非瓣膜病心房颤动或心房扑动患者应用不同起始剂量华法林对INR达标速度的影响

目的观察我国非瓣膜病心房颤动（NVAF）或心房扑动（AFL）患者应用不同起始剂量华法林时,国际标准化比值（INR）首次达标和稳定的时间及出血并发症的发生率等,以进一步了解中国人应用国产华法林的最佳起始剂量。方法人选84例,随机分入起始剂量3．125mg组（第1组）,起始5mg,2d后改为3．125mg组（第2组）和起始5mg治疗组（第3组）。于治疗第3、4、5、7、9天测定INR,根据INR调整华法林剂量,直到INR稳定于1．8～3．0,随访1个月。结果第3组比第1、2组提早达标并稳定,第1、2组差异无统计学意义。3组均无明显出血及血栓栓塞事件,INR增高发生率差异无统计学意义。结论对于中国NVAF或AFL患者,以5mg为初始剂量应用华法林能使INR安全、迅速、有效地达标并稳定。服药3次后即于第4天起测INR是安全的。     

老年人非瓣膜病心房颤动患者华法林5mg起始治疗的有效性及安全性

目的探讨老年人非瓣膜病心房颤动(NVAF)患者应用华法林5 mg起始治疗的疗效及安全性。方法入选具有华法林抗凝适应证的NVAF老年患者91例,随机分为2组,分别以5 mg/d或3 mg/d起始治疗,于治疗前、治疗后第3、4、5、8天测定国际标准化比值(INR),根据INR调整服药剂量,至INR稳定。结果 5 mg/d起始治疗第3、4、5、8天INR的达标率分别为3.9%、29.4%、43.1%和72.5%,INR达稳定时间为(9.8±2.3)d,与3 mg/d组0%、5%、22.5%、50%[(12.5±2.7)d]比较,差异有统计学意义(均P<0.05),出血发生率两组差异无统计学意义。结论 5 mg/d起始,连续4 d的华法林起始治疗方案能使INR迅速、安全、有效地达到稳定,无严重出血并发症发生。     

Initiation of warfarin therapy in elderly medical inpatients: a safe and accurate regimen

PURPOSE: Elderly patients are at high risk of over-anticoagulation when treated with warfarin, especially during treatment induction. We developed a simple low-dose regimen for starting warfarin therapy in elderly inpatients. The daily maintenance dosage is predicted from the international normalized ratio (INR) measured the day after the third daily intake of a 4-mg dose. We conducted a prospective multicenter study to evaluate the accuracy and safety of this regimen. METHODS: We studied 106 elderly (age >or=70 years) inpatients (mean [+/- SD] age, 85 +/- 6 years; range, 71 to 97 years) who had a target INR of 2.0 to 3.0. Accuracy in predicting the daily maintenance dose from INR value on day 3 was evaluated. RESULTS: The predicted daily maintenance warfarin dose (3.1 +/- 1.6 mg/d) correlated closely with the actual maintenance dose (3.2 +/- 1.7 mg/d; R(2) = 0.84). The predicted dose was equal to the actual dose in 77 patients (73%; 95% confidence interval [CI]: 64% to 81%) and within 1 mg in 101 patients (95%; 95% CI: 91% to 99%). The mean time needed to achieve a therapeutic INR was 6.7 +/- 3.3 days (median, 6.0 days); the mean time needed to achieve the maintenance dose was 9.2 +/- 4.5 days (median, 7.0 days). None of the patients had an INR >4.0 during this period. One fatal bleeding event was recorded in a patient with an INR in the therapeutic range. CONCLUSION: Our warfarin induction regimen was simple, safe, and accurate in predicting the daily maintenance warfarin dose in elderly hospitalized patients.     

Warfarin resistance

Warfarin, the only available oral coumarin anticoagulant in South Africa, is widely prescribed for the prevention and management of arterial and venous thrombo-embolism. It has a narrow therapeutic index and a wide inter-individual variability in therapeutic response. Genetic polymorphism of the VKORC1 and CYP2C9 genes, as well as clinical factors such as age, gender, body mass index and interacting drugs explain less than 55% of variability in warfarin dose requirements. True warfarin resistance is rare (< 0.1%) and is defined as warfarin requirements greater than 70 mg per week to maintain the international normalised ratio (INR) in the target therapeutic range. As hereditary warfarin resistance is rare, non-adherence, laboratory errors and interactions should be excluded in patients with persistent sub-therapeutic INR levels. Pharmacogenetic models to estimate individualised warfarin doses do not take into account the mutations associated with warfarin resistance. In patients with presumed warfarin resistance, higher doses that maintain the INR in the target therapeutic range should be given, and the INR closely and regularly monitored.     

Peripheral arterial compliance is lower in Afro-Caribbeans compared to white Caucasians with type 2 diabetes after adjustment for blood pressure

Arterial compliance declines with age. However this decline occurs more rapidly in both the hypertensive and diabetic states. Afro-Caribbeans have a higher prevalence of hypertension and other complications of diabetes than the indigenous white Caucasian population. We hypothesise that accelerated decline in arterial compliance may account for this racial difference. Forty-one volunteers, age 62.5 +/- 6.8 years (mean +/- s.d., range 48-75), were selected from diabetic clinics. Twenty-one were Caucasian and 20 were Afro-Caribbean. Pulse wave velocity (PWV) was measured using non-invasive techniques: the 'Complior' system was used to record PWV in the carotid-to-radial (C-R) and carotid-to-femoral (C-F) regions. Central arterial compliance (CAC) was measured by simultaneous aortic flow velocimetry and carotid artery applanation tonometry. The duration of diabetes was taken as the time from clinical diagnosis. Baseline characteristics in the two racial groups were comparable for age, BMI, cholesterol, HbA1c, blood pressure and duration of diabetes. Comparing the PWV in the C-F region showed that the mean PWV was 13.84 +/- 0.28 m/sec in the Caucasians and 13.97 +/- 0.34 m/sec in the Afro-Caribbeans (P = 0. 86) whereas in the C-R region the mean PWV was 11.13 +/- 0.28 m/sec in Caucasians and 12.10 +/- 0.34 m/sec in the Afro-Caribbeans (P = 0. 03). In agreement with the C-F findings there was no statistical difference in CAC between the two races. Adjustment of PWV in the carotid-radial (C-R) region for systolic and diastolic blood pressure, confirmed that the racial differences were independent of blood pressure (difference 0.91 m/sec, P = 0.046 after adjustment for diastolic pressure and 0.89 m/sec, P = 0.056 after adjustment for both systolic and diastolic blood pressure). Accelerated decline in peripheral arterial compliance may account for the increased stroke rate with diabetes in Afro-Caribbeans.     

Factors associated with obesity in South Asian, Afro-Caribbean and European women

OBJECTIVE: To investigate correlates of body mass index (BMI) and other anthropometric measurements in South Asian, Afro-Caribbean and European women in the UK. SUBJECTS: 291 South Asian, 303 Afro-Caribbean, and 559 European women aged 40-69y in West London, UK. DESIGN: Cross-sectional survey. MAIN OUTCOME MEASURES: BMI, waist-to-height ratio (WHt), and skinfold thicknesses. RESULTS: Compared with European women, South Asian and Afro-Caribbean women were more like to be obese (odds ratios (OR) 1.83 and 3.01, respectively), but less likely to rate themselves as overweight (BMI-adjusted OR 0.19 and 0.34, respectively). The proportion of women who walked at least 2.5 km/d, excluding activity at work, was lower in South Asians (22%) than in Europeans (44%) or Afro-Caribbeans (40%). Among employed women, the proportion who were active at work was higher in South Asians (63%) and Afro-Caribbeans (70%) than in Europeans (49%). In Europeans, obesity was inversely associated with social class, education, smoking, alcohol intake, and distance walked, and positively associated with time spent watching television. Adjustment for alcohol intake, smoking, education and transport, physical activity explained over 80% of the difference in BMI between South Asians and Europeans, but not the difference between Afro-Caribbeans and Europeans. CONCLUSION: The factor that may be most amenable to intervention in South Asian women is low physical activity outside the workplace. The high prevalence of obesity in Afro-Caribbean women, however, is not accounted for by any behavioural factors measured in this study, and the reasons for high rates of obesity in this group remain to be established.     

华法林对超高龄患者抗凝治疗价值研究

目的分析华法林抗凝治疗在80岁以上患者中临床应用的现状,评价其临床适应证、疗效及风险,探讨在超高龄患者中华法林的合理应用方法。方法回顾性分析2006年1月至2010年12月于北京大学第一医院心内科31例华法林抗凝治疗的80岁以上患者的临床资料,总结华法林的起始及维持剂量、国际标准比值(INR)监测及栓塞和出血事件的发生。结果 93.55%患者均属于被动抗栓治疗。70.97%的患者INR达2.0～3.0,70.97%的患者达标剂量<3 mg/d,41.94%的患者维持1.5 mg起始剂量。发生缺血性卒中2例,INR<2.0;出血事件2例,INR>2.5。结论 80岁以上超高龄患者的华法林抗凝治疗,1.5 mg/d的起始剂量安全有效;INR维持在2.0～2.5较为适宜。     

Ethnic differences in blood pressure and the prevalence of hypertension in England

The objective of this study was to examine the prevalence of hypertension and mean blood pressures among Afro-Caribbeans and South-Asians in England compared with Caucasians. Data from the Birmingham Factory Screen, Birmingham INTERSALT volunteers, and four West Midlands churches were combined into a single database (n = 2853), since all three studies employed identical methods. The cohort comprised 2169 (76%) Caucasians (71% men); 453 (16%) Afro-Caribbean (60% men); and 231 (8%) South-Asian men. The results were that overall prevalence of hypertension (> or =160/95 mm Hg or taking antihypertensives) was greater in both Afro-Caribbean men (31%) and women (34%) (both P < 0.001), compared with Caucasians (19% and 13% respectively), while South-Asian men had a similar overall prevalence to Caucasians (16%). Compared with Caucasians, Afro-Caribbeans had significantly higher mean systolic blood pressure, with higher mean diastolic blood pressures evident among Afro-Caribbean women. After adjustment for age, body mass index, smoking, and weekly alcohol intake, the odds ratios (95% CI) for being hypertensive were 1.56 (1.14 to 2.13; P = 0.005) and 2.40 (1.51 to 3.81; P = 0.0002) for Afro-Caribbean men and women, respectively and 1.31 (0.88 to 1.97; P = 0.19) for South-Asian men, compared with Caucasians. In conclusion the prevalence of hypertension and mean blood pressures are higher among Afro-Caribbeans compared with Caucasians. South-Asian men had similar rates of hypertension and mean blood pressures to Caucasians.     

Risks and benefits of combined use of bucolome and warfarin in anticoagulation therapy

Although bucolome has been used empirically to enhance and stabilize warfarin action in some institutes, the clinical risks and benefits of this combination are unclear. In the present study, warfarin monotherapy (WM) and bucolome combination (BC) therapy were compared in anticoagulation therapy.One hundred and ninety-five patients indicated for anticoagulation therapy were randomly assigned to WM (n = 98) or BC (bucolome 300 mg/day, n = 97). The dosage of warfarin was optimized in each patient to maintain the international normalized ratio (INR) level in the appropriate zone, ie, 1.6-2.6 for lower risk and 2.0-3.0 for higher risk patients. The clinical characteristics, clinical events, and time in therapeutic range (TTR) were evaluated and compared between the two groups. TTR was calculated using Rosendaal's linear interpolation method.The optimal dosage of warfarin was 3.3 ± 1.0 mg/day in WM and 1.4 ± 0.5 mg/day in BC (P < 0.001). During the observation period of 18 ± 6 months, no serious complication was observed and INR was measured 11 ± 3 times in each case. TTR was 0.61 ± 0.13 in WM and 0.62 ± 0.14 in BC (NS), but TTR in the WM subgroup with warfarin > 3 mg (0.58 ± 0.13) was lower than in the WM subgroup with warfarin ≤ 3 mg (0.64 ± 0.13, P = 0.026) and BC (P = 0.042).BC reduced the optimal dosage of warfarin without increasing clinical events. There was no significant difference in TTR between WM and BC, but BC may have benefits in selected cases, such as warfarin resistance.     

Exaggerated initial response to warfarin following heart valve replacement.

The response to initiation of oral anticoagulants at a usual dose of 5 mg of warfarin has been retrospectively evaluated in patients following heart valve replacement (HVR). Patients starting oral anticoagulants after HVR have a lower target International Normalized Ratio (INR) (1.5 to 2.6) until the pacing wires are removed after operation. The mean daily doses and INR responses after HVR and nonsurgical patients were retrospectively compared during the first 5 days of warfarin treatment. In a subset from both groups, the mean dose of warfarin was correlated with age, body weight, and albumin levels. Eighty-four HVR and 32 nonsurgical patients were studied. The mean daily warfarin dosage was 3.29 +/- 1.29 mg after HVR and 4.96 +/- 1.76 mg in controls (p <0.001), and the mean INRs 2.08 +/- 0.60 and 1.60 +/- 0.54, respectively (p <0.001). Of the HVR patients and controls, 48.8% and 21.8%, respectively, exceeded the upper level of the targeted range (p = 0.014), 86.9% and 40.6% had the dose reduced after the first 5 mg (p <0.001), and 54.7% and 28.1%, respectively, had warfarin withheld for at least 1 day (p = 0.015). Thirty-nine patients were included in the subset analysis. Patients with serum albumin levels <35 g/L required significantly less warfarin (3.84 mg/day) than patients with levels > or =35 g/L (5.37 mg/day; p <0.05). Thus, patients starting oral anticoagulation after HVR are significantly more sensitive to warfarin than nonsurgical patients. Patients with serum albumin levels below the normal values require less warfarin than patients with normal values during the initial phase of treatment.     

80岁及以上心房颤动患者低强度抗凝治疗的安全性和疗效观察

目的 评价年龄80岁及以上非瓣膜性心房颤动患者低强度抗凝治疗的疗效和安全性.方法入选年龄80岁及以上住院非瓣膜性心房颤动患者180例,随机抽签分为低强度和标准强度华法林抗凝治疗,低强度组目标国际标准化比值(INR)1.6～2.0,标准强度组目标INR 2.0～3.0.主要观察终点为两组患者随访期间各种出血并发症及各种栓塞事件发生率;次要观察为INR达标需要的华法林剂量,随访中INR＞3.0的测定次数.结果 两组患者均在半个月内达标,其后随访1年,随访期间低强度组和标准强度组血栓栓塞事件发生率分别为4.4%(4/90)与3.3%(3/90),差异无统计学意义(P＞0.05).但各种出血事件低强度组低于标准强度组,分别为5.6%(5/90)与16.7%(15/90),差异有统计学意义(P＜0.05),同时华法林使用剂量低强度组低于标准强度组,分别为(1.55±0.63)mg与(2.31±0.57)mg,差异有统计学意义(P＜0.05),随访中INR＞3.0的次数低强度组亦少于标准强度组(P＜0.05).结论 在年龄80岁及以上非瓣膜性心房颤动患者中,采用目标INR1.6～2.0低强度抗凝治疗,较常规标准抗凝治疗疗效差异无统计学意义,出血事件及风险明显减少.

Abstract：

Objective To investigate the effectiveness and safety of low-intensity warfarin anticoagulation in over 80-year-old patients with nonvascular atrial fibrillation (NVAF). Methods The 180 NVAF patients aged over 80 years were randomly assigned into 2 groups: 90 patients in lowintensity warfarin anticoagulation group (target value of INR 1.6-2.0), the other 90 patients in standard-intensity warfarin anticoagulation group (target value of INR 2. 0-3.0). All patients were followed up in outpatient-department for one year. Main outcome measures included the incidence rates of bleeding and thromboembolic events, and secondary outcome measures included the warfarin dosage and times of INR＞3.0. Results The incidence rate of thromboembolic events was 4.4% (4/90) in low-intensity group and 3.3% (3/90) in standard-intensity group with no statistically significant difference between these two groups (P＞0. 05). However, the incidence rate of hemorrhage was significantly lower in low-intensity group than in standard-intensity group [5.6% (5/90) vs. 16.7%(15/90), P＜0. 05]. Meanwhile the warfarin dosage was significantly lower in low-intensity group than in standard-intensity group [(1. 55±0. 63) mg vs. (2.31±0.57) mg, P＜0.05]. The times of INR＞3.0 were less in low-intensity group than in standard-intensity group (P＜0. 05). Conclusions Therapy with low-intensity warfarin anticoagulation in NVAF patients aged over 80 years may be equally effective as, but safer than that with standard-intensity warfarin.     

Clinical characteristics and 30-day mortality among Caucasians, Hispanics, Asians, And African-Americans in the 2003 California coronary artery bypass graft surgery outcomes reporting program

The importance of differences in clinical characteristics between ethnic groups on operative mortality of coronary artery bypass grafting (CABG) has not been clarified. Data reporting to the California CABG outcomes reporting program is mandated under state law in California. Data from 121 hospitals in 2003 were analyzed, including clinical characteristics and predicted and observed operative mortalities in patients who underwent isolated CABG. In total 21,272 isolated CABGs were reported in 2003. Compared with Caucasians (n = 15,069), Hispanics (n = 2,561), Asians (n = 1,772), and African-Americans (n = 785) were younger, more likely to be women, and had more hypertension, diabetes, renal failure, and severe liver disease (all p values <0.05). Hispanics had more heart failure and Asians had a lower body mass index compared with Caucasians, whereas African-Americans had a higher body mass index and more peripheral artery disease and heart failure (all p values <0.05). Based on a multivariate model, the predicted operative mortality for Hispanics (3.2%), Asians (3.3%), and African-Americans (3.6%) was higher (all p values <0.001) than that of Caucasians (2.8%). However, observed operative mortality was similar across ethnic groups, although there was a trend toward higher mortality in Asians compared with Caucasians (3.5% vs 2.8%, p = 0.077). In conclusion, significant differences in risk profile for CABG exist across ethnicities. Although the predicted operative mortality for Hispanics, Asians, and African-Americans was significantly higher than that for Caucasians, there was no significant difference in the observed operative mortality.     

Procedural success and complications following percutaneous coronary interventions among Asians and Pacific Islanders

BACKGROUND: Although Asians and Pacific Islanders (PI) make up the fastest growing ethnic group in the United States, little is known about the clinical characteristics, procedural success, and procedure-related complications of those who undergo percutaneous coronary interventions (PCI). HYPOTHESIS: This study investigated PCI procedural success and procedural complications among PI and Asian patients in comparison with Caucasians. METHODS: We examined clinical characteristics, procedural success (post-PCI lesion < 50%) and procedure-related complications (hemorrhage, renal failure, myocardial infarction, stroke, bypass surgery, death) for all patients undergoing PCI at our hospital from January 1999 to June 2003. RESULTS: Overall, 2,598 PCIs were performed--1,058 (39%) in Caucasians, 1,163 (43%) in Asians, and 377 (14%) in PIs. The mean age of PIs (59 +/- 11 years) was significantly lower than that of Caucasians (65 +/- 12 years) and Asians (66 +/- 12 years). The mean body mass index (26 +/- 5) of Asians was significantly lower, while that of PIs (31 +/- 7) was significantly higher than that of Caucasians (28 +/- 6). More Asians (33.3%) and PIs (40.5%) had diabetes mellitus than did Caucasians (19.9%). More Asians (71.6%) and PIs (76.1%) had hypertension than did Caucasians (61.9%). Renal failure was more prevalent in Asians and PIs (6.0 and 7.4%, respectively) than in Caucasians (3.8%). Other than a higher prevalence of disease involving the left anterior descending vessel in Asians (56.4%) compared with Caucasians (50.4%), angiographic features across the three races were similar. There was no significant difference in procedural success (approximately 94%) or procedure-related complications among Caucasians (6.4%), Asians (7.1%), and PIs (4.3%). CONCLUSION: Although PIs and Asians have a substantially higher burden of comorbidities than Caucasians, race does not appear to influence PCI procedural success or procedure-related complications.     

The association of vitamin K status with warfarin sensitivity at the onset of treatment

We investigated the association of vitamin K status with warfarin sensitivity among 40 orthopaedic patients beginning perioperative algorithm-dosed warfarin. Baseline vitamin K status was assessed using plasma vitamin K-1 and vitamin K-1 2,3 epoxide concentrations, and a questionnaire-based estimation of usual vitamin K intake. Warfarin sensitivity was assessed as the increase in the International Normalized Ratio (INR) after two doses of 5 mg of warfarin and as the 4-d accumulation of under-gamma-carboxylated prothrombin (PIVKA-II), adjusted for warfarin dose requirement. Multivariate models were used to assess vitamin K variables as predictors of warfarin sensitivity. The mean INR increase was 0.53 U and the mean PIVKA-II increase was 771 ng/ml/mg warfarin. Demographic factors were not associated with warfarin response. For each 1 standard deviation (SD) lower value of plasma vitamin K-1, but not the other vitamin K variables, the INR rose 0.24 U (P < or = 0.01). A higher usual vitamin K intake and plasma vitamin K-1, and lower plasma vitamin K-1 2,3 epoxide, were all associated with a lower PIVKA-II increase over 4 d. Respective differences in PIVKA-II accumulation per SD increase of each variable were -165, -218 and 236 ng/ml/mg warfarin (all P < or = 0.05). We concluded that dietary and biochemical measures of vitamin K status were associated with early warfarin sensitivity.     

The variation in anti-ENA characteristics between different ethnic populations with systemic lupus erythematosus over a 10-year period

OBJECTIVE: To assess how anti-ENA characteristics change in patients with systemic lupus erythematosus from different ethnic backgrounds over a 10-year period follow-up study. RESULTS: There were 61 patients, of whom 37 were Caucasian, 12 were Asian and 12 were Afro-Caribbean. At the first available bleed 12/37 (32%) Caucasians were anti-ENA positive compared to 6/12 (50%) Asians and 9/12 (75%) of Afro-Caribbeans (Chi-squared P=0.01 for Caucasian vs Afro-Caribbean) and these proportions remained essentially unchanged after 10 y of follow-up. However, over the 10 y of follow-up anti-ENA patterns did change, with anti-Ro being the commonest antibody pattern to emerge and anti-Ro/La the commonest antibody pattern to disappear. There were 20/37(54%) Caucasians, 1/12(8%) Afro-Caribbeans and 5/12(42%) Asians who remained negative for anti-ENA throughout the 10-year follow-up (Chi-squared P=0.03 for Caucasian vs Afro-Caribbean). CONCLUSION: Anti-ENA were more commonly found in the Afro-Caribbean than the Caucasian population. The commonest patterns of anti-ENA differ between ethnic groups and, over a 10-year period, anti-ENA patterns in individual patients changed in a significant number of individuals. However, Caucasians were more likely to remain anti-ENA negative over 10 y of follow-up than Afro-Caribbeans.     

老年心房颤动高危患者抗凝治疗的药物选择及安全性

目的探讨老年心房颤动患者抗凝治疗的药物剂量选择及安全性。方法选择确诊的老年心房颤动患者210例,按照年龄将60～79岁130例作为老年段及≥80岁80例作为高龄段。2个年龄段患者按服药治疗不同分为老年华法林组30例、高龄华法林组30例,老年联合用药组50例(氯吡格雷75 mg+阿司匹林100 mg),老年阿司匹林组50例和高龄阿司匹林组50例(阿司匹林100 mg)。观察服用华法林剂量及国际标准化比值(INR);各组患者栓塞及出血发生率。结果高龄华法林组剂量(2.88±0.46)mg,INR 2.29±0.55,老年华法林组剂量(2.93±0.75)mg,INR 2.30±0.52,差异无统计学意义(P>0.05)。老年华法林组和高龄华法林组及老年联合用药组栓塞发生率明显低于老年阿司匹林组和高龄阿司匹林组(P<0.05)。与老年华法林组和高龄华法林组及老年阿司匹林组和高龄阿司匹林组比较,老年联合用药组出血发生率明显高(P<0.05)。结论老年心房颤动患者服用华法林或氯吡格雷+阿司匹林能更有效预防脑卒中事件的发生,老年、尤其是高龄高危患者服用华法林治疗,INR控制在1.5～2.5是安全、有效。对于不适合应用华法林的患者,可应用氯吡格雷+阿司匹林预防血栓形成。     

Ethnic differences in left ventricular size and the prevalence of left ventricular hypertrophy among hypertensive patients vary with electrocardiographic criteria

The objective of this study was to investigate differences in electrocardiographic (ECG) parameters and the prevalence of left ventricular hypertrophy (LVH) by various ECG criteria between different ethnic groups in west Birmingham, United Kingdom. In all, 380 consecutive patients, mean age 63 (7.8) years, 75 (20%) female patients assessed for inclusion in hypertension trials in a city centre teaching hospital were studied: 303 (80%) were Caucasian, 43 (11.4%) Afro-Caribbean and 32 (8.5%) South Asian. LVH was assessed using seven different criteria, with adjustment for age and body mass index (BMI). The performance of the various criteria were compared between the three ethnic groups. There were significant differences in the R-wave voltage in lead aVL, the Sokolow-Lyon voltage and in criteria based on limb lead voltages alone between the three ethnic groups. Highest ECG voltages were seen in Afro-Caribbeans, and this translated into a significantly higher prevalence of LVH when assessed by the R-wave in aVL and the Sokolow-Lyon criteria. There were no significant differences between Caucasians and South Asians. These differences were abolished after adjustment for age and BMI. There was no difference in the Cornell voltage or its derivatives in men between the three ethnic groups. In conclusion, apparent differences in electrocardiographic voltage and the prevalence of LVH between ethnic groups are dependent upon the criteria chosen and may simply be secondary to differences in BMI. Unlike Afro-Caribbean patients, South Asians do not demonstrate significant differences in ECG voltage compared with Caucasians.     

Racial background is a determinant factor in the maintenance dosage of Warfarin

Warfarin is a drug commonly used in the prevention of thromboembolic events. There have been reports suggesting that racial background may influence warfarin dose requirements. Malaysia is a multiracial country in which there are 3 major races, Malay, Chinese, and Indian. We examined 100 patients from our hospital on stable maintenance doses of warfarin, with international normalized ratio (INR) of 2.0 to 3.5. We found that the mean warfarin dose for Indian patients (n = 19) was 6.9 mg, for Chinese patients (n = 55) was 3.6 mg, and for Malay patients (n = 26) was 3.2 mg. The results showed that the Indian patients required a statistically significantly higher warfarin dose than did patients of the other 2 races (P < .0005). Age was also found to affect the daily warfarin maintenance dose.     

不同抗栓干预对心房颤动患者体内血小板活化的影响

目的 观察不同抗栓干预对非瓣膜性心房颤动(nonvalvular atrial fibrillation,NVAF)患者血浆溶血磷脂酸(lysophosplmidic acid,LPA)含量变化的影响,为临床抗栓治疗提供依据.方法 经临床和辅助检查确诊的235例未接受抗栓治疗的NVAF患者,随机分为阿司匹林+双嘧达莫组(n=76,阿司匹林100 mg/d,双嘧达莫100 mg/d)、阿司匹林+固定剂量华法林组(n=79,阿司匹林100 mg/d,华法林1.25mg/d)和调整剂量华法林组(n=80,INR 1.5～2.1).根据患者年龄,每组再分为<60岁组、60～75岁组和≥76岁组.测定治疗前、治疗后2周和6周时血浆LPA含量,比较含量变化.结果 阿司匹林+固定剂量华法林组血浆LPA含量降低较阿司匹林+双嘧达莫组和调整剂量华法林组更为显著(P均<0.01).<60岁组经阿司匹林+双嘧达莫治疗后2周和6周,血浆LPA含量较治疗前显著降低(P均<0.01).<60岁组经阿司匹林+固定剂量华法林治疗后2周和6周,血浆LPA含量较治疗前显著降低(P均<0.01).60～75岁组经阿司匹林+固定剂量华法林治疗后2周和6周,血浆LPA含量较治疗前显著降低(P均<0.01).各年龄组患者经调整剂量华法林(INR 1.5～2.1)治疗后2周和6周,血浆LPA含量均较治疗前显著降低.结论 不同抗栓治疗方式对不同年龄组NVAF患者体内血小板活化均有不同程度的影响.<60岁组可给予阿司匹林+双嘧达莫治疗,75岁以下的患者可给予阿司匹林+固定剂量华法林治疗,>75岁的患者推荐应用调整剂量华法林(INR1.5～2.1)治疗.