[Modern coronary surgery, the SYNTAX trial and updated guidelines]. / Moderne Koronarchirurgie in Zusammenhang mit der SYNTAX-Studie und aktuellen Leitlinien.

Coronary artery bypass grafting (CABG), a modern and safe procedure, is considered the therapy of choice in the care of patients with multi-vessel disease. The 3-year results of the SYNTAX trial not only showed surgical advantages in terms of repeat revascularisation, but the results also demonstrated significant surgical benefit for myocardial infarction and survival rates. More differentiated analyses showed distinct disadvantages in percutaneous coronary intervention (PCI) associated with the greater complexity of coronary pathology. PCI tends to be a comparable therapeutic option only in certain cases of left main stem lesions or multi-vessel disease. The findings from the SYNTAX study herald a new era in the treatment of coronary heart disease in which, as recommended in the updated guidelines issued by the EACTS/ESC in 2010, the interventionalist and the surgeon, working closely together as a"heart team", provide a sound therapy plan for affected patients.

Octogenarians undergoing combined aortic valve replacement and myocardial revascularization: perioperative mortality and medium-term survival.

OBJECTIVE: Aim of the study was to answer the question whether the mortality and morbidity of octogenarians undergoing combined aortic valve replacement and myocardial revascularization (AVR + CABG) is higher than that of younger patients. PATIENTS AND METHODS: Between 01/1995 and 12/2002, 242 patients underwent AVR + CABG in our institution. 37 patients were older than 80 years (16 male, 21 female, median pressure gradient over the aortic valve: 53 mmHg, median EF: 62%), 205 patients were younger than 80 years (133 male, 72 female, median gradient 48 mmHg, median EF: 61%). NYHA class, aortic valve area and valve calcification were worse in the 80+ group. Biological valve prostheses were implanted in 94.6% of the older and in 45.4% of the younger patients (p < 0.001). RESULTS: Perioperative complications occurred more often (p = 0.0188) in the 80+ group (86.5% experienced 1 or more complications) than in the 80- group (66.3%). Similarly, the MACE (Major Adverse Cardiovascular Events) rate was higher (p = 0.0448) in the 80+ group than in the 80- group. Bleeding occurred (p = 0.092) more often in younger (9.3%) than in older (0%) patients, while renal insufficiency was more frequent (p = 0.0164) in older (21.6%) than in younger patients (7.8 %). The 30-day mortality was higher (p = 0.0045) in older (21.6%) than in younger patients (5.8%). Multivariate analysis revealed an odds ratio for early death of 2.9 (CI 1.014-8.397) for patients older than 80 years. The late death rate within the first 5 years after surgery was comparable in both groups (80- group 24.4%, 80+ group 24.3%). Postoperative quality of life was significantly worse in the 80+ group in 4 out of 8 functions. CONCLUSIONS: Octogenarians undergoing AVR + CABG have a relatively high perioperative complication rate and mortality, but show a stable medium-term survival. The perioperative complication rate is higher in older than in younger patients, and the postoperative quality of life with regard to bodily functions is acceptable but significantly worse than that of younger patients.

A novel pulse duplicator system: evaluation of different valve prostheses.

BACKGROUND: The hemodynamic characteristics of different heart valve prostheses have been investigated in vitro with a novel pulse duplicator. A novel valved stent for transapical or percutaneous valve implantation has been compared with a native heart valve and mechanical heart valves. METHODS: All experiments were designed to imitate both physiologic pressure ratios and flow characteristics in diastole and systole. After calibrating the system using a human aortic valve (primary orifice diameter: 22.0 mm), the following valves were studied under aortic pulsatile flow conditions: Hall-Kaster (Medtronic-Hall, 20.0 mm), St. Jude Medical (20.0 mm), a newly developed tricuspid valved stent (Tricumed TM4, 20.7 mm) and a newly developed biomechanical valve (Engage aortic valve Model 6000, 21.0 mm). All valves including the human aortic valve were assessed by videotape observation under pulsatile flow conditions. Measured flow-related parameters include in vitro mean transvalvular pressure, regurgitant volume, effective orifice area and performance index. RESULTS: The optical assessment of all five valves demonstrated a complete opening during systole and closing at the beginning of diastole. All valves were optically sufficient during diastole. Engage aortic valve Model 6000 showed the highest maximum transvalvular pressure (27.5 +/- 8.2 mmHg), whereas both Hall-Kaster (17.9 +/- 1.5 mmHg) and St. Jude Medical (16.7 +/- 0.7 mmHg) had a lower gradient than the native aortic valve (24.0 +/- 0.2 mmHg) and Tricumed TM4 (21.8 +/- 3.8 mmHg). The maximum effective orifice area of St. Jude Medical amounted to 258.7 +/- 3.4 mm(2), followed by Tricumed TM4 with an area of 222.1 +/- 1.9 mm(2) and the human aortic valve with 160.4 +/- 2.9 mm(2). Hall-Kaster and Engage aortic valve Model 6000 had an area of 198.9 +/- 1.6 mm(2) and 176.7 +/- 3.1 mm(2), respectively. CONCLUSIONS: The pulse duplicator proved to be highly accurate and yielded reproducible results. Since it has been calibrated with a human aortic valve, the hemodynamics of any heart valve prosthesis can be compared with the human valve. This system can evaluate and promote the development of new biological and mechanical heart valve prostheses.

Should the aortic valve be replaced in patients with mild aortic stenosis admitted for coronary surgery?

BACKGROUND: The question whether the aortic valve in patients with mild aortic stenosis undergoing coronary artery bypass grafting (CABG) should be replaced or left alone is still controversial. METHODS: Between 01/1995 and 03/2004, 38 patients (30 male, 8 female, mean age 70.9 +/- 7.8 years) required redo AVR 7.1 +/- 4.8 years after primary CABG, while 202 patients (125 male, 77 female, mean age 72.7 +/- 7.8 years) underwent combined AVR and CABG (1.9 +/- 0.8 grafts/patient). To evaluate the different approaches, the data of the redo-AVR group were compared with the data of a propensity-score matched group of AVR + CABG patients. RESULTS: All patients survived the procedure; the 30-day survival was 94.7 % in both groups. The 1- and 5-year survival rates were 94.7 % and 83.8 % in the AVR after CABG group, and 94.7 % and 86.9 % in the AVR + CABG group, respectively. The late mortality was 28.9 % in the AVR after CABG and 25 % in the AVR + CABG group. Statistically, significant differences regarding perioperative mortality and morbidity could not be detected, neither with nor without propensity score analysis. CONCLUSION: Combined AVR and CABG in patients with coronary artery disease and mild to moderate aortic stenosis seems advisable in an institution with an equally low perioperative risk for both procedures, because the patient will need only one surgical procedure instead of undergoing surgery with all the associated risks twice.

Prevention of device-related tissue damage during percutaneous deployment of tissue-engineered heart valves.

BACKGROUND: Endovascular application of pulmonary heart valves has been recently introduced clinically. A tissue-engineering approach was pursued to overcome the current limitations of bovine jugular vein valves (degeneration and limited longevity). However, deployment of the delicate tissue-engineered valves resulted in severe tissue damage. Therefore the objective of this study was to prevent tissue damage during the folding and deployment maneuver. MATERIAL AND METHODS: Porcine pulmonary heart valves, small intestinal submucosa, and ovine carotid arteries were obtained from a slaughterhouse. After dissection and antimicrobial incubation, the valves were trimmed (removal of sinus and most of the muscular ring) to fit into the deployment catheter. The inside (in-stent group, n = 6) or outside (out-stent group, n = 6) of a nitinol stent was covered by an acellular small intestinal submucosa, and the valves were sutured into the stent. The valves were folded, tested for placement in the deployment catheter, and decellularized enzymatically. Myofibroblasts were obtained from carotid artery segments and seeded onto the scaffolds. The seeded constructs were placed in a dynamic bioreactor system and cultured for 16 consecutive days. After endothelial cell seeding, the constructs were folded, deployed, and processed for histology and surface electron microscopy. RESULTS: The valves opened and closed competently throughout the entire dynamic culture. Surface electron microscopy revealed an almost completely preserved tissue in the in-stent group. Stents covered with small intestinal submucosa on the outside, however, showed severe damage. CONCLUSION: This study demonstrates that small intestinal submucosa covering of the inside of a pulmonary valved stent can prevent stent strut-related tissue damage.