Outcomes of surgical bioprosthetic aortic valve replacement for aortic insufficiency

BackgroundResults and durability of aortic valve replacement in aortic stenosis are well known, but no study has focused on the results of aortic valve replacement in aortic insufficiency.AimThe aim of this retrospective study was to describe our mid-term outcomes after aortic valve replacement for aortic insufficiency.MethodsAll consecutive adult patients who underwent bioprosthetic aortic valve replacement for aortic insufficiency at two European centres (in France and Germany) between May 2005 and December 2020 were analysed.ResultsDuring the study period, 289 patients were included. Mean age was 56.9 ± 12.5 years. Overall operative mortality was 1.5%, and the 10-year survival estimate rate was 75.0%, which was significantly lower than in the age- and sex-matched general population, with a standardized mortality ratio of 2.88 (95% confidence interval 1.96–4.08; P < 0001). Freedom from aortic valve-related death was 87.6%, and from aortic valve-related reoperation was 87.4%. No patient aged > 60 years was reoperated on during follow-up. Freedom from severe structural valve deterioration at 10 years was 73.3%, and freedom from moderate structural valve deterioration at 10 years was 50.3%. Freedom from major adverse valve-related events at 10 years was 69.7%.ConclusionsAlthough bioprosthetic aortic valve replacement for aortic insufficiency shows good early results, 10-year mortality and major adverse valve-related event rates in young patients may be a concern, with a reduction in life expectancy compared with the general population.     

Transaortic transcatheter aortic valve implantation within a previous bioprosthetic aortic valve replacement

This report documents the first reported case of transaortic transcatheter aortic valve implantation (TAVI) using the CoreValve ReValving system (Medtronic CoreValve System, Luxembourg), within a previous bioprosthetic aortic valve replacement. TAVI has become a recognized percutaneous treatment for patients with severe native or bioprosthetic aortic valve stenosis. However, as the number of patients screened for TAVI increases, a number of patients are found with absolutely no option for peripheral arterial access, either from the femoral or subclavian routes. Transaortic CoreValve placement offers an alternate minimally invasive hybrid surgical/interventional technique when peripheral access is not possible. A CoreValve prosthesis was implanted via the transaortic route in an 81‐year‐old woman with severe bioprosthetic aortic valve stenosis (21 mm Mitroflow pericardial valve, peak instantaneous gradient of 99 mmHg, effective valve orifice area (EOA) of 0.3 cm², as ilio‐femoral and left subclavian angiography revealed small calibre vessels (<6 mm). Access was achieved via a mini thoracotomy via the left anterior second intercostal space. The procedure went without complication. Post procedure the patient was transferred directly to the Cardiac Care Unit for recuperation. Post procedure echocardiography showed that the TAVI was well positioned with no para‐valvular leak and a reduction in peak instantaneous gradient to 30 mmHg and an increase in EOA to 1.5 cm². She was discharged on the third post‐procedural day in sinus rhythm with a narrow QRS complex. CoreValve implantation within previous surgical bioprosthesis is now an established treatment. The transaortic approach to transcatheter implantation is a promising recent development, when due to anatomical reasons, transfemoral or subclavian TAVI is not feasible. © 2011 Wiley‐Liss, Inc.     

新型肺动脉带瓣管道移植动物实验与血流动力学评价

目的:对我们与佰仁公司共同研制的肺动脉带瓣管道进行犬移植实验并进行血流动力学评价。方法:肺动脉带瓣管道在体外循环辅助心脏不停跳下对犬行肺动脉瓣置换术,术后持续监测生命体征,术中及术后观察瓣膜血流动力学变化。结果:8条犬6条存活,且存活均超过1个月,存活个体状态良好。死亡的犬中1条由于呼吸机故障,1条可能与瓣膜不匹配有关。手术前后无明显血流动力学变化,手术后右室-肺动脉无明显压差。结论:新型改良肺动脉带瓣管道植入实验犬是适合的。新型肺动脉带瓣管道已显示出优良的血流动力学优势。     

Glycosaminoglycan-degrading enzymes in porcine aortic heart valves: implications for bioprosthetic heart valve degeneration

BACKGROUND AND AIM OF THE STUDY: Glutaraldehyde (GA)-fixed aortic valves used in heart valve replacement surgery have limited durability due to tissue degeneration and calcification. Despite their structural and functional importance, very little is known about the fate of glycosaminoglycans (GAGs) within the extracellular matrix of bioprosthetic heart valves. The study aim was to investigate the stability of GAGs in GA-fixed tissues and to identify enzymatic mechanisms that may be responsible for GAG degeneration. METHODS: Porcine aortic valve cusps were fixed with GA and implanted subdermally in rats for 21 days. Fresh, fixed and explanted cusps were analyzed for GAG content by hexosamine determination, and GAG-degrading enzyme activity was evaluated using zymography. GAG classes in fresh cusps were also assessed by flurorophore-assisted carbohydrate electrophoresis. Fresh and GA-fixed cusps were also exposed in vitro to hyaluronidase and chondroitinase in order to test the susceptibility of cusp GAGs towards enzymatic degradation. RESULTS: Native aortic cusps contained -3.5% GAGs by dry weight, consisting of hyaluronic acid, chondroitin sulfate and dermatan sulfate. Significantly lower GAG levels were found in aortic cusps after fixation with GA, and even lower levels were found after subdermal implantation in rats. GAG levels in GA-fixed cusps were also significantly reduced by in-vitro incubation with hyaluronidase and chondroitinase. Novel GAG-degrading enzymes were detected in considerable levels in native cusps, in lower levels in GA-fixed cusps and significantly increased levels after subdermal implantation of GA-fixed cusps. CONCLUSION: The combined action of active GAG-degrading enzymes and the failure of GA to stabilize GAGs towards enzymatic digestion may contribute significantly to bioprosthetic heart valve degeneration and subsequent structural failure.     

Cardiovascular risk factors as predictors of early and late survival after bioprosthetic valve replacement for aortic stenosis

BACKGROUND AND AIM OF THE STUDY: Cardiovascular risk factors have been associated with aortic valve stenosis, which is considered as an atherosclerosis-like process. The study aim was to assess the effect of cardiovascular risk factors on early and late outcome after valve replacement with a bioprosthesis for aortic stenosis (AS), and the impact of these factors on the outcome of the bioprosthesis. METHODS: Preoperative clinical, biological and echocardiographic data were recorded in 222 patients (110 males, 112 females; mean age 73 +/- 8 years) who underwent surgery for severe AS between 1989 and 1993. The mean follow up was 7.3 +/- 4.7 years; total follow up was 1,621 patient-years (pt-yr). RESULTS: Overall 12-year actuarial survival rate was 36.1%. Independent predictors of mortality were age (hazards ratio (HR) 1.11; 95% CI: 1.08-1.14, p < 0.0001), diabetes mellitus (DM) (HR 2.53; 95% CI: 1.65-3.88, p < 0.0001), male gender (HR 2.17; 95% CI: 1.53-3.12, p < 0.0001), and NYHA class (HR 1.66; 95% CI: 1.17-2.34, p = 0.004). Other cardiovascular risk factors had no significant effect on survival. DM and NYHA class were also independent predictive factors for valve-related death and overall valve-related complications. The 12-year actuarial survival was 13% in DM patients compared to 38% in non-diabetic patients (p = 0.003), with a significant increase in cardiovascular death (p = 0.0028), and a non-significant increase in thromboembolic events (p = 0.08) in DM patients. The only independent predictive risk factor of structural valve failure in multivariate analysis was renal failure (HR 1.1, 95% CI: 1.03-1.16, p = 0.047). Cardiovascular risk factors such as hypercholesterolemia, DM, hypertension, tobacco smoking and obesity had no effect on the outcome of the bioprosthesis. CONCLUSION: Age, male gender, DM and NYHA class were the main predictors for long-term mortality after bioprosthesis implantation for AS. DM significantly impaired survival, with an excess of cardiovascular deaths and thromboembolic events. Other cardiovascular risk factors had no significant effect on either survival or bioprosthesis durability.     

Long-term results of pulmonary autograft for aortic valve replacement

Eighty-five survivors who left hospital after pulmonary autograft replacement for severe aortic regurgitation have been followed critically. Five patients died in the first five years and 80 were followed for six to 11 years. Important aortic regurgitation occurred only early and was always related to technical malpositioning of one autograft cusp. Seven patients with fascial pulmonary valves had problems, requiring removal in four. There was a small (2%) morbidity from the right sided homograft and six were removed five to seven years later for progressive calcification; three of these had been irradiated. Despite a high incidence of trivial diastolic murmurs this valve replacement is still preferred for young patients without dilated aortic roots since the survivors remain well, with excellent, maintained relief of outflow obstruction, without problems from haemolysis and thromboembolism, and without deteriorating autograft function or need for anticoagulants. Histology of five autografts examined up to seven years after operation has shown normal living architecture.     

生物瓣应用于老年心脏瓣膜置换术的临床总结

目的 探讨老年心脏瓣膜病患者应用生物瓣置换的价值.方法 对36例老年患者施行生物瓣膜置换术,其中行二尖瓣置换18例,主动脉瓣置换10例,二尖瓣及主动脉瓣置换8例;同期行三尖瓣成形术12例,冠脉搭桥术6例.结果 本组围手术期死亡2例.出院后随访1～48个月,心功能恢复至Ⅰ级9例、Ⅱ级21例、Ⅲ级2例.结论 老年患者应用生物瓣具有良好的耐久性,并可避免因抗凝治疗出现的各种并发症,临床应用值得推广。     

Preoperative cholesterol levels do not predict explant for structural valve deterioration in patients undergoing bioprosthetic aortic valve replacement

BACKGROUND AND AIM OF THE STUDY: Structural valve deterioration (SVD) is the most common cause of bioprosthetic valve failure. Coronary disease risk factors, including hypercholesterolemia, might predict SVD. Here, the relationship was examined between preoperative cholesterol levels and SVD in patients undergoing bioprosthetic aortic valve replacement (AVR). METHODS: A total of 7,150 patients (mean age 68 +/- 12 years) was identified who underwent bioprosthetic AVR at the Cleveland Clinic Foundation, between January 1975 and December 2002. Preoperative and postoperative variables were retrieved from a prospective, computerized database. A parametric method was used to estimate the distribution of valve explants; a multivariable risk factor model was then developed to include patient demographics, cardiac and non-cardiac comorbidities, valve type and interactions. The primary end-point was explant for SVD. All explants were examined, and observations were censored at the time of any explant or death. Bootstrap analysis was used to validate the model. RESULTS: Among 7,150 patients, 208 had explants for SVD. Mean preoperative total cholesterol (TC) was 203 +/- 48 mg/dl, HDL-cholesterol 45 +/- 15 mg/dl, and LDL-cholesterol 121 +/- 41 mg/dl. The average follow up was 3.7 years, and 1,169 patients (16%) were followed for more than eight years. In multivariable analysis, only younger age (p < 0.0001), greater body weight (p < 0.0001), elevated serum creatinine level (p = 0.0004) and use of a pericardial valve (p = 0.04) predicted SVD. Neither preoperative cholesterol nor its fractions predicted valve explant for SVD (log-rank p = 0.19) Moreover, no cardiovascular risk factors were predictive of SVD. CONCLUSION: Preoperative cholesterol levels do not predict SVD in patients undergoing bioprosthetic AVR. Whether long-term hypercholesterolemia or statin therapy impacts SVD requires further investigation.     

Long-term results of pulmonary autograft for aortic valve replacement.

Eighty-five survivors who left hospital after pulmonary autograft replacement for severe aortic regurgitation have been followed critically. Five patients died in the first five years and 80 were followed for six to 11 years. Important aortic regurgitation occurred only early and was always related to technical malpositioning of one autograft cusp. Seven patients with fascial pulmonary valves had problems, requiring removal in four. There was a small (2%) morbidity from the right sided homograft and six were removed five to seven years later for progressive calcification; three of these had been irradiated. Despite a high incidence of trivial diastolic murmurs this valve replacement is still preferred for young patients without dilated aortic roots since the survivors remain well, with excellent, maintained relief of outflow obstruction, without problems from haemolysis and thromboembolism, and without deteriorating autograft function or need for anticoagulants. Histology of five autografts examined up to seven years after operation has shown normal living architecture.     

Percutaneous heart valve replacement: an update

Valvular heart disease continues to be an important health care problem. Although surgical valve replacement remains the standard treatment, minimally invasive approaches for valve repair and replacement are becoming attractive alternatives among physicians and patients. In fact, percutaneous procedures can extend treatment to the increasing population of elderly patients with severe comorbidities who cannot withstand the stress of open heart surgery and to the younger patients at the early stage of valve disease, who are not treated until older ages to avoid multiple invasive surgeries. Feasibility of this technique has been shown in the first clinical experiences, and the early results are promising. However, it is clear that percutaneous valve replacement therapy is still at the early stage of development and requires enhanced implantation procedures and substantial design improvements as well as long-term follow-up to show the safety and effectiveness of this new treatment modality.