Long-term survival and complications in patients with mechanical aortic valves without anticoagulation. A follow-up study from 1 to 15 years.

In aortic valve replacement most centres prefer to use a mechanical valve for younger patients without special bleeding risks and treat the patient with lifelong anticoagulation. However, a few patients do not receive anticoagulation at all or have this withdrawn after some time. We examined the prognosis of 43 patients, 37 men and 6 women (mean age 52 years), who were treated with anticoagulation for approximately only 1 year (mean 13 months; range 4-35 months) after isolated aortic valve replacement with a mechanical valve. The mean follow-up period was 7 years and 3 months (1.5 months to 15 years and 10 months). After 5 and 10 years, 70% and 59%, respectively, were free of thromboembolic events, 65% and 55%, respectively, were free of valve-related events, and 87% and 83%, respectively, had survived. These figures correspond to linearized rates of thromboembolic events of 5.2%/pt-yr, valve-related events of 6.2%/pt-yr and death of 2.9%/pt-yr. We conclude that the best postoperative treatment in isolated aortic valve replacement with a mechanical valve is lifelong anticoagulation.     

Oral anticoagulation therapy during pregnancy in patients with mechanical mitral valves: a prospective study

Reports on phenindione toxicity have limited its use as an oral anticoagulant. Our aim was to evaluate its risks in pregnant women. Thirty-one pregnancies in 29 women with mitral (+/-aortic) St. Jude mechanical valves were followed-up prospectively. Eighteen patients received phenindione. Eleven patients (37.9%) received in addition to phenindione 225 mg dipyridamole, which was given in three doses. The target INR was 2.5-3.5 in the former and 2-2.5 in the latter treatment. A fortnight before delivery, intravenous heparinotherapy was substituted. There were no maternal complications, apart from a single postpartum hemorrhage (3.2%). After the deliveries the results were: 26 mature babies (83.9%), 3 premature babies (9.7%) and 2 cases of stillbirth (6.4%). Outcome was dose related; being 57.2+/-20.9 mg/day for mature babies and 82.5+/-11.2 mg/day for prematures and stillbirths (P=0.016). Phenindione provided safe and effective anticoagulation during pregnancy. A larger study is necessary to confirm the relationship between the dosage and outcome.     

Pregnancy and mechanical heart valves replacement; dilemma of anticoagulation.

OBJECTIVES: To establish a uniform anticoagulation regimen for pregnant patients with mechanical heart valves taking into account the socio-economic background and to evaluate the incidence of anticoagulant related complications. METHODS: A retrospective study on 63 pregnancies in 21 women with mechanical heart valves was evaluated. These pregnancies were divided into two groups: Group I (n=42) received oral anticoagulants throughout pregnancy and Group II (n=21) received subcutaneous heparin in the 1st trimester and oral anticoagulants for the rest of pregnancy period. Both groups received heparin at time of delivery. RESULTS: There was no case of coumarin embryopathy seen and there was no maternal death. Life threatening valve thrombosis occurred in two patients who were both from Group II and needed emergency re-replacement. Group I had a higher incidence of spontaneous abortion than Group II although this was not statistically significant. CONCLUSIONS: The role of coumarin embryopathy has been overstated. We recommend the use of oral anticoagulants throughout pregnancy especially in countries with similar socio-economic background.     

Left ventricular mass regression following aortic valve replacement with mechanical valves

Objective The degree of Left Ventricular Mass Index (LVMI) regression following aortic valve replacement correlates with long-term survival. This study aims to assess the extent of LVMI regression at 3 months following aortic valve replacement (AVR) with different types and sizes of mechanical valves in rheumatic aortic valve disease. Methods The LVMI regression was studied in 34 consecutive patients, undergoing elective AVR for rheumatic aortic stenosis and/or regurgitation. They were grouped in A and B, matched in age, body surface area and pre-operative LVMI, receiving respectively a tilting disc and a bileaflet mechanical valve. The LVMI was calculated by M-mode echocardiography using the Devereux' formula pre-operatively and three months post-operatively. The trend of LVMI reduction was compared between the two groups and amongst the patients with stenotic, regurgitant and mixed aortic valve, pathologies; and receiving different sizes of valves. Results The mean preoperative LVMI was 199g±79.5 g/m². At three months post aortic valve replacement, the mean LVMI was 130g±49.0 g/m². There was a significant reduction of LVMI post-operatively (p=0.001) at three months follow-up. The extent of LVMI regression following surgery amongst the groups A and B did not vary significantly (p=0.92). The extent of LVMI regression did not vary significantly in patients with different aortic valve pathology nor with different sizes of the valves implanted. Conclusions There is a significant early LVMI regression following aortic valve replacement in rheumatic aortic valve disease. The type and the size of the mechanical prosthesis or the rheumatic pathology do not appear to influence this regression.     

心脏机械瓣膜置换术后妊娠妇女低强度华法林抗凝治疗56例

目的 探讨心脏机械瓣膜置换术后妊娠妇女低强度抗凝治疗的方法,以及抗凝药物对孕妇和胎儿的影响.方法 随访56例心脏机械瓣膜置换术后妇女妊娠、分娩期抗凝治疗情况.结果 56例(61例次)妊娠全程均口服华法林行抗凝治疗,42例用国产华法林(3.02±0.85)mg/日,14例用进口华法林(2.84±0.57)mg/日,国际标准比值(INR)均值为1. 67±0.58.所有孕妇均无严重出血及栓塞等并发症发生,仅11例次有一般性出血现象.本组足月妊娠47例,早产7例,自然流产6例,死产(畸胎)1例;低体重儿6例.新生儿均无畸形发生.结论 心脏机械瓣膜置换术后妇女妊娠全程服用较小剂量华法林(＜5 mg/日)行低强度抗凝治疗(INR=1.5～2.0)对孕妇安全、方便,且胎儿并发症发生率较低.

Abstract：

Objective To evaluate the method of low-intensity anticoagulation therapy in the pregnant women who had received mechanical heart valve replacemant, and the effects of warfarin on the pregnant women and their fetus. Methods This retrospective study involved 56 pregnant women( 61 pregnancies)who had received mechanical heart valve replacement.Their pregnant status, delivery, and anticoagulation therapy were observed and followed-up between May 1986 and November 2009 at West China Hospital of Sichuan University. Results All patients took oral anticoagulant (warfarin) throughout pregnancy. The dose of domestic warfarin was ( 3.02 ± 0.85 ) mg/d ( in 42 cases), and the dose of imported warfarin was (2.84 ± 0.57 )mg/d (in 14 cases). The mean INR value of 401 samples from patients was 1.67 ±0.58. No thromboembolism or major hemorrhagic complications occurred. Minor bleeding occurred in 11 pregnancies. Forty-seven patients had term delivery, 7 had premature birth, 6 had spontaneous abortion, and 1 had intrauterine fetal death. Six newborns were born with low birth weight (2.3 ± 0. 5 ) kg, and no abnormal fetus was observed. Conclusion The low-intensity anticoagulation therapy with warfarin (at a dose of less than 5 mg/d) and a INR target of 1.5 to 2.0 was safe and convenient for the pregnant women,who had received mechanical heart valve replacement. The abnormalities rate of fetus was low.     

Long-term results of mechanical valves in aortic position and biological valves in mitral and tricuspid positions

The long-term results of patients undergoing aortic valve replacement (AVR) with a mechanical valve (AM), mitral valve replacement with a biological valve (MB), and tricuspid valve replacement (TVR) with a biological valve (TB) operated upon from 1977 to 1988 were retrospectively analysed. A total of 899 patients received 1117 valves (381 AM, 633 TB, 103 TB) with a follow-up 3778 patient-years and 4582 valve-years. A significant incidence of thromboembolism, hemorrhage, and endocarditis was not found among AVR, MVR, TVR, or multiple valve replacement. We found a significantly decreased incidence of survival rate in multiple valve replacement compared with AVR or MVR, and a significantly increased incidence of reoperation in MB compared with AM and TB. We use AM and TB in any adult patients as a first choice. However, we prefer a mechanical valve in the mitral position except in patients over 65 years old, who have a short life expectancy, in whom anticoagulation is thought to be difficult, and who desire a biological valve.     

Long-term clinical results after aortic valve replacement with mechanical heart valves and mitral valve replacement with porcine valves]

Long-term clinical results of aortic valve replacement (AVR) with mechanical heart valves and mitral valve replacement (MVR) with porcine valves were analysed. Sixty-three patients received isolated AVR and 48 received isolated MVR. Sixty-eight patients with MVR including double or triple valve replacement were also added in order to evaluate the primary tissue failure (PTF). The patients with operative deaths were excluded. Survival rate at 11 years in AVR was 68 +/- 10% and 67 +/- 15% in MVR without statistical difference. At 11 years, 76 +/- 8% of the patients in AVR were free from valve-related complications in contrast with the poor result of 34 +/- 31% in MVR (p less than 0.01). Main cause of this poor result in MVR was PTF as indicated in following event free rates; 83 +/- 9% at 7 years, 61 +/- 25% at 10 years and 49 +/- 31% at 13 years. There was no statistical difference between patients of above 50 years and below 49 years in PTF. Valve-related death event free was 93 +/- 5% in AVR and 86 +/- 11% in MVR at 11 years (not significant), however, there was statistical difference in re-operation event free rate as 94 +/- 5% in AVR and 76 +/- 11% in MVR at 11 years (p less than 0.001). These results suggest that the use of porcine valves in mitral position is confined to the selected patients.     

The hemodynamics of transcatheter aortic valves in transcatheter aortic valves

BackgroundThe durability of transcatheter aortic valves (TAVs) remains their greatest disadvantage, given that fixed tissue leaflets are not immune to structural degeneration from calcification and thrombosis. Therefore, a second intervention is necessary, especially given that TAV in low-risk patients has shown noninferior outcomes compared with surgery. This study aimed to assess the hemodynamic and turbulent properties of the flow downstream with different TAV-in-TAV configurations, to offer basic hemodynamic guidance for future interventions when currently implanted valves structurally degrade.MethodsSix TAV-in-TAV configurations were chosen: 23 mm Evolut-in-26 mm Evolut, 23 mm Evolut-in-23 mm SAPIEN 3, 26 mm Evolut-in-26 mm Evolut, 26 mm Evolut-in-23 mm SAPIEN 3, 23 mm SAPIEN3-in-26 mm Evolut, and 23 mm SAPIEN3-in-23 mm SAPIEN 3. Their hemodynamic performance was assessed in a pulse duplicator for 100 cycles. High-speed imaging and particle image velocimetry were performed to assess turbulence. Effective orifice area (EOA), pinwheeling index (PI), and Reynolds shear stress (RSS) were evaluated.ResultsThe largest mean EOA was obtained with 23 mm SAPIEN-in-26 mm Evolut (2.07 ± 0.06 cm²), and the smallest was obtained with 23 mm Evolut-in-23 mm SAPIEN (1.50 ± 0.04 cm²) (P < .001). The highest mean PI was obtained with SAPIEN-in-SAPIEN (26.5 ± 2.00%), and the lowest was obtained with 26 mm Evolut-in-26 mm Evolut (7.5 ± 1.6%) (P < .01). At peak systole, the least detrimental RSS range was obtained with 23 mm Evolut-in-26 mm Evolut (up to ～340 Pa), and the most detrimental RSS range was obtained with 23 mm Evolut-in-SAPIEN (～900 Pa) (P < .01).ConclusionsThis study shows that best hemodynamic parameters are TAV-specific (implanted and to be implanted). In addition, it shows that RSS levels, which are indicative of turbulence levels and associated with blood damage, are 2- to 3-fold higher after TAV-in-TAV.     

Hospital readmission rates are similar between patients with mechanical versus bioprosthetic aortic valves

Background

The aim of this study was to evaluate hospital readmission rates and clinical outcomes between bioprosthetic (bAVR) and mechanical (mAVR) aortic valve replacements (AVR).

Methods

Adults aged 50 years or older undergoing isolated or concomitant AVR between 2011 and 2017 were included. The primary outcome was 5‐year hospital readmission. Multivariable logistic regression analysis was used to evaluate the risk‐adjusted impact of bAVR versus mAVR on outcomes.

Results

A total of 2981 patients were included: 406 (14%) mAVR and 2575 (86%) bAVR. Mean follow‐up was 2.9 ± 1.9 years. Operative mortality was comparable (4% bAVR vs 3% mAVR; P = 0.30). There was no risk‐adjusted difference in 30‐day (hazard ratio [HR] 1.32, P = 0.46), 1‐year (HR 1.17, P = 0.52), or 5‐year mortality (HR 0.99, P = 0.93). Aortic valve 5‐year reoperation rates were comparable (1%, P = 0.32). Risk‐adjusted hospital readmissions were similar at 30 days (14% vs 15%; P = 0.63), 1 year (30% vs 27%; P = 0.43), and 5 years (55% vs 53%; P = 0.83) in the bAVR and mAVR groups, respectively. Similar findings were demonstrated when evaluating readmissions for bleeding (5‐year readmission: 8% bAVR vs 10% mAVR; P = 0.36).

Conclusions

In this analysis of over 2900 AVRs, readmissions within 5 years were comparable between groups at approximately 50%, with patients being at highest risk in the early postdischarge period. Readmissions for bleeding constituted a minority of all readmissions for both cohorts.     

Intermediate-term outcomes of aortic valve replacement with bioprosthetic or mechanical valves in patients on hemodialysis

ObjectiveTo investigate the influence of choice of prosthesis (bioprosthetic valves or mechanical valves) on intermediate-term outcomes in patients on hemodialysis undergoing aortic valve replacement (AVR).MethodsA multi-institutional retrospective cohort study was conducted in 18 Japanese centers. All adult patients on chronic hemodialysis who underwent AVR from 2008 and 2015 were included (n = 491). The early and late results were compared between groups. The hazard ratios were calculated using Cox regression and Fine–Gray models with adjustment for propensity score based on 41 confounders. The mean follow-up period was 2.5 ± 2.1 years (up to 8.3 years) with 98% completeness.ResultsThere were 323 patients who received a bioprosthetic valve (group B), and 168 patients who received a mechanical valve (group M). There was no significant difference for in-hospital death rate between groups (group B: 12.1%; group M: 8.9%; P = .29). The overall survival rate at 5 years after surgery was 39.3% in group B and 50.4% in group M (P = .42). Freedom from reoperation at 5 years was 97.1% in group B and 97.8% in group M (P = .88). On propensity-score adjusted analyses, there were no significant differences in overall survival between groups.ConclusionsThere were no significant differences in overall survival between bioprosthetic valves and mechanical valves in patients on hemodialysis undergoing AVR.     

Comparative analysis of mechanical and bioprosthetic valves after aortic valve replacement

Comparative long-term performance characteristics of Bj?rk-Shiley mechanical and bioprosthetic valves were analyzed for patients undergoing aortic valve replacement between 1976 and 1981. A total of 419 patients received either a standard Bj?rk-Shiley (n = 266) or bioprosthetic (porcine, n = 126, or pericardial, n = 27) aortic valve. Cumulative patient follow-up was 1,705 patient-years; the average patient follow-up was 4.1 +/- 2.7 years. Survival data were obtained for all but 11 patients (97% complete follow-up) up to 9 years after operation. Survival at 5 years was 81% +/- 4% (+/- standard error) for Bj?rk-Shiley and for bioprosthetic valve recipients. Valve failure in the Bj?rk-Shiley group was predominantly due to valve-related mortality and did not result from structural failure. Patients with bioprosthetic valves experienced valve failure as a result of prosthetic valve endocarditis and intrinsic valve degeneration. Although patients with bioprostheses experienced a lower incidence of valve-related morbidity than Bj?rk-Shiley valve recipients (p less than 0.03), no difference could be demonstrated in the incidence of valve-related mortality or valve failure at 5 years between bioprosthetic and Bj?rk-Shiley valves. Mortality rate from valve failure was higher for Bj?rk-Shiley (86%, 12/14) than bioprosthetic valves (36%, 5/14) (p less than 0.01).     

A method for anticoagulation of children on mechanical circulatory support

Anticoagulation of children on mechanical circulatory support presents a challenge. We implanted 28 devices in children and infants using a consistent anticoagulation protocol. We performed a retrospective review of all children implanted in our program with mechanical assist devices since 1997. Heparin, dipyridamole, and aspirin were used for anticoagulation and antiaggregation. Coagulation monitoring included thromboelastography (TEG), platelet aggregration studies, international normalized ratio, partial thromboplastin time, and platelet count. Twenty-eight children, ages 1 month to 16 years (mean 5.3; median 2.4 years), were implanted for 3-107 days (mean 27; median 17). Eighteen received left ventricular assist devices, seven received biventricular assist devices, and three received total artificial hearts. Adverse events during the 720 days of device support included the following: six (21%) reoperations for bleeding; seven strokes (25%): two fatal, two with a mild residual deficit, and three without deficit; and three (11%) visceral emboli: two fatal and one nonfatal. There were eight deaths (29%). Causes of death were embolic (four), graft failure post-transplantation (one), preimplant anoxic brain damage (two), and postexplant heart failure (one). 24/28 (86%) survived to transplantation or weaning from device and 20/28 (71%) were discharged from the hospital, 10 after transplantation and 10 after native heart recovery. All 20 early survivors survived long term. We describe an anticoagulation protocol based upon TEG and platelet aggregation studies and using heparin, aspirin, and dipyridamole. Adequate anticoagulation is more difficult in children. However, 71% of the patients in our study survived long term.     

Perioperative anticoagulation management for prosthetic heart valves

OBJECTIVES: The practices and the guidelines over the perioperative management of the anticoagulation of patients with cardiac valves prothesis are the object of no consensual attitude. The thrombotic risk over the time is well known. It depends of the type or the location on the valve, of their associations and the age of the patient. In the perioperative period, the antithrombotic treatment must be interrupted according to the surgical haemorrhagic risk. STUDY DESIGN: Short review. RESULTS: Only patients, without associated risk factor, carriers of bioprosthesis from more than 3 months, can be maintained only under antiplatelets agents. In others situations, the caution imposes a bridge of anticoagulants from 48 to 72 hours with unfractionated heparin (subcutaneous at home, intravenous at the hospital). Low molecular weight heparin has no commercial authorization in this indication. The resumption of the anticoagulation by unfractionated heparin in postoperative period must be the most premature possible after the decrease of the surgical bleeding. The relay by vitamin K antagonists has to be made over 48 to 72 hours. Within the framework of the urgency, the surgical haemorrhagic risk is weak for an INR <1.5. According to the urgency of the surgery, a treatment by vitamin K (if the delay is over 12 hours) or by prothrombinic complex allows to correct this INR. The identification of thrombotic complications requires a particular attention. In the postoperative period, as soon as there is suspicion of thrombosis, clinical manifestations must be consolidated by the practice of a transoesophageal echography, which only confirm the diagnosis.     

Intermediate-term results with 1,019 carbomedics aortic valves

BACKGROUND: A retrospective study was conducted to evaluate the intermediate-term outcome in patients with the Carbomedics aortic valve prosthesis. METHODS: The study included 1,019 primary valve replacements between 1989 and 1997. Seventy-two percent of patients were men; mean (standard deviation) age was 61 (10) years. The preoperative New York Heart Association functional class was III or IV in 70% of patients. Follow-up at 9 years was 99.6% complete, comprising 2,730 patient-years (mean, 2.7 years). RESULTS: Patient survival, including operative deaths, was 80% at 7 years. The linearized death rate was 2.9%/year. Statistically significant risk factors for mortality were diabetes, pure valve insufficiency, advanced age at operation, and advanced preoperative functional class. Linearized rates were thrombosis, 0.1%/year; thromboembolism, 1.0%/year; hemorrhage, 1.7%/year; endocarditis, 0.1%/year; paravalvular leak, 0.1%/year; reoperation, 0.1%/year; and all events, 3.0%/year. The 7-year estimates of freedom from complications were thrombosis, 99%; thromboembolism, 93%; hemorrhage, 89%; endocarditis, 99%; paravalvular leak, 99.7%; reoperation, 99%; and all events, 82%. No structural valve failure was observed. CONCLUSIONS: The low incidence of valve-related complications favors the continued use of the Carbomedics valve in the aortic position.