人工机械瓣膜低强度抗凝治疗的观察

目的探讨适合我国人工机械瓣膜置换术后病人特点的抗凝治疗强度标准.方法对407例置换人工机械瓣膜的病人,采用了低强度的抗凝标准(INR1.3～2.3),通过对这组病人的术后随访,总结不同抗凝标准时人工机械瓣膜各种并发症的发生率.结果本组发生血栓栓塞8例(1.09%人年),发生与抗凝有关的出血5例(0.68%人年),3年生存率为(96.3±1.2)%.最终INR1.85±0.28,口服华法林剂量(2.7±0.9)?mg.结论采用低强度抗凝治疗标准,在我国病人中,不仅能够获得满意的预防血栓栓塞发生的效果,同时能够减少与抗凝有关的出血发生率.     

Self-management of oral anticoagulant therapy for mechanical heart valve patients

OBJECTIVE: Self-management of oral anticoagulant therapy (OAT) has shown good results on a short-term basis. We hypothesize that self-management of OAT provides a better quality of treatment than conventional management also on a long-term basis. The aim of this study was to assess the quality of self-management of OAT in patients with mechanical heart valve prostheses on a 4-year perspective in a prospective, non-randomized study. DESIGN: Twenty-four patients with mechanical heart valves and on self-managed OAT were followed for up to 4 years. A matched, retrospectively selected group of conventionally managed heart valve patients (control group) was used as reference. RESULTS: The median observation time was 1175 days (range: 174-1428 days). The self-managed patients were within therapeutic INR target range for a mean of 78.0% (range: 36.1%-93.9%) of the time compared with 61.0% (range 37.4%-2.9%) for the control group. CONCLUSION: Self-management of OAT is a feasible and safe concept for selected patients with mechanical heart valve prostheses also on a long-term basis. It provides at least as good and most likely better quality of anticoagulant therapy than conventional management assessed by time within the therapeutic International Normalized Ratio (INR) target range.     

Valve-related complications after mechanical heart valve implantation

The number of heart valve surgeries is increasing, and 19,164 patients underwent heart valve surgery in Japan in 2011. The early mortality rate has remained stable for more than 10 years. Many patients now survive for many years, with a reported 10-year survival rate of at least 60 %. However, unfavorable complications can occur after valve surgery. Valve-related complications include thromboembolisms, bleeding complications and prosthetic valve endocarditis, followed by structural and nonstructural prosthetic valve dysfunctions. Our review of studies published after 2000 revealed that the rate of all valve-related complications was 0.7–3.5 % per patient-year. Thromboembolisms occur at a rate of approximately 1 % per patient-year, and bleeding complications occur at almost 0.5 % per patient-year. Thromboembolic and hemorrhagic events related to anticoagulant therapy should be considered during life-long follow-up. The occurrence rate of endocarditis reaches 0.5 % per patient-year, with a poor postoperative survival. Structural dysfunctions have been largely overcome, and the nonstructural dysfunction rate is 0.4–1.2 % per patient-year. The nonstructural dysfunctions induced by paravalvular leaks and pannus ingrowth are also issues that need to be resolved.     

Thromboembolic and bleeding complications after mitral valve replacement

One thousand six hundred and sixty-eight consecutive patients who underwent isolated mitral valve replacement (MVR) from 1963 to 1984 were evaluated retrospectively. Thromboembolism occurred with a linearised rate of 2.5% +/- 0.2%/patient-year (PY) for Starr-Edwards disc prosthesis Model 6520, 2.4% +/- 0.3%/PY for Bj?rk-Shiley plane prosthesis, 3.0% +/- 0.8%/PY for Bj?rk-Shiley convexo-concave 60 degrees prosthesis, 3.0% +/- 0.8%/PY for St. Jude Medical prosthesis and 3.4% +/- 0.5%/PY for Carpentier-Edwards tissue valve without the differences reaching significance. In the SJM group, the incidence of thromboembolism was significantly higher (P less than 0.025) in smaller sizes (less than M29) probably due to a more turbulent flow. The linearised rate for major haemorrhage was 1.6% +/- 0.1%/PY. Twenty-three percent of the thromboembolic and 18% of the bleeding events were fatal. Sixty-eight percent of the emboli involved the central nervous system and bleeding apart from fatalities was predominantly non-cerebral (81%). Whereas thromboembolism was a time-related event with more than twice as high a risk in the first postoperative year (4.2% +/- 0.5% vs. 1.7% +/- 0.8%, P less than 0.01), bleeding occurred with a constant rate over time (0.9% +/- 0.4%). Adequacy of anticoagulation was an important risk factor for postoperative embolism with the prothrombin time (PT) exceeding the therapeutic range in 65% of all events. A preoperative history of embolism was the only additional patient-related risk factor for postoperative embolism (18.3% vs. 9.6%, P less than 0.001). In 30% of all haemorrhage, the PT was below 15%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mechanical heart valve patients can manage oral anticoagulant therapy themselves.

OBJECTIVES: Thromboembolism and anticoagulant related bleeding are still the most common complications in mechanical heart valve patients. Management of the oral anticoagulant therapy is therefore a key determinant for these clinical complications. We hypothesize that patients selected to self-managed oral anticoagulant therapy have a better treatment quality than patients in conventional oral anticoagulant therapy. The aim of this study was to assess the time within the therapeutic International Normalized Ratio (INR) target range and the incidence of clinical complications in our group of patients, and compare these data with published data on conventional management. METHODS: Mechanical heart valve patients (N=94) with a mean age of 47.6 years (range 4.2-76.6 years) were trained in home blood analysis of INR using a CoaguChek home coagulometer and coumarin dosage adjustment. After training, the patients were followed by weekly INR measurements. The therapeutic range was a target INR +/-0.5. The indications for initiating oral anticoagulant therapy were: aortic valve (N=62), mitral valve (N=29), tricuspid valve (N=1) and multiple valves (N=2). RESULTS: The mean observation time was 2.1 years (range 0.04-6.2 years), and the total number of patient-years was 197. The patients were within the therapeutic INR target range for a median of 76.0% (range 32.1-100.0%) of the time. There were two major thromboembolic events and five major bleedings events, comprised of two deep vein thromboses (both in the same patient), four episodes of epistaxis and one case of gastrointestinal bleeding. All the events required short hospitalization, and after treatment all the patients were discharged from the hospital without any sequelae or other complications. Using published work as references the expected number of major thromboembolic and bleeding complications in conventional management was four and 12, respectively. CONCLUSIONS: Self-management of oral anticoagulant therapy provides a good treatment quality for mechanical heart valve patients. We therefore consider self-management of oral anticoagulant therapy as an equally as good or potentially better treatment option for selected patients compared to conventional management.     

Sarpogrelate reduces mechanical hemolysis in patients with heart valve prostheses.

OBJECTIVE: We evaluate the clinical efficacy of sarpogrelate, an antiplatelet drug that improves red blood cell deformability, to reduce the intravascular hemolysis problems suffered frequently by patients implanted with heart valve prostheses. SUBJECTS: Subjects were 34 patients undergoing mechanical heart valve replacement and having serum lactate dehydrogenase concentrations 20% above the maximum normal range. METHOD: Sarpogrelate was given daily, 100 mg orally for the first 6 months and 200 mg thereafter. RESULTS: Average serum lactate dehydrogenase decreased significantly from 423 +/- 108 IU/l, to 391 +/- 83 IU/l with the 100 mg dose, and to 361 +/- 86 IU/l with the 200 mg dose. The percentage of reticulocytes decreased from 15.5 +/- 5.3/1000 to 15.3 +/- 5.7/1000 at the 100 mg dose and 13.1 +/- 4.0/1000 at the 200 mg dose. Serum iron concentrations increased significantly from 63.2 +/- 24.8 micrograms/dl to 76.2 +/- 16.2 micrograms/dl at the 100 mg dose, and to 70.9 +/- 26.2 micrograms/dl with the 200 mg dose. CONCLUSION: Sarpogrelate is a useful drug for patients with implanted heart valve prostheses and subsequent high serum lactate dehydrogenase because it works as an antiplatelet drug and reduces mechanical hemolysis.     

Thromboembolic complications after mitral valve replacement with Hancock xenograft

Case histories of 140 patients who had mitral valve replacement with the Hancock xenograft were reviewed according to the incidence of thromboembolic complications. There were 16 patients with preoperative and/or postoperative low-output syndrome (Group A.) Eight of these patients died, and six had autopsies which showed major thrombi on the heterograft valve. In 126 long-term survivors (followed 1 to 33 months) nine thromboembolic events occurred (thromboembolic incidence 5.3 percent per patient-year). All patients with emboli were in atrial fibrillation. Additional predisposing factors included a history of systemic emboli and the presence of atrial clots at the time of surgery. The majority (7/9) of emboli occurred during the first 3 postoperative months. Two emboli occurred immediately following the operation (before oral anticoagulation therapy could have been begun). Five occurred in patients who were not on anticoagulation (Group B) and two occurred under warfarin treatment (Group C). There was no thromboembolic event in patients taking aspirin (Group D). It is concluded that hemodynamically stable patients have a decreased risk of thromboembolism and do not require anticoagulation. Patients with atrial fibrillation have an increased thromboembolic risk and should be on a regimen of warfarin for 3 months postoperatively and then on aspirin therapy.     

Hemolysis after mitral valve replacement with mechanical valve prostheses

OBJECTIVE: We evaluated effects of type, size, and orientation of mechanical mitral valve prostheses on hemolysis. METHODS: Subjects were 84 patients who had undergone mitral valve replacement. Lactate dehydrogenase was mainly used as a marker of hemolysis and was measured before surgery, 1 month after surgery, and in the late postoperative period. RESULTS: Valves used included 16 Medtronic-Hall, 32 St. Jude Medical, and 36 CarboMedics valves. Medtronic-Hall valves caused less hemolysis than St. Jude Medical or CarboMedics valves in the late postoperative period. This resulted because hemolysis due to Medtronic-Hall valves was more severe 1 month after surgery than in the late postoperative period and because hemolysis due to St. Jude Medical or CarboMedics valves was more severe in the late postoperative period than 1 month after surgery. One reason for this finding is that cardiac output was greater in the late postoperative period than 1 month after surgery, making regurgitation through the pivots of bileaflet valves more severe. The orifice area and the orientation of prostheses did not affect hemolysis. CONCLUSION: St. Jude Medical or CarboMedics valves caused more severe hemolysis than Medtronic-Hall valves in the late postoperative period.     

心脏机械瓣膜置换术后抗凝治疗

抗凝治疗中的出血与栓塞是心脏机械瓣膜置换术后最重要的远期并发症.我国心脏机械瓣膜置换术后患者抗凝治疗的主要矛盾是出血,应降低抗凝强度,减少出血并发症.近年来,心脏机械瓣膜置换术后抗凝治疗的主要进展是采用国际标准比值(INR)监测抗凝和低强度抗凝治疗.目前国内采用的INR为1.5～2.0,凝血酶原时间比值(PTR)为1.3～1.5的抗凝治疗强度,有利于降低抗凝患者的出血病死率以及妊娠妇女、新生儿的并发症,并能改善患者的生活质量.     

Thrombo-embolic and bleeding complications in patients with mechanical valve replacements--a prospective observational study.

BACKGROUND AND OBJECTIVES: Long-term anticoagulation therapy is essential to prevent thrombo-embolic events in patients with mechanical valve replacements. In order to offer indigent patients mechanical heart valve replacement surgery, dedicated anticoagulation clinics are necessary for follow-up. This study assessed the safety and efficacy of lifelong oral anticoagulation therapy in Johannesburg General Hospital mechanical heart valve replacement recipients. The incidence of bleeding and thrombo-embolic complications was documented in three groups of patients with mechanical valve replacements. The groups included patients with aortic valve replacements (AVRs), mitral valve replacements (MVRs) and double (aortic and mitral) valve replacements (DVRs). MATERIALS AND METHODS: A prospective observational study was conducted over a 4-month period. Data on 306 patients attending the Johannesburg General Hospital anticoagulation clinic between 2000 and 2005 were analysed. Of the total patients selected, 205 were assigned to the mechanical valve replacement group (which included 63 patients with AVRs, 93 with MVRs and 49 with DVRs); a control group of 101 nonmechanical valve replacement patients were also included. At each visit the level of anticoagulation was assessed from the international normalised ratio (INR) values, and the presence of bleeding and/or thrombo-embolic complications was documented. RESULTS: There were a total of 51 bleeding and thrombo-embolic complications in the study population. Patients with DVRs had a higher proportion of combined complications (30.61%) than patients with single valve replacements (14.29% in the AVR group and 18.05% in the MVR group) and patients in the control group (12.87%). There were 38 bleeding complications, 30 minor and 8 major. Twelve thrombo-embolic events were documented. Individually, there was no significant difference in thrombo-embolic and bleeding complications between the subgroups. Eighty-two per cent of patients in the mechanical valve replacement group were within the therapeutic range for anticoagulant control (INR 2.5-3.5) v. 54% in the control group (INR 2.0-3.0). Anticoagulant control was of a high quality and was not a contributing factor to the incidence of bleeding and/ or thrombo-embolic complications. CONCLUSION: The finding of a low incidence of bleeding and thrombo-embolic complications in patients with mechanical valve replacements supports the continued placement of mechanical valves in our setting and use of oral anticoagulation therapy at an INR of 2.5-3.5. However the increased risk of both bleeding and thrombo-embolic complications in the DVR group is cause for great concern and warrants further investigation.     

Surgery for patients with mechanical heart valves--adjustment and tailoring of anticoagulant therapy

Valvular surgery in patients (pts) with long history of cardiac valve disease is accomplishing improvement of symptoms, functional status and longevity. The numbers are very big also in our country. Our census numbers are not reliable, but estimation of above 15000 pts with prosthetic heart valve implants is close to correct. Since significant increase in survival and longevity of those pts, the possibility and necessity for non cardiac operative procedures are also increased. Because of specificity and complex constant regular anticoagulation therapy in order to prevent catastrophic prosthetic valve thrombosis and common thromboembolic complication good, but safe reduction of anticoagulation status to accomplish also safe haemostatic condition necessary for all surgical procedures. Individual adjustment and tailoring of anticoagulant and anti aggregation therapies according to accepted international protocols should be carefully done with necessery variation depending on the non cardiac organ and system involved: urgent either minor or major surgical interventions; bleeding peptic ulcer; elective surgery including ophtalmic and common dental procedures with risk of bleeding.     

Spontaneous and non-spontaneous bleeding complications in patients with oral vitamin K antagonist therapy

Purpose

The aim of the study was to evaluate potential differences between patients with spontaneous and non-spontaneous bleeding episodes during treatment with vitamin K antagonists which mainly resulted in compartment syndromes.

Methods

The population in this study comprised 116 patients who suffered at least one bleeding complication which required surgical treatment during therapy with an oral vitamin K antagonist. The patients were treated between September 2001 and July 2008.

Results

Significant differences were observed between the two patient groups with regard to the presence of renal failure, arterial hypertension, and diabetes mellitus, which occurred more frequently in patients with spontaneous bleeding. Also, significantly more patients with spontaneous bleedings developed compartment syndrome that needed emergency operation. Overall mortality was 9.6 %, was associated with multiorgan failure in all patients, and was not different between the two patient groups.

Conclusions

The identification of high-risk patients before treatment with an oral vitamin K antagonist is of major importance. The existence of over-anticoagulation syndrome and compartment syndrome is associated with significant mortality and morbidity and should not be underestimated.     

Coumarin anticoagulation during pregnancy in patients with mechanical valve prostheses

Between January 1987 and December 1989, 20 female patients with one mechanical valve prosthesis (MVP) for at least 1 year postoperatively were studied while on coumarin therapy for the full length of pregnancy. In each case, caesarean section was scheduled for the 38th week. Patients were selected according to the following criteria: (1) prothrombin ratios remaining within the therapeutic range for more than 85% of their total estimations in the previous 12 months with mean daily doses of warfarin less than 5 mg; (2) stable cardiac status; (3) no previous obstetric diseases and (4) full acceptance of the risks involved in the protocol. The patients were in NYHA functional class I or II. Their ages ranged from 23 to 31 years (mean 26 +/- 3). Ten patients had a mitral prosthesis and 10 an aortic prosthesis. Among the 20 mechanical valve prostheses, 10 were Sorin, 6 Starr-Edwards, 2 Bj?rk-Shiley, and 2 Lillehei-Kaster. Eighteen patients were in sinus rythm, 1 in chronic atrial fibrillation, and 1 had a permanent endocardial pacemaker. Nineteen were delivered by caesarean section: warfarin was withdrawn 48 h before surgery and resumed 24 h thereafter. One patient had premature spontaneous delivery at 36 weeks. The mean prothrombin ratio measured weekly in the 20 patients was 2.06 +/- 0.45 INR, using a mean daily warfarin dose of 4.1 mg +/- 1.63. The mean value of the prothrombin ratio during caesarean section for the 19 patients was 1.23 +/- 0.38 INR. In the 20 live births, the mean birth weight was 2.9 kg +/- 0.40.(ABSTRACT TRUNCATED AT 250 WORDS)