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.     

心脏机械瓣膜置换术后抗凝治疗中的颅内出血

目的　探讨心脏机械瓣膜置换术后抗凝治疗中 ,颅内出血的危险因素及其防治措施。方法　随访 14例心脏机械瓣膜置换术后抗凝治疗颅内出血病人 ,分析其发生的危险因素。结果　 (1)出血组14例病人中 9例行开颅血肿清除 ,1例行颅骨钻孔引流术 ,术后生存 5例 ;3例未手术者 ,死亡 ;1例经保守治疗 ,痊愈。 (2 )出血组国际标准比值 (INR) (2 4 8± 0 5 1)明显高于对照组 (1 4 4± 0 4 2 ) (P <0 0 5 )。 (3)出血组合并使用抗血小板药的人数比例 (4 8% )明显大于对照组 (13% ) (P <0 0 5 )。 (4 ) 6 4 % (9/ 14例 )的出血病人发病时间在术后 3个月内。结论　心脏机械瓣膜置换术后抗凝治疗中颅内出血的危险因素有 :抗凝强度过大 ;合并使用抗血小板药物 ;抗凝治疗早期 (前 3月 )。并探讨抗凝治疗中颅内出血的诊治方法。     

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.     

心脏机械瓣置换后不同强度抗凝对病人凝血激活的影响

目的　探讨不同强度抗凝时 ,心脏机械瓣置换术后病人的凝血激活状态。方法　将 16 2例心脏机械瓣置换术后病人 ,根据抗凝强度 (INR)分成 4组 :A组 (<1 5 ) 2 5例 ;B组 (1 5～ <2 0 ) 4 4例 ;C组 (2 0～ <3 0 ) 6 1例 ;D组 (3 0～ <4 5 ) 32例。 2 0例正常成人为对照组。采用酶联免疫吸附法 (ELISA)测定各组血浆凝血酶原片段 1+2 (F1 + 2 )、D 二聚体浓度。结果　A、B、C、D和对照组F1 + 2 浓度分别为(2 4 8± 1 32 )、(1 2 3± 0 6 5 )、(0 81± 0 4 5 )、(0 73± 0 39)、(1 11± 0 35 )nmol L ;D 二聚体浓度分别为(0 4 5± 0 2 4 )、(0 30± 0 17)、(0 2 4± 0 10 )、(0 2 5± 0 11)、(0 2 1± 0 0 9)mg L。A组F1 + 2 和D -二聚体浓度均显著高于对照组 (P <0 0 1) ;B组F1 + 2 浓度与对照组无差异 (P >0 0 5 ) ,D 二聚体浓度显著高于对照组 (P <0 0 5 ) ;C、D组F1 + 2 浓度均显著低于对照组 (P <0 0 5 ) ,但C、D两组间差异无显著性 (P >0 0 5 ) ;C、D组D 二聚体浓度与对照组之间均差异无显著性 (P >0 0 5 )。结论　在INR 2 0～ 3 0的抗凝强度下 ,心脏机械瓣置换术后病人凝血激活受到明显抑制     

Carbomedics机械瓣置换术后低强度抗凝治疗的观察

目的观察Carbomedics双叶机械瓣膜置换术后低强度抗凝治疗的可行性,探讨适合中国人的抗凝监测方式. 方法对连续61例置换Carbomedics双叶机械瓣膜患者,采用低强度抗凝标准[国际标准比值(INR)1.5～2.0],随访观察其抗凝指标、临床并发症发生情况和超声心动图变化. 结果术后随访57例,随访时间1～24个月,平均17.9±6.4个月.本组发生与抗凝有关的出血8例,发生栓塞1例,1年生存率平均为98.4%±0.3%.平均INR值为1.7±0.4,平均华法林剂量为2.54±0.60 mg/d. 结论 Carbomedics双叶机械瓣膜置换术后低强度抗凝治疗效果可靠,随访抗凝监测方式安全方便.抗凝强度过高和波动性增大是导致出血并发症的重要危险因素.     

心脏瓣膜置换术后中远期疗效分析

目的　分析探讨心脏瓣膜置换术的中远期疗效。方法　 1978年至 2 0 0 1年 12月 ,行瓣膜置换手术 2 14 1例 ,同期随访 16 81例 ,计 80 2 1 1人·年 ,平均 4 77人·年。通过回顾病因、手术方式、瓣膜类型等因素 ,观察术后病人心功能改善情况 ,病死率及并发症等 ,采用t检验 ,多因素回归等统计学方法分析。结果　 92例死亡。总体生存率 5年为 (92 3± 2 2 ) % ,10年生存率为 (90 1± 2 7) %。并发症有血栓栓塞、机械瓣膜功能障碍、瓣周漏、溶血、机械瓣膜感染性心内膜炎。术后心功能 (NYHA)与术前比较有明显的提高。结论　 1.机械瓣置换术后中远期疗效满意 ,病死率及并发症均较低 ;与术前心功能和手术种类直接相关 ;2 .使用保留瓣下结构及三尖瓣成形术对术后心功能恢复有明显效果 ;3.术中良好心肌保护是提高手术成功率的关键。     

心脏瓣膜置换术后低强度抗凝研究

目的　研究我国南方地区人工机械瓣膜置换术后行低强度抗凝的可行性及安全强度。方法　75例置换人工机械瓣膜的患者按国际标准化比值(INR)分为A、B、C 3组。术后定时分别检测其凝血酶原时间(PT)及INR、D 二聚体浓度、抗凝血酶Ⅲ活性(AT Ⅲ:C) ,并定时监测术后出血及血栓形成的发生率。结果　机械瓣膜置换术后,INR控制于1.6～2 .5范围,可保持D 二聚体浓度、AT Ⅲ:C与对照组差异无统计学意义(P >0 .0 5 )。2 5 5人次INR控制1.6～2 .5之间,3组均未出现血栓形成,有16人次轻微出血,其中A组有4人次(4 /15 5 ,2 .5 % ) ;B组有5人次(5 /70 ,7.1% ) ;C组有7人次(7/3 0 ,2 3 .3 % ) ,明显高于A、B两组(P <0 .0 1)。结论　我国南方地区人工机械瓣膜置换术后低强度抗凝是可行的,INR控制在1.6～2 .5范围较安全。     

经食管超声心动图在心血管手术麻醉与监测中的应用

目的　评价经食管超声心动图 (TEE)在心血管手术麻醉中的价值。方法　本组共完成 1 2 2例TEE监测。主要观察指标 :(1 )对 4 1例瓣膜置换患者的瓣膜作返流和狭窄分级及评价机械或生物瓣的功能 ;(2 ) 4 8例不停跳冠状动脉搭桥 (CABG)患者手术前后心功能变化〔①面积减少分数(FAC) ;②E波与A波峰值流速比率 (E/A)和各自的流速时间积分比率 (VTIE/VTIA) ;③E波减速时间 (DT) ;④心脏指数 (CI)〕 ;(3)手术前后对 2 0例不停跳CABG患者左室室壁 (前壁、后壁、侧壁和室间隔 )运动分级 ;(4 )监测先心病矫正前后心脏结构变化。结果　TEE检测瓣膜病变与经胸超声结果一致 ,手术后瓣膜活动正常。术后FAC、CI和VTIE/VTIA分别为 (0 5 2± 0 0 8)、(2 6 4± 0 6 9)L·min 1 ·m 2 和 1 2 9± 0 1 8,与术前比较 (0 4 2± 0 0 9)、(2 0 5± 0 4 8)L·min 1 ·m 2 和 1 1 4± 0 1 6有显著性差异 (P <0 0 5 ) ;术后E/A 0 86± 0 2 1与术前 0 77± 0 1 8比较P <0 0 1。DT无显著性变化。术前节段性室壁运动异常大于 2级的占 1 0 % ,术后为 5 %。结论　在心血管手术中 ,TEE是一种新的有用的监测技术     

围手术期的抗凝控制(英)

对于那些已经作过抗凝治疗而又需要手术的病人,在手术中如何保持血栓栓塞与出血这一对对立状况之间的平衡,确是一个相当棘手的问题.但是,至今对于围手术期的抗凝控制仍然尚无详细的方案可以依循,作者根据各方面的经验归纳成以下几条指导性意见,供临床医生参考.1)进行非心脏手术的患者,在术前6天以及手术之中,停用抗凝药物看来是安全的;2)作抗凝治疗的病人大致可分成二大类:心脏瓣膜(机械瓣)置换和因其它原因应用华法令治疗(例如静脉血栓形成、肺栓塞以及心室室壁瘤等).二种病人的围手术期的抗凝处理有所不同,分述如下:(1)心脏瓣膜(机械瓣)置换者,术前三天停用华法令,最后一次用药(华法令)之后24小时,开始由静脉途径给予肝素,初始剂量为15000u/12小时,给药12小时后的     

血小板单采对体外循环心脏瓣膜置换手术的血液保护作用

20 0 0年 5月至 2 0 0 1年 2月 ,我们在体外循环 (ＣＰＢ)心脏瓣膜置换手术中应用血小板单采技术 ,观察其血液保护作用。现报道如下。资料和方法　 2 1例择期心脏瓣膜置换手术病人 ,术前 2周内均未用过抗凝、抗血小板药物 ,血小板计数均 >10 0×10 9/Ｌ ,随机分为试验组与对照组 (表 1)。表 1　试验组和对照组临床资料比较项　目对照组 ( 11例 )试验组 ( 10例 )男 /女 (例 ) 3/83/7体重 (ｋｇ) 6 1 2 3± 6 72 6 3 2 2± 7 31年龄 (岁 ) 41 2 0± 6 42 44 44± 5 36二尖瓣置换术 (例 ) 7 5主动脉瓣置换术 (例 ) 2 3双瓣膜置换术 (例 ) 2 …     

心脏机械瓣膜置换术后低强度抗凝治疗中的缺血性脑卒中

目的探讨心脏机械瓣膜置换术后低强度抗凝治疗中缺血性脑卒中发生的危险因素及其防治方法。方法将2004年3月至2008年7月我科收治的机械瓣膜置换术后发生缺血性脑卒中患者23例纳入研究（缺血性脑卒中组）,随机选择同期行心脏机械瓣膜置换术后患者120例作为对照（对照组）,比较两组患者的性别、年龄、华法林用量、抗凝强度[国际标准化比值（INR）]及INR复查间隔时间、左心房内径、心律等指标,采用logistic回归分析缺血性脑卒中发生的危险因素。结果（1）缺血性脑卒中组患者入院后经相关治疗均顺利出院,住院期间无1例死亡,出院后随访1个月～3年,全组患者神经系统并发症均有明显恢复,无再发栓塞及抗凝治疗中的严重出血发生;（2）两组患者性别、年龄、华法林用量比较差异无统计学意义（P〉0．05）;（3）对影响因素进行非条件logistic回归分析结果,心房颤动（P=0．000）、左心房增大（P=0．002）、抗凝强度过低（P=0．012）、INR复查间隔过长（P=0．047）为心脏机械瓣膜置换术后低强度抗凝治疗中缺血性脑卒中发生的危险因素。结论（1）心脏机械瓣膜置换术后低强度抗凝治疗中缺血性脑卒中的预后相对于颅内出血较好,其发生与多个危险因素有关;（2）临床上应该尽可能减少各项危险因素对抗凝治疗的影响,以避免缺血性脑卒中的发生;（3）心脏机械瓣膜置换术后抗凝治疗中发生缺血性脑卒中的患者早期进行低强度抗凝治疗较安全、有效。     

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.     

三尖瓣置换术及抗凝治疗70例临床分析

目的 探讨三尖瓣置换术(TVR)的手术指征、瓣膜选择及术后抗凝治疗方法.方法 1998年5月至2008年1月,共有70例患者接受TVR,其中风湿性心脏病患者59例.手术包括:二尖瓣置换术(MVR)+TVR 37例,MVR+主动脉瓣置换术(AVR)+TVR 18例,TVR 13例,TVR+AVR 2例.全部患者自术后2 d开始采用华法林进行抗凝治疗.结果 术后3例患者因低心排血量死亡,死亡率4.3%.1例发生Ⅲ度房窒传导阻滞,1例发生急性肾功能衰竭,并发症率7.1%.随访59例,随访率88.1%,平均随访(3.6±5.2)年,共243.5人年.1例患者于术后3个月死亡;远期死亡率0.4%人年.5例患者出现一般性出血,出血率2.1%人年.1例发生脑梗死,1例因三尖瓣血栓形成再手术,栓塞率0.8%人年.门诊随访INR均值1.87±0.68.患者术后心功能(NYHA分级)Ⅰ～Ⅱ级52例,Ⅲ级7例.结论 风湿性心脏病三尖瓣病变严重者应行TVR;双叶机械瓣膜应用于TVR效果满意;TVR术后抗凝治疗强度尚有待探讨.     

东北人群人工机械瓣膜置换术后低强度抗凝治疗的单中心研究

目的 探讨适合我国东北人群特点的人工机械瓣膜置换术后抗凝治疗强度标准。 方法 对2005年1月至2013年6月在吉林大学第二医院心血管外科完成的856例 ［男406例、女450例,年龄（45.2±13.3） 岁］ 置换人工机械瓣膜的东北人群患者,采用了低强度的抗凝标准 ［国际标准化比值（INR） 1.5～2.2,主动脉瓣置换术（AVR）：1.5～1.8;二尖瓣置换术 （MVR）：1.8～2.2］,通过术后随访,分析该抗凝标准下人工机械瓣膜术后与抗凝相关的并发症发生率。 结果 本组患者随访时间1～78 （18.3±12.2） 个月,总随访率为75.4%,发生血栓栓塞12 例（1.86%）。发生与抗凝有关的出血10例（1.55%）。随访口服华法林剂量（3.4±0.8） mg/d,随访INR 1.94±0.54。 结论 在我国东北患者中采用低强度抗凝治疗（INR 1.5～2.2：AVR 1.5～1.8,MVR 1.8～2.2）标准,可以获得满意的预防血栓栓塞,减少与抗凝有关的出血等并发症的效果。     

International normalized ratio self-management after mechanical heart valve replacement: is an early start advantageous?

BACKGROUND: Severe thromboembolic and hemorrhagic complications after mechanical heart valve replacement essentially depend on the intensity of oral anticoagulation and the fluctuation of individual international normalized ratio (INR) values. METHODS: After heart valve replacement with Medtronic Hall, St. Jude Medical, and CarboMedics implants, patients were randomly divided into two groups, one controlling INR values at home, the other being monitored by family practitioners. RESULTS: Almost 80% of the INR values recorded by patients at home were within the stipulated therapeutic range, INR 2.5 to 4.5, compared with just 62% of INR values recorded by family practitioners. The overall complication rate (hemorrhages and thromboembolic events) of the self-management group was significantly (p < 0.05) decreased compared with the conventional group. CONCLUSIONS: Through INR self-management, an improvement in the quality of ongoing oral anticoagulation could be shown. Starting this form of therapeutic control early after mechanical heart valve replacement appears to effect a further reduction in anticoagulant-induced complications.     

Aortic valve selection in the elderly patient

To determine the influence of valve selection on valve-related morbidity and mortality and patient survival, comparative long-term performance characteristics of mechanical (N = 68) and bioprosthetic (N = 73) heart valves were analyzed for 141 patients more than 70 years old who underwent isolated aortic valve replacement between 1970 and 1985. Cumulative patient follow-up was 491 patient-years (average, 4.3 years per patient). Hospital mortality was 18% and 19% for patients with mechanical valves and bioprosthetic valves, respectively. Survival at 5 years was 61 +/- 7% (+/- the standard error) and 67 +/- 10% for recipients of mechanical valves and bioprosthetic valves, respectively. Male sex (p = 0.014) and urgency of operation (p = 0.006) were independent risk factors for hospital mortality. Atrial fibrillation increased valve-related mortality (p = 0.01). No patient required reoperation or experienced structural valve failure. While anticoagulant-related hemorrhage was increased in recipients of mechanical valves (9.2 +/- 2.1%/patient-year) compared with recipients of bioprosthetic valves (2.3 +/- 1.1%/patient-year), it did not result in a death or lead to permanent disability. There was no difference in freedom from any valve-related complication at 5 years. However, when all morbid events are considered, recipients of bioprosthetic valves experienced fewer valve-related complications than patients receiving mechanical valves (10.7 +/- 2.3%/patient-year versus 17.6 +/- 2.5%/patient-year, respectively; p less than 0.05). The reduced incidence of anticoagulant-related hemorrhage and the infrequent need for warfarin sodium anticoagulation favor selection of a bioprosthetic heart valve in patients older than 70 years.     

Late results after Starr-Edwards valve replacement in children

Selection of types of prosthetic heart valves for children remains controversial. The case histories of 50 children surviving valve replacement with Starr-Edwards prostheses between 1963 and 1978 were reviewed to evaluate the long-term performance of mechanical valves. The 31 boys and 19 girls ranged from 6 months to 18 years in age (mean 10.4 years); 19 patients had had aortic valve replacement, 24 patients had had mitral valve replacement, and one patient had had both. Among the six patients who had had tricuspid valve replacement, four had corrected transposition, so that the tricuspid valve was the systemic atrioventricular valve. Mean (+/- standard deviation) follow-up interval was 7.9 +/- 4.9 years (maximum 17 years). For all patients, the 5 year survival rate was 86% +/- 6%. At 10 years postoperatively, the survival rate (+/- standard error) was 90% +/- 7% after aortic valve replacement and 76% +/- 8% after systemic atrioventricular valve replacement. At follow-up, 39 patients were alive, and 38 were in New York Heart Association Class I or II. Of the 11 deaths, four were valve-related. Seven patients had major (requiring hospitalization) thromboembolic events, and five patients had minor transient neurological symptoms suggesting thromboembolism; 50% of these patients were not taking warfarin (Coumadin) at the time of the thromboembolic event. The incidence of late (greater than 30 days) thromboembolism was 5.3 per 100 patient-years after aortic and 2.0 per 100 patient-years after systemic atrioventricular valve replacement. At 10 years postoperatively, 66% +/- 15% of patients who had had aortic valve replacement and 91% +/- 6% of those who had had systemic atrioventricular valve replacement were free of thromboembolism. The excellent long-term survival, absence of mechanical failure, and relatively low rate of thromboembolism with this prosthesis contrast with our experience with biological valves, in which 41% of children required reoperation in 5 years. Currently, mechanical valves, such as the Starr-Edwards prostheses, are our preferred valves for pediatric patients.     

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.     

What is the optimal level of anticoagulation in adult patients receiving warfarin following implantation of a mechanical prosthetic mitral valve?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was what is the optimal target INR for warfarin therapy in patients who have undergone implantation of a prosthetic mechanical mitral heart valves? Altogether 894 papers were identified on Medline and 1235 on Embase using the reported search including all major international guidelines. Twelve papers and publications represented the best evidence on the topic. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses were tabulated. We conclude that after implantation of new generation prosthetic mechanical mitral valves, patients should receive warfarin to a target INR of 2.5-3.5. For older types of valve the target INR should be 3.5-4.5. Warfarin therapy should be administered to maintain stable INR values ensuring lowest possible variation in the intensity of anticoagulation. In selected patients with a history of thromboembolic disease and/or coronary artery disease warfarin therapy consideration should be given to supplementing warfarin with low-dose aspirin.