Prévention des évènements ischémiques majeurs au cours de l’artériopathie oblitérante des membres inférieurs : l’aspirine a-t-elle un rôle ?

OBJECTIVE

To determine the effect of aspirin among patients with lower limb occlusive arterial disease.

DESIGN

Meta-analysis of trials issuing from a collaborative meta-analysis of randomized trials of anti-platelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients. Five trials were identified as comparing aspirin (with or without dipyridamole) to placebo, in 1 029 patients with lower limb occlusive arterial disease. There was no new publication found comparing aspirin and placebo in lower limb occlusive arterial disease.

MAIN OUTCOME MEASURE

As in the main meta-analysis, "serious vascular event": non fatal myocardial infarction, non fatal stroke or vascular death.

RESULTS

Among these 1 029 patients, allocation to aspirin did not reduce the outcome of serious vascular event, nor of any of the individual events. This result, as opposed to the enhancement of 23% +/- 8% announced in the main meta-analysis, clearly demonstrate that the beneficial effect cannot be attributable to aspirin.

DISCUSSION

In the collaborative meta-analysis, aspirin was the most widely used product (75% of the trials) and it showed its beneficial effect when administered at doses ranging from 75 to 150 mg/day, as compared to placebo. Among the other anti-platelet treatments analyzed, clopidogrel was the only product for which large scale randomized evidence versus aspirin was available. Various national health institutions, in the United States as well as in Europe, show a major concern regarding the use of anti-platelet treatments, in peripheral arterial occlusive disease as well as in other manifestations of cardiovascular disease. Their guidelines take of course the patient's health into account but the economical aspect of this prevention is increasingly hard to circumvent. Based on the results of the collaborative meta-analysis, these guidelines all recommend a lifetime use of low doses of aspirin, reserving clopidogrel for patients intolerant to aspirin, mainly because they do not consider the additional benefit recognized with clopidogrel as important enough to counterbalance the cost of the treatment. While aspirin as a first choice antiplatelet therapy cannot be discussed in coronary disease, after a myocardial infarction, or in cerebrovascular disease, its use in lower limb occlusive arterial disease does not enable a reduction in morbi-mortality. From an economical point of view, the use of a cheap but inefficient preventive treatment could also lead to an increased cost for curing the complications expected with an uncontrolled widely spread disease as chronic lower limb ischemia.

Deficiency of the 5-Hydroxytryptamine Transporter Gene Leads to Cardiac Fibrosis and Valvulopathy in Mice

Background— Serotonin (5-hydroxytryptamine; 5-HT) overproduction is responsible for cardiac valvular disease in patients with carcinoid tumors. Reduced 5-HT inactivation is one proposed mechanism of the valvulopathy observed in individuals treated with the appetite suppressants fenfluramine and phentermine. One key protein limiting systemic availability of 5-HT is the 5-HT transporter (5-HTT) expressed by platelets and pulmonary vascular cells; 5-HTT is responsible for 5-HT uptake and subsequent inactivation of the amine passing through the lung. Here we investigated whether 5-HTT–deficient (5-HTT-KO) mice developed structural and/or functional cardiac abnormalities and valvulopathy.

Methods and Results— Cardiac endothelial cells expressed large amounts of 5-HTT in wild-type mice. 5-HTT deficiency appeared to be associated with marked interstitial, perivascular, and valvular fibrosis as evidenced by staining of cardiac collagen in 5-HTT-KO mice. Histological analysis provided evidence for valvulopathy characterized by valvular hyperplasia and prominent fibrosis at the attachment site and base of the leaflets. Echocardiography revealed an increase in left ventricular lumen diameter and a decrease in left ventricular diameter fractional shortening. Although 5-HT 1B receptors mediated the 5-HT–induced collagen secretion by human cardiac myofibroblasts, the contribution of this receptor type to valvulopathy was ruled out because double-KO mice deficient in both 5-HTT and 5-HT 1B receptors showed the same cardiac alterations as 5-HTT-KO mice.

Conclusions— The present results establish a link between 5-HTT and the development of cardiac fibrosis and valvulopathy in vivo. 5-HTT-KO mice represent an especially relevant model for studying the mechanisms by which 5-HT induces valvulopathy.

Drug eluting stents: an updated meta-analysis of randomised controlled trials

OBJECTIVE

To confirm the overall benefit of drug eluting stents (DES), to evaluate the effect of different DES, and to assess the global safety of DES compared with bare stents through a meta-analysis of randomised controlled trials.

METHODS

Randomised controlled trials comparing sirolimus and derivates or paclitaxel and derivates eluting stents versus bare stents. Binary restenosis and major adverse cardiac events (MACE) were chosen as primary end points. Death, Q wave myocardial infarction (MI), and stent thrombosis up to 12 months' follow up were also analysed.

RESULTS

MACE overall occurrence was highly reduced with DES from 19.9% to 10.1% (odds ratio (OR) 0.46, 95% confidence interval (CI) 0.41 to 0.52, p < 0.001). A significant heterogeneity (p < 0.001) was found between subgroups according to the drug: MACE OR was 0.28 (95% CI 0.22 to 0.35) in the sirolimus subgroup and 0.62 (95% CI 0.53 to 0.73) in the paclitaxel subgroup. Restenosis was also highly reduced from 31.7% with bare stents to 10.5% with DES (OR 0.25, 95% CI 0.22 to 0.29, p < 0.001) with a similar heterogeneity between subgroups. Mortality, Q wave MI, and stent thrombosis were not significantly different between DES and control group, whereas Q wave MI and stent thrombosis tended to be more frequent with paclitaxel.

CONCLUSION

This meta-analysis confirms the overall benefit of DES on restenosis and MACE with significant heterogeneity between drugs, suggesting higher efficacy of sirolimus eluting stents. Additional data with longer follow up and in high risk populations are needed to clarify issues on stent thrombosis.

Revascularization strategies in acute myocardial infarction: a meta-analysis

OBJECTIVE

Many treatments and procedures have been tested to reduce complications after myocardial infarction. Our objective was to assess in this clinical situation the best evidence-based medicine revascularization strategy including the most recently developed interventions such as thrombolysis, angioplasty, stent implantation and glycoprotein IIb/IIIa (GpIIb/IIIa) antagonists.

MATERIAL AND METHODS

We performed the meta-analyses of randomized controlled trials by testing the addition of a stent to primary angioplasty, the addition of GpIIb/IIIa antagonists to primary angioplasty, the addition of GpIIb/IIa antagonists to primary angioplasty + stent and finally addition of GpIIb/IIIa antagonists to thrombolytics. The primary outcome was the combined endpoint of death or myocardial infarction or urgent revascularization at 1 month.

RESULTS

The combined endpoint was significantly reduced by 31% (95% CI: 11% - 47%) at 30 days when stent was added to primary angioplasty. GpIIb/IIIa blockers provided an additional benefit by reducing the combined criteria by 50% (95% CI: 27% - 66%) in patients who underwent primary angioplasty, and by 42% (95% CI: 16% - 60%) when associated with angioplasty and stent implantation. Administration of GpIIb/IIIa in addition to thrombolytics, aspirin and heparin was associated with a significant reduction in the combined criteria by 17% (95% CI: 10% - 23%) and a significant excess of major bleeding by 69% (95% CI: 38% - 109%). However, the risk/benefit ratio indicates that patients with this association should be treated with the corresponding doses used in these trials.

CONCLUSION

In acute myocardial infarction, stent implantation provides therapeutic benefit when added to primary angioplasty. The addition of GpIIb/IIIa blockers appears to provide further benefit if bleeding complications are minimized.

Transfer for Primary Angioplasty Versus Immediate Thrombolysis in Acute Myocardial Infarction

Background— The benefit of primary percutaneous coronary intervention (PCI) over thrombolysis has been clearly demonstrated in acute myocardial infarction (AMI). However, the best therapeutic strategy for a patient with AMI presenting to acute care services without catheterization facilities remains under debate. Our objective was to gather all available information from clinical trials comparing transfer of patients experiencing AMI for angioplasty versus immediate thrombolysis.

Methods and Results— We performed a meta-analysis of all data available from published randomized trials and from presentations in scientific sessions of major cardiology congresses comparing the 2 strategies. The primary end point was the combined criteria (CC) of death/reinfarction/stroke as defined in each trial. Relative risk (RR) evaluated the treatment effect. We identified 6 clinical trials including 3750 patients. Transfer time was always <3 hours. The CC was significantly reduced by 42% (95% confidence interval [CI] 29% to 53%, P <0.001) in the group transferred for primary PCI compared with the group receiving on-site thrombolysis. When CC parameters were considered separately, reinfarction was significantly reduced by 68% (95% CI, 34% to 84%; P <0.001) and stroke by 56% (95% CI, −15% to 77%; P =0.015). There was a trend toward reduction in all-cause mortality of 19% (95% CI, −3% to 36%; P =0.08) with transfer for PCI.

Conclusion— Even when transfer to an angioplasty center is necessary, primary PCI remains superior to immediate thrombolysis. Organization of ambulance systems, prehospital management, and adequate PCI capacity appear now to be the key issues in providing reperfusion therapy for AMI.

Sensitive determination of tenofovir in human plasma samples using reversed-phase liquid chromatography

A new high-performance liquid chromatography assay was developed for the determination of tenofovir, a nucleotide analogue, in plasma. A solid-liquid extraction procedure was coupled with a reversed-phase HPLC system. The system requires a mobile phase containing Na(2)HPO(4) buffer, tetrabutylammonium hydrogen sulfate and acetonitrile for different elution through a C(18) column with UV detection. The method proved to be accurate, precise and linear between 10 and 4000 ng/ml. The method was applied to determine trough levels of tenofovir in 11 HIV-infected patients with virologic failure under multiple antiretroviral therapy. This method was also successfully applied to a pharmacokinetic study in an HIV infected patient with renal failure.

Traitement anticoagulant dans la fibrillation auriculaire

Atrial fibrillation is the most frequent arrhythmia in the general population, and it increases with age. The prevention of thromboembolic events, the most important complication of the disease, is a major problem. Antivitamin K is to date the most efficient therapeutic class for the prevention of these events. Although they allow a decrease in stroke by at least 50%, they are associated with an increased haemorrhagic risk (annual incidence ranging from 7% to 22%). This risk makes oral anticoagulant treatment underused in high risk patients, particularly in the elderly populations. Optimisation of the management of patients with atrial fibrillation should be based on an individual evaluation of the thromboembolic and haemorrhagic risks. Several stratifications have been performed to identify the risk predictors of thromboembolic and haemorrhagic events in patients with atrial fibrillation, allowing an evaluation of the benefit/risk ratio of antithrombotic treatments and using indices such as NNT (number of patients needed to treat to avoid an event) and NNH (number of patients needed to harm with haemorrhagic event). The available data do not allow, however, to evaluate precisely the individual level of haemorrhagic risk.

Anticoagulant (fluindione)-aspirin combination in patients with high-risk atrial fibrillation. A randomized trial (Fluindione, Fibrillation Auriculaire, Aspirin et Contraste Spontané; FFAACS)

BACKGROUND

A combination of low-dose aspirin with anticoagulants may provide better protection against thromboembolic events compared to anticoagulants alone in high-risk patients with atrial fibrillation.

OBJECTIVE

Evaluation of the preventive efficacy against nonfatal thromboembolic events and vascular deaths of the combination of the oral anticoagulant fluindione and aspirin (100 mg) in patients with high-risk atrial fibrillation.

METHODS

A multicenter, placebo-controlled, double-blind, randomized trial was conducted at 49 investigating centers in France. Atrial fibrillation patients with a previous thromboembolic event or older than 65 years and with either a history of hypertension, a recent episode of heart failure or decreased left ventricular function were included in the study. Patients were treated with fluindione plus placebo (i.e. anticoagulant alone) or fluindione plus aspirin (i.e. combination therapy), with an international normalized ratio target of between 2 and 2.6. The combined primary endpoint was stroke (ischemic or hemorrhagic), myocardial infarction, systemic arterial emboli or vascular death. The secondary endpoint was the incidence of hemorrhagic complications.

RESULTS

The 157 participants (average age 74 years; 52% women; 42% with paroxysmal atrial fibrillation) were followed for an average of 0.84 years. Three nonfatal thromboembolic events were observed (1 in the anticoagulation group, 2 in the combination group) and 6 patients died (3 in the anticoagulation group, 3 in the combination group), none of them from a thromboembolic complication. However, 3 deaths were secondary to severe hemorrhagic complications (1 in the anticoagulation group, 2 in the combination group). Nonfatal hemorrhagic complications occurred more often in the combination group (n = 10, 13.1%) compared to the anticoagulation group (n = 1, 1.2%) (p = 0.003).

CONCLUSION

The combination of aspirin with anticoagulant is associated with increased bleeding in elderly atrial fibrillation patients. The effect on thromboembolism and the overall balance of benefit to risk could not be accurately assessed in this study due to the limited number of ischemic events.

Beta-blockade treatment in heart failure: the cardiac insufficiency bisoprolol study (CIBIS) project. CIBIS Committees and Investigators. Cardiac Insufficiency Bisoprolol Study

The efficacy of treatment with diuretics and vasodilators in heart failure has shown that compensatory mechanisms may induce vicious circles that can precipitate the deterioration of congestive heart failure (CHF). By counteracting sympathetic stimulation of cardiac beta-receptors, beta-blocking drugs could provide some benefit in CHF. Indeed, the sympathetic stimulation enhances metabolic costs and could lead to a further deterioration of myocardial fiber function. This could be counteracted by beta-blockade. On the contrary, the loss of adrenergic responsiveness due to beta-adrenergic downregulation and depletion of norepinephrine stores from sympathetic nerves could be responsible for the progressive deterioration of cardiac function. Moderate doses of beta-blocking agents could restore such a catecholamine sensitivity by upregulation of beta-receptors and restoration of norepinephrine stores. Results of clinical trials with beta-blockade in CHF are so far controversial. Most studies enrolled patients with cardiomyopathy and included small numbers of patients or were uncontrolled. The CIBIS trial (Cardiac Insufficiency Bisoprolol Study) has been launched in Europe to answer the question of the potential benefit on prognosis of beta-blockade therapy in heart failure from any etiology, especially ischemic CHF. It is a randomized, placebo-controlled, double-blind multicentric trial involving two parallel groups of patients (300 in each group) followed over a 2-year period. Results from the CIBIS trial should provide conclusive information concerning the use of beta-blocking therapy in CHF.

Pharmacodynamics and pharmacokinetics of single nasal (5 mg and 10 mg) and oral (50 mg) doses of ephedrine in healthy subjects

OBJECTIVE

To determine the cardiovascular, subjective effects and potential of abuse liability of single dose (-) ephedrine (E) administered orally (50 mg) or intranasally (10 mg and 5 mg).

METHODS

Sixteen healthy Caucasian men with no history of drug/alcohol/nicotine abuse or dependence received intranasal single doses of E 5 mg, 10 mg and oral doses of 50 mg and placebo in a double-blind, double-dummy, crossover study. Dependent measures included assessment of subjective feelings by Addiction Research Centre Inventory (ARCI). Profile of Mood States (POMS). visual analogue scales (VAS); "drug liking", "any drug effect", subjective quality of sleep and blood pressure and heart rate. Plasma E concentrations were also determined.

RESULTS

(-) E increased supine systolic, diastolic blood pressure (P < 0.01). Changes in supine systolic blood pressure (areas under the 8 h of the experimental sessions) were -59 +/- 47 mmHgh with placebo, -59 +/- 57 mmHg-h with E5 mg by the nasal route, -18 +/- 48 mmHg x h with E 10 mg by the nasal route and 13 +/- 58 mmHgh with E 50 mg by the oral route (P<0.001). (-) E-induced orthostatic hypotension (P < 0.01) (maximal systolic blood pressure drop: E 50 mg 14 +/- 10 mmHg, P < 0.03; E 10 mg 11 +/- 6 mmHg, P = 0.08 compared with placebo) and resulted in decreased tiredness (placebo -2 +/- 39 mm x h, E 5 mg -17 +/- 39 mm x h, E 10 mg -30 +/- 42 mm x h, E 50 mg -24 +/- 35 mm x h; P < 0.03). E did not modify ARCI subscales--in particular the "amphetamine" subscale--but showed a tendency for drug liking (P= 0.09). On the "any drug effect" questionnaire, subjects could identify drug effect (P=0.007). Maximal plasma E concentration (Cmax) and areas under the curves for up to 8 h were proportional to the doses. Elimination half-life was approximately 6 h. A clockwise hysteresis was observed for systolic blood pressure in all but one subject with E 50 mg by the oral route.

CONCLUSION

E even at low doses and by the nasal route can decrease tiredness in healthy persons; this is accompanied by a substantial increase in blood pressure and orthostatic hypotension exposing individuals in case of intensive physical exercise to cardiovascular risks. No clear evidence of abuse liability in healthy drug naive subjects was observed.

Results from post-hoc analyses of the CIBIS II trial: effect of bisoprolol in high-risk patient groups with chronic heart failure

BACKGROUND

The beneficial effects of the beta-blocker bisoprolol on mortality and rate of hospitalisation as well as its safety in patients with chronic heart failure has been proven. However, its efficacy in patients in whom beta-blockers have traditionally been contraindicated or caution has been advised has not been clearly determined. Therefore, analyses in high-risk subgroups of patients taking part in CIBIS II have been performed to investigate the effect of bisoprolol in elderly patients, in patients with type 2 diabetes, with renal failure, NYHA functional class IV or concomitantly treated with digitalis, aldosterone antagonists or amiodarone.

METHODS

High-risk subgroups of patients with chronic heart failure taking part in the CIBIS II study were retrospectively analysed with respect to mortality, hospitalisation, combined endpoint of cardiovascular mortality or hospitalisation for cardiovascular reasons and treatment withdrawal as well as cause of death and hospitalisation. Analysis is based on intention-to-treat.

RESULTS

It was demonstrated that in spite of the expected increase in the overall risk of death and hospitalisation, patients who are diabetic, have renal impairment, NYHA class IV symptoms, are elderly, are taking either digitalis, amiodarone or aldosterone antagonists as co-medication benefit equally from beta-blockade with bisoprolol as patients without these complications or drugs. Benefit was shown for the primary endpoint all cause mortality, as well as for the secondary endpoints.

CONCLUSIONS

Contrary to the hitherto prevailing doctrine of not using beta-blockers in high risk patient groups with chronic heart failure, retrospective analyses of the CIBIS II study justify the use of this drug class in patients regardless of age, NYHA functional class, the presence of diabetes, renal impairment or concomitant treatment with digitalis, amiodarone or aldosterone antagonists.

[Bisprolol in heart failure: efficacy and costs in a French setting according to CIBIS II]

After a significant mortality benefit with bisoprolol in heart failure was demonstrated in CIBIS-II, an economic evaluation has been performed in cost-effectiveness terms. Average direct costs per patient were based on clinical data from 231 French patients, and measured in the perspective of the French National Health Insurance, effectiveness being expressed in terms of life days gained per patient. The extra cost of bisoprolol treatment and follow-up (averaging FF 1300 per 1.3 years) is outweighed by the reduction in hospitalization costs (representing a saving of FF 10,500 per patient) and other medication costs. Finally, bisoprolol therapy induces benefits in terms of both cost and survival: on average FF 9500 and 11 life days per patient. Sensitivity analyses confirm these results.

[Does statin therapy reduce the risk of stroke? A meta-analysis]

Large scale clinical trials have clearly demonstrated that the HMG-CoA reductase inhibitors (statins) reduce cardiovascular mortality by about 30%. The specific benefit on stroke prevention remains however to be determined. We reviewed all controlled clinical trials comparing statins versus placebo in primary and secondary prevention of cardiovascular disease. We identified 13 studies including 4S, CARE, WOSCOPS and LIPID. More than 32000 patients were randomized. The meta-analysis was performed using relative risk as treatment effect parameter. Statin treatment induced a significant relative risk reduction (RRR) of 24% (95% CI [12%-34%]) for stroke (2.1% vs 2.8%). RRR achieved 25% (95% CI [17%-32%]) for cardiovascular mortality and 34% (95% CI [30%-38%]) for myocardial infarction, without heterogeneity between trials. Stroke was reduced by 25% in secondary prevention, and by 15% in primary prevention, without significant heterogeneity between them. RRR of stroke was similar with pravastatin (RRR=0.79, p=0.0038) and with simvastatin (RRR=0.71, p=0.049). The effect model analysis (relationship between annual incidence of events in treated group versus placebo group in each trial) showed that RRR was constant whatever the baseline risk. These results are in favor of a preventive efficacy of statin treatment against stroke in middle aged patients with coronary heart disease. Complementary information will be needed to clarify the mechanism of this beneficial effect and to demonstrate statin efficacy in a population with a higher risk of stroke such as the elderly.

Beta-blocker treatment in heart failure

Heart failure treatment has markedly changed during the last few decades, with demonstration of benefit of afterload reduction by vasodilator therapy and introduction of the concept of the deleterious consequences of the neuro-hormonal compensatory stimulation. Blockade of beta-adrenergic receptors, initially contra-indicated in heart failure, provide a marked reduction of mortality and morbidity in combination with diuretics and angiotensin-converting enzyme inhibitors, as demonstrated in many clinical trials. We performed a review of all clinical trials that compare beta-blockers vs. placebo in chronic heart failure. Beta-blockers with different pharmacological profiles have been tested, mainly metoprolol, bisoprolol, bucindolol and carvedilol. With progressive dose increment, tolerance of such treatment was generally good, left ventricular function improved, hospitalisations for heart failure were less frequent and mortality was reduced. The meta-analysis of the 16 randomised trials, with at least one death in each treatment group, provides a 24% relative risk reduction for such hospitalisations (95% CI=19%-29%) and 22% reduction for mortality (95% CI=16%-28%). Heterogeneity of beta-blocker effect for mortality was found and related to the non-significant benefit obtained in the BEST trial with bucindolol. When such a trial is excluded, the effect model analysis shows that relative risk reduction (beta-blocker induced benefit) is constant whatever the severity of the disease. The mechanism of beta-blocker induced benefit remains unclear, but is at least partly related to left ventricular function improvement and prevention of severe ventricular arrhythmias. In conclusion, beta-blocker treatment has become an established therapy for heart failure, in combination with diuretics and ACE inhibitors. Complementary informations will be needed to clarify the mechanism of benefit and to define the best therapeutic strategy according to the individual characteristics of patients with heart failure.

Heart rate and cardiac rhythm relationships with bisoprolol benefit in chronic heart failure in CIBIS II Trial

BACKGROUND

beta-Blockade-induced benefit in heart failure (HF) could be related to baseline heart rate and treatment-induced heart rate reduction, but no such relationships have been demonstrated.

METHODS AND RESULTS

In CIBIS II, we studied the relationships between baseline heart rate (BHR), heart rate changes at 2 months (HRC), nature of cardiac rhythm (sinus rhythm or atrial fibrillation), and outcomes (mortality and hospitalization for HF). Multivariate analysis of CIBIS II showed that in addition to beta-blocker treatment, BHR and HRC were both significantly related to survival and hospitalization for worsening HF, the lowest BHR and the greatest HRC being associated with best survival and reduction of hospital admissions. No interaction between the 3 variables was observed, meaning that on one hand, HRC-related improvement in survival was similar at all levels of BHR, and on the other hand, bisoprolol-induced benefit over placebo for survival was observed to a similar extent at any level of both BHR and HRC. Bisoprolol reduced mortality in patients with sinus rhythm (relative risk 0.58, P:<0.001) but not in patients with atrial fibrillation (relative risk 1.16, P:=NS). A similar result was observed for cardiovascular mortality and hospitalization for HF worsening.

CONCLUSIONS

BHR and HRC are significantly related to prognosis in heart failure. beta-Blockade with bisoprolol further improves survival at any level of BHR and HRC and to a similar extent. The benefit of bisoprolol is questionable, however, in patients with atrial fibrillation.

Prediction of fluindione maintenance dosage hampered by large intraindividual variability

In a previous study, the authors proposed a method to individualize fluindione dosage regimen, based on a pharmacokinetic/pharmacodynamic model describing the evolution of the International Normalized Ratio (INR). In this method, daily maintenance dosage for a target INR depends on the product of individual Cl and C50. The present work shows the results of a follow-up study in 50 patients for whom target INR was 2.5. INR measurements and dosage regimens were recorded both during hospital stay and during the 1st month of treatment. Patients were defined as equilibrated after 1 month if the last two INRs were in the range 1.5-3.5 under a stable dosage regimen. Actual maintenance dose was compared with the dose predicted using the three first INRs measured in the hospital. Intraindividual variability of Cl*C50 between hospital stay and after 1 month was evaluated. After 1 month, only 27 patients (54%) were equilibrated. Actual maintenance dose varied from 5 to 30 mg daily. There was no bias between predicted and actual maintenance dose (1.4 mg), but a large root mean squared error (8 mg) was found. The intraindividual variability in Cl*C50 between hospital and maintenance regimen was high (93%), which may explain the dispersion in the predicted maintenance dose.

[Study of combined anticoagulant (fluindione)-aspirin therapy in patients with atrial fibrillation at high risk for thromboembolic complications. A randomized trial (FFAACS)]

BACKGROUND

A combination of low-dose aspirin (A) and anticoagulation (AC) may provide better protection against thromboembolic events compared with AC alone in high-risk patients with atrial fibrillation (AF).

METHODS

We performed a multicentric placebo-controlled double blind-trial to test the preventive efficacy against thromboembolic events of the addition of aspirin (A) (100 mg) or placebo (P) to anticoagulant treatment in patients with high-risk atrial fibrillation. A total of 157 patients were included, with atrial fibrillation and previous thromboembolic event or older than 65 years with either a history of hypertension, a recent episode of heart failure or a left ventricular dysfunction. All patients received fluindione (F) and P or F and A, with an INR target between 2 and 2.6. The primary endpoint was a combined endpoint of stroke (ischaemic or haemorrhagic), myocardial infarction, systemic arterial emboli or vascular death.

RESULTS

The study had to be stopped prematurely owing to a too low recruitment rate. During follow-up (0.84 years) 3 non-fatal thromboembolic events were recorded (1P, 2A) and 6 patients died (3P, 3A), none of them from a thromboembolic complication. However, 3 deaths were secondary to severe haemorrhagic complications (1P, 2A). Non-fatal haemorrhagic complications occurred more often in group A (n = 10, 13.1 pour cent) compared with group P (n = 1, 1.2 pour cent), p = 0.003.

CONCLUSION

The FFAACS study was not able to show any therapeutic benefit from the addition of aspirin to anticoagulant in patients with high-risk AF. Such a combination increased the incidence rate of bleeding complications, which therefore greatly reduces its potential overall benefit.

Prognostic value of neurohormonal activation and cardiopulmonary exercise testing in patients with chronic heart failure

We compared the value of plasma neurohormones and cardiopulmonary exercise testing for predicting long-term prognosis in patients with moderate congestive heart failure (CHF). We studied 264 consecutive patients with CHF due to left ventricular systolic dysfunction. Plasma atrial natriuretic peptide (ANP), norepinephrine, and endothelin-1 were measured at rest in all patients, who also underwent a symptom-limited maximal exercise with oxygen consumption (VO(2)) determination. After a median follow-up of 789 days, 52 deaths and 31 heart transplantations occurred, of which 4 were urgent. In an univariate analysis, New York Heart Association functional class, systolic blood pressure at rest, left ventricular end-diastolic diameter, left ventricular ejection fraction, peak VO(2), percent of predicted peak VO(2), plasma ANP, plasma norepinephrine, and plasma endothelin-1 were associated with survival without urgent heart transplantation. In a multivariate stepwise regression analysis, only plasma ANP (p = 0.0001), left ventricular ejection fraction (p = 0.007), and plasma norepinephrine (p = 0.035), but neither peak VO(2) nor percentage of predicted peak VO(2), were independent predictors of death or urgent heart transplantation. Determination of plasma ANP and norepinephrine provides additional independent information for long-term prognostic determination compared with exercise testing alone. Measurement of plasma neurohormones should therefore be considered routinely as a complementary or alternative tool for identifying high-risk patients with moderate CHF.

Plasma adrenomedullin, a new independent predictor of prognosis in patients with chronic heart failure

BACKGROUND

Adrenomedullin, a potent endogenous vasodilating and natriuretic peptide, may play an important role in the pathophysiology of chronic heart failure. Plasma levels of immunoreactive adrenomedullin were examined for prediction of prognosis in chronic heart failure.

METHODS AND RESULTS

Plasma levels of immunoreactive-ADM (ir-ADM) were measured by radioimmunoassay in 117 chronic heart failure patients with idiopathic or ischaemic cardiomyopathy (mean ejection fraction: 28 +/- 10%, in the NYHA functional class I/II/III/IV:8/73/29/7, and treated with ACE inhibitors and diuretics. Plasma levels of immunoreactive adrenomedullin were significantly increased in chronic heart failure patients by comparison to controls (618 +/- 293 pg x ml(-1) vs 480 +/- 135 pg x ml(-1), P=0.01). During the follow-up period (237 +/- 137 days) 14 cardiovascular deaths and four urgent cardiac transplantations occurred. In the univariate Cox model, immunoreactive adrenomedullin plasma levels were related to prognosis (P=0.004). A multivariate analysis including heart rate, systolic blood pressure, NYHA class, left ventricular ejection fraction, left ventricular echocardiographic end-diastolic diameter, plasma levels of immunoreactive adrenomedullin, endothelin-1, norepinephrine and atrial natriuretic peptide was performed: plasma levels of immunoreactive adrenomedullin (P=0.03), of endothelin-1 (P=0.0001), and systolic blood pressure (P=0.003) were significantly associated with outcome.

CONCLUSION

Our results suggest that elevated plasma levels of immunoreactive adrenomedullin are an independent predictor of prognosis in predominantly mild to moderate chronic heart failure treated by conventional therapy and provide additional prognostic information.

Beraprost sodium-fluindione combination in healthy subjects: pharmacokinetic and pharmacodynamic aspects

Beraprost sodium (BPS), an orally active PGI2 (prostaglandine 12) analogue possesses vasodilatating and platelet aggregation inhibiting properties. It is being developed in peripheral arterial occlusive disease. As in future clinical practice BPS might be co-prescribed with oral anticoagulants, we investigated its interaction with fluindione, a vitamin K antagonist in healthy subjects in a randomised, double-blind, placebo-controlled, crossover study. Twelve healthy Caucasian male subjects randomly received BPS 40 microg t.i.d. or placebo for 3 days. There was a 7 day wash out between the two treatment periods. On day 3 of each treatment, the subjects ingested concomitantly a single oral dose of 20 mg of fluindione. The main assessment criterion was fluindione's pharmacokinetics. Secondarily, pharmacodynamic measurements of coagulation (prothrombin time, and International Normalised Ratio, INR) and platelet function (in vitro closure time assessed by PFA-100) were performed. Fluindione was assayed by HPLC with UV detection up to 96 h post-drug. No statistical difference could be evidenced on any fluindione pharmacokinetic parameters between BPS and placebo phases: t 1/2 (h): 35.9 (8.2) vs. 34.0 (4.2) [90% CI 105.8 (95.5-116.2)]; T(max) (h): 2.0 (0.5-6.0) vs. 4.0 (0.5-6.0) [90% CI 136.4 (70.7-208.9)]; Cmax (mg/L): 3.1 (0.6) vs. 2.9 (0.5) [90% CI 94.1 (85.8-103.2)]; AUC 0-inf (mg/h/L): 117.0 (31.5) vs. 113.9 (33.8) [90% CI 97.6 (87.5-108.8)]. The studied doses of BPS did not affect platelet function, at least as assessed by the in vitro platelet function testing. Twenty milligrams of fluindione marginally modified the PT ratio and INR, however, no statistically significant difference was found between BPS and placebo phases. In conclusion, a 3 day regimen of BPS 40 microg t.i.d. by oral route does not seem to affect pharmacokinetic parameters of a fluindione 20 mg single dose.

Effects of prolonged propranolol treatment on left ventricular remodeling and oxidative stress after myocardial infarction in rats

Mechanisms determining the benefit of beta blockade in patients with heart failure remain incompletely understood but are assumed consequent to prevention of deleterious effects of catecholamines. Recent studies have demonstrated that oxidative stress in congestive heart failure may be related to increased catecholamine levels. The aim of this study was to examine effects of long-term treatment with propranolol on progression of left ventricular (LV) dysfunction, remodeling and oxidative stress on an experimental model of chronic heart failure. Six weeks after myocardial infarction by coronary ligation, Wistar rats were randomized to two groups: 10 weeks of therapy with propranolol (50 mg/kg/day in drinking water) and no treatment (infarcted controls). A third group was sham-operated rats without treatment. Animals were anesthetized for hemodynamic measurements, and hearts were then removed for histologic analysis, papillary muscle contractility study, and oxidative stress measurements using thiobarbituric acid reactive substance (TBARS) determination. Control infarcted rats demonstrated significant alterations of hemodynamic parameters and remodeling with increase of heart weight/body weight, of right ventricular lateral wall thickness, of LV circumference, LV septal area/body weight, and LV papillary muscle weight/body weight as compared with sham. In propranolol-treated rats, hypertrophy of the LV septum, papillary muscle, and right ventricle were similar to those of the infarcted control. Myocardial oxidative stress was significantly increased in control infarcted rats compared with sham, and propranolol prevented such oxidative stress increase. Papillary muscle isometric tension parameters were not significantly different among groups. Propranolol treatment prevented isoprenaline-induced spontaneous papillary muscle activity in vitro. Oxidative stress is increased in the rat model of heart failure secondary to coronary ligation. Long-term treatment with propranolol in vivo does not modify the compensatory process of hypertrophy but completely abolishes the oxidative stress increase and reduces the increased cardiac sensitivity to catecholamine-induced arrhythmias observed in this experimental model of heart failure.

Predictors of medical events in patients enrolled in the cardiac insufficiency bisoprolol study (CIBIS): a study of the interactions between beta-blocker therapy and occurrence of critical events using analysis of competitive risks

BACKGROUND

The risk of occurrence of medical events in a clinical trial is competitive in nature; that is, in a given patient the risk of having a critical event depends on the amount of time elapsed since random assignment and on the previous events that may have occurred in the patient. The purpose of this study was to examine the relations between baseline variables, the interactions between treatment, bisoprolol, or placebo, and the occurrence of critical events during the CIBIS trial, a mortality and morbidity trial of beta-blockade in patients with heart failure.

METHODS AND RESULTS

A Cox model for censored data was used to analyze the relations between baseline variables, total deaths, permanent treatment withdrawals, nonlethal cardiovascular events, and their interactions with bisoprolol or placebo. We examined the influence of treatment on the occurrence of deaths, permanent treatment withdrawals, and nonlethal cardiovascular events by using the technique of event history analysis, which takes into account competitive risks between events. Compared with placebo, bisoprolol reduced mortality rates in patients with a left ventricular ejection fraction < or =20% (relative risk [RR] 0.49; 95% confidence interval [CI] 0.27 to 0.88; P =.02). In patients whose baseline heart rate was in the upper tertile of distribution, permanent treatment withdrawals were less frequent in patients randomly assigned to bisoprolol than in patients randomly assigned to placebo (RR 0.50; 95% CI 0.28 to 0.88; P =.02). Bisoprolol reduced the incidence of nonlethal cardiac events in patients in whom heart failure was present for at least 4 years (RR 0.44; 95% CI 0.27 to 0.71; P <.01). Event history analysis revealed that among patients who died under treatment after having at least 1 nonlethal cardiovascular event, 20 patients were treated with placebo but only 7 patients were treated with bisoprolol (RR 0.41; 95% CI 0.17 to 0.98; P <.05).

CONCLUSIONS

Some patients with heart failure derive more benefit from beta-blocker therapy than others. In the CIBIS trial, they are those patients with the lower left ventricular ejection fractions and those who have nonlethal cardiovascular events but in whom beta-blocker therapy is not permanently discontinued.

Different effects of bisoprolol on heart rate in patients with ischemic or idiopathic dilated cardiomyopathy (a 24-hour Holter substudy of the Cardiac Insufficiency Bisoprolol Study [CIBIS])

The effect of beta blockade on heart rate in patients with either idiopathic or ischemic cardiomyopathy was studied. It was found that beta blockade reduced the early morning increase in heart rate to a greater extent in patients with idiopathic dilated cardiomyopathy than in those with ischemic dilated cardiomyopathy.