patients above 65 years: a propensity score analysis

BackgroundDespite the advantages of bilateral mammary coronary revascularization, many surgeons are still restricting this technique to the young patients. The objective of this study is to demonstrate the safety and potential advantages of bilateral mammary coronary revascularization in patients older than 65 years.MethodsGroup I included 415 patients older than 65 years with exclusively bilateral mammary revascularization. Using a propensity score we selected 389 patients (group II) in whom coronary bypass operations were performed using the left internal mammary artery and the great saphenous vein.ResultsThe incidence of postoperative stroke was higher in group II (1.5% vs. 0%, P = 0.0111). The amount of postoperative blood loss was higher in group I (908 ± 757 ml vs. 800 ± 713 ml, P = 0.0405). There were no other postoperative differences between both groups.ConclusionBilateral internal mammary artery revascularization can be safely performed in patients older than 65 years. T-graft configuration without aortic anastomosis is particularly beneficial in this age group since it avoids aortic manipulation, which is an important risk factor for postoperative stroke.