Stentless Bioprostheses for Aortic Valve Replacement in Octogenarians: The Influence of Coronary Artery Disease.

BACKGROUND: We sought to determine the long-term results of stentless biological heart valve replacement in octogenarians to find out whether coronary artery disease or the coronary artery bypass grafting (CABG) procedure itself influences survival in these aged patients. METHODS: From 4,012 patients undergoing aortic valve replacement (AVR) with a stentless prosthesis (Freestyle, Medtronic) at a single center, 721 patients were older than 80 years. They had a mean age of 83 ± 2 (2,320 patient years), the male/female ratio was 42:58, NYHA (New York Heart Association) class I and II was prevalent in 22.8%, preoperative atrial fibrillation (AF) in 20.6%, coronary artery disease in 56.1%, mitral valve disease in 12.5%, and aortic disease in 3.5%. Follow-up included a total of 11,546 patient years (mean follow-up time: 74 ± 53 months); follow-up mortality data were 96.3% complete. RESULTS: In these aged patients, 30-day mortality in the isolated AVR group (10.3%) was similar to that in the AVR + CABG group (13.4%). Although long-term survival (15 years) in the octogenarian population is low (9% in the AVR group and 6% in the AVR + CABG group), it was not different (p = 0.191) between patients with and without coronary artery disease. The stroke rate and the myocardial infarction rate, respectively, in the AVR + CABG group (0.43%/100 patient years and 0.17%/100 patient years) were only insignificantly higher than that in the isolated AVR group (each 0.01%/100 patient years). The actuarial freedom from reoperation was 99% in both the groups. CONCLUSION: Use of the Freestyle stentless valve prosthesis for AVR is feasible also in octogenarians. The existence of coronary artery disease leads to concomitant bypass surgery, but not a higher level of perioperative or long-term mortality.

Freestyle stentless bioprosthesis for aortic valve therapy: 17-year clinical results.

BACKGROUND: Aortic valve replacement with stentless bioprostheses has been shown to produce lower aortic gradients than stented bioprostheses, thus facilitating left ventricular mass regression and preventing heart failure. We sought to determine the long-term results of stentless biological aortic valve replacement over a 17-year follow-up. METHODS: Between 1996 and 2012, 2551 patients underwent isolated aortic valve replacement with a stentless prosthesis (Medtronic Freestyle) at a single center. The mean patient age was 72 ± 10 years, 55% were male, 24.1% were in New York Heart Association class I and II, 9.6% had undergone previous surgery, 18.1% had coronary artery disease, and 23.1% had diabetes. For the long-term follow-up, patients were contacted in writing and by telephone; follow-up was 96.3% complete, resulting in 11,546 patient-years. RESULTS: At 30 days, mortality (5.4%), renal failure (3.9%), myocardial infarction (0.7%), and stroke (1.4%) rates were acceptable. During long-term follow-up of 1-17 years, the bleeding rate (2.9%) was higher than the thromboembolic event rate (0.7%) despite 18.1% of patients being on oral anticoagulants. New pacemaker implantation (4.5%; 0.87 events/100 patient-years), neurological disorders (5%; 0.52 events/100 patient-years), valve insufficiency (0.7%; 0.16 events/100 patient-years), paravalvular leakage (0.4%; 0.09 events/100 patient-years) and reoperation due to valvular complications (0.7%; 0.38 events/100 patient-years) were rare. Long-term survival was 41.8% ± 1.6 after 10 years, 21.3% ± 2.3 after 15 years, and 12.1% ± 3.9 after 17 years. CONCLUSION: Long-term results after aortic valve replacement with stentless biological prostheses compare favorably with those obtained with stented bioprostheses.

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.

BACKGROUND: Despite 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. METHODS: Group 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. RESULTS: The 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. CONCLUSION: Bilateral 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.

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.

The concept of negative pressure wound therapy (NPWT) after poststernotomy mediastinitis--a single center experience with 54 patients.

Deep sternal infections, also known as poststernotomy mediastinitis, are a rare but often fatal complication in cardiac surgery. They are a cause of increased morbidity and mortality and have a significant socioeconomic aspect concerning the health system. Negative pressure wound therapy (NPWT) followed by muscular pectoralis plasty is a quite new technique for the treatment of mediastinitis after sternotomy. Although it could be demonstrated that this technique is at least as safe and reliable as other techniques for the therapy of deep sternal infections, complications are not absent. We report about our experiences and complications using this therapy in a set of 54 patients out of 3668 patients undergoing cardiac surgery in our institution between January 2005 and April 2007.

The Freestyle stentless bioprosthesis in more than 1000 patients: a single-center experience over 10 years.

BACKGROUND AND AIM: Early and mid-term clinical outcomes after aortic valve replacement (AVR) with stentless bioprostheses in a large cohort of patients are presented. METHODS: Between April 1996 and November 2005, 1014 patients underwent AVR with the stentless Medtronic Freestyle bioprosthesis, with 168 using the full-root technique. The mean age was 73+/-3 (range: 20 to 90) years. Follow-up included 2953 patient-years and was 95% complete for adverse events. RESULTS: Operative mortality was 3.4% (N=34). Overall survival was 46+/-9% at nine years and similar to age- and gender-matched German general population. Freedom from prosthetic valve endocarditis, major bleeding, neurological events, and reoperation after nine years was 97+/-6%, 92+/-7%, 70+/-16%, and 92+/-9%, respectively. Freedom from structural valve deterioration was 97+/-5% at 9 years. During the learning phase, mean transprosthetic gradients of 23.5+/-3.0 mmHg and 24.8+/-3.1 mmHg were observed for valve sizes 21 and 23 mm, respectively, 10 days after subcoronary implantation in 1997, which could be lowered to 16+/-2.1 mmHg and 14.9+/-0.9 mmHg in 2005, respectively, with increasing experience of the surgeons. During the follow-up period, mean gradients dropped on average by 15 mmHg in patients presenting higher gradients at discharge. CONCLUSIONS: The Freestyle stentless bioprosthesis showed encouraging midterm durability with low rates of valve-related morbidity, and can be safely implanted without increased operative risk even during the learning phase. Special training of the surgeons is recommended to achieve optimal hemodynamic performance.

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.

Current determinants of 30-day and 3-month mortality in over 2000 aortic valve replacements: Impact of routine laboratory parameters.

OBJECTIVE: Haematological and biochemical measurements are performed routinely before surgery to exclude organ malfunction and blood cell and coagulation abnormalities. We aimed to test routinely obtained laboratory data as factors predicting operative risk. METHODS: Between 1996 and 2003, 2198 patients underwent aortic valve replacement (AVR) (908 of them with concomitant CABG) in our institute. The mean age of the study population was 69+/-11 years (range 13-91, 43% female). Clinical and laboratory parameters based on the consolidated data mart set were evaluated by multiple logistic regression analysis. RESULTS: The overall operative mortality (within 30 days) was 3.8% and the mortality after 3 months was 5.9%. In addition to clinical characteristics, the following laboratory values were identified as independent predictors of 30-day mortality: fasting blood glucose, antithrombine III, partial thromboplastine time and creatinine kinase. As independent predictors of 3-month mortality, the following laboratory values were indentified: fasting blood glucose, serum creatinine, antithrombine III, partial thromboplastine time, lactate dehydrogenase, sodium concentration and serum proteins. The discriminative power of the models increased if laboratory parameters were included in addition to preoperative clinical characteristics (from 0.75 to 0.79 and from 0.75 to 0.78 for 30-day and 3-month mortality, respectively). The discriminative power using the logistic EuroScore was lower (0.71 and 0.7, for 30-day and 3-month mortality, respectively). CONCLUSIONS: Laboratory parameters as objective markers for organ function and nutritional status are useful data for the prediction of 30-day and 3-month mortality after aortic valve replacement. Using modern methods of information technology, these valuable data which are stored electronically in most hospitals, can be used efficiently for research and quality control.

Body mass index: a risk factor for 30-day or six-month mortality in patients undergoing aortic valve replacement?

BACKGROUND AND AIM OF THE STUDY: In recent studies, the impact of a low or high body mass index (BMI) on outcome after cardiac surgery has been the subject of controversy. A retrospective study was conducted to determine the influence of BMI on 30-day and six-month mortality after aortic valve replacement (AVR). METHODS: A multivariable logistic regression was performed on data from 1,241 consecutive patients (mean age 69 +/- 11 years) who underwent AVR either with (n = 514; 41%) or without coronary artery bypass grafting CABG between 2000 and 2003. A wide spectrum of periprocedural variables was collected, including laboratory data as markers for nutritional status and comorbidity. Patients were followed up for six months after AVR (99% complete). RESULTS: Mortality rates after 30 days and after six months were 3.9% (n = 49) and 7.6% (n = 94), respectively. A low BMI was identified as an independent risk factor for 30-day (OR (odds ratio) 0.87; CI (confidence interval) 0.8-0.94) and six-month mortality (OR 0.91; CI 0.86-0.96). The relationship between the logit function and BMI was linear; however, a BMI value of 24 was considered an appropriate cut-off point. Both models containing the BMI linearly or dichotomic were equivalent. As patients with a lower BMI differ in their preoperative risk profile compared to those with a higher BMI, a saturated propensity score estimating the propensity towards having a BMI < 24 was calculated. The propensity score was not significant in the final models for 30-day and six-month mortality (0.24 and 0.73, respectively), and the OR for BMI remained largely unaltered (0.89 and 0.91, respectively). CONCLUSION: A BMI < 24 is predictive of an increased risk of mortality after AVR, independently of malnutrition, advanced heart disease, or valve size. Further studies are required to investigate the role of adipose tissue in extreme situations and chronic disease. It is mandatory to include BMI in outcome studies after AVR.

Current determinants of operative mortality in 1400 patients requiring aortic valve replacement.

BACKGROUND: Determinants of operative mortality after aortic valve replacement vary with a changing patient population due to advances in operative management and increasing life expectancy. In order to predict current groups of high risk patients, a statistically valid large study population base recruited over a short period of time is required. METHODS: Between January 1996 and June 2001, 1408 aortic valves were replaced in 1400 patients (572 of them with simultaneous coronary artery bypass grafting). The data were analyzed by multivariate logistic regression to evaluate the operative risk. Mean age of the study population was 68 +/- 11 years (range 19 to 90 years old, 44% female). RESULTS: Overall operative mortality (within 30 days) was 3.8%. Independent predictive factors for operative mortality were previous bypass surgery, emergency operation, simultaneous mitral valve replacement, renal dysfunction, more than 80 years old, simultaneous bypass surgery in female patients with a body mass index greater than 29 kg/m(2), and height smaller than 1.57 m for patients more than 71 years old. Simultaneous coronary artery bypass grafting in general (p = 0.6), previous aortic valve replacement (p = 0.59), and implantation of stented bioprostheses (p = 0.39) or stentless bioprostheses (p = 0.7) were not identified as independent risk factors. CONCLUSIONS: Certain groups of patients with a high operative risk were identified: patients more than 80 years old, women with a body mass index greater 29 kg/m(2) undergoing simultaneous coronary artery bypass surgery, and "small" patients more than 71 years old.