Applicability of the ankle-brachial-index measurement as screening device for high cardiovascular risk: an observational study

Background

Screening with ankle-brachial index (ABI) measurement could be clinically relevant to avoid cardiovascular events in subjects with asymptomatic atherosclerosis. To assess the practical impact of guidelines regarding the use of ABI as a screening tool in general practice, the corresponding number needed to screen, including the required time investment, and the feasibility of ABI performance, was assessed.

Methods

An observational study was performed in the setting of 955 general practices in the Netherlands. Overall, 13,038 subjects of ≥55 years presenting with symptoms of intermittent claudication and/or presenting with ≥ one vascular risk factor were included. Several guidelines recommend the ABI as an additional measurement in selected populations for risk assessment for cardiovascular morbidity.

Results

Screening of the overall population of ≥50 years results in ≈862 subjects per general practice who should be screened, resulting in a time-requirement of approximately 6 weeks of full time work. Using an existing clinical prediction model, 247 patients per general practice should be screened for PAD by ABI measurement.

Conclusion

Screening the entire population of ≥50 years will in our opinion not be feasible in general practice. A more rationale and efficient approach might be screening of subsets of the population of ≥55 years based on a clinical prediction model.

The effects of Hartcoach, a life style intervention provided by telephone on the reduction of coronary risk factors: a randomised trial

Background

Cardiovascular disease (CVD) is the leading cause of death worldwide. Secondary prevention is essential, but participation rates for cardiac rehabilitation are low. Furthermore, current programmes do not accomplish that patients with CVD change their lifestyle in a way that their individual risk factors for recurrent events decrease, therefore more effective interventions are needed. In this study, the effectiveness of the Hartcoach-programme, a telephonic secondary prevention program focussing on self management, is studied.

Methods/design

A multicenter, randomised parallel-group study is being conducted. Participants are 400 patients with acute myocardial infarction (STEMI, NSTEMI,) and patients with chronic or unstable angina pectoris (IAP). Patients are recruited through the participating hospitals and randomly assigned to the experimental group (Hartcoach-programme plus usual care) or the control group (usual care).

The Hartcoach-programme consists of a period of six months during which the coach contacts the patient every four to six weeks by telephone. Coaches train patients to take responsibility for the achievement and maintenance of the defined target levels for their particular individual modifiable risk factors. Target levels and treatment goals are agreed by the nurse and patient together. Data collection is blinded and occurs at baseline and after 26 weeks (post-intervention). Primary outcome is change in cardiovascular risk factors (cholesterol, body mass index, waist circumference, blood pressure, physical activity and diet). Secondary outcomes include chances in glucose, HbA1c, medication adherence, self-management and quality of life.

Discussion

This study evaluates the effects of the Hartcoach-programme on the reduction of individual risk factors of patients with CVDs. Patients who are not invited to follow a hospital based rehabilitation programme or patients who are unable to adhere to such a programme, may be reached by this home based Hartcoach-programme. If positive results are found, the implementation of the Hartcoach-programme will be extended, having implications for the management of many people with CVD.

Trial registration

NTR2388

A comparative analysis of three widely used lipid management guidelines in the EPIC-Norfolk cohort

AIMS

To compare the impact of three major guidelines for the prevention of cardiovascular disease (CVD).

METHODS AND RESULTS

21,263 men and women aged 39-79 years from the EPIC (European Prospective Investigation of Cancer) Norfolk cohort were retrospectively classified at baseline by statin therapy recommendations according to the NICE, ESC and ATPIII CVD prevention guidelines. Recommendations based on baseline data were related to 10-year follow-up to calculate number of new CVD events that could be prevented by statins, number-needed-to-treat (NNT) and CVD incidence decrease. Statin therapy was recommended to 34% by the NICE guideline, 29% by ESC and 32% by ATPIII. A total of 263 events could potentially have been prevented by application of the NICE guideline, 219 by ESC and 199 by ATPIII. The NNT with statins over 10 years was 27 with the NICE guideline, 28 with ESC and 34 with ATPIII. Application of the NICE guideline could have decreased CVD incidence by 13%; using ESC guidelines the figure is 11% and with ATPIII it is 10%.

CONCLUSIONS

The NICE guideline selected greater percentages of elderly and subjects with prevalent CVD risk factors. It performed best in recommending statins and could have prevented the greatest number of CVD events. With all guidelines, nearly half the subjects who developed a CVD event were not considered eligible for statins at baseline. Less selective prevention strategies need to be explored.

RESPONSE study: Randomised Evaluation of Secondary Prevention by Outpatient Nurse SpEcialists: Study design, objectives and expected results

Background. Patients with coronary artery disease are at high risk of coronary events and death, but effective secondary prevention can reduce this risk. There is a gap between guidelines on secondary prevention and the implementation of these measures, which could potentially be reduced by nurse led prevention clinics (NLPC).Objectives. The aim of the current study is to quantify the impact of NLPC on the risk of cardiovascular events in patients with established coronary artery disease.Methods. A randomised, multicentre clinical trial of NLPC in addition to usual care or usual care alone in post-acute coronary syndrome patients. (Neth Heart J 2009;17:322-8.).

Effects on cardiovascular disease risk of a web-based health risk assessment with tailored health advice: a follow-up study

Introduction:

A large proportion of the cardiovascular disease (CVD) burden can potentially be prevented by primary prevention programs addressing major causal risk factors. A Web-based health risk assessment (HRA) with tailored feedback for individual health promotion is a promising strategy. We evaluated the effect on CVD risk of such a program among employees of a Dutch worksite.

Methods:

We conducted a prospective follow-up study among 368 employees who voluntarily participated in a Web-based HRA program at a single Dutch worksite in 2008. The program included a multicomponent HRA through a Web-based electronic questionnaire, biometrics, and laboratory evaluation. The results were combined with health behavior change theory to generate tailored motivational and educational health advice. On request, a health counseling session with the program physician was available. Follow-up data on CVD risk were collected 1 year after initial participation. The primary outcome was a change in Framingham CVD risk at 6 months relative to baseline. We checked for a possible background effect of an increased health consciousness as a consequence of program introduction at the worksite by comparing baseline measurements of early program participants with baseline measurements of participants who completed the program 6 months later.

Results:

A total of 176 employees completed follow-up measurements after a mean of 7 months. There was a graded relation between CVD risk changes and baseline risk, with a relative reduction of 17.9% (P = 0.001) in the high-risk category (baseline CVD risk ≥20%). Changes were not explained by additional health counseling, medication, or an increase in health consciousness within the company.

Conclusions:

Voluntary participation in a Web-based HRA with tailored feedback at the worksite reduced CVD risk by nearly 18% among participants at high CVD risk and by nearly 5% among all participants. Web-based HRA could improve CVD risk in similar populations. Future research should focus on the persistence of the effects underlying the CVD risk reduction.

A systematic review of selective and non-selective beta blockers for prevention of vascular events in patients with acute coronary syndrome or heart failure

BACKGROUND

To assess the influence of beta2-receptor suppression on top of selective beta1-receptor blockade on the occurrence of vascular events and on all-cause mortality in patients with acute coronary syndrome (ACS) or heart failure (HF ).

METHODS

Systematic review of studies published since 1980. Randomised controlled trials directly comparing beta1 blockers with beta1+2 blockers, or comparing the two beta blockers with placebo, were included. Studies had a minimum treatment period of three months and total mortality or vascular events as their primary or secondary outcome.

RESULTS

Of the included studies, five directly compared beta blockers (3733 patients) and 28 compared beta blockers with placebo (30,889 patients). These latter studies were heterogeneous in study population, dose and type of beta blockers. In ACS, the only study directly comparing different beta blockers was underpowered to detect a difference on mortality, while in HF beta1+2 blockers significantly decreased mortality compared with b1 blockers (RR 0.86, 95% confidence interval 0.78 to 0.94). In ACS, beta1 blockers in placebo-controlled trials non-significantly reduced total mortality (RR 0.82, 0.67 to 1.01) or vascular events (RR 0.68, 0.42 to 1.11), while beta1+2 blockers were associated with a significant decrease in total mortality (RR 0.73, 0.64 to 0.82), and vascular events (RR 0.71, 0.59 to 0.84). In HF, beta1 and beta1+2 blockers reduced total mortality, while only beta1+2 blockers decreased vascular events (RR 0.80, 0.64 to 1.00).

CONCLUSIONS

Additional beta2-receptor blockade may be more effective than beta1-receptor blockade alone in preventing total mortality and vascular events in patients with ACS or, to a lesser extent, HF . However, only a few studies directly compared beta blockers, and indirect comparisons were subject to heterogeneity, which weakens firm conclusions.

The prevalence of intolerance for low-dose acetylsalicylacid in the secondary prevention of atherothrombosis

Daily low-dose acetylsalicylacid (ASA) is prescribed to patients with atherothrombosis frequently to prevent vascular complications. In reports on complications and side effects of low-dose ASA use in the literature there is a range of definitions. We explored the incidence, characteristics and consequences of symptoms suggestive of ASA intolerance in patients on low-dose ASA. General practitioners and specialists in 105 centres were asked to review their patient files for the last 10 consecutive patients who were prescribed ASA. Participating patients completed a questionnaire about their current ASA use (doctors completed the questionnaire together with the patients), use of co-medication and symptoms suggestive of ASA intolerance. A total of 947 patients were included in this study. Sixty patients (6.6%) had ceased ASA treatment, predominantly because of the occurrence of side effects suspected to be caused by ASA use. A quarter of the patients concomitantly used an anti-acid agent. Of the 947 patients, 271 (30.6%) indicated symptoms during ASA intake. The most common symptoms were related to the gastrointestinal tract (25.1%). In patients prescribed a low-dose of ASA monotherapy, side effects suggestive of intolerance are common. More awareness should be created to detect and treat these symptoms, because the occurrence of side effects is the most important reason for patients to discontinue ASA treatment.

[First cracks in smoking ban in catering establishments]

The first exemption to the comprehensive ban on smoking in public places in the Netherlands was made on 14 May 2009. The exemption was based on a technicality in the wording of the law, and could potentially lead to further exemptions to the smoking ban being made. The authors argue that focusing solely on the wording is a sidetrack in the main discussion. Furthermore, they argue that the smoking ban only bans smoking in public places and that the individual's right to perform actions potentially hazardous to their own health should not be limited, as long as it puts no-one else at risk. That is exactly what smoking in public places does. They also argue that other legislative measures comparable to the smoking ban are already in effect. In conclusion, the ban on smoking in public places does not remove the right to smoke, but serves to create a healthier social environment for everyone.

Single cells isolated from human sinoatrial node: action potentials and numerical reconstruction of pacemaker current

Pacemaker activity of the sinoatrial node has extensively been studied in laboratory animals of various species, but is virtually unexplored in man. Most experimental data have been obtained from rabbit, where the hyperpolarization-activated 'funny' current (If), also known as the 'pacemaker current', plays an important role in diastolic depolarization and thus in setting pacing rate. Recently, we isolated pacemaker cells from excised human sinoatrial node tissue, and recorded action potentials and If using the whole-cell patch-clamp technique in current clamp and voltage clamp mode, respectively. Single sinoatrial node pacemaker cells showed a spontaneous beating rate of 73 +/- 3 beats/min (mean +/- SEM, n = 3) with a remarkably slow diastolic depolarization. If was identified in voltage clamp experiments as the 2 mmol/L Cs+-sensitive inward current activating upon 2-s hyperpolarizing voltage clamp steps. The If reversal potential and (de)activation kinetics were similar to those in rabbit. However, the fully-activated If conductance was 3-4 times smaller than typically found in rabbit. Furthermore, the half-maximal activation voltage was approximately 20 mV more negative than in rabbit. These differences would both act to reduce the functional role of If in human pacemaker cells. To assess this functional role, we carried out a numerical reconstruction of the If time course during an experimentally recorded human sinoatrial node action potential, based on the obtained data on If amplitude and kinetics. This reconstruction revealed that If provides a small but significant inward current in the voltage range of diastolic depolarization. We conclude that human sinoatrial node pacemaker cells functionally express If and that this If contributes to pacemaking in human sinoatrial node.

The role of fondaparinux as an adjunct to thrombolytic therapy in acute myocardial infarction: a subgroup analysis of the OASIS-6 trial

AIMS

No antithrombotic therapy has been shown to reduce mortality when used with thrombolytics in acute myocardial infarction (AMI). In the OASIS-6 trial, fondaparinux significantly reduced mortality and reinfarction without increasing bleeding in 12 092 patients with acute ST elevation MI.

METHODS AND RESULTS

We report the results of a subgroup analysis in the 5436 patients (45%) receiving thrombolytics. According to local practice, 4415 patients did not have an indication for unfractionated heparin (stratum 1) and 1021 did (stratum 2). Fondaparinux reduced the primary study outcome of death or MI at 30 days [Hazard ratio (HR) 0.79, 95% confidence interval (CI) 0.68-0.92] with consistent reductions in both mortality (HR and CI) and reinfarction (HR and CI). There was a non-significantly lower rate of stroke (HR 0.77, CI 0.48-1.25). The risk of severe bleeding was significantly reduced (HR 0.62, CI 0.40-0.94), and thus the balance of benefit and risk (death, MI and severe haemorrhage) was clearly reduced by fondaparinux (HR 0.77, 95% CI 0.67-0.90). Results were consistent in the two strata, by the different types of thrombolytics and across various time intervals from symptom onset to treatment.

CONCLUSION

In STEMI patients treated with thrombolytic agents (predominantly streptokinase), fondaparinux significantly reduced the risk of death, re-MI and severe bleeds.

[The endocannabinoid system, overweight, and the CB1-endocannabinoid-receptor antagonist rimonabant]

--Obesity is an important healthcare issue. --Recent research has led to insights into the role of the endocannabinoid system in the regulation of body weight. --Rimonabant is a CB1-endocannabinoid-receptor antagonist. --Four trials were published recently on the efficacy and safety of rimonabant in the treatment of people with obesity. --When combined with a hypocaloric diet, rimonabant 20 mg/day was more effective than placebo in achieving and maintaining weight loss. In addition, treatment with rimonabant had beneficial effects on insulin resistance, HDL-cholesterol and hypertriglyceridaemia. --There is concern regarding the increased incidence of depression during treatment. --Whether the beneficial effects of rimonabant on weight reduction and cardiovascular risk factors translate into a reduction in cardiovascular morbidity and mortality remains to be established in large phase III trials.

[Clinical placements cannot start in the third year of medical training]

A solid knowledge base is essential in order for clinical placements that include some responsibilities to be meaningful. As it takes at least 3 years to discuss all principal organ systems, clinical placements should not commence after only two years. In addition, the limited numbers of patients and clinical teachers may be better reserved for full senior clinical placements.

Efficacy and safety of fondaparinux versus enoxaparin in patients with acute coronary syndromes undergoing percutaneous coronary intervention: results from the OASIS-5 trial

OBJECTIVES

This study reports a prospectively planned analysis of patients with acute coronary syndrome who underwent early percutaneous coronary intervention (PCI) in the OASIS-5 (Fifth Organization to Assess Strategies in Ischemic Syndromes) trial.

BACKGROUND

In the OASIS-5 trial, fondaparinux was similar to enoxaparin for short-term efficacy, but reduced major bleeding by one-half and 30-day mortality by 17%.

METHODS

The OASIS-5 trial was a double-blind, randomized comparison of fondaparinux and enoxaparin in 20,078 patients with acute coronary syndrome. A total of 12,715 patients underwent heart catheterization during the initial hospitalization, and 6,238 patients underwent PCI. In the fondaparinux group, intravenous fondaparinux was given for PCI. In the enoxaparin group, no additional anticoagulant was given if PCI was <6 h from last subcutaneous dose, and additional intravenous unfractionated heparin (UFH) was given if PCI was >6 h.

RESULTS

Fondaparinux compared with enoxaparin reduced major bleeding by more than one-half (2.4% vs. 5.1%, hazard ratio [HR] 0.46, p < 0.00001) at day 9, with similar rates of ischemic events, resulting in superior net clinical benefit (death, myocardial infarction, stroke, major bleeding: 8.2% vs. 10.4%, HR 0.78, p = 0.004). Fondaparinux reduced major bleeding 48 h after PCI irrespective of whether PCI was performed <6 h of the last enoxaparin dose (1.6% vs. 3.8%, HR 0.42, p < 0.0001) or >6 h when UFH was given (1.3% vs. 3.4%, HR 0.39, p < 0.0001). Catheter thrombus was more common in patients receiving fondaparinux (0.9%) than enoxaparin alone (0.4%), but was largely prevented by using UFH at the time of PCI, without any increase in bleeding.

CONCLUSIONS

Upstream therapy with fondaparinux compared with upstream enoxaparin substantially reduces major bleeding while maintaining efficacy, resulting in superior net clinical benefit. The use of standard UFH in place of fondaparinux at the time of PCI seems to prevent angiographic complications, including catheter thrombus, without compromising the benefits of upstream fondaparinux.

Pacemaker current (If) in the human sinoatrial node

AIMS

Animal studies revealed that the hyperpolarization-activated pacemaker current, I(f), contributes to action potential (AP) generation in sinoatrial node (SAN) and significantly determines heart rate. I(f) is becoming a novel therapy target to modulate heart rate. Yet, no studies have demonstrated that I(f) is functionally present and contributes to pacemaking in human SAN. We aimed to study I(f) properties in human SAN.

METHODS AND RESULTS

In a patient undergoing SAN excision, we identified SAN using epicardial activation mapping. From here, we isolated myocytes and recorded APs and I(f) using patch-clamp techniques. Pacemaker cells generated spontaneous APs (cycle length 828 +/- 15 ms) following slow diastolic depolarization, maximal diastolic potential - 61.7 +/- 4.3 mV, and maximal AP upstroke velocity 4.6 +/- 1.2 V/s. They exhibited an hyperpolarization-activated inward current, blocked by external Cs(+) (2 mmol/L), characterizing it as I(f). Fully-activated conductance was 75.2 +/- 3.8 pS/pF, reversal potential - 22.1 +/- 2.4 mV, and half-maximal activation voltage and slope factor of steady-state activation - 96.9 +/- 2.7 and - 8.8 +/- 0.5 mV. Activation time constant ranged from approximately 350 ms (-130 mV) to approximately 1 s (-100 mV), deactivation time constant 156 +/- 45 ms (-40 mV). The role of I(f) in pacemaker activity was demonstrated by slowing of pacemaker cell diastolic depolarization and beating rate by Cs(+).

CONCLUSION

I(f) is functionally expressed in human SAN and probably contributes to pacemaking in human SAN.

The effect of a minimal intervention strategy in addition to nicotine replacement therapy to support smoking cessation in cardiovascular outpatients: a randomized clinical trial

BACKGROUND

Smoking is an important risk factor for recurrent events in cardiovascular patients. Evidence exists that nicotine replacement therapy (NRT) approximately doubles smoking cessation rates. The minimal intervention strategy (MIS) has been used successfully to assist patients to quit smoking in general practice, and was recently adapted for cardiology inpatients (C-MIS). It is hypothesized that in cardiovascular outpatients the combination of C-MIS and NRT significantly increases the number of quitters compared to NRT alone.

METHODS

A randomized clinical trial in 385 smoking patients who attended the cardiovascular outpatient departments in the Academic Medical Centre, Amsterdam for the treatment of atherosclerotic disease. Patients were allocated to either NRT + C-MIS or NRT alone. Self-reported and biochemically validated abstinence rates were measured at 12 months' follow-up.

RESULTS

Including patients with incomplete follow-up as smokers, abstinence was reported by 19% of the NRT + C-MIS group and 14% of the NRT group [absolute risk reduction (ARR) = 0.05; 95% confidence interval (CI) = -0.02; 0.12]. According to biochemical markers, abstinence rates were 28 and 24%, respectively (ARR = 0.04, 95% CI = -0.06; 0.14). Hence, no significant differences between groups were found. The number of cigarettes smoked a day decreased significantly at 12 months: from 21 to 15 a day in the experimental group, and from 21 to 14 in the control group (P<0.001), but did not differ between groups (P=0.32).

CONCLUSIONS

The effectiveness of a minimal contact intervention was investigated in order to reach as many cardiovascular patients as possible in the setting of outpatient departments. This intervention was not found to be effective.

[New scientific arguments for further reducing the use of tobacco, also in the hotel, restaurant and catering business]

The prohibition of smoking in public places that has been implemented in various European countries has led to a noticeable decrease in the number of hospital admissions for acute myocardial infarction. This effect became manifest within one year after the adoption of the measure. A significant proportion of the benefit can probably be ascribed to the reduction of passive smoking. The recently published INTERHEART study is a case-control study involving approximately 12,500 patients who had been admitted for an acute myocardial infarction and approximately 14,500 apparently healthy controls. The study was carried out in 52 countries and reveals that an increased risk of acute myocardial infarction as the result of tobacco use can be seen in all investigated countries and races. Smoking as well as the chewing or sniffing of tobacco are associated with an increased risk; there is also a clear proportional relationship between the level of tobacco use and the degree of risk. Moreover, passive smoking was again shown to be an important and avoidable cause ofacute myocardial infarction. In the Netherlands, smoking in public buildings has been prohibited since 1990, with the exception of the hotel, restaurant and catering industry. It would be a good thing if this exception were eliminated in our country as well.

Long-term clopidogrel therapy in patients receiving percutaneous coronary intervention

BACKGROUND

The PCI-CURE (Percutaneous Coronary Intervention-Clopidogrel in Unstable Angina to Prevent Recurrent Events) and CREDO (Clopidogrel for the Reduction of Events During Observation) studies have demonstrated that, in addition to aspirin, pre-treatment with clopidogrel followed by long-term (i.e. 9-12 months) therapy significantly reduces the risk of atherothrombotic events in patients undergoing percutaneous coronary intervention (PCI).

OBJECTIVE

To examine the economic implications, from the Dutch healthcare perspective, of the use of clopidogrel in patients undergoing PCI (elective procedures or in patients with acute coronary syndrome), comparing pre-treatment followed by long-term therapy with only 4 weeks of treatment.

METHODS

A lifetime Markov model was used to combine data from the PCI-CURE and CREDO trials with data from the literature concerning epidemiology, costs and quality of life. The model was run separately for each trial. Only direct healthcare costs (euro, year 2004 values) were considered. Costs and outcomes were discounted at 4% per anum. For each trial, the cost effectiveness is expressed as costs per life-year and QALY gained. Uncertainties are addressed by uni- and probabilistic multivariate sensitivity analysis.

RESULTS

When starting with the data from the PCI-CURE trial, pre-treatment plus 9-month clopidogrel therapy was predicted to save 1119 euros and gain 0.03 life-years and 0.07 QALYs per patient compared with short-term treatment. When starting with the data from the CREDO trial, the combination of pre-treatment and prolonged clopidogrel therapy (1 year) was estimated to save 497 euros and gain 0.10 life-years and 0.14 QALYs per patient. Univariate and probabilistic multivariate sensitivity analyses suggested that the conclusions were generally robust, but that the expected gain in survival for the PCI-CURE population was very sensitive to the effects on mortality within the combined endpoint of myocardial infarction/stroke-free survival.

CONCLUSIONS

In The Netherlands, pre-treatment plus long-term (9-12 months) therapy with clopidogrel is estimated to save costs and increase (quality-adjusted) survival in the prevention of ischaemic events among patients undergoing elective PCI (CREDO) and in patients with acute coronary syndrome (PCI-CURE) compared with short-term treatment with clopidogrel without pre-treatment.

Physical activity, C-reactive protein levels and the risk of future coronary artery disease in apparently healthy men and women: the EPIC-Norfolk prospective population study

BACKGROUND

Physical activity is inversely associated with the risk of future coronary artery disease. Whether this relationship is in part mediated by lower levels of systemic inflammation, as indicated by C-reactive protein concentrations, is unknown.

METHODS

We performed a nested case-control study among apparently healthy men and women enrolled in the European Prospective Investigation into Cancer and Nutrition-Norfolk prospective population study, to investigate the relationship among habitual (work-related and leisure time) physical activity, cardiovascular risk factors and the risk of future coronary artery disease.

RESULTS

Among men, those with an active lifestyle had a significantly lower risk of future coronary artery disease than those with an inactive lifestyle [odds ratio (OR) 0.65; 95% confidence interval (CI) 0.47-0.90; P for linearity, 0.008], after adjustment for smoking, systolic blood pressure, diabetes, body mass index and low-density lipoprotein and high-density lipoprotein cholesterol. Additional adjustment for C-reactive protein levels attenuated this relationship only slightly (OR 0.68; 95%CI 0.49-0.93; P for linearity, 0.02). Similarly, active women had an adjusted odds ratio of 0.48 (0.28-0.82; P for linearity <0.001) for future coronary artery disease compared with inactive women. Additional adjustment for C-reactive protein levels attenuated this relationship slightly (OR 0.51; 0.30-0.87; P for linearity, 0.003).

CONCLUSIONS

We observed that people with an active lifestyle had a substantially lower risk of future coronary artery disease than people with an inactive lifestyle, and that this relationship was partly mediated through lower levels of established cardiovascular risk factors and in addition, C-reactive protein. This observation suggests that reduced systemic inflammation may be one of the mechanisms through which physical activity leads to reduced cardiovascular risk.

Smoking cessation may not improve quality of life in atherosclerotic patients

The benefits of smoking cessation on patients' medical conditions are well documented. Cardiovascular patients who quit smoking significantly reduce their risk of a new event compared with those who continue smoking. Several studies have found that smoking is related to poor quality of life (QoL). In cardiovascular patients, however, less attention has been given to the effect of smoking cessation on patients' QoL. The present study examined the extent to which smoking cessation leads to changes in QoL in these patients within the first year of follow-up. Data were collected in the context of a randomized clinical trial. Smoking outpatients (N = 346) with atherosclerotic disease were included and received medical treatment. They were randomized to receive either nicotine replacement therapy (NRT) or NRT plus a behavioral intervention meant to promote smoking cessation. At baseline, sociodemographic and clinical characteristics were established. Generic and disease-specific QoL as well as smoking status were assessed at baseline and with three follow-up measurements. Multilevel modeling showed that generic and disease-specific QoL in atherosclerotic patients improved significantly within the first year of follow-up. No main differences were found between quitters and smokers in terms of improvement in QoL. In fact, some subgroups reported a poorer QoL after smoking cessation: More highly educated patients reported lower general QoL (p < .05), and patients suffering from coronary artery disease who had a low level of education (p < .01) and patients suffering from peripheral arterial disease who had low nicotine dependency (p < .01) reported lower disease-specific QoL. Atherosclerotic patients' QoL improved significantly but was not enhanced by smoking cessation activities.

Adherence to nicotine replacement patch therapy in cardiovascular patients

Nicotine Replacement Therapy (NRT) is the most frequently used pharmacological intervention for smoking cessation. Research on the effect of NRT showed serious nonadherence among users. We investigated adherence to NRT in cardiovascular patients. A number of 174 outpatients (N = 174), who smoked > 5 cigarettes a day, received free patches and intensive instructions from nurses. Questionnaires were sent to patients assessing patient characteristics, adherence to a 7-8 weeks time frame and appliance instructions, side effects/withdrawal symptoms, and reasons for nonadherence. Only 38% of the patients was adherent to the time frame. Appliance instructions were followed in 76-96% of the cases, except for smoking; 50% continued to smoke during NRT. In conclusion, despite considerable attention to appliance instructions, access to free patches and additional behavioral support, adherence to NRT in these patients is rather low.

Comparison of fondaparinux and enoxaparin in acute coronary syndromes

BACKGROUND

The combined use of anticoagulants, antiplatelet agents, and invasive coronary procedures reduces ischemic coronary events but also increases bleeding in patients with acute coronary syndromes. We therefore assessed whether fondaparinux would preserve the anti-ischemic benefits of enoxaparin while reducing bleeding.

METHODS

We randomly assigned 20,078 patients with acute coronary syndromes to receive either fondaparinux (2.5 mg daily) or enoxaparin (1 mg per kilogram of body weight twice daily) for a mean of six days and evaluated death, myocardial infarction, or refractory ischemia at nine days (the primary outcome); major bleeding; and their combination. Patients were followed for up to six months.

RESULTS

The number of patients with primary-outcome events was similar in the two groups (579 with fondaparinux [5.8 percent] vs. 573 with enoxaparin [5.7 percent]; hazard ratio in the fondaparinux group, 1.01; 95 percent confidence interval, 0.90 to 1.13), satisfying the noninferiority criteria. The number of events meeting this combined outcome showed a nonsignificant trend toward a lower value in the fondaparinux group at 30 days (805 vs. 864, P=0.13) and at the end of the study (1222 vs. 1308, P=0.06). The rate of major bleeding at nine days was markedly lower with fondaparinux than with enoxaparin (217 events [2.2 percent] vs. 412 events [4.1 percent]; hazard ratio, 0.52; P<0.001). The composite of the primary outcome and major bleeding at nine days favored fondaparinux (737 events [7.3 percent] vs. 905 events [9.0 percent]; hazard ratio, 0.81; P<0.001). Fondaparinux was associated with a significantly reduced number of deaths at 30 days (295 vs. 352, P=0.02) and at 180 days (574 vs. 638, P=0.05).

CONCLUSIONS

Fondaparinux is similar to enoxaparin in reducing the risk of ischemic events at nine days, but it substantially reduces major bleeding and improves long term mortality and morbidity. (ClinicalTrials.gov number, NCT00139815.).

Effects of fondaparinux on mortality and reinfarction in patients with acute ST-segment elevation myocardial infarction: the OASIS-6 randomized trial

CONTEXT

Despite many therapeutic advances, mortality in patients with acute ST-segment elevation myocardial infarction (STEMI) remains high. The role of additional antithrombotic agents is unclear, especially among patients not receiving reperfusion therapy.

OBJECTIVE

To evaluate the effect of fondaparinux, a factor Xa inhibitor, when initiated early and given for up to 8 days vs usual care (placebo in those in whom unfractionated heparin [UFH] is not indicated [stratum 1] or unfractionated heparin for up to 48 hours followed by placebo for up to 8 days [stratum 2]) in patients with STEMI.

DESIGN, SETTING, AND PARTICIPANTS

Randomized double-blind comparison of fondaparinux 2.5 mg once daily or control for up to 8 days in 12,092 patients with STEMI from 447 hospitals in 41 countries (September 2003-January 2006). From day 3 through day 9, all patients received either fondaparinux or placebo according to the original randomized assignment.

MAIN OUTCOME MEASURES

Composite of death or reinfarction at 30 days (primary) with secondary assessments at 9 days and at final follow-up (3 or 6 months).

RESULTS

Death or reinfarction at 30 days was significantly reduced from 677 (11.2%) of 6056 patients in the control group to 585 (9.7%) of 6036 patients in the fondaparinux group (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.77-0.96; P = .008); absolute risk reduction, 1.5%; 95% CI, 0.4%-2.6%). These benefits were observed at 9 days (537 [8.9%] placebo vs 444 [7.4%] fondaparinux; HR, 0.83; 95% CI, 0.73-0.94; P = .003, and at study end (857 [14.8%] placebo vs 756 [13.4%] fondaparinux; HR, 0.88; 95% CI, 0.79-0.97; P = .008). Mortality was significantly reduced throughout the study. There was no heterogeneity of the effects of fondaparinux in the 2 strata by planned heparin use. However, there was no benefit in those undergoing primary percutaneous coronary intervention. In other patients in stratum 2, fondaparinux was superior to unfractionated heparin in preventing death or reinfarction at 30 days (HR, 0.82; 95% CI, 0.66-1.02; P = .08) and at study end (HR, 0.77; 95% CI, 0.64-0.93; P = .008). Significant benefits were observed in those receiving thrombolytic therapy (HR, 0.79; P = .003) and those not receiving any reperfusion therapy (HR, 0.80; P = .03). There was a tendency to fewer severe bleeds (79 for placebo vs 61 for fondaparinux; P = .13), with significantly fewer cardiac tamponade (48 vs 28; P = .02) with fondaparinux at 9 days.

CONCLUSION

In patients with STEMI, particularly those not undergoing primary percutaneous coronary intervention, fondaparinux significantly reduces mortality and reinfarction without increasing bleeding and strokes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT00064428.

Benefit of clopidogrel according to timing of percutaneous coronary intervention in patients with acute coronary syndromes: further results from the Clopidogrel in Unstable angina to prevent Recurrent Events (CURE) study

BACKGROUND

The CURE study demonstrated the benefit of clopidogrel in patients with non-ST elevation (NSTE) acute coronary syndromes (ACSs), including those undergoing percutaneous coronary intervention (PCI). It did not report the relation between clopidogrel and timing of PCI or, more specifically, the role of clopidogrel in patients managed with an early interventional strategy, the current preferred treatment option for patients with NSTE ACSs. In the present study, we examined the relation between clopidogrel therapy, timing of PCI, and cardiovascular (CV) events in patients participating in the CURE study.

METHODS

A total of 12562 patients with NSTE ACSs was randomized in double-blind fashion to clopidogrel or placebo (300 mg loading dose, then 75 mg/d) in addition to aspirin for up to 1 year. We analyzed the data of the 2658 CURE patients undergoing PCI and related the incidence of outcome events (CV death/myocardial infarction [MI]) to timing of PCI after randomization: early (< 48 hours, median 1.0 day, n = 370), intermediate (> or = 48 hours to initial hospital discharge, median 6.8 days, n = 1360), and late (after initial hospital discharge, median 47.6 days, n = 928).

RESULTS

Clopidogrel showed consistent treatment benefit over the 12-month (mean 9 months) follow-up period irrespective of timing of PCI (relative risk [RR] 0.53 for the early group, RR 0.72 for the intermediate group, RR 0.70 for the late group). After adjustment for propensity to undergo PCI, the greatest treatment benefit of clopidogrel was observed in patients undergoing PCI < 48 hours after randomization (RR 0.45, 95% CI 0.21-0.96, P = .038), although with overlap between groups. The lowest absolute event rate (6.7% CV death/MI) was observed in patients treated with clopidogrel and undergoing PCI within 48 hours. There was no increased risk of major bleeding in the early PCI group.

CONCLUSIONS

The benefit of therapy with clopidogrel in addition to aspirin in patients presenting with NSTE ACSs was significant irrespective of the timing of PCI. The combination of clopidogrel and an early (< 48 hours) interventional strategy was associated with low absolute event rates for CV death/nonfatal MI.

Design and rationale of the MICHELANGELO Organization to Assess Strategies in Acute Ischemic Syndromes (OASIS)-5 trial program evaluating fondaparinux, a synthetic factor Xa inhibitor, in patients with non-ST-segment elevation acute coronary syndromes

BACKGROUND

Factor Xa plays a central role in the generation of thrombin, making it a novel target for treatment of arterial thrombosis. Fondaparinux, a synthetic pentasaccharide, is a factor Xa inhibitor, which has been shown to be superior to enoxaparin for the prevention of venous thrombosis. We designed a large, phase III, randomized trial to evaluate the efficacy and safety of fondaparinux compared with enoxaparin in acute coronary syndromes.

STUDY DESIGN

The OASIS-5 trial is a randomized, double-blind trial of fondaparinux versus enoxaparin in 20,000 patients with unstable angina or non-ST-segment elevation myocardial infarction. The primary objective is to determine whether fondaparinux is noninferior to enoxaparin in preventing the composite of death, new myocardial infarction, and refractory ischemia at 9 days (primary outcome) and at 30 days (secondary outcome) after randomization. There will be additional follow-up of all patients for 3 to 6 months after randomization. If noninferiority is established at 9 days, superiority will be tested. The primary safety outcome is to evaluate the rates of major bleeds in the 2 groups with the balance of benefit and risk assessed by comparing the impact on the composite of the primary and safety outcomes. Secondary outcomes are each component of the composite primary outcome separately at days 9, 30, and up to 6 months. The TIMACS, a major substudy using a partial 2x2 factorial design evaluating whether early angiography and intervention (within 24 hours) are superior to a more delayed approach (after 36 hours) in reducing major ischemic events at 6 months after randomization.

CONCLUSIONS

The MICHELANGELO OASIS 5 program will provide a comprehensive and reliable evaluation of fondaparinux in a broad spectrum of patients with ACS.

C-reactive protein levels and coronary artery disease incidence and mortality in apparently healthy men and women: the EPIC-Norfolk prospective population study 1993-2003

INTRODUCTION

Measurement of C-reactive protein (CRP) levels has been proposed as a useful marker to improve the prediction of future coronary artery disease (CAD) risk, but this notion has been challenged recently.

METHODS AND RESULTS

We performed a prospective case-control study among apparently healthy men and women. The odds ratio (OR) for future CAD incidence was 2.49 (95% CI=2.02-3.08, p for linearity <0.0001) unadjusted, and 1.66 (95% CI=1.31-2.12, p for linearity <0.0001), after adjustment for classical cardiovascular risk factors, for top versus bottom quartile of the CRP distribution. Notably, the risk factor adjusted predictive value was substantially stronger for fatal CAD (OR=2.92, 95% CI=1.83-4.67, p for linearity <0.0001) than for non-fatal CAD (OR=1.25, 95% CI=0.93-1.66, p for linearity=0.06). CRP levels were among the strongest predictors of CAD incidence and mortality. CRP levels remained a statistically significant predictor of future CAD, even after adjustment for the Framingham risk score.

CONCLUSIONS

In this British cohort with risk factor levels representative of a contemporary Western population, CRP concentration was among the strongest predictors of CAD incidence and mortality. We suggest that current guidelines on CRP measurement in clinical practice should be based on contemporary and representative populations.

Smoking and the patency of lower extremity bypass grafts: A meta-analysis

OBJECTIVE

Smoking is the major risk factor associated with the development and progression of peripheral arterial disease (PAD). To establish the best estimate of the effect of smoking, smoking cessation, and the dose-response relationship on the patency of lower extremity bypass grafts, we performed a systematic review.

METHODS

A search of medical articles and reviews relating to the influence of smoking on the patency of arterial reconstructive grafts in patients with PAD was made. Studies considered for inclusion were those that evaluated the influence of smoking on the primary, secondary, or cumulative patency rates of arterial reconstructive surgery in the lower extremities in patients with PAD. Primary data were used to calculate summary estimates with standard meta-analysis techniques.

RESULTS

The 29 eligible studies included 4 randomized clinical trials, 12 prospective studies, and 13 retrospective studies. The effect of smoking on graft patency in the randomized clinical trials and other prospective studies had a 3.09-fold (2.34 to 4.08; P < .00001) increase in graft failure. A comparison of patency rates among all studies that used autogenous or polyester grafts showed no difference. A clear dose-response relationship was present, with a decreased patency in heavy smokers compared with moderate smokers. Smoking cessation restores patency rates toward the never smokers group.

CONCLUSION

Continued smoking after lower limb bypass surgery results in a threefold increased risk of graft failure. Smoking cessation, even if instigated after the operation, restored graft patency towards the patency of never smokers. These results indicate that adequate smoking cessation strategies in patients eligible for lower limb bypass surgery are of utmost importance.

[Acute respiratory tract infections and acute coronary syndromes]

Epidemiological research indicates a correlation between respiratory-tract infections and acute cardiovascular events. Chronic infections have been linked to the development of atherosclerosis. As a result of chronic infections a prolonged and elevated inflammatory activity arises. Inflammation and the associated vessel-wall damage play an important role in the pathophysiology of atherosclerosis. Acute infections have been linked to a transient increased risk of unstable angina pectoris and an acute myocardial infarct. The consequence of acute infections is a systemic inflammatory response which results in changes in the atherosclerotic plaque, thrombotic activation and a prothrombotic condition. The inflammatory response and prothrombotic condition reinforce each other. This can result in coagulation on ruptured atherosclerotic plaques and erosions in the vessel wall, which can give rise to the sudden constriction or blockage of coronary arteries.

Randomized, Blinded Trial Comparing Fondaparinux With Unfractionated Heparin in Patients Undergoing Contemporary Percutaneous Coronary Intervention

Background— Factor Xa plays a central role in the generation of thrombin, making it a novel target for treatment of arterial thrombosis. Fondaparinux is a synthetic factor Xa inhibitor that has been shown to be superior to standard therapies for the prevention of venous thrombosis. We performed a randomized trial to determine the safety and feasibility of fondaparinux in the percutaneous coronary intervention (PCI) setting.

Methods and Results— A total of 350 patients undergoing elective or urgent PCI were randomized in a blinded manner to receive unfractionated heparin (UFH), 2.5 mg fondaparinux IV, or 5.0 mg fondaparinux IV. Randomization was stratified for planned or no planned use of glycoprotein (GP) IIb/IIIa antagonists. The primary safety outcome was total bleeding, which was a combination of major and minor bleeding events. The incidence of total bleeding was 7.7% in the UFH group and 6.4% in the combined fondaparinux groups (hazard ratio, 0.81; 95% confidence interval, 0.35 to 1.84; P =0.61). Bleeding was less common in the 2.5-mg fondaparinux group compared with the 5-mg fondaparinux group (3.4% versus 9.6%, P =0.06). The composite efficacy outcome of all-cause mortality, myocardial infarction, urgent revascularization, or need for a bailout GPIIb/IIIa antagonist was 6.0% in the UFH group and 6.0% in the fondaparinux group, with no significant difference in efficacy among the fondaparinux doses compared with UFH. Coagulation marker analysis at 6 and 12 hours after PCI demonstrated that fondaparinux was superior to UFH in inducing a sustained reduction in markers of thrombin generation, as measured by prothrombin fragment F1.2 ( P =0.02).

Conclusions— In this pilot study of patients undergoing contemporary PCI, factor Xa inhibition with the synthetic anticoagulant fondaparinux in doses of 2.5 and 5.0 mg was comparable to UFH for clinical safety and efficacy outcomes. These data form the basis for further evaluation of fondaparinux in arterial thrombosis.

Macrophage migration inhibitory factor and the risk of myocardial infarction or death due to coronary artery disease in adults without prior myocardial infarction or stroke: the EPIC-Norfolk Prospective Population study

PURPOSE

To determine whether plasma levels of macrophage migration inhibitory factor, a proinflammatory cytokine involved in atherogenesis, are predictive of myocardial infarction or death from coronary artery disease.

METHODS

We performed a prospective case-control study nested in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohort. We selected men and women who did not report a history of myocardial infarction or stroke at baseline. Baseline concentrations of macrophage migration inhibitory factor were measured among 777 patients who had a myocardial infarction or died of coronary artery disease during follow-up, and 1554 matched controls who remained free of coronary artery disease.

RESULTS

Baseline macrophage migration inhibitory factor concentrations were higher in cases than controls (median, 107.4 microg/L vs. 90.7 microg/L, P = 0.001). The risk of myocardial infarction or death from coronary artery disease increased with increasing quartiles of macrophage migration inhibitory factor (P for linearity <0.0001). Patients in the highest quartile had the greatest likelihood of myocardial infarction or death due to coronary artery disease (unadjusted odds ratio [OR] = 1.6; 95% confidence interval [CI]: 1.2 to 2.0). After adjustment for traditional risk factors and C-reactive protein level, the odds ratio decreased slightly (OR = 1.3; 95% CI: 1.0 to 1.7). Upon additional adjustment for white cell count, this association was no longer statistically significant.

CONCLUSION

Prospective data suggest that the relation between macrophage migration inhibitory factor and the risk of myocardial infarction or death due to coronary artery disease in adults without a history of myocardial infarction or stroke is not very strong. However, the data support a regulatory role for macrophage migration inhibitory factor in the process of atherosclerosis.

Plasma Levels of Cholesteryl Ester Transfer Protein and the Risk of Future Coronary Artery Disease in Apparently Healthy Men and Women

Background— Low plasma levels of cholesteryl ester transfer protein (CETP) are associated with elevated levels of HDL cholesterol (HDL-C), but it remains unclear whether this translates into a concomitant reduction in the risk of coronary artery disease (CAD). Evidence exists that the effect of CETP depends on metabolic context, in particular on triglyceride levels.

Methods and Results— A nested case-control study was performed in the prospective EPIC-Norfolk cohort study. Cases were apparently healthy men and women aged 45 to 79 years who developed fatal or nonfatal CAD during follow-up. Control subjects were matched by age, sex, and enrollment time. CETP levels were not significantly different between cases and controls (4.0±2.2 versus 3.8±2.1 mg/L, P =0.07). CETP levels were significantly related to plasma levels of total cholesterol, LDL cholesterol, and HDL-C. The risk of CAD increased with increasing CETP quintiles ( P for linearity=0.02), such that subjects in the highest quintile had an adjusted OR of 1.43 (95% CI 1.03 to 1.99, P =0.03) versus those in the lowest. Among individuals with triglyceride levels below the median (1.7 mmol/L), no relationship between CETP levels and CAD risk was observed ( P for linearity=0.5), but this relationship was strong among those with high triglyceride levels ( P for linearity=0.02), such that those in the highest CETP quintile had an OR of 1.87 (95% CI 1.06 to 3.30, P =0.02).

Conclusions— Elevated CETP levels are associated with an increasing risk of future CAD in apparently healthy individuals, but only in those with high triglyceride levels.

Beta-receptor blockade decreases elevated plasma levels of factor VIII:C in patients with deep vein thrombosis

BACKGROUND

An elevated plasma level of factor VIII:C (FVIII:C) is a strong and dose-dependent risk factor for venous thromboembolism (VTE). The cause of elevated FVIII:C in patients with thrombophilia is as yet unknown. FVIII:C increases significantly after infusion of epinephrine, vasopressin or physical exercise. The aim of the present study was to investigate whether beta-receptor blockade will lower sustained elevated FVIII:C in patients with VTE.

METHODS AND RESULTS

Two cohorts of patients with documented deep vein thrombosis and an elevated FVIII:C (>175 IU dL(-1)) and healthy volunteers, were studied. One cohort was treated with the beta-receptor blocker, whereas the other cohort served as non-treatment controls. The patient treatment group and healthy volunteers were given 40 mg propranolol, thrice daily, for 14 days. The mean baseline level of FVIII:C was 220 IU dL(-1) and 102 IU dL(-1) in patients and healthy volunteers, respectively. After 2 weeks of propranolol a significant 23% reduction of FVIII:C (- 52 IU dL(-1); 95%CI:[-65; -39]) compared with no change over time in the patient no- treatment group (-1.8 IU dL(-1); 95%CI:[-34; 30]). After discontinuation of propranolol FVIII:C returned to its initial high level. In healthy volunteers propranolol had no effect on the plasma concentration of FVIII:C.

CONCLUSION

This study demonstrates that in patients with VTE a sustained elevated FVIII:C concentration can be decreased with the use of propranolol. This observation may be of potential clinical relevance, since it has been shown that each increase of 10 IU dL(-1) in FVIII:C concentration enhanced the risk of a recurrent VTE by 24%.

IL-8 plasma concentrations and the risk of future coronary artery disease in apparently healthy men and women: the EPIC-Norfolk prospective population study

OBJECTIVE

To study the role of IL-8 in predicting future coronary artery disease (CAD) in apparently healthy men and women.

METHODS AND RESULTS

A nested case-control study was performed in the prospective EPIC-Norfolk population study. We measured baseline IL-8 concentrations among 785 apparently healthy individuals in whom fatal or nonfatal CAD developed during follow-up and 1570 matched controls. Baseline IL-8 concentrations were higher in cases than in matched controls (3.5 pg/mL versus 3.1 pg/mL, P=0.001). The risk of future CAD increased with increasing quartiles of IL-8 (P linearity <0.0001). Among individuals in the highest IL-8 quartile, the unadjusted odds ratio for future CAD was 1.72 (95% CI, 1.34 to 2.21; P<0.0001). The odds ratio for future CAD was still significant after adjustment for traditional risk factors (OR, 1.58; 95%CI, 1.19 to 2.09; P=0.002) and after additional adjustment for C-reactive protein and white cell count (OR, 1.77; 95% CI, 1.21 to 2.60; P=0.001).

CONCLUSIONS

We conclude that among apparently healthy men and women, elevated levels of IL-8 are associated with an increased risk of future CAD. These prospective data support a role for IL-8 in the development of CAD events.

Recombinant factor VIIa reverses the anticoagulant effect of the long-acting pentasaccharide idraparinux in healthy volunteers

We investigated whether the anticoagulant effect of idraparinux, a selective long-acting factor Xa inhibitor, could be neutralized by recombinant factor VIIa (rFVIIa) in healthy male volunteers. We performed a randomized, placebo-controlled trial, comparing idraparinux [7.5 mg subcutaneous (s.c.)] followed at 3 h by rFVIIa [90 microg/kg intravenous (i.v.)] (n = 6), or idraparinux (7.5 mg s.c) followed after 1 week by rFVIIa (90 microg/kg i.v.)(n = 6). rFVIIa, given 3 h after idraparinux, significantly reversed the increased thrombin generation time (TGT), the increased activated partial thromboplastin time (aPTT) and prothrombin time (PT), and the reduced prothrombin fragment 1+2 (F1+2) levels caused by idraparinux, although no clear effect of rFVIIa on the endogenous thrombin potential (ETP) was observed. One week after idraparinux, injection of rFVIIa resulted in a similar relative reduction of the remaining increased aPTT, PT and TGT, with correction to pre-idraparinux values. A clear increase of F1+2 was observed, together with a small increase in ETP. We conclude that rFVIIa has significant effects on the idraparinux-inhibited thrombin generation and clotting parameters. These results suggest that rFVIIa may be useful in serious bleeding complications in idraparinux treated patients.

Inhibition of the tissue factor pathway of coagulation by recombinant nematode anticoagulant protein c2 during elective coronary stent implantation

BACKGROUND

Exposure of tissue factor (TF) to the circulation during coronary stent implantation initiates coagulation activation and may contribute to the risk of thrombotic complications. In this study, we investigated whether inhibition of TF-factor VIIa by recombinant Nematode Anti-coagulant Protein c2 (rNAPc2) is able to suppress haemostatic and inflammatory activity in patients undergoing elective intracoronary stenting.

METHODS

In a randomised, double-blind design, 102 patients received either placebo or rNAPc2 (biological half-life >50 hours) at doses of 3.5, 5.0, 7.5 and 10.0 μg/kg as a single subcutaneous administration two to six hours before angioplasty. All patients also received aspirin, clopidogrel and unfractionated heparin (activated clotting time >250 seconds during angioplasty). Serial blood samples were collected before and after the intervention.

RESULTS

At 30 hours after stenting, all rNAPc2 treatment groups but not the placebo group demonstrated a reduction from baseline of prothrombin fragment F1+2 and D-dimer plasma levels (to 23 and 12% below baseline values at the highest dose, respectively), which were significantly lower in three rNAPc2 groups compared with placebo (p≤0.03). TF plasma levels were initially reduced in all rNAPc2 groups and returned to baseline values 18 hours after stent implantation. These three markers all increased to above baseline values in the placebo group. Levels of P-selectin, antithrombin III and interleukin-8 were not or only slightly affected by the intervention or by rNAPc2, whereas a significant 2.8 to 4.1 fold increase of C-reactive protein plasma levels was found in all patient groups after the procedure.

CONCLUSION

In contrast to the inflammatory response, coagulation activation after elective coronary stent implantation, which is observed in spite of the use of multiple antithrombotic drugs, can be attenuated by inhibition of the TF-factor VIIa complex using rNAPc2. Inhibition of the TF-mediated pathway of coagulation may be an important target to prevent thrombotic complications after coronary stenting.

Interaction between a genetic variant of the platelet fibrinogen receptor and fibrinogen levels in determining the risk of cardiovascular events

BACKGROUND

The PlA1A2 polymorphism of glycoprotein IIIa (GPIIIa), which affects postoccupancy signaling by the platelet fibrinogen receptor IIbIIIa, has been investigated as a potential genetic risk factor for cardiovascular events in numerous studies, without consistent results. We investigated whether the effect of this genetic variant of the platelet fibrinogen receptor on the risk of cardiovascular events is affected by fibrinogen plasma levels.

METHODS

The GPIIIa PlA1A2 polymorphism and fibrinogen levels were determined in 455 men with angiographically documented coronary atherosclerosis.

RESULTS

Neither carriership of the rare PlA2 allele nor fibrinogen plasma levels affected the time to cardiovascular event, as assessed in a proportional hazards model. However, there was a significant interaction between PlA2 carriership and fibrinogen plasma levels (P =.002). Carriership of the variant PlA2 allele significantly affected event-free survival only in individuals within the highest fibrinogen quartile (hazard ratio, 2.7; 95% CI, 1.1 to 7.1; P =.03).

CONCLUSIONS

We observed a statistically significant interaction between a genetic variant of the platelet fibrinogen receptor and fibrinogen levels in determining the risk of cardiovascular events. This interaction may account for the inconsistent results of genetic association studies investigating this genotype as a genetic risk factor in thrombotic cardiovascular events.

Recurrent cardiac ischemic events early after discontinuation of short-term heparin treatment in acute coronary syndromes

OBJECTIVES

The aim of this study was to determine whether discontinuation of low-molecular-weight heparin (LMWH) treatment results in a clustering of cardiac ischemic events as previously observed after cessation of unfractionated heparin (UFH) in acute coronary syndrome (ACS) patients.

BACKGROUND

Clinical trials in patients with ACS have shown early recurrent ischemic events after discontinuation of UFH treatment. We analyzed whether LMWH cessation also results in early ischemic recurrence events and if continuation of a fixed-dose LMWH prevents this complication.

METHODS

The combined incidence of death, myocardial infarction, or urgent revascularization in the first seven days after discontinuation of UFH (n = 3,012), short-term enoxaparin 1 mg/kg subcutaneously twice a day (n = 2,011), and short-term enoxaparin followed by prolonged enoxaparin 60 mg subcutaneously twice a day (n = 1,075) was analyzed from the combined Thrombolysis In Myocardial Infarction (TIMI) 11B/Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q-Wave Coronary Events (ESSENCE) database in a per patient analysis.

RESULTS

The cessation of both UFH and short-term enoxaparin resulted in a similar clustering of recurrent ischemic events on the first day, with an incidence of the primary end point of 2.8% in both groups. Of all recurrent events in the first week after cessation, 40% occurred in the first 24 h. The continuation of a fixed-dose enoxaparin treatment prevented this early excess, with a first day incidence of 0.4% (p < 0.0001). The TIMI risk score characteristics predicted the incidence of early rebound ischemic events.

CONCLUSIONS

There is significant clustering of recurrent ischemic events within 24 h after cessation of both short-term UFH and enoxaparin treatment, and patients should be carefully monitored during that period. This early rebound may be prevented by continuation of a fixed dose of enoxaparin.

Smoking Cessation Interventions in Cardiovascular Patients

OBJECTIVES

To review current evidence for the effectiveness of smoking cessation interventions in cardiovascular patient populations.

DESIGN AND MATERIALS

Studies were obtained from systematic reviews of the Cochrane Tobacco Addiction Review Group. Twelve Cochrane reviews related to secondary prevention in a variety of populations were used to extract eligible studies. Studies were eligible when they considered smokers diagnosed with symptomatic cardiovascular disease.

METHODS

Data concerning the comparison between the intervention of interest and a placebo or standard treatment group were derived from eligible papers. Based on these data, Absolute Risk Reduction figures were calculated to express the effectiveness of each intervention on smoking cessation.

RESULTS

We found 12 studies examining smoking cessation interventions in cardiovascular patients. Five studies reported significant results. No evidence was found for Nicotine Replacement Therapy or other pharmacology to be effective, neither for self-help materials, group, individual or telephone counseling. There is limited evidence for physician's advice and nurse-delivered interventions to be effective.

CONCLUSIONS

Smoking cessation studies in cardiovascular patients are scarce. The available studies show very limited effects. The reasons for the lack of success of smoking cessation strategies in these patients remain unclear. Further research is needed to find effective cessation strategies for patients with cardiovascular diseases.

Molecular variation at the apolipoprotein B gene locus in relation to lipids and cardiovascular disease: a systematic meta-analysis

Apolipoprotein B (apoB) is the sole protein component of low-density lipoprotein (LDL) and is thought to play an important role in atherogenesis. We performed a meta-analysis of the associations between the three most frequently investigated polymorphisms (XbaI, signal peptide insertion/deletion, EcoRI) in the apolipoprotein B (APOB) gene, lipid parameters, and the risk of ischemic heart disease (IHD). We restricted our analysis to Caucasians. Homozygotes for the XbaI X+ allele had significantly elevated levels of LDL cholesterol (LDL-C) and apoB, but a decreased risk (OR=0.80; 95%CI: 0.66-0.96) of IHD. Homozygosity for the signal peptide deletion allele was associated with similarly increased levels of LDL-C and apoB, and with an increased risk of IHD (OR=1.30; 95%CI: 1.08-1.58). Subjects homozygous for the rare EcoRI allele had significantly decreased levels of total and LDL cholesterol, but unaltered risk of IHD. We conclude that all three polymorphic apoB sites are associated with altered lipid levels, but not necessarily with a consistently altered risk of IHD. These data suggest that the relationship between apoB levels, hypercholesterolemia and IHD risk cannot have a simple molecular basis in the apoB gene.

Effects of aspirin dose when used alone or in combination with clopidogrel in patients with acute coronary syndromes: observations from the Clopidogrel in Unstable angina to prevent Recurrent Events (CURE) study

BACKGROUND

We studied the benefits and risks of adding clopidogrel to different doses of aspirin in the treatment of patients with acute coronary syndrome (ACS).

METHODS AND RESULTS

In the Clopidogrel in Unstable angina to prevent Recurrent Events (CURE) trial, 12 562 patients with ACS using aspirin, 75 to 325 mg daily, were randomized to clopidogrel or placebo for up to 1 year. In this analysis, patients were divided into the following 3 aspirin dose groups: < or =100 mg, 101 through 199 mg, and > or =200 mg. The combined incidence of cardiovascular death, myocardial infarction, or stroke was reduced by clopidogrel regardless of aspirin dose, as follows: < or =100 mg, 10.5% versus 8.6% (relative risk [RR], 0.81 [95% CI, 0.68 to 0.97]); 101 to 199 mg, 9.8% versus 9.5% (RR, 0.97 [95% CI 0.77 to 1.22]); and > or =200 mg, 13.6% versus 9.8% (RR, 0.71 [95% CI, 0.59 to 0.85]). The incidence of major bleeding increased with increasing aspirin dose both in the placebo group (1.9%, 2.8%, and 3.7%, respectively; P=0.0001) and the clopidogrel group (3.0%, 3.4%, and 4.9%, respectively; P=0.0009); thus, the excess risk with clopidogrel was 1.1%, 1.2%, and 1.2%, respectively. The adjusted hazard ratio for major bleeding for the highest versus the lowest dose of aspirin was 1.9 (95% CI 1.29 to 2.72) in the placebo group, 1.6 (95% CI 1.19 to 2.23) in the clopidogrel group, and 1.7 (95% CI 1.36 to 2.20) in the combined group.

CONCLUSIONS

In patients with ACS, adding clopidogrel to aspirin is beneficial regardless of aspirin dose. Bleeding risks increase with increasing aspirin dose, with or without clopidogrel, without any increase in efficacy. Our findings suggest that the optimal daily dose of aspirin may be between 75 and 100 mg, with or without clopidogrel.

The impact on coagulation of an intravenous loading dose in addition to a subcutaneous regimen of low-molecular-weight heparin in the initial treatment of acute coronary syndromes

OBJECTIVES

We sought to quantify the impact of adding an intravenous loading dose to a subcutaneous regimen of enoxaparin in patients with an acute coronary syndrome (ACS).

BACKGROUND

It is unclear whether an intravenous (i.v.) loading dose of enoxaparin should be added to a subcutaneous (s.c.) regimen in patients with ACS.

METHODS

Patients admitted with ACS were randomized to i.v.+s.c.(n = 14) or s.c. alone (n = 11) enoxaparin treatment. Coagulation markers were measured at nine time points during the first 24 h of treatment.

RESULTS

The i.v.+s.c. therapy immediately resulted in therapeutic anti-Xa levels, which remained significantly higher for 6 h compared with s.c. alone, without reaching excessively high levels. A rapid decrease of plasma prothrombin fragments 1+2 (F(1+2)) levels was observed as soon as 5 min after the i.v. injection (33% lower; p = 0.007), and these levels remained lower up to 2 h after the start of treatment compared with SQ alone. The ex vivo thrombin generation time was maximally prolonged at 5 min post-injection in the i.v.+s.c. group and remained significantly prolonged up to 6 h post-injection compared with s.c. alone. The tissue factor pathway inhibitor plasma activity was immediately increased by 194% with i.v.+s.c., whereas the maximum increase with s.c. alone was 47% at 3 h.

CONCLUSIONS

Therapeutic plasma levels of enoxaparin are achieved significantly earlier by an i.v.+s.c. regimen compared with s.c. alone, without leading to unacceptably high levels. As the risk of thrombotic complications is greatest early after admission, the observed differences in antithrombotic effects may translate into a clinical benefit. However, this remains to be established.

Recombinant nematode anticoagulant protein c2, an inhibitor of the tissue factor/factor VIIa complex, in patients undergoing elective coronary angioplasty

OBJECTIVES

We investigated the safety and pharmacodynamics of escalating doses of recombinant nematode anticoagulant protein c2 (rNAPc2) in patients undergoing elective coronary angioplasty.

BACKGROUND

Recombinant NAPc2 is a potent inhibitor of the tissue factor/factor VIIa complex, which has the potential to reduce the risk of thrombotic complications in coronary artery disease.

METHODS

In a randomized, double-blinded, dose-escalation, multicenter trial, 154 patients received placebo or rNAPc2 at doses of 3.5, 5.0, 7.5, and 10.0 microg/kg body weight as a single subcutaneous administration 2 to 6 h before angioplasty. All patients received aspirin, unfractionated heparin during angioplasty, and clopidogrel in case of stent implantation.

RESULTS

Minor bleeding rates for the doses 3.5 to 7.5 microg/kg were comparable to that with placebo (6.7%), whereas an incidence of 26.9% was observed at the 10.0 microg/kg dose level (p < 0.01). Major bleedings occurred in the 5.0 microg/kg (n = 3) and 7.5 microg/kg (n = 1) dose groups. The three patients in the 5.0 microg/kg dose group also received a glycoprotein IIb/IIIa receptor inhibitor at the moment of major bleeding. Systemic thrombin generation, as measured by prothrombin fragment 1+2 (F(1+2)), was suppressed in all rNAPc2 dose groups to levels below pretreatment values for at least 36 h. In the placebo group, a distinct increase of F(1+2) levels was observed following cessation of heparin.

CONCLUSIONS

Inhibition of the tissue factor/factor VIIa complex with rNAPc2, at doses up to 7.5 microg/kg, in combination with aspirin, clopidogrel, and unfractionated heparin appears to be a safe and effective strategy to prevent thrombin generation during coronary angioplasty.

Variants of toll-like receptor 4 modify the efficacy of statin therapy and the risk of cardiovascular events

BACKGROUND

Atherosclerosis is increasingly considered to be a chronic inflammatory process. We examined whether genetic variants of the toll-like receptor 4 (TLR4), which are correlated with impaired innate immunity and with progression of carotid atherosclerosis, are also associated with coronary atherosclerosis and predict the risk of cardiovascular events.

METHODS AND RESULTS

Two polymorphisms of the TLR4 gene (Asp299Gly and Thr399Ile) were determined in 655 men with angiographically documented coronary atherosclerosis. All patients participated in a prospective cholesterol-lowering trial evaluating the effect on coronary artery disease and were randomly assigned to either pravastatin or placebo for 2 years. There were no significant differences between genetically defined subgroups with respect to baseline risk factors, treatment, or in-trial changes of lipid, lipoprotein, or angiographic measurements. Genotype was not associated with progression of atherosclerosis. In the pravastatin group, 299Gly carriers had a lower risk of cardiovascular events during follow-up than noncarriers (2.0% versus 11.5%, P=0.045). Among noncarriers, pravastatin reduced the risk of cardiovascular events from 18.1% to 11.5% (P=0.03), whereas among 299Gly carriers this risk was strikingly reduced from 29.6% to 2.0% (P=0.0002, P=0.025 for interaction).

CONCLUSIONS

Among symptomatic men with documented coronary artery disease, the TLR4 Asp299Gly polymorphism was associated with the risk of cardiovascular events. This variant also modified the efficacy of pravastatin in preventing cardiovascular events, such that carriers of the variant allele had significantly more benefit from pravastatin treatment.