Weight management and determinants of weight change in patients with coronary artery disease

OBJECTIVE

To study the effects of a comprehensive secondary prevention programme on weight loss and to identify determinants of weight change in patients with coronary artery disease (CAD).

METHODS

We performed a secondary analysis focusing on the subgroup of overweight CAD patients (BMI ≥27 kg/m²) in the Randomised Evaluation of Secondary Prevention by Outpatient Nurse SpEcialists-2 (RESPONSE-2) multicentre randomised trial. We evaluated weight change from baseline to 12-month follow-up; multivariable logistic regression with backward elimination was used to identify determinants of weight change.

RESULTS

Intervention patients (n=280) lost significantly more weight than control patients (n=257) (-2.4±7.1 kg vs -0.2±4.6 kg; p<0.001). Individual weight change varied widely, with weight gain (≥1.0 kg) occurring in 36% of interventions versus 41% controls (p=0.21). In the intervention group, weight loss of ≥5% was associated with higher age (OR 2.94), lower educational level (OR 1.91), non-smoking status (OR 2.92), motivation to start with weight loss directly after the baseline visit (OR 2.31) and weight loss programme participation (OR 3.33), whereas weight gain (≥1 kg) was associated with smoking cessation ≤6 months before or during hospitalisation (OR 3.21), non-Caucasian ethnicity (OR 2.77), smoking at baseline (OR 2.70), lower age (<65 years) (OR 1.47) and weight loss programme participation (OR 0.59).

CONCLUSION

The comprehensive secondary prevention programme was, on average, effective in achieving weight loss. However, wide variation was observed. As weight gain was observed in over one in three participants in both groups, prevention of weight gain may be as important as attempts to lose weight.

TRIAL REGISTRATION NUMBER

NTR3937.

Health literacy and hypertension outcomes in a multi-ethnic population: the HELIUS study

BACKGROUND

Hypertension disproportionately affects ethnic minority groups. Although health literacy may play role in these ethnic inequalities, little is known about the extent to which health literacy affects hypertension prevalence, awareness, treatment and control in different ethnic groups. Therefore, we assessed these associations in a multi-ethnic population.

METHODS

Baseline data from the HELIUS study were used including participants of Dutch (n = 1948), South-Asian Surinamese (n = 2054) and African Surinamese (n = 1932) origin aged 18-70 years, who lived in Amsterdam, the Netherlands, were fluent in Dutch and underwent health literacy assessment through the Rapid Estimate of Adult Literacy in Medicine-Dutch (REALM-D). The REALM-D was categorized either as low (<60 sumscore) or adequate (≥60 sumscore) health literacy. Participants completed questionnaires and underwent physical examination.

RESULTS

After adjusting for confounding variables, Dutch [odds ratio (OR) 2.02; 95% confidence interval (CI), 1.11-3.64] and African Surinamese (OR 1.36; 1.03-1.79) with low health literacy were more likely than those with adequate health literacy to have hypertension, whereas in South-Asian Surinamese this association was not significant. No significant associations were found between health literacy and hypertension awareness, treatment and control in any of the ethnic groups.

CONCLUSION

Findings indicate that health literacy is associated with hypertension prevalence in selected ethnic groups, but not with hypertension awareness, treatment and control. Targeting health literacy might be an entry point for tackling ethnic inequalities in hypertension prevalence. To substantially reduce these inequalities, further research is needed to explore other factors and pathways through which health literacy may impact hypertension outcomes in different ethnic groups.

Lifestyle modification in older versus younger patients with coronary artery disease

Objective

To compare the treatment effect on lifestyle-related risk factors (LRFs) in older (≥65 years) versus younger (<65 years) patients with coronary artery disease (CAD) in The Randomised Evaluation of Secondary Prevention by Outpatient Nurse SpEcialists 2 (RESPONSE-2) trial.

Methods

The RESPONSE-2 trial was a community-based lifestyle intervention trial (n=824) comparing nurse-coordinated referral with a comprehensive set of three lifestyle interventions (physical activity, weight reduction and/or smoking cessation) to usual care. In the current analysis, our primary outcome was the proportion of patients with improvement at 12 months follow-up (n=711) in ≥1 LRF stratified by age.

Results

At baseline, older patients (n=245, mean age 69.2±3.9 years) had more adverse cardiovascular risk profiles and comorbidities than younger patients (n=579, mean age 53.7±6.6 years). There was no significant variation on the treatment effect according to age (p value treatment by age=0.45, OR 1.67, 95% CI 1.22 to 2.31). However, older patients were more likely to achieve ≥5% weight loss (OR old 5.58, 95% CI 2.77 to 11.26 vs OR young 1.57, 95% CI 0.98 to 2.49, p=0.003) and younger patients were more likely to show non-improved LRFs (OR old 0.38, 95% CI 0.22 to 0.67 vs OR young 0.88, 95% CI 0.61 to 1.26, p=0.01).

Conclusion

Despite more adverse cardiovascular risk profiles and comorbidities among older patients, nurse-coordinated referral to a community-based lifestyle intervention was at least as successful in improving LRFs in older as in younger patients. Higher age alone should not be a reason to withhold lifestyle interventions in patients with CAD.

Associations between healthcare consumption in country of origin and in country of residence by people with Turkish and Moroccan backgrounds living in the Netherlands: the HELIUS study

BACKGROUND

In Europe, a substantial percentage of the 22 million inhabitants with histories of migration from non-European countries utilize healthcare in their countries of origin. That could reflect avoidance of healthcare in the country of residence, but this has not been studied previously.

METHODS

We linked Dutch healthcare reimbursement data to the multi-ethnic population-based data from the HELIUS study conducted in Amsterdam. In multivariable logistic regression and negative binomial generalized estimating equation (GEE) analyses, we examined associations between healthcare use in country of origin and in country of residence by people with Turkish and with Moroccan backgrounds (N = 2920 and N = 3031, respectively) in the period 2010-15.

RESULTS

Participants with Turkish and Moroccan backgrounds who utilized healthcare one or multiple times in the country of origin (n = 1335 and n = 558, respectively) were found to be more likely, in comparison with non-users (n = 1585, n = 2473), to be frequent attenders of services by general practitioners, medical specialists and/or allied health professionals in the Netherlands [odds ratios between 1.21 (95% CI 0.91-1.60) and 3.15 (95% CI 2.38-4.16)]. GEE analyses showed similar results.

CONCLUSION

People with Turkish or Moroccan backgrounds living in the Netherlands who use healthcare in their countries of origin are more likely than non-users to be higher users of healthcare in the Netherlands. We thus found no indications for avoidance of healthcare in the country of residence.

Estimation of cardiovascular risk based on total cholesterol versus total cholesterol/high-density lipoprotein within different ethnic groups: The HELIUS study

Aims

European guidelines recommend estimating cardiovascular disease risk using the Systematic COronary Risk Evaluation (SCORE) algorithm. Two versions of SCORE are available: one based on the total cholesterol/high-density lipoprotein cholesterol ratio, and one based on total cholesterol alone. Cardiovascular risk classification between the two algorithms may differ, particularly among ethnic minority groups with a lipid profile different from the ethnic majority groups among whom the SCORE algorithms were validated. Thus in this study we determined whether discrepancies in cardiovascular risk classification between the two SCORE algorithms are more common in ethnic minority groups relative to the Dutch.

Methods

Using HELIUS study data (Amsterdam, The Netherlands), we obtained data from 7572 participants without self-reported prior cardiovascular disease of Dutch, South-Asian Surinamese, African Surinamese, Ghanaian, Turkish and Moroccan ethnic origin. For both SCORE algorithms, cardiovascular risk was estimated and used to categorise participants as low (<1%), medium (1–5%), high (5–10%) or very high (≥10%) risk. Odds of differential cardiovascular risk classification were determined by logistic regression analyses.

Results

The percentage of participants classified differently between the algorithms ranged from 8.7% to 12.4% among ethnic minority men versus 11.4% among Dutch men, and from 1.9% to 5.5% among ethnic minority women versus 6.2% among Dutch women. Relative to the Dutch, only Turkish and Moroccan women showed significantly different (lower) odds of differential cardiovascular risk classification.

Conclusion

We found no indication that discrepancies in cardiovascular risk classification between the two SCORE algorithms are consistently more common in ethnic minority groups than among ethnic majority groups.

Reproducibility of sublingual microcirculation parameters obtained from sidestream darkfield imaging

BACKGROUND

Changes in the microcirculation may be used as a surrogate outcome in studies on cardiovascular disease. We assessed the reliability characteristics of the sublingual microcirculation parameters Vascular Density (VD), Red Blood Cell Filling (RBCF), and Perfused Boundary Region (PBR) as obtained by sidestream darkfield imaging.

METHODS

For each of the three parameters, the variance components of measurement, the Intraclass Correlation Coefficient (ICC), the Standard Error of Measurement, and the limits of agreement were estimated for the intra-rater setting (N = 50) and the inter-rater setting (N = 48). Subsequently, as a proof of concept, the reliability measures were used for a power analysis to design studies to evaluate the effect of acute stimuli-i.e. having a meal (N = 50) and cigarette smoking (N = 21) on the three parameters.

RESULTS

Reproducibility was poor for all three parameters. The intra-rater ICC for 2 measurements was 0.28 (95% CI: 0.04, 0.53) for the VD, 0.51 (95% CI: 0.27, 0.69) for the RBCF, and 0.33 (95% CI: 0.08-0.56) for the PBR. The standard errors of measurement and the limits of agreement for all three parameters were larger than most statistically significant intra-individual or inter-individual differences reported in previous studies. The proofs of concept showed that sample sizes in excess of 600 subjects are necessary to reach statistical significance for the observed effects of having a meal or smoking on VD and PBR.

CONCLUSIONS

The reliability of the three sublingual microcirculation parameters in their current form appears to be low and a large sample size is advisable for their use in conditions similar to those we describe.

Intensive Blood Pressure Lowering in Patients With and Patients Without Type 2 Diabetes: A Pooled Analysis From Two Randomized Trials

OBJECTIVE

The Action to Control Cardiovascular Risk in Diabetes Blood Pressure (ACCORD-BP) study did not find a significant beneficial effect of intensive systolic blood pressure (SBP) lowering on cardiovascular events in hypertensive patients with type 2 diabetes mellitus (T2DM), while the Systolic Blood Pressure Intervention Trial (SPRINT) did find a significant beneficial effect in patients without T2DM. The objective of this analysis was to assess the effect of both T2DM and baseline cardiovascular disease risk on the treatment effect of intensive blood pressure lowering.

RESEARCH DESIGN AND METHODS

The individual patient data from the ACCORD-BP and SPRINT studies were pooled and follow-up durations harmonized. Both studies randomized hypertensive patients to an SBP target of <120 mmHg or a target of <140 mmHg. The composite primary end point consisted of unstable angina, myocardial infarction, acute heart failure, stroke, and cardiovascular death. The interaction between intensive blood pressure lowering and both T2DM and 10-year cardiovascular risk was assessed using Cox proportional hazards models.

RESULTS

The cohort consisted of 14,094 patients with mean age 66 ± 8.9 years and mean baseline SBP 139.5 ± 15.6 mmHg; 33.6% had T2DM. The hazard ratio for the primary composite end point was 0.82 (95% CI 0.73-0.93), P = 0.0017. The interaction between intensive blood pressure lowering and T2DM was nonsignificant (P = 0.13). The 10-year cardiovascular risk was higher in primary prevention patients with T2DM, but risk did not interact with the treatment effect (P = 0.84).

CONCLUSIONS

Intensive blood pressure lowering may have a similar favorable effect and appears to decrease cardiovascular events in both patients with and patients without T2DM.

Nurse-coordinated care improves the achievement of LDL cholesterol targets through more intensive medication titration

Background

Nurse-coordinated care (NCC) improves the achievement of low-density lipoprotein-cholesterol (LDL-C) targets after an acute coronary syndrome (ACS). We hypothesised that NCC improves achievement of LDL-C targets through more intensive medication titration.

Methods

We used data from Randomised Evaluation of Secondary Prevention by Outpatient Nurse Specialists (RESPONSE), a multicentre randomised trial on the efficacy of NCC in 754 ACS patients. Follow-up data were collected at 6 and 12 months. To enable comparison between the various types and dosages of statins, we used the average lipid-lowering potency (ALLP, % LDL-C lowering) as an indicator of lipid-lowering medication intensity.

Results

Most patients in NCC intervention and usual care groups (96%) had started lipid-lowering therapy during the index hospitalisation. At 6 months, titration activities (up or down) were applied in 45% of NCC patients compared with 24% of patients receiving usual care (p<0.001), and a difference was also seen at 12 months follow-up (52% vs 34%, p<0.001). In patients not on LDL-C target at baseline, titration activities at 6 months were recorded in 63% and 30% of NCC and usual care patients respectively (p<0.001), with increased titration activities in both groups at 12 months (69% vs 43%, p<0.001).

Conclusion

NCC is associated with more frequent and intense lipid-lowering medication titration to reach LDL-C targets as compared with usual care alone. Further, merely starting the guideline-recommended dose is insufficient to reach the guideline-recommended LDL-C target level.

Trial Registration number

TC1290 (Netherlands).

Case Finding and Medical Treatment of Type 2 Diabetes among Different Ethnic Minority Groups: The HELIUS Study

Aims. Prevention of diabetes complications depends on the level of case finding and successful treatment of diabetes, which may differ between ethnicities. Therefore, we studied the prevalence by age, awareness, treatment, and control of type 2 diabetes, among a multiethnic population. Methods. We included 4,541 Dutch, 3,032 South-Asian Surinamese, 4,109 African Surinamese, 2,323 Ghanaian, 3,591 Turkish, and 3,887 Moroccan participants (aged 18-70 y) from the HELIUS study. The prevalence of diabetes was analysed by sex, ethnicity, and 10-year age groups. Ethnic differences in the prevalence, awareness, treatment, and control of diabetes were studied by logistic regression. Results. From the age of 31-40 years and older, the prevalence of diabetes was 3 to 12 times higher among ethnic minority groups than that among the Dutch host population. Awareness and medical treatment of diabetes were 2 to 5 times higher among ethnic minorities than that among Dutch. Among those medically treated, only 37-53% had HbA1c levels on target (≤7.0%); only Dutch men had HbA1c levels on target more often (67%). Conclusions. Our results suggest that the age limit for case finding among ethnic minority groups should be lower than that for the general population. Importantly, despite higher awareness and treatment among ethnic minorities, glycemic control was low, suggesting a need for increased efforts to improve the effectiveness of treatment in these groups.

Association of Family History With Cardiovascular Disease in Hypertensive Individuals in a Multiethnic Population

BACKGROUND

Hypertension alone is a poor predictor of the individual risk of cardiovascular disease. Hereditary factors of which hypertension is merely a marker may explain why some hypertensive individuals appear more susceptible to cardiovascular disease, and why some ethnicities have more often seemingly hypertension-related cardiovascular disease than others. We hypothesize that, in hypertensive individuals, a positive family history of cardiovascular disease identifies a high-risk subpopulation.

METHODS AND RESULTS

Healthy Life in Urban Settings (HELIUS) is a cohort study among participants of Dutch, South-Asian Surinamese, African Surinamese, Ghanaian, Turkish, and Moroccan origin aged 70 years and younger. In participants with hypertension (n=6467), we used logistic regression to assess the association of family history of cardiovascular disease with prevalent stroke and nonstroke cardiovascular disease, adjusting for sex, age, education, and smoking. To detect ethnic differences, we tested for interaction between family history and ethnicity and stratified the analysis by ethnicity. A positive family history was associated with a higher prevalence of nonstroke cardiovascular disease (odds ratio [OR], 2.05; 95% CI, 1.65-2.54) and stroke (OR, 1.62; 95% CI, 1.19-2.20). The strongest association of family history with nonstroke cardiovascular disease was found among the Dutch (OR, 2.47; 95% CI, 1.37-4.44) and with stroke among the African Surinamese (OR, 2.17; 95% CI, 1.32-3.57). The interaction between family history and African Surinamese origin for stroke was statistically significant.

CONCLUSIONS

In multiethnic populations of hypertensive patients, a positive family history of cardiovascular disease may be used clinically to identify individuals at high risk for nonstroke cardiovascular disease regardless of ethnic origin and African Surinamese individuals at high risk for stroke.

Efficient heterocyclisation by (di)terpene synthases

While cyclic ether forming terpene synthases are known, the basis for such heterocyclisation is unclear. Here it is reported that numerous (di)terpene synthases, particularly including the ancestral ent-kaurene synthase, efficiently produce isomers of manoyl oxide from the stereochemically appropriate substrate. Accordingly, such heterocyclisation is easily accomplished by terpene synthases. Indeed, the use of single residue changes to induce production of the appropriate substrate in the upstream active site leads to efficient bifunctional enzymes producing isomers of manoyl oxide, representing novel enzymatic activity.

Influence of chronic kidney disease on anticoagulation levels and bleeding after primary percutaneous coronary intervention in patients treated with unfractionated heparin

Unfractionated heparin (UFH) plasma protein binding and elimination might be impaired in patients with chronic kidney disease (CKD-defined as creatinine clearance <60 ml/min). It is currently unknown at which UFH bolus dose persistent prolongation of activated partial thromboplastin time (aPTT) occurs in ST-segment elevation myocardial infarction (STEMI) patients with CKD. We investigated the effect of different UFH bolus doses on the first aPTT measured within 6 and 12 h after PPCI in 1071 STEMI patients with and without CKD undergoing primary percutaneous coronary intervention (PPCI) between 1-1-2003 and 31-07-2008. In the first 6 h after PPCI, aPTT ratio was 5.1 for patients with CKD versus 3.4 for those without (p < 0.001). The proportion of patients with markedly high aPTTs (aPTT ratio ≥ 4 times control) increased with increasing heparin bolus and beyond 130 IU/kg there was a marked difference between patients with and without CKD (74.1 and 42.3 % respectively, p < 0.001). By multivariable analysis, CKD was associated with an increased risk of markedly high aPTTs (odds ratio (OR) 2.04; 95 % confidence interval (CI) 1.27-3.27), driven largely by an increased risk of aPTT prolongation in patients treated with UFH boluses ≥130 IU/kg (OR 3.69; 95 % CI 1.85-7.36; p for interaction = 0.009). In conclusion, CKD is associated with severe persistent aPTT prolongation in STEMI patients undergoing PPCI, possibly due to impaired plasma protein binding and reduced UFH elimination. A lower heparin bolus dose might result in lower aPTTs and less bleeding complications in patients with CKD undergoing PPCI.

Relationship between sleep duration and arterial stiffness in a multi-ethnic population: The HELIUS study

We examined the relationship between sleep duration and arterial stiffness among a multi-ethnic cohort, and whether the associations differed among ethnic minority groups in the Netherlands. Data were derived from 10 994 participants (aged 18-71 years) of the Healthy Life in an Urban Setting (HELIUS) study. Self-reported sleep duration was categorized into: short (<7 h/night), healthy (7-8 h/night) and long (≥9 h/night). Arterial stiffness was assessed by duplicate pulse-wave velocity (PWV in m/s) measurements using the Arteriograph system. The association of sleep duration with PWV was analysed using linear regression (β) with 95% confidence interval (CI). Results showed that neither short nor long sleep was related to PWV in all ethnic groups, except for long sleep in Dutch men which was associated with higher PWV (indicating stiffer arteries) after adjustment for potential confounders (β = 0.67, 95%CI, 0.23-1.11). Our study showed no convincing evidence that sleep duration was related to arterial stiffness among various ethnic groups. The link between sleep duration and cardiovascular outcomes does not seem to operate through arterial stiffness. Further research is needed to consolidate these findings.

Estimated 10-year cardiovascular mortality seriously underestimates overall cardiovascular risk

OBJECTIVE

The European Society of Cardiology's prevention guideline suggests that the risk of total (fatal plus non-fatal) cardiovascular disease (CVD) may be calculated from the risk of CVD mortality using a fixed multiplier (3×). However, the proposed multiplier has not been validated. We investigated the ratio of total CVD to CVD mortality in a large population-based cohort.

METHODS

CVD mortality and total CVD (fatal plus non-fatal CVD requiring hospitalisation) were analysed using Kaplan-Meier estimates among 24 014 men and women aged 39-79 years without baseline CVD or diabetes mellitus in the prospective population-based European Prospective Investigation of Cancer and Nutrition-Norfolk cohort. CVD outcomes included death and hospitalisations for ischaemic heart disease, heart failure, cerebrovascular disease, peripheral artery disease or aortic aneurysm. The main study outcome was the ratio of 10-year total CVD to 10-year CVD mortality stratified by age and sex.

RESULTS

Ten year CVD mortality was 3.9% (900 CVD deaths, 95% CI 3.6% to 4.1%); the rate of total CVD outcomes was 21.2% (4978 fatal or non-fatal CVD outcomes, 95% CI 20.7% to 21.8%). The overall ratio of total CVD to CVD mortality was 5.4. However, we found major differences in this ratio when stratified by gender and age. In young women (39-50 years), the ratio of total CVD to CVD mortality was 28.5, in young men (39-50 years) 11.7. In the oldest age group, these ratios were considerably lower (3.2 in women and 2.4 in men aged 75-79 years).

CONCLUSIONS

The relationship between 10-year total CVD and CVD mortality is dependent on age and sex, and cannot be estimated using a fixed multiplier. Using CVD mortality to estimate total CVD risk leads to serious underestimation of risk, particularly in younger age groups, and particularly in women.

Ethnic differences in arterial stiffness the Helius study

OBJECTIVE

Well-known ethnic differences in cardiovascular risk exist, which may be explained by ethnic differences in arterial stiffness. Our aim was to assess ethnic differences in arterial stiffness, to explore whether these differences are accounted for by conventional cardiovascular risk factors, and study whether they differ across age.

METHODS

Cross-sectional data of 1797 Dutch, 1846 South-Asian Surinamese, 1840 African Surinamese, and 1673 Ghanaian participants of the observational HELIUS study (aged 18-70 years) were used. Arterial stiffness was assessed by duplicate pulse wave velocity (PWV) measurements using the Arteriograph system.

RESULTS

Linear regression showed that South-Asian Surinamese had higher PWVs as compared with Dutch (age-adjusted mean difference (95% CI) was 0.55 (0.39-0.70) m/s in men and 0.82 (0.63-1.01) m/s in women). These differences were largely, but not completely, explained by conventional risk factors (particularly age and MAP). These ethnic differences were not found at young age (<35 years). African Surinamese and Ghanaians had higher PWVs as compared with Dutch across the entire age range (ranging from 0.22 (0.06-0.39) m/s in African Surinamese men to 1.07 (0.89-1.26) m/s in Ghanaian women), but these differences disappeared or reversed after adjustment for risk factors.

CONCLUSIONS

PWV levels paralleled the well-known ethnic differences in cardiovascular risk. After adjustment for cardiovascular risk factors, however, these ethnic differences in PWV largely disappear. Together with the absence of ethnic differences in PWV at young age, our results support the hypothesis that higher PWV in South-Asian and African ethnic groups develops due to higher exposure to cardiovascular risk factors.

Hypertension control in a large multi-ethnic cohort in Amsterdam, The Netherlands: the HELIUS study

OBJECTIVE

Hypertension is a major problem among European ethnic minority groups. We assessed the current situation of hypertension prevalence and its management among a multi-ethnic population in Amsterdam, The Netherlands.

METHODS

Data from the HELIUS study were used including 12,974 participants (1871 Ghanaian, 2184 African Surinamese, 2278 South-Asian Surinamese, 2277 Turkish, 2222 Moroccan and 2142 Dutch origin people), aged 18-70 years. Comparisons among groups were made using proportions and age-adjusted prevalence ratios (PRs).

RESULTS

Hypertension prevalence ranged from 24% and 16% in Moroccan men and women to 52% and 62% in Ghanaian men and women. Except for Moroccan women, age-adjusted PR of hypertension was higher in all the ethnic minority groups than in Dutch. Among hypertensives, ethnic minority groups generally had higher levels of hypertension awareness and BP lowering treatment than Dutch. Moreover, prevalence rates for the prescription of more than one BP lowering drug were generally higher in African and South-Asian origin groups compared with Dutch origin people. By contrast, BP control levels were lower in all the ethnic groups than in Dutch, with control rates being significantly lower in Ghanaian men (26%, PR=0.49; 95% CI, 0.37-0.66) and women (45%, PR=0.64; 0.52-0.77), African-Surinamese men (30%, PR=0.61; 0.46-0.81) and women (45%, PR=0.72; 0.51-0.77), and South-Asian Surinamese men (43%, PR=0.77; 0.61-0.97) and women (47%, PR=0.76; 0.63-0.92) compared with Dutch men (53%) and women (61%).

CONCLUSION

Our findings indicate poor BP control in ethnic minority groups despite the high treatment levels. More work is needed to unravel the potential factors contributing to the poor control in order to improve BP control in ethnic minority groups, particularly among African and South-Asian origin groups.

The prognostic value of bleeding academic research consortium (BARC)-defined bleeding complications in ST-segment elevation myocardial infarction: a comparison with the TIMI (Thrombolysis In Myocardial Infarction), GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries), and ISTH (International Society on Thrombosis and Haemostasis) bleeding classifications

OBJECTIVES

The aim of the present analysis was to compare 1-year mortality prediction of Bleeding Academic Research Consortium (BARC)-defined bleeding complications with existing bleeding definitions in patients with ST-segment elevation myocardial infarction (STEMI) and to investigate the prognostic value of the individual data elements of the bleeding classifications for 1-year mortality.

BACKGROUND

BARC recently proposed a novel standardized bleeding definition.

METHODS

The in-hospital occurrence of bleeding defined according to the BARC, TIMI (Thrombolysis In Myocardial Infarction), GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries), and ISTH (International Society on Thrombosis and Haemostasis) bleeding classifications was assessed in 2,002 STEMI patients undergoing primary percutaneous coronary intervention between January 1, 2003, and July 31, 2008.

RESULTS

BARC types 2, 3, 4, and 5 bleeding occurred in 4.4%, 14.2%, 1.4%, and 0.3% of patients, respectively. By multivariable analysis, GUSTO- and ISTH-defined bleeding was not significantly associated with 1-year mortality, whereas TIMI major and BARC type 3b or 3c bleeding conferred a 2-fold higher risk of 1-year mortality (hazard ratios [HRs]: 2.00 [95% confidence interval (CI): 1.32 to 3.01] and 1.84 [95% CI: 1.23 to 2.77], respectively). Data elements most strongly associated with mortality were a hemoglobin decrease ≥5 g/dl (HR: 1.94 [95% CI: 1.26 to 2.98]), the use of vasoactive agents for bleeding (HR: 2.01 [95% CI: 0.91 to 4.44]), cardiac tamponade (HR: 2.38 [95% CI: 0.56 to 10.1]), and intracranial hemorrhage (HRs for 1-year mortality were not computable because there was only 1 patient with intracranial bleeding).

CONCLUSIONS

Both the BARC and TIMI bleeding classification identified STEMI patients at risk of 1-year mortality.

Improving guideline adherence for cardiac rehabilitation in the Netherlands

BACKGROUND

In 2004, the Netherlands Society of Cardiology released the current guideline on cardiac rehabilitation. Given its complexity and the involvement of various healthcare disciplines, it was supplemented with a clinical algorithm, serving to facilitate its implementation in daily practice. Although the algorithm was shown to be effective for improving guideline adherence, several shortcomings and deficiencies were revealed. Based on these findings, the clinical algorithm has now been updated. This article describes the process and the changes that were made.

METHODS

The revision consisted of three phases. First, the reliability of the measurement instruments included in the 2004 Clinical Algorithm was investigated by evaluating between-centre variations of the baseline assessment data. Second, based on the available evidence, a multidisciplinary expert advisory panel selected items needing revision and provided specific recommendations. Third, a guideline development group decided which revisions were finally included, also taking practical considerations into account.

RESULTS

A total of nine items were revised: three because of new scientific insights and six because of the need for more objective measurement instruments. In all revised items, subjective assessment methods were replaced by more objective assessment tools (e.g. symptom-limited exercise instead of clinical judgement). In addition, four new key items were added: screening for anxiety/depression, stress, cardiovascular risk profile and alcohol consumption.

CONCLUSION

Based on previously determined shortcomings, the Clinical Algorithm for Cardiac Rehabilitation was thoroughly revised mainly by incorporating more objective assessment methods and by adding several new key areas.

Ethnicity and waterpipe smoking among US students

OBJECTIVES

To examine the effect of ethnicity on waterpipe smoking among college students.

DESIGN

A cross-sectional study utilized data from University of Houston students through an online survey (n = 2334) from March to April 2011. The survey included questions on demographic characteristics (sex, age, race/ethnicity), tobacco use experience, risk perception, social acceptability and popularity. Multivariate logistic regression was used to determine predictors of waterpipe use with three outcomes: ever-use vs. no use, past-year use vs. no use and past-month use vs. no use.

RESULTS

Half of the sample had previously smoked tobacco using a waterpipe, approximately a third in the past year and 12.5% in the past month. Significant predictors included Middle Eastern ethnicity, Middle Eastern friend, past cigarette or cigar use. Perception of harm was associated with less use in the ever-use model, while perceived addictiveness, social acceptability and popularity of waterpipes were predictors in all models.

CONCLUSION

Our findings underscore the importance of developing culturally appropriate interventions to control waterpipe smoking among Middle Eastern Americans and those of Indian/Pakistani descent to curb further spread in US society, and highlight the importance of developing interventions that target the perceived addictiveness, social acceptability and popularity of waterpipe smoking.

When is supervised exercise therapy considered useful in peripheral arterial occlusive disease? A nationwide survey among vascular surgeons

OBJECTIVES

Although international guidelines state that supervised exercise therapy (SET) should be offered to all patients with intermittent claudication (IC), SET appears to be underutilised in clinical practice. The aim of this study was to document current opinions of Dutch vascular surgeons on SET as treatment option for peripheral arterial occlusive disease (PAOD).

MATERIALS AND METHODS

Vascular surgeons and fellows in vascular surgery were asked to complete a 24-question survey either at the 2011 Annual Meeting of the Dutch Society for Vascular Surgery or online.

RESULTS

Ninety-one participants, including 83 vascular surgeons (51% of all Dutch vascular surgeons), completed the survey. The respondents would refer 75.4% of newly diagnosed patients with IC for SET. SET was considered less useful in patients with IC and major (cardiopulmonary) co-morbidity or a significant iliac artery stenosis. In critical limb ischaemia, the combination of SET and angioplasty was considered useful in 71.9%. Respondents regarded patient satisfaction (63.3%) and improvement in pain-free or maximal walking ability (26.6%) as clinically most relevant goals of SET. Most (84.4%) agreed that SET should also include lifestyle management.

CONCLUSION

Although the vast majority of Dutch vascular surgeons consider SET as an important treatment option for PAOD, SET should receive more emphasis in clinical practice since arguments not to refer for SET are outdated. Furthermore, vascular surgeons agree that lifestyle management should be integrated in SET.

ST-segment resolution prior to primary percutaneous coronary intervention is a poor indicator of coronary artery patency in patients with acute myocardial infarction

BACKGROUND

The prognostic value of ST-segment resolution (STR) after initiation of reperfusion therapy has been established by various studies conducted in both the thrombolytic and mechanic reperfusion era. However, data regarding the value of STR immediately prior to primary percutaneous coronary intervention (PCI) to predict infarct-related artery (IRA) patency remain limited. We investigated whether STR prior to primary PCI is a reliable, noninvasive indicator of IRA patency in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

The study population consisted of STEMI patients who underwent primary PCI at our institution between 2000 and 2007. STR was analyzed in 12-lead electrocardiograms recorded at first medical contact and immediately prior to primary PCI and defined as complete (> or =70%), partial (70%- 30%), or absent (<30%).

RESULTS

In 1253 patients with a complete data set, STR was inversely related to the probability of impaired preprocedural flow (P(for trend) < 0.001). Although the sensitivity of incomplete (<70%) STR to predict a Thrombolysis in Myocardial Infarction (TIMI) flow of <3 was 96%, the specificity was 23%, and the negative predictive value of incomplete STR to predict normal coronary flow was only 44%.

CONCLUSIONS

This study establishes the correlation between STR prior to primary PCI and preprocedural TIMI flow in STEMI patients treated with primary PCI. However, the negative predictive value of incomplete STR for detection of TIMI-3 flow is only 44% and therefore should not be a criterion to refrain from immediate coronary angiography in STEMI patients.

Guideline adherence for antithrombotic therapy in acute coronary syndrome: an overview in Dutch hospitals

OBJECTIVE

To assess current Dutch antithrombotic treatment strategies for acute coronary syndrome (ACS) in light of the current European Society of Cardiology (ESC) guidelines.

METHODS

For every Dutch hospital with a coronary care unit (CCU) (n = 93) a single cardiologist was interviewed concerning heparin, thienopyridine and GP IIb/IIIa inhibitor (GPI) treatment. In each hospital, we randomly approached one cardiologist assuming equal policy among physicians employed at the same hospital.

RESULTS

The response rate was 90%. In 59% of hospitals, treatment of ST-elevation myocardial infarction (STEMI) occurred according to the 2008 ESC STEMI guideline, with unfractionated heparin. In contrast, although not recommended, low-molecular-weight heparin (LMWH) was used in 39% (enoxaparin 19%, dalteparin 12%, nadroparin 8%). In non-STEMI, low-molecular-weight-heparins (LMWHs) were used in 97% of all hospitals. Fondaparinux, agent of choice in a noninvasive strategy for the treatment of non-STEMI, was applied in only 2% of hospitals. Although recommended by the ESC, dose adjustment of LMWH therapy for patients with renal failure is not applied in 71% of hospitals. Likewise, LMWH dose adjustment is not applied for patients aged over 75 years in 92% of hospitals.

CONCLUSION

To a great extent treatment of ACS in the Netherlands occurs according to ESC guidelines. Additional benefit may be achieved by routine dose adjustment of LMWH for patients with renal insufficiency and aged >75 years, since these patients are at high risk of bleeding complications secondary to antithrombotic treatment. Periodical evaluation of real-life practice may improve guideline adherence and potentially improve clinical outcome. (Neth Heart J 2010;18:291-9.).

Persistent precordial "hyperacute" T-waves signify proximal left anterior descending artery occlusion

OBJECTIVE

To describe patients with a distinct electrocardiogram (ECG) pattern without ST-segment elevation in the presence of an acute occlusion of the proximal left anterior descending (LAD) artery.

DESIGN

Single-centre observational study.

PATIENTS

Patients with acute anterior wall myocardial infarction who were referred for primary percutaneous coronary intervention (PCI) between 1998 and 2008.

RESULTS

We identified patients with a static, distinct ECG pattern without ST-segment elevation and an occlusion of the proximal LAD artery during urgent coronary angiography before PCI. Of 1890 patients who underwent primary PCI of the LAD artery, we could identify 35 patients (2%) with this distinct ECG pattern. The ECG showed ST-segment depression at the J-point of at least 1 mm in precordial leads with upsloping ST-segments continuing into tall, symmetrical T-waves. Patients with this distinct ECG pattern were younger, more often male and more often had hypercholesterolaemia compared to patients with anterior myocardial infarction and ST-segment elevation.

CONCLUSIONS

In patients presenting with chest pain, ST-segment depression at the J-point with upsloping ST-segments and tall, symmetrical T-waves in the precordial leads of the 12-lead ECG signifies proximal LAD artery occlusion. It is important for cardiologists and emergency care physicians to recognise this distinct ECG pattern, so they can triage such patients for immediate reperfusion therapy.

Potential markers of female condom use among inner city African-American women

Despite the availability of the female condoms and theoretically based interventions to promote its use, studies have indicated a low level of acceptability of their use among women in most populations. We aimed to determine female condom use prevalence and the potential markers among African-American women. In an intervention trial to test the efficacy of the Information-Motivation-Behavioral Skills model in increasing condom use, we utilized the baseline data of 280 subjects and examined the potential predictors of female condom use. Chi square statistic and unconditional logistic regression were used to test for group independence among users and non-users of the female condom and to assess the potential markers of female condom use respectively. After adjustment for relevant covariates associated independently with female condom use, the significant potential markers for female condom use were age, multiple sexual relationships, knowledge of female condom, and educational status. Women having multiple sexual relationships compared with a monogamous relationship were five times more likely to use the female condom, while women with high school education were three times more likely to use the female condom; prevalence odds ratio, POR=5.32, 95% CI=1.79-15.83 and POR=3.01, 95% CI=1.01-8.93. Women who were not knowledgeable of the female condom, compared to those who were, were 81% less likely to use the female condom, POR=0.19, 95% CI=0.08-0.45. Among African-American women in this sample, knowledge of female condom use, age, educational status, and multiple sexual relationships were significant markers of female condom use. This study is therefore suggestive of the need to educate African-American women on female condom use, given the obstacles in male condom negotiation, especially among the socio-economically challenged.

Rationale and design of ACTIVE: the atrial fibrillation clopidogrel trial with irbesartan for prevention of vascular events

BACKGROUND

Atrial fibrillation (AF) is the most frequently occurring cardiac arrhythmia with often serious clinical consequences. Many patients have contraindications to anticoagulation, and it is often underused in clinical practice. The addition of clopidogrel to aspirin (ASA) has been shown to reduce vascular events in a number of high-risk populations. Irbesartan is an angiotensin receptor-blocking agent that reduces blood pressure and has other vascular protective effects.

METHODS AND RESULTS

ACTIVE W is a noninferiority trial of clopidogrel plus ASA versus oral anticoagulation in patients with AF and at least 1 risk factor for stroke. ACTIVE A is a double-blind, placebo-controlled trial of clopidogrel in patients with AF and with at least 1 risk factor for stroke who receive ASA because they have a contraindication for oral anticoagulation or because they are unwilling to take an oral anticoagulant. ACTIVE I is a partial factorial, double-blind, placebo-controlled trial of irbesartan in patients participating in ACTIVE A or ACTIVE W. The primary outcomes of these studies are composites of vascular events. A total of 14000 patients will be enrolled in these trials.

CONCLUSIONS

ACTIVE is the largest trial yet conducted in AF. Its results will lead to a new understanding of the role of combined antiplatelet therapy and the role of blood pressure lowering with an angiotensin II receptor blocker in patients with AF.

The relationship between future orientation and street substance use among Texas alternative school students

Self-reported substance use data were collected from 963 alternative school students in grades 7-12 who were surveyed through the Safer Choices 2 study in Houston, Texas. Data were collected between October 2000 and March 2001. Logistic regression analyses indicated that lower levels of future orientation was significantly associated (OR = 0.88, 95% CI = 0.81-0.97) with thirty-day substance use after controlling for age and gender. In addition, lower levels of future orientation was found to have a significant association with students' lifetime substance use (OR = 0.93, 95% CI = 0.87-.99) after controlling for age, race, and gender. While the relationships tested in this study are exploratory, they provide evidence for an important connection between future orientation and substance use among adolescents attending alternative schools.

The maize An2 gene is induced by Fusarium attack and encodes an ent-copalyl diphosphate synthase

Using the technique of differential display, a maize transcript was identified whose silk tissue expression is induced in the presence of the ear rot pathogen Fusarium graminearum. The 3445 nt transcript includes a 727 nt 5' untranslated leader with the potential for extensive secondary structure and represents the maize gene An2. An2 encodes a copalyl diphosphate synthase (CPS)-like protein with 60% amino acid sequence identity with the maize An1 gene product involved in gibberellin (GA) biosynthesis. Recombinant expression and functional analysis demonstrated that both AN1 and AN2 are ent-copalyl diphosphate (ent-CPP) synthases (ent-CPS). Notably, the presence of an additional ent-CPS gene is consistent with previous reports that maize GA biosynthesis can proceed in the absence of An1. In addition, northern blot analysis showed that An2 transcript levels were strongly up-regulated by Fusarium attack, with an increase in silk, husk and ear tip tissues as early as 6 h after inoculation of silk channels with spore suspensions of various Fusarium sp. Gene expression of a third maize CPS-like gene, Cpsl1, is not affected by Fusarium infection. The Fusarium-inducible nature of An2 is also consistent with a previous report that cell-free extracts from maize seedlings produce ent-CPP derived diterpenes in response to Fusarium infection. However, it is not known whether An2 is involved in defense-related secondary metabolism in addition to GA synthesis.

A vector-based, 5-electrode, 12-lead monitoring ECG (EASI) is equivalent to conventional 12-lead ECG for diagnosis of acute coronary syndromes

AIMS

The conventional 12-lead electrocardiogram (cECG) derived from 10 electrodes using a cardiograph is the gold standard for diagnosing myocardial ischemia. This study tested the hypothesis that a new 5-electrode 12-lead vector-based ECG (EASI; Philips Medical Systems, formerly Hewlett Packard Co, Boeblingen, Germany) patient monitoring system is equivalent to cECG in diagnosing acute coronary syndromes (ACSs).

METHODS

Electrocardiograms (EASI and cECG) were obtained in 203 patients with chest pain on admission and 4 to 8 hours later. Both types of ECGs were graded as ST-elevation myocardial infarction if at least 1 of the 2 consecutive recordings showed ST elevation more than 0.2 mV, as ACS if one or both showed ST elevation less than 0.2 mV, T-wave inversion, or ST depression. Otherwise, the ECG was graded negative.

RESULTS

Final diagnosis was identical in 177 patients (87%; 95% confidence interval [CI], 82%-91%; kappa = 0.81; SE = 0.035). ST-elevation myocardial infarction was correctly identified or excluded by EASI with a specificity of 94% (95% CI, 89%-97%) and a sensitivity of 93% (95% CI, 86%-97%; using cECG as the gold standard). Of 118 patients with enzyme elevations, an almost identical number (72 [61% by EASI] and 73 [62% by cECG]) had ST elevations. Both techniques were equivalent in predicting subsequent enzyme elevation (identical, 108/143; 75% of ACS and ST-elevation myocardial infarction ECGs by EASI and cECG). Thus, both ECG methods had exactly the same specificity of 59% (95% CI, 48%-69%) and sensitivity of 91% (95% CI, 85%-96%) for detecting myocardial injury.

CONCLUSION

EASI is equivalent to cECG for the diagnosis of myocardial ischemia.

The role of hearing protectors in leisure noise

Ear muffs and ear plugs are widely used in the workplace to provide hearing protection for employees exposed to high levels of noise. Through an examination of the use of ear protectors in the workplace this paper explores the extent to which these devices can play a similar role in protecting members of the public from hearing damage arising from exposure to high levels of noise from leisure activities. It is concluded that the major limitation to the effective use of ear protectors for leisure use is likely to be the lack of easily accessible information, advice and guidance on the nature of the hearing protection risk from noisy leisure activities, and on the availability, selection and use of protectors, and of the need for regular hearing checks.

Genetic variation in coagulation and fibrinolytic proteins and their relation with acute myocardial infarction: a systematic review

BACKGROUND

It is pathophysiologically conceivable that genetic variations in coagulation and fibrinolytic proteins are associated with the risk of myocardial infarction. Methods and Results- We performed a literature search to identify published case-control studies correlating the factor V Leiden or prothrombin G20210A mutations or fibrinogen G-455A or plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphisms with the risk of myocardial infarction. Studies were included only if they used solid diagnostic criteria and complied with published methodological criteria. A common OR with corresponding 95% CI was calculated for the risk of myocardial infarction in a fixed-effect model according to Mantel-Haenszel. The factor V Leiden and prothrombin G20201A mutations did not significantly correlate with myocardial infarction (OR 1.26, 95% CI 0.94 to 1.67, P=0.12 and OR 0.89, 95% CI 0.59 to 1.35, P=0.6, respectively). Inclusion of the studies that investigated young patients (<55 years) made the association significant for factor V Leiden (OR 1.29, 95% CI 1.03 to 1.61, P=0.02). Homozygosity for the fibrinogen -455A allele was significantly associated with a decreased risk of myocardial infarction (OR 0.66, 95% CI 0.44 to 0.99, P=0.04), whereas the PAI-1 4G4G genotype was significantly associated with increased risk (OR 1.20, 95% CI 1.04 to 1.39, P=0.04).

CONCLUSIONS

Associations between these genetic variations and myocardial infarction were weak or absent. In the absence of clinical implications, our results indicate that screening of patients with myocardial infarction for these genetic variations is not warranted.

The solution structure of the viral binding domain of Tva, the cellular receptor for subgroup A avian leukosis and sarcoma virus

The cellular receptor for subgroup A avian leukosis and sarcoma virus (ALSV-A) is Tva, which contains a motif related to repeats in the low density lipoprotein receptor (LDLR) ligand binding repeat (LBr) and which is necessary for viral entry. As observed with LBr repeats of LDLR, the 47 residue LBr domain of Tva (sTva47) requires calcium during oxidative folding to form the correct disulfide bonds, and calcium enhances the structure of correctly oxidized sTva47, as well as its ability to bind the viral envelope protein (Env). However, solution nuclear magnetic resonance studies indicate that, even in the presence of excess calcium, sTva47 exists in an ensemble of conformations. Nonetheless, as reported here, the structure of the predominant sTva47 solution conformer closely resembles that of other LBr repeats, with identical S-S binding topology and octahedral calcium coordination. The location of W48 and other critical residues on the surface suggests a region of the molecule necessary for Env binding and to mediate post-binding events important for ALSV-A cell entry.

Brain areas specific for attentional load in a motion-tracking task

Although visual attention is known to modulate brain activity in the posterior parietal, prefrontal, and visual sensory areas, the unique roles of these areas in the control of attentional resources have remained unclear. Here, we report a dissociation in the response profiles of these areas. In a parametric functional magnetic resonance imaging (fMRI) study, subjects performed a covert motion-tracking task, in which we manipulated "attentional load" by varying the number of tracked balls. While strong effects of attention--independent of attentional load--were widespread, robust linear increases of brain activity with number of balls tracked were seen primarily in the posterior parietal areas, including the intraparietal sulcus (IPS) and superior parietal lobule (SPL). Thus, variations in attentional load revealed different response profiles in sensory areas as compared to control areas. Our results suggest a general role for posterior parietal areas in the deployment of visual of attentional resources.

Bifunctional abietadiene synthase: free diffusive transfer of the (+)-copalyl diphosphate intermediate between two distinct active sites

Abietadiene synthase (AS) catalyzes two sequential, mechanistically distinct cyclizations in the conversion of geranylgeranyl diphosphate to a mixture of abietadiene double bond isomers as the initial step of resin acid biosynthesis in grand fir (Abies grandis). The first reaction converts geranylgeranyl diphosphate to the stable bicyclic intermediate (+)-copalyl diphosphate via protonation-initiated cyclization. In the second reaction, diphosphate ester ionization-initiated cyclization generates the tricyclic perhydrophenanthrene-type backbone, and is directly coupled to a 1,2-methyl migration that generates the C13 isopropyl group characteristic of the abietane family of diterpenes. Using the transition-state analogue inhibitor 14,15-dihydro-15-azageranylgeranyl diphosphate, it was demonstrated that each reaction of abietadiene synthase is carried out at a distinct active site. Mutations in two aspartate-rich motifs specifically delete one or the other activity and the location of these motifs suggests that the two active sites reside in separate domains. These mutants effectively complement each other, suggesting that the copalyl diphosphate intermediate diffuses between the two active sites in this monomeric enzyme. Free copalyl diphosphate was detected in steady-state kinetic reactions, thus conclusively demonstrating a free diffusion transfer mechanism. In addition, both mutant enzymes enhance the activity of wild-type abietadiene synthase with geranylgeranyl diphosphate as substrate. The implications of these results for the kinetic mechanism of abietadiene synthase are discussed.

Effects of pretreatment with clopidogrel and aspirin followed by long-term therapy in patients undergoing percutaneous coronary intervention: the PCI-CURE study

BACKGROUND

Despite the use of aspirin, there is still a risk of ischaemic events after percutaneous coronary intervention (PCI). We aimed to find out whether, in addition to aspirin, pretreatment with clopidogrel followed by long-term therapy after PCI is superior to a strategy of no pretreatment and short-term therapy for only 4 weeks after PCI.

METHODS

2658 patients with non-ST-elevation acute coronary syndrome undergoing PCI in the CURE study had been randomly assigned double-blind treatment with clopidogrel (n=1313) or placebo (n=1345). Patients were pretreated with aspirin and study drug for a median of 6 days before PCI during the initial hospital admission, and for a median of 10 days overall. After PCI, most patients (>80%) in both groups received open-label thienopyridine for about 4 weeks, after which study drug was restarted for a mean of 8 months. The primary endpoint was a composite of cardiovascular death, myocardial infarction, or urgent target-vessel revascularisation within 30 days of PCI. The main analysis was by intention to treat.

FINDINGS

There were no drop-outs. 59 (4.5%) patients in the clopidogrel group had the primary endpoint, compared with 86 (6.4%) in the placebo group (relative risk 0.70 [95% CI 0.50-0.97], p=0.03). Long-term administration of clopidogrel after PCI was associated with a lower rate of cardiovascular death, myocardial infarction, or any revascularisation (p=0.03), and of cardiovascular death or myocardial infarction (p=0.047). Overall (including events before and after PCI) there was a 31% reduction cardiovascular death or myocardial infarction (p=0.002). There was less use of glycoprotein IIb/IIIa inhibitor in the clopidogrel group (p=0.001). At follow-up, there was no significant difference in major bleeding between the groups (p=0.64).

INTERPRETATION

In patients with acute coronary syndrome receiving aspirin, a strategy of clopidogrel pretreatment followed by long-term therapy is beneficial in reducing major cardiovascular events, compared with placebo.

Randomized comparison of a novel anticoagulant, vasoflux, and heparin as adjunctive therapy to streptokinase for acute myocardial infarction: results of the VITAL study (Vasoflux International Trial for Acute Myocardial Infarction Lysis)

BACKGROUND

Vasoflux is a low-molecular-weight heparin derivative that inhibits factor IXa activation of factor X and catalyzes fibrin-bound thrombin inactivation by heparin cofactor II. We studied whether vasoflux improves the results of thrombolysis with streptokinase for acute myocardial infarction.

METHODS AND RESULTS

We randomized 277 patients with acute myocardial infarction to standard intravenous unfractionated heparin (UFH) or intravenous vasoflux 1, 4, 8, or 16 mg/kg as a bolus followed by 1, 4, 8, or 16 mg/kg per hour infusion, on top of streptokinase and aspirin, until angiography at 90 minutes. Patency and corrected Thrombolysis in Myocardial Infarction (TIMI) frame count were studied at 60 and 90 minutes. Rates of TIMI grade 3 flow with vasoflux at any dose (35% to 42%) were not different from UFH (41%) at either time point, nor was the corrected TIMI frame count. However, there was an excess of bleeding in the patients randomized to vasoflux 8 or 16 mg/kg: 78% and 71%, compared with 53% for UFH (P =.004 and.043, respectively). Major bleeding was observed in 13% and 28% at these vasoflux doses compared with 8% with UFH (P =.558 and.01, respectively).

CONCLUSION

At doses that increase the risk of bleeding, the addition of vasoflux to streptokinase and aspirin did not lead to improved patency rates compared with UFH. Targeting factor IXa and heparin cofactor II may not be a useful adjunct to thrombolysis.

Adenosine induced ventricular arrhythmias in the emergency room

While adenosine effectively terminates most supraventricular tachycardias (SVT), rare case reports have demonstrated its proarrhythmic potential, including induction of ventricular tachycardia (VT). The aim of this study was to define the proarrhythmic effects of adenosine in a large, unselected population. During a 5-year period, adenosine was used (average dose 9.7 mg) in the emergency room to manage 187 episodes of tachycardia in 127 patients. In two thirds of the cases, adenosine induced ventricular ectopy following successful termination of SVT, including premature ventricular complexes (PVC) and nonsustained VT. The adenosine induced PVCs and VT were transient and self-terminating. More than half had a right bundle branch block morphology with a superior axis that suggested an origin in the inferior left ventricular septum. In conclusion, although adenosine is commonly used in clinical practice to treat SVTs, we found that it induced PVCs and VT in two thirds of the patients. The high incidence of ventricular arrhythmias following adenosine infusion was surprising but did not require further intervention. These arrhythmias appeared to frequently originate from the inferior left ventricular septum, suggesting that this area may be particularly susceptible to the proarrhythmic effects of adenosine.

Early lumen diameter loss after percutaneous transluminal coronary angioplasty is related to coronary plaque burden: a role for viscous plaque properties in early lumen diameter loss

OBJECTIVES

We tested the hypothesis that lumen diameter loss within 1 h after percutaneous transluminal coronary angioplasty is related to plaque volume parameters.

BACKGROUND

Early lumen diameter loss after coronary balloon angioplasty may predict restenosis and may paradoxically decrease late lumen diameter loss. Viscous properties of the vessel wall, as would be determined by tissue volume and composition, may be involved in early lumen diameter loss.

METHODS

Early lumen diameter loss was measured with quantitative coronary angiography as the loss in lesion lumen diameter (significant loss 0.4 mm) occurring between 5 min and a median of 40 min after successful coronary balloon angioplasty in 68 patients. Thirty-nine patients were evaluated with intravascular ultrasound at the narrowest lumen cross-section of the dilated lesion, 29 patients formed a control group without intravascular ultrasound imaging. We tested the relation between intravascular ultrasound parameters and early lumen diameter loss.

RESULTS

Early lumen diameter loss of > or = 0.4 mm was present in eight patients (12%), decreasing lumen diameter from 2.26 +/- 0.36 mm to 1.73 +/- 0.43 mm. There was no difference in the frequency of early lumen diameter loss between the groups with or without intravascular ultrasound imaging. Univariate intravascular ultrasound determinants of early lumen diameter loss were media bounded area (p = 0.01), maximal plaque thickness (p = 0.02), eccentricity index (p = 0.03) and the presence of hard lesions (p = 0.02).

CONCLUSION

Early lumen diameter loss in the first hour after successful coronary balloon angioplasty occurs in a small proportion of patients. It is related to hard lesion type, maximal plaque thickness and eccentricity index, favoring a role for viscous plaque properties in early lumen diameter loss.

Safe discharge from the cardiac emergency room with a rapid rule-out myocardial infarction protocol using serial CK-MB(mass)

OBJECTIVE

To determine whether a new protocol, using a rapid and sensitive CK-MB(mass) assay and serial sampling, can rule out myocardial infarction in patients with chest pain and decrease their length of stay in the cardiac emergency room without increasing risk.

DESIGN

The combined incidence of cardiac death and acute myocardial infarction at 30 days, six months, and 24 months of follow up were compared between patients discharged home from the cardiac emergency room after ruling out myocardial infarction with a CK-MB(activity) assay in 1994 and those discharged home after a rapid CK-MB(mass) assay in 1996.

SETTING

Cardiac emergency room of a large university hospital.

PATIENTS

In 1994 and 1996, 230 and 423 chest pain patients, respectively, were discharged home from the cardiac emergency room with a normal CK-MB and an uneventful observation period.

RESULTS

The median length of stay in the cardiac emergency room was significantly reduced, from 16.0 hours in 1994 to 9.0 hours in 1996 (p < 0.0001). Mean event rates in patients from the 1994 and 1996 cohorts, respectively, were 0.9% (95% confidence interval (CI) -0.3% to 2.1%) v 0.7% (95% CI -0.1% to 1. 5%) at 30 days, 3.0% (95% CI 0.8% to 5.2%) v 2.8% (95% CI 1.2% to 4. 4%) at six months, and 7.0% (95% CI 3.7% to 10.3%) v 5.7% (95% CI 3. 5% to 7.9%) at 24 months. Kaplan-Meier survival analysis showed no difference in mean event-free survival at 30 days, six months, and 24 months of follow up.

CONCLUSIONS

Using a rule-out myocardial infarction protocol with a rapid and sensitive CK-MB(mass) assay and serial sampling, the length of stay of patients with chest pain in the cardiac emergency room can be reduced without compromising safety.

Abietadiene synthase from grand fir (Abies grandis): characterization and mechanism of action of the "pseudomature" recombinant enzyme

The oleoresin secreted by grand fir (Abies grandis) is composed of resin acids derived largely from the abietane family of diterpene olefins as precursors which undergo subsequent oxidation of the C18-methyl group to a carboxyl function, for example, in the conversion of abieta-7,13-diene to abietic acid. A cDNA encoding abietadiene synthase has been isolated from grand fir and the heterologously expressed bifunctional enzyme shown to catalyze both the protonation-initiated cyclization of geranylgeranyl diphosphate to the intermediate (+)-copalyl diphosphate and the ionization-dependent cyclization of (+)-copalyl diphosphate, via a pimarenyl intermediate, to the olefin end products. Abietadiene synthase is translated as a preprotein bearing an N-terminal plastidial targeting sequence, and this form of the recombinant protein expressed in Escherichia coli proved to be unsuitable for detailed structure-function studies. Since the transit peptide-mature protein cleavage site could not be determined directly, a truncation series was constructed to delete the targeting sequence and prepare a "pseudomature" form of the enzyme that resembled the native abietadiene synthase in kinetic properties. Both the native synthase and the pseudomature synthase having 84 residues deleted from the preprotein converted geranylgeranyl diphosphate and the intermediate (+)-copalyl diphosphate to a nearly equal mixture of abietadiene, levopimaradiene, and neoabietadiene, as well as to three minor products, indicating that this single enzyme accounts for production of all of the resin acid precursors of grand fir. Kinetic evaluation of abietadiene synthase with geranylgeranyl diphosphate and (+)-copalyl diphosphate provided evidence for two functionally distinct active sites, the first for the cyclization of geranylgeranyl diphosphate to (+)-copalyl diphosphate and the second for the cyclization of (+)-copalyl diphosphate to diterpene end products, and demonstrated that the rate-limiting step of the coupled reaction sequence resides in the second cyclization process. The structural implications of these findings are discussed in the context of primary sequence elements considered to be responsible for binding the substrate and intermediate and for initiating the respective cyclization steps.

Activation of clotting factors XI and IX in patients with acute myocardial infarction

In acute coronary events, plaque rupture and the subsequent formation of the catalytic tissue factor-factor VIIa complex is considered to initiate coagulation. It is unknown whether clotting factors XI and IX are activated in acute coronary events. Therefore, we prospectively investigated the activation of clotting factors XI and IX as well as activation of the contact system and the common pathway in 50 patients with acute myocardial infarction (AMI), in 50 patients with unstable angina pectoris (UAP), and in 50 patients with stable angina pectoris (SAP). Factor XIa-C1 inhibitor complexes, which reflect acute activation of factor XI, were detected in 24% of the patients with AMI, 8% of the patients with UAP, and 4% of the patients with SAP (P<0.05), whereas factor XIa-alpha(1)-antitrypsin complexes, which reflect chronic activation, were observed equally in all 3 study groups. Factor IX peptide levels were significantly higher in the patients with AMI and UAP compared with the patients with SAP (P<0.01). No differences regarding markers of the common pathway were demonstrated. Fibrinopeptide A levels were elevated in patients with AMI compared with patients with UAP and those with SAP (P<0.01). Factor XIIa- or kallikrein-C1 inhibitor complexes were not increased. In conclusion, this is the first demonstration of the activation of clotting factors XI and IX in patients with acute coronary syndromes. Because these clotting factors are considered to be important for continuous thrombin generation and clot stability, their activation might have clinical and therapeutic consequences.

Successful attenuation of venous thrombus growth in rabbits after the administration of a novel oral thrombin inhibitor

Current antithrombotic compounds have several limitations in clinical practice. The present study was designed to investigate a novel orally available direct thrombin inhibitor, BSF 208791. Intravenous administration of BSF 208791 showed superior antithrombotic properties as compared with Polyethylenglycol-Hirudin (PEG-Hirudin) and low molecular weight heparin (LMWH) in a model of venous thrombosis in rabbits. The thrombus growth was 22%, 30%, 37% and 50% after BSF 208791, PEG-Hirudin. LMWH, and saline administration, respectively. Moreover, bleeding time was less affected after administration of BSF 208791 as compared with PEG-Hirudin. The oral administration of BSF 208791 resulted in adequate bioavailability and significantly reduced venous thrombus growth to 36% as compared with 60% in the saline treated rabbits. The antithrombotic effect of BSF 208791 appears to be superior to PEG-Hiridin and LMWH without affecting the bleeding time. BSF 208791 is an orally available agent that might be a promising candidate for future antithrombotic therapy.