Sex-specific relevance of diabetes to occlusive vascular and other mortality: a collaborative meta-analysis of individual data from 980 793 adults from 68 prospective studies

BACKGROUND

Several studies have shown that diabetes confers a higher relative risk of vascular mortality among women than among men, but whether this increased relative risk in women exists across age groups and within defined levels of other risk factors is uncertain. We aimed to determine whether differences in established risk factors, such as blood pressure, BMI, smoking, and cholesterol, explain the higher relative risks of vascular mortality among women than among men.

METHODS

In our meta-analysis, we obtained individual participant-level data from studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration that had obtained baseline information on age, sex, diabetes, total cholesterol, blood pressure, tobacco use, height, and weight. Data on causes of death were obtained from medical death certificates. We used Cox regression models to assess the relevance of diabetes (any type) to occlusive vascular mortality (ischaemic heart disease, ischaemic stroke, or other atherosclerotic deaths) by age, sex, and other major vascular risk factors, and to assess whether the associations of blood pressure, total cholesterol, and body-mass index (BMI) to occlusive vascular mortality are modified by diabetes.

RESULTS

Individual participant-level data were analysed from 980 793 adults. During 9·8 million person-years of follow-up, among participants aged between 35 and 89 years, 19 686 (25·6%) of 76 965 deaths were attributed to occlusive vascular disease. After controlling for major vascular risk factors, diabetes roughly doubled occlusive vascular mortality risk among men (death rate ratio [RR] 2·10, 95% CI 1·97-2·24) and tripled risk among women (3·00, 2·71-3·33; χ2 test for heterogeneity p<0·0001). For both sexes combined, the occlusive vascular death RRs were higher in younger individuals (aged 35-59 years: 2·60, 2·30-2·94) than in older individuals (aged 70-89 years: 2·01, 1·85-2·19; p=0·0001 for trend across age groups), and, across age groups, the death RRs were higher among women than among men. Therefore, women aged 35-59 years had the highest death RR across all age and sex groups (5·55, 4·15-7·44). However, since underlying confounder-adjusted occlusive vascular mortality rates at any age were higher in men than in women, the adjusted absolute excess occlusive vascular mortality associated with diabetes was similar for men and women. At ages 35-59 years, the excess absolute risk was 0·05% (95% CI 0·03-0·07) per year in women compared with 0·08% (0·05-0·10) per year in men; the corresponding excess at ages 70-89 years was 1·08% (0·84-1·32) per year in women and 0·91% (0·77-1·05) per year in men. Total cholesterol, blood pressure, and BMI each showed continuous log-linear associations with occlusive vascular mortality that were similar among individuals with and without diabetes across both sexes.

INTERPRETATION

Independent of other major vascular risk factors, diabetes substantially increased vascular risk in both men and women. Lifestyle changes to reduce smoking and obesity and use of cost-effective drugs that target major vascular risks (eg, statins and antihypertensive drugs) are important in both men and women with diabetes, but might not reduce the relative excess risk of occlusive vascular disease in women with diabetes, which remains unexplained.

FUNDING

UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Union BIOMED programme, and National Institute on Aging (US National Institutes of Health).

Vascular risk factors and morphometric data in cervical artery dissection: a case-control study

BACKGROUND

Limited knowledge exists on vascular risk factors, body height and weight in patients with spontaneous cervical artery dissection (sCAD).

PATIENTS AND METHODS

In this case-control study, major vascular risk factors, body weight, body height and body mass index (BMI) of 239 patients obtained from a prospective hospital-based sCAD registry were compared with 516 age- and sex-matched healthy controls undergoing systematic health examinations in the Clinical and Preventive Investigations Center, Paris. Gender-specific analyses were performed.

RESULTS

The mean body height was higher in sCAD patients than in controls (171.3 cm (SD 8.6) vs 167.7 cm (8.9); p<0.0001) and sCAD patients had a significantly lower mean body weight (67.5 (12.2) kg vs 69.3 (14.6) kg; p<0.001) and mean BMI (22.9 (3.3) kg/m2 vs 24.5 (4.2) kg/m2; p<0.0001) than controls. The overall frequency of hypertension, diabetes, current smoking, past smoking and hypercholesterolaemia did not differ significantly between sCAD patients and controls. The mean total plasma cholesterol level was identical in both groups (5.5 mmol/l, SD 1.1). Gender specific subgroup analyses showed similar results for men and women.

CONCLUSION

Patients with sCAD had a higher body height and a lower body weight and BMI than controls, while major vascular risk factors were similar in sCAD patients and controls.

[Management of sudden death in a semi-rural district, Seine-et-Marne: the DEFI 77 study]

Sudden death is a major problem in public health, affecting around 50 000 people a year in France. The prognosis for cardiac arrest is abysmal because for every minute lost the chances of survival diminish by 10%. The aim of this work was to prospectively evaluate the characteristics of cardiac arrest victims across an entire 6000 km? area, the Seine-et-Marne district, distinguished by the paradox of lying just outside the capital whilst actually being semi-rural, and to determine the current methods of dealing with this emergency. The DEFI 77 prospective epidemiological survey was carried out with the collaboration of the SAMU emergency medical service, the SDIS fire/ambulance service, the general hospitals and the Paris-Ile-de-France cardiological association. Between January 2001 and December 2005 there were 2001 cardiac arrests (mean age 68 +/- 20 years, 67% male) at home in 80% of cases. The arrest was in front of a witness in 72% of cases, but they performed resuscitation in only 14.3% of cases. The SAMU and SMUR emergency medical services attempted cardio-pulmonary resuscitation in 78% of cases. In 29% of cases, one or more external electric shocks were carried out, using a semi-automatic defibrillator 79% of the time. Only 11.5% of patients arrived at the emergency department alive, the overall hospital survival rate being less than 2%. Only eight patients subsequently underwent automatic defibrillator implantation. The results of this observational study are to a large extent explained by an extremely long delay (12 minutes) before help was called for, the delay between the call and the arrival of medical assistance (9.5 +/- 4 min), the low percentage of active witnesses, and the variability in management (invasive in particular). In conclusion, at the dawn of the third millennium the prognosis of cardiac arrest remains very poor and fully justifies educating the general public about calling for help early and about actions that can save lives, particularly external cardiac massage before the arrival of the emergency services, as well as the benefits of using automated external defibrillators.

Characteristics and six-month outcomes in a cohort of 8288 diabetic and non-diabetic patients with previous history of acute coronary syndrome or stroke: the French PREVENIR 3 survey

AIMS

To evaluate the cardiovascular prognosis of 1845 Diabetic Patients (DP) and 6443 Non-Diabetic Patients (NDP) in secondary prevention.

METHODS

Patients were recruited prospectively if they had had a previous history of ischemic stroke or acute coronary syndrome (ACS) i.e. Myocardial Infarction (MI) or Unstable Angina (UA) within a period of five years preceding inclusion. For each patient, the number of hospitalizations and vital status were recorded each month over a 6-month period (mean follow-up: 4.8 months).

RESULTS

306 patients (9.5/100--person years; 95% CI, 8.5 to 10.6) had undergone at least one subsequent event (hospitalization for ACS, ischemic stroke, or cardiovascular death). A majority of these events were non-fatal ACS (n=248). The cumulative incidence rate of subsequent events was higher in DP: 12.6/100- person years (10.0 to 15.2) than in NDP: 8.6/100--person years (7.5 to 9.8). DP were significantly at higher risk of subsequent cardiovascular events (OR: 1.34; P=0.025) after adjustment for confounding factors. 93% of coronary DP and NDP underwent a recurrent event affecting the same location. When the index episode was a stroke, 71% of DP had a subsequent stroke vs. 47% of NDP.

CONCLUSION

in secondary prevention, the risk of mortality and subsequent vascular events is independently higher in French DP than in NDP. The locations affected by each type of subsequent cardiovascular event seemed correlated to the baseline diagnosis, whatever the diabetic status, even when the frequency of subsequent strokes increased (not significantly) in DP when compared to NDP.

Cardiovascular risk markers associated with the metabolic syndrome in a large French population: the SYMFONIE study

OBJECTIVE

The SYMFONIE study was designed to analyze the clinical and biological characteristics, and the cardiovascular risk markers, in men and women with the metabolic syndrome compared to control subjects.

RESEARCH DESIGN AND METHODS

The study population included 101,697 men and women, 18 to 80 years of age, who had a health checkup at the Centre d'Investigations Preventives et Cliniques (Paris, France) between 1997 to 2002. The metabolic syndrome was defined according to the ATpiiI-NCEP 2001 criteria.

RESULTS

Out of the 66,202 men (47.4+/-11.8 years) and 35,495 women (48.5+/-13.6 years) included in this population, 6761 men (10.2%) and 2155 women (6.1%) presented the metabolic syndrome. Among subjects < or =40 years of age, the prevalence of the metabolic syndrome was 5.0% in men and 2.2% in women, and rose to 14.1% and 12.0%, respectively, among men and women >70 years of age. After adjustment for age, patients with the metabolic syndrome presented higher pulse pressure (systolic minus diastolic blood pressure), higher heart rate, lower vital respiratory capacity, lower physical activity, an increase in inflammatory status assessed through leukocyte count and dental inflammation, hepatic abnormalities, and increased levels of stress and depression.

CONCLUSION

In this large French population, the prevalence of the metabolic syndrome is lower than in North American and northern European populations. Patients with the metabolic syndrome present several additional hemodynamic, inflammatory and psychological risk markers which could contribute to the poor cardiovascular prognosis of these subjects.

[Survey into cardiac pacing in the Ile-de-France area for the year 2001: evaluation of indications]

A survey into the implantation of cardiac pacemakers during 2001 in the Ile-de-France area was carried out by the French National Insurance Medical Service in order to evaluate performance in all centres performing more than 10 primary implantations per year.

METHODS AND RESULTS

In 2001, 12 centres out of a total of 49 performed less than 50 primary implantations per year, representing 5% of the total regional activity, which was estimated to be 6414 procedures. The remaining 95% of procedures were spread evenly among 8 high-throughput centres (> 200 primary implantations per year) and 29 medium-throughput centres (50 to 200 primary implantations per year). Indications for pacing were analysed retrospectively by a team of regulatory doctors on a sample of 2176 patients with reference to the ACC/AHA/NASPE guidelines. After examination of the medical records, the indication was ranked as being class I, II or Ill (absence of indication). A valid indication was lacking in 8.2% of cases. Sinus node dysfunction represented 74.6% of the non-indications, and this classification had the predictive factors of asymptomatic dysfunction, and treatment with anti-arrhythmic or bradycardic medication. The proportion of class III interventions was significantly lower in the high-throughput centres (5.8 vs 9.9%, p < 0.05).

CONCLUSION

8.2% of primary pacing procedures were not indicated and resulted principally from asymptomatic sinus node dysfunction.

[Long-term evaluation of endocavitary cryoablation of nodal reentry]

Radiofrequency ablation is the reference treatment of refractory nodal reentry. Cryoablation has the advantage of having more modulable effects and minimises the risk of permanent atrioventricular block (AVB). Its immediate efficacy seems comparable to that of radiofrequency ablation but the long-term results are not well known. Endocavitary cryoablation of the slow pathway was undertaken in 26 patients (18 women) with an average age of 47.7 +/- 72.8 years with re-entrant nodal tachycardia refractory to medical therapy. The primary success rate was 92% (24 out of 26). On average, 2.6 +/- 2.2 (1 to 10) cryoablations at - 70 degrees C were delivered and were preceded by 6.4 +/- 4.5 (1 to 16) cryomappings to locate the site of the slow pathway. During cryomapping, 8 episodes of AVB were observed in 6 patients (6 second or third degree), all of which were revertible on rewarming. No cases of permanent AVB were observed. An oesophageal stimulation test of inducibility was performed on the 4th day in 21 patients, 16 of which were not reinducible. During follow-up of 355 +/- 194 days, 22 of the 26 patients (85%) had no recurrence of the arrhythmia. Two of the 24 primary successes had a recurrence, in addition to the two primary failures. Two of the four recurrences occurred in a non-sustained form which was less disabilitating for the patient and the recurrences were controlled in the 4 patients by antiarrhythmic therapy. These results suggest that cryoablation may be a reliable and effective long-term treatment of re-entrant nodal tachycardias. If confirmed in larger series in terms of efficacy and safety, cryoablation could become the treatment of choice of re-entrant nodal tachycardia.

[Automobile driving and implantable defibrillators]

The consequences of implanting an automatic cardioverter defibrillator (ICD) on vehicle driving in France are poorly known. This retrospective study examined the behaviour at the wheel of ICD recipients who were recommended to abstain from driving for 3 to 6 months after device implantation. The study population included 98 patients (mean age = 59.5 +/- 14.8 years) followed for a mean of 24. +/- 23.9 months, who underwent ICD implant for ventricular tachycardia (65% of patients ventricular fibrillation (15%), syncope (8%), as part of a research protocol of myocardial cell transplantation 6%, or for primary prevention (5%). The underlying heart disease was ischemic in 59% of patients dilated cardiomyopathy in 11%,hypertrophic cardiomyopathy in 8%, valvular in 6%. Brugada syndrome in 4%, right ventricular arrhythmogenic cardiomyopathy in 2%, and miscellaneous disorders in 9% of patients. Five patients died without post mortem interrogation of the ICD. Only 28% of drivers remembered, and 13% observed, the recommended driving limitations. However, 45% (the oldest) claimed to drive prudently. During follow-up, 47% of patients received an ICD shock. Their mean it ventricular ejection fraction was 34 +/- 14%, versus 43 +/- 18% in patients who received no ICD therapy (p = 0.015). Syncope occurred in 16% who received ICD shocks. Shocks were delivered during driving in 6 patients, without consequent accident. Despite their non-observance of recommended driving limitations. ICD recipients suffered few traffic accidents. Legislation in France should reproduce the guidelines issued by European professional societies and enacted by the British laws.

[New energy sources for ablative methods]

Radiofrequency current is the reference energy source for endocavitary ablation of arrhythmias. It is particularly well adapted for the ablation of focal arrhythmogenic substrates such as accessory pathways or foyers of automatism. Technological advances have made the lesions larger but the extension of the indications of percutaneous ablation to more complex substrates such as atrial fibrillation have justified the evaluation of alternative energies. The production of linear transmural lesions or deeper lesions which respect the parietal myocardial architecture and endocardial structure are a challenge for these energies. The capacity of functional mapping specific to cryogenics has provided this energy source with a clinical application for ablation of high risk structures whereas other energies, despite the chronicity of their experimental evaluation, are still at the stage of preliminary clinical trials with the sophisticated catheters in special indications.

[Predictive criteria of early recurrence of atrial arrhythmia after reduction by electrical cardioversion]

The management of atrial arrhythmias aims not only to restore sinus rhythm but also to maintain it. Ten to thirty per cent of patients have early recurrence of atrial arrhythmias, the treatment of which remains empiric. The aim of this study was to define factors predictive of early recurrence of atrial arrhythmias and the consequences on the length of hospital stay. A series of 131 patients who underwent reduction of atrial arrhythmias by electrical cardioversion was studied retrospectively. A recurrence within 24 hours was observed in 12.2% of the patients. These recurrences significantly increased the length of hospital stay (6.8+/-6.3 versus 3.6+/-3.8 days, p=0.005). This study confirms two previously reported results with respect to more long-term recurrences. In the "early recurrence" group, the duration of the atrial arrhythmia was longer (p=0.003) and there were fewer treatments with amiodarone (p=0.03). In addition, original results were obtained. In the "early recurrence" group, the patients were more often treated with furosemide (p=0.02), class Ic antiarrhythmics (p=0.007) or anaesthetised with thiopental (p=0.002) than patients without early recurrences. Experimental data explain these results. However, they require confirmation by a prospective randomised trial.

[External electrical cardioversion of atrial arrhythmia: predictive criteria of success]

AIM

Supraventricular arrhythmia is a major public health problem because of its prevalence and clinical consequences. The first step of the treatment usually consists in restoring sinusal rhythm. The aim of this study is to evaluate results and predictive factors of success of electrical cardioversion.

METHODS

We studied a series of 143 consecutive electric cardioversion preformed in 131 French patients.

RESULTS

The rate of successful direct current cardioversion was 91.2%. Negative predictive factors are the height body mass index and the age of arrhythmia. Atrial flutter is a predictive factor of success. These results agree with published results. Our study highlights the interest of some nonantiarrhythmic drugs received by the patient during the period before the direct current cardioversion. Thus, a spironolactone treatment appears to be a new predictive factor of the success of electrical cardioversion (success in patients treated with spironolactone: 100% vs 89% without, P = 0.04).

CONCLUSIONS

Our results agree with usual predictive factors of the success of cardioversion. Nevertheless, a new approach is that of the positive effect of spironolactone on cardioversion. A prospective randomized study is necessary to confirm this result.

Antithrombotic therapy is associated with better survival in patients with severe heart failure and left ventricular systolic dysfunction (EPICAL study)

BACKGROUND

In patients with congestive heart failure (CHF), clinical trials have demonstrated the benefit of a number of drugs on morbidity and mortality. Nevertheless so far, there is no published controlled study of long-term antithrombotic therapy in patients with CHF. The aim of this work was to identify the relationship between cardiovascular drug use, especially antithrombotic therapy, and survival of CHF patients in current clinical practice, using an observational, population-based database.

METHODS

The EPICAL study (Epidémiologie de l'Insuffisance Cardiaque Avancée en Lorraine) has identified prospectively all patients with severe CHF in the community of Lorraine. Inclusion criteria were age 20-80 years in 1994, at least one hospitalisation for cardiac decompensation, NYHA III/IV HF, ventricular ejection fraction < or =30% or cardiothoracic index > or =60% and arterial hypotension or peripheral and/or pulmonary oedema. A total of 417 consecutive patients surviving at hospital discharge were included in the database. The average follow-up period was 5 years. Univariate Cox models were used to test the relationship of baseline biological and clinical factors to survival. Cardiovascular drug prescriptions were tested in a multivariate Cox model adjusted by other known predictive factors.

RESULTS

Duration of disease >1 year, renal failure, serum sodium > or =138 mmol/l, old age, serious comorbidity, previous decompensation, high doses of furosemide and vasodilators use were independently associated with poor prognosis at 1 and 5 years. Oral anticoagulants, aspirin, lipid lowering drugs and beta-blockers use were associated with better survival. There was no interaction between aspirin and angiotensin converting enzyme inhibitor use on survival.

CONCLUSION

Antithrombotic therapy was associated with a better long-term survival in our study population of severe CHF. These results together with other previously published circumstantial evidence urge for a prospective, controlled and randomised trial specifically designed to evaluate optimal oral anticoagulants and aspirin in patients with congestive heart failure.

Reproducibility of the ventricular synchronization parameters assessed by multiharmonic phase analysis of radionuclide angiography in the normal heart

Radionuclide angiography (RNA) permits analysis of contractility and conduction abnormalities. We determined the parameters of normal ventricular synchronization, assessed the reproducibility of the technique, and compared first harmonic (1H) and third harmonic (3H) analysis. Forty-four normal subjects (28 men and 16 women) were studied. RNA was performed in left anterior oblique (LAO) and left lateral (LL) projections. The onset (To), mean time (Tm), total contraction time (Tt) for right ventricle (RV) and left ventricle (LV), interventricular time (T(RV-LV) = Tm(LV - Tm(RV)) in LAO, and the apex-to-base time (T(a-b)) in LL were measured on the histograms of the time-activity curve. Reproducibility (R) was tested by studying 26 consecutive patients with two successive RNAs. RV starts contracting 25 ms before LV (To(RV) = 29 +/- 37 ms; To(LV) = 54 +/- 39 ms; mean +/- SD) with a 37 ms longer total contraction time. T(RV-LV) is 3 +/- 16 ms. In LL projection, apex and base contract synchronously: T(a-b) = 2 +/- 16 ms. 3H analysis enlarges all duration parameters (To, Tm and Tt), but does not alter synchronization (deltaT(a-b) and deltaT(RV-LV) between 1H and 3H <1%, p = NS). Reproducibility of the duration (T(tLV) and T(tRv)) and synchronization parameters (T(a-b) and T(RV-LV)) is high (R < or = 2.2%). In conclusion, the simultaneous contraction of right and left ventricles and of apex and base can be quantified by RNA phase analysis with high reproducibility. These results, consistent with published electrophysiological data, provide the basis for further non-invasive investigations of ventricular resynchronization in patients with basal electrical or mechanical asynchrony.

Combined effects of systolic blood pressure and serum cholesterol on cardiovascular mortality in young (<55 years) men and women

AIMS

To evaluate the combined effects of the two most frequent modifiable risk factors, systolic blood pressure and serum cholesterol, on cardiovascular and coronary mortality, in a large French population aged 18 to 55 years.

METHODS AND RESULTS

We studied 108,879 men (mean age 39.1+/-9.4 years) and 84,931 women (mean age 37.3+/-10.0 years) who had a health check-up at the IPC Center between 1978 and 1988. Mortality data for a mean period of 13 years were analysed. Systolic blood pressure and cholesterol levels were classified according to the cut-points proposed by international guidelines. In men, the prevalence of high cholesterol was more than twice as high in hypertensives as in normotensives; in women, it was more than three times higher. The combination of these two risk factors has additive effects on cardiovascular disease and coronary heart disease risk. In men, a borderline elevation of both systolic blood pressure (130-139 mmHg) and cholesterol (200-239 mg x dl(-1)) leads to a three- to four-fold increase in cardiovascular disease risk. Men with systolic blood pressure >or=160 mmHg represent a small percentage (about 5%) who have a 10-fold increase in cardiovascular disease and coronary heart disease risk, especially when high cholesterol is present. In women of the same age, similar trends were observed, but the results were less significant, probably due to the low cardiovascular disease mortality rates.

CONCLUSIONS

In conclusion, in French subjects under 55 years of age, a combination of high systolic blood pressure and high serum cholesterol dramatically increased cardiovascular disease and coronary heart disease risk, especially in men. A more aggressive public health policy is needed to prevent the development of risk factors in younger subjects.

[Characteristics and predictive value of quality of life in a French cohort of angina patients]

The study of quality of life (QoL) in a French cohort of patients suffering from angina pectoris was one of the objectives of the ELAN longitudinal study. It concerned 3,954 subjects (76% males) mean age: 67 +/- 11 years, followed up by 613 cardiologists which were invited to complete a series of baseline sociodemographic and clinical data and to answer a series of questions upon one year outcome (3,261 medical records available). QoL was assessed at baseline via a self-administered 12-item general questionnaire, the Short-Form 12 (SF-12), enabling to compute a mental component summary (CS-12) and a physical component summary (PCS-12) score. Mean MCS-12 in the ELAN cohort (49 +/- 7.5) was very close to the standards derived from general American population (50 +/- 10) or to the data available in a general French population (51.2 +/- 7.4). Whereas mean PCS-12 was hardly lower (about one standard deviation) in comparison with general American population (50 +/- 10) or with a general French population (48.4 +/- 9.4). QoL was higher in males and linked to age in a contrasted way (higher MCS-12 and lower PCS-12 in elderly; p < 0.0001). It depended on the clinical condition (lower MCS-12 associated with mixed-type angina pectoris or with more severe angina and with persistent smoking; lower PCS-12 associated with mixed type or more severe angina, with cardiac failure episodes, arteritis obliterans, stroke antecedents or left ventricular hypertrophy). Both scores were negatively correlated, in multivariate regression analysis, with the severity of persisting angina at one year, after controlling for the severity of baseline angina and the other confounding variables. Above all, MCS-12 and especially PCS-12, predicted major coronary events at one year (death, myocardial infarction, angioplasty, coronary by-pass surgery). In a multivariate logistic regression analysis, low baseline PCS-12 was associated with higher risk for cardiovascular death at one year (OR = 2.44; 95% CI = 1.25-4.74; p < 0.01). These results confirm the clinical validity of SF-12 (cross sectional stage of the study) and stress its prognostic value independent from the other risk factors (longitudinal stage of the study).

[Paroxysmal atrial fibrillation in community medicine: management intentions and cost estimates]

This study was undertaken to describe the declared management of atrial fibrillation in community medicine in France for patients between 50 and 80 years of age, and to estimate the total cost of treatment for Society in the year 2000. A questionnaire was sent to a sample of 306 private sector cardiologists, representative for their geographic location: 100 replies were received. Only 10% of cardiologists prescribed a treatment in patients without cardiovascular precedents who had a single regressive episode of atrial fibrillation and three quarters of them advised follow-up. This management cost an average between 228 and 296 Euros/year. When the episode of fibrillation was persistent at the time of consultation, 82% of practitioners prescribed antiarrhythmic reduction (amiodarone) after antithrombotic treatment (oral anticoagulants) followed by an antiarrhythmic therapy (class lc mainly) with an average cost of 659 to 783 Euros/year. In patients with previous cardiovascular disease, when a first episode of atrial fibrillation was present at the time of consultation, 92% of cardiologists prescribed pharmacological reduction with amiodarone, followed by long-term therapy when successful for an average cost of 755 to 1,092 Euros/year. All cardiologists requested systematic blood tests to search for thyroid complications of amiodarone with an average cost of 59 Euros/year. The costs were high, especially in chronic and recurrent pathology: the cost of treatment of the first two episodes of atrial fibrillation in the over 65 age group was 305 million Euros/year.

Pulse pressure and heart rate: independent risk factors for cancer?

In the present study, the roles of heart rate (HR) and pulse pressure (PP) on cancer mortality, after taking into account physical activity, cigarette smoking, alcohol consumption and other confounding factors or underlying disease, were examined in men. The study included 125,513 men aged 20 to 95 years who had a health check-up at the IPC Center between 1978 and 1988. HR and PP were classified into three groups: < 60, 60-80, > 80 bpm for HR and < 50, 51-64, > or = 65 mmHg for PP. Adjusted risk ratios related to the increment from one class of HR or PP to the next for all cancer mortality were 1.4 (1.2-1.5) and 1.3 (1.1-1.4), respectively. This relationship was independent of several known risk and confounding factors, especially cigarette smoking and physical activity, and could not be explained by the presence of underlying disease.

Aortic stiffness is an independent predictor of all-cause and cardiovascular mortality in hypertensive patients

Although various studies reported that pulse pressure, an indirect index of arterial stiffening, was an independent risk factor for mortality, a direct relationship between arterial stiffness and all-cause and cardiovascular mortality remained to be established in patients with essential hypertension. A cohort of 1980 essential hypertensive patients who attended the outpatient hypertension clinic of Broussais Hospital between 1980 and 1996 and who had a measurement of arterial stiffness was studied. At entry, aortic stiffness was assessed from the measurement of carotid-femoral pulse-wave velocity (PWV). A logistic regression model was used to estimate the relative risk of all-cause and cardiovascular deaths. Selection of classic risk factors for adjustment of PWV was based on their influence on mortality in this cohort in univariate analysis. Mean age at entry was 50+/-13 years (mean+/-SD). During an average follow-up of 112+/-53 months, 107 fatal events occurred. Among them, 46 were of cardiovascular origin. PWV was significantly associated with all-cause and cardiovascular mortality in a univariate model of logistic regression analysis (odds ratio for 5 m/s PWV was 2.14 [95% confidence interval, 1.71 to 2.67, P<0.0001] and 2.35 [95% confidence interval, 1.76 to 3.14, P<0.0001], respectively). In multivariate models of logistic regression analysis, PWV was significantly associated with all-cause and cardiovascular mortality, independent of previous cardiovascular diseases, age, and diabetes. By contrast, pulse pressure was not significantly and independently associated to mortality. This study provides the first direct evidence that aortic stiffness is an independent predictor of all-cause and cardiovascular mortality in patients with essential hypertension.

Cardiovascular mortality in hypertensive men according to presence of associated risk factors

To evaluate the risk of cardiovascular disease (CVD) mortality in hypertensive men according to the presence of associated risk factors (ARFs). The population was composed of 29 640 normotensive men without ARFs (reference group) and 60 343 hypertensive men (with and without ARFs) who had a standard health checkup at the Centre d'Investigations Préventives et Cliniques between 1978 and 1988. Mortality data for a mean period of 14 years were analyzed. The following ARFs were considered: total cholesterol >/=2.5 g/L, personal history of diabetes, smoking (current smokers), body mass index >28 kg/m(2), and heart rate >80 bpm. CVD risk related to the presence of isolated hypertension (assessed in hypertensive subjects without ARFs versus the reference group) increased linearly from 15% at the age of 30 years to 134% at the age of 80 years. In hypertensive subjects, one additional ARF increased CVD risk by 56% (47% to 65%, P<0.01) in younger subjects but only by 4% (-8% to 17%, P=NS) in older subjects. The role of hypercholesterolemia and tobacco smoking in CVD mortality was significantly higher in hypertensive subjects aged <55 years than in hypertensive subjects aged >/=55 years (P<0.01), whereas the roles of tachycardia and obesity were not affected by age. In younger hypertensive subjects, evaluation of CVD risk and therapeutic strategies should target ARFS: In older subjects, the presence of high blood pressure levels seems to be the major determinant of CVD risk.

New diagnostic criteria for diabetes and coronary artery disease: insights from an angiographic study

OBJECTIVES

The goal of this research was to study coronary atherosclerosis in patients with type 2 diabetes compared with patients without diabetes according to the new definition of diabetes advocated by the American Diabetes Association in 1997.

BACKGROUND

Patients with diabetes (fasting plasma glucose above 7.0 mM/L) have a higher risk of cardiovascular death. The correlation with the pattern and severity of their coronary atherosclerosis, especially in the new patients with "mild" diabetes (7.0 mM/L < or = fasting plasma glucose < 7.8 mM/L), remains unclear.

METHODS

A cohort of 466 patients undergoing coronary angiography but free of any previous infarction, coronary intervention and insulin therapy were prospectively recruited. Ninety-three had diabetes (fasting plasma glucose > 7.0 mM/L or hypoglycemic oral treatment). Five angiographic indexes were calculated to describe severity and extent of coronary atherosclerosis.

RESULTS

Overall, patients with diabetes had more diffuse coronary atherosclerosis, a greater prevalence of mild, moderate and severe stenoses and a two-fold higher occlusion rate than patients without diabetes, even after adjustment for age, gender, body mass index, hypertension, lipid parameters, smoking, family history of cardiovascular events and ischemic symptoms. Patients with "mild diabetes" had a coronary atherosclerosis pattern more similar to patients with normal fasting plasma glucose than to patients formerly defined as diabetic according to the World Health Organization criteria, except that they had a higher prevalence of <50% stenoses.

CONCLUSIONS

In patients with type 2 diabetes, those with 7.0 mM/L < or = fasting plasma glucose < 7.7 mM/L have a slightly greater prevalence of mildly severe lesions that may partly explain their higher cardiovascular event rate.

Combined effects of heart rate and pulse pressure on cardiovascular mortality according to age

OBJECTIVES

The aim of the study was to assess the combined effects of pulse pressure (PP) and heart rate (HR) on cardiovascular mortality in a large French population.

DESIGN

The study population was composed of 125,513 men and 96,301 women aged 16-95 years who had a health check-up at the IPC Center between January 1978 and December 1988. Subjects taking antihypertensive treatment were excluded. Mortality was assessed for an 8-year period. HR and PP were classified into three groups. HR groups were: < 60, 60-79 and > or = 80 beats per minute (bpm). PP groups were: < 50, 50-64 and > or = 65 mmHg.

RESULTS

In men, PP and HR were both positively associated with cardiovascular mortality risk. In women, mean arterial pressure (MAP) but not PP or HR was associated with cardiovascular mortality. In men, a combined elevation of PP and HR was associated with an important increase of cardiovascular mortality risk. The group with the highest PP and the highest HR had a 4.8-fold increase in cardiovascular mortality risk as compared to the reference group (PP < 50 mmHg and HR < 60 bpm). This effect was more pronounced in younger men (5.4-fold increase) than in older men (3.7-fold increase), as compared to the reference groups of the same age. In women, the combined effects of PP and HR on cardiovascular mortality were not significant.

CONCLUSION

A combined elevation of the two components of pulsatile arterial stress is associated with an important increase in cardiovascular mortality in men, especially in younger men. In women, steady-state stress (evaluated primarily by MAP), but not pulsatile stress, is an important determinant of cardiovascular mortality.

[Arrhythmic cardiomyopathy]

Arrhythmic cardiomyopathy (ACM) is a clinical entity which can be reproduced in experimental models and which corresponds to all myocardial changes induced by chronic tachycardia. It may affect the atria and/or ventricles and, in this case, occur with all types of arrhythmia. Arrhythmia complicating a cardiomyopathy is the differential diagnosis of ventricular ACM. Nevertheless, the potential deleterious haemodynamic changes of any chronic arrhythmia may aggravate pre-existing ventricular dysfunction and, therefore, should always be considered. The development of ACM is usually progressive and depends on the heart rate, but there may also be a myocardial predisposition in certain cases. ACM is an association of haemodynamic, electrophysiological, metabolic and histological changes. Regression, which is the rule, starts in the first days following control of the ventricular rhythm but continues clinically over several months. The physiopathological mechanisms of ACM are multiple and include essentially abnormal cellular calcium concentrations. The treatment is optimally the restoration and maintenance of sinus rhythm, or at least control of the ventricular rate. Because of its curative effects, selective radiofrequency ablation of the arrhythmogenic substrate is the treatment of choice when this is localised. In chronic atrial fibrillation, when sinus rhythm cannot be maintained, the control of the ventricular response at rest and on exercise depends on pharmacological treatment, and, when ineffective, on radiofrequency modification of atrioventricular conduction with optimisation of the pacing mode.

Association of circulating cellular adhesion molecules with menopausal status and hormone replacement therapy. Time-dependent change in transdermal, but not oral estrogen users

The incidence of coronary heart disease is lower in premenopausal than in postmenopausal women, and estrogen use may be cardioprotective among postmenopausal women. Cellular adhesion molecules (CAM) are involved in the early stage of atherosclerosis, and short-term administration of oral estrogen decreased plasma concentrations of their soluble forms in postmenopausal women. However, data evaluating transdermal estrogen are sparse and long-term effect of hormone replacement therapy (HRT) on CAM is unknown. Therefore, we have investigated the association of circulating CAM (cCAM) with menopausal status and long-term HRT. Plasma levels of intercellular adhesion molecule-1 (cICAM-1), vascular cell adhesion molecule-1 (cVCAM-1), P-selectin, E-selectin, C-reactive protein (CRP), and fibrinogen were measured in 74 premenopausal women, 60 postmenopausal women not using HRT, 30 postmenopausal women using opposed oral estrogen therapy, and 30 postmenopausal women using opposed transdermal estrogen therapy. All women were apparently healthy and aged between 45 and 54 years. Duration of HRT ranged from 3 to 96 months. Postmenopausal women not receiving HRT had 24% higher mean levels of cICAM-1 than premenopausal women (318 vs. 255 ng/ml, P < .001). In postmenopausal women, users of oral estrogen had 16% lower, and users of transdermal estrogen had 17% lower mean levels of cICAM-1 than non-users (268 and 264 vs. 318 ng/ml, P = .001 for both comparisons). Furthermore, in users of transdermal route, the lowering effect of estrogen on cICAM-1 was dependent on treatment duration, while no time-dependent effect was seen in oral estrogen users. Users of transdermal estrogen had lower cVCAM-1 and P-selectin levels than postmenopausal non-users (327 vs. 364 ng/ml (P = .05) and 18 vs. 23 ng/ml (P = .05). There was no difference in CRP and E-selectin levels between the groups. Adjustment for age and body mass index (BMI) made no substantial change in the results. These data suggest that oral and transdermal estrogen may play a long-term cardioprotective role through favourable changes in endothelial function.

Should diastolic and systolic blood pressure be considered for cardiovascular risk evaluation: a study in middle-aged men and women

OBJECTIVES

The goal of this study was to evaluate the role of diastolic blood pressure (DBP) in cardiovascular mortality for different systolic blood pressure (SBP) levels in middle-aged men and women.

BACKGROUND

In middle-aged subjects it is unclear whether DBP, in addition to SBP, should be considered for risk evaluation.

METHODS

Subjects (77,023 men; 48,480 women) aged 40 to 70 years old, had no major cardiovascular disease, no antihypertensive treatment and were examined at the Centre d'Investigations Preventives et Cliniques between 1972 and 1988. Mortality was assessed for an 8- to 12-year period.

RESULTS

In both genders, cardiovascular mortality increased with the SBP level. In men and women with normal SBP levels, DBP did not influence cardiovascular mortality after adjustment for age and SBP. In men with systolic hypertension, a U-shaped curve relationship between cardiovascular mortality and DBP was observed, with the lowest mortality rates in the group with DBP 90 to 99 mm Hg. Compared with this group, age- and SBP-adjusted cardiovascular mortality was higher by 73% (p < 0.02) in the group with DBP <90 mm Hg and by 65% (p < 0.001) in the group with DBP > or =110 mm Hg. In women with systolic hypertension, however, DBP was positively correlated with cardiovascular mortality.

CONCLUSIONS

In middle-aged subjects, classification of cardiovascular risk according to DBP levels should take into account gender, especially when SBP levels are elevated. Men with systolic hypertension are at higher risk when their DBP is "normal" than when they present a mild to moderate increase in DBP. In women of the same age, however, systolic-diastolic hypertension represents a higher risk than isolated systolic hypertension.

Biventricular pacing in severe heart failure patients reverses electromechanical dyssynchronization from apex to base

Biventricular (BV) pacing is an emerging treatment for patients with severe dilated cardiomyopathy and ventricular asynchrony. Radionuclide angioscintigraphy has shown that BV can reduce activation delays between left (LV) and right ventricles (RV), but alterations of electromechanical asynchrony between the LV base and apex have not been previously described. Radionuclide angioscintigraphy with Tc99m red cell labeling was performed in 21 patients, 64 +/- 17 years of age, in NYHA functional Class III or IV, and with a mean QRS duration of 180 +/- 15 ms. Right (RVEF) and LV ejection fraction (LVEF), and the synchronization between LV apex and base (Tab) in the left lateral view, were measured by a phase analysis program (1) at baseline, (2) on day 8 after BV pacemaker implantation (D8), and (3) at 12-month follow-up in BV (M12). BV pacing reversed Tab from 42 +/- 47 ms at baseline to -57 +/- 75** on D8, and -37 +/- 76** on M12. LVEF increased from 17.8 +/- 6.3% to 19.9 +/- 8.3 on D8, and 24.2 +/- 10.8* on M12, and RVEF increased from 27.6 +/- 16% to 29.9 +/- 16 on D8 and 34.1 +/- 12.1* on M12 (*P < 0.05, **P < 0.001). A close correlation was found between early LV apex-to-base resynchronization induced by BV and late increase in LVEF (r = 0.59**). In parallel with its known interventricular resynchronization effect, BV pacing reverses the apex-to-base ventricular activation sequence, causing early contraction of the LV base followed by the apex. These changes persisted up to 12 months along with an improvement in LV systolic function.

How can hypertensive patients be better treated? The contribution of combination therapy

Recent studies demonstrated that target blood pressure (BP) in treated hypertensive patients should be below 140 mmHg for systolic blood pressure (SBP) and below 90 mmHg for diastolic blood pressure (DBP). However, population studies from several countries have demonstrated that in clinical practice the proportion of controlled hypertensive patients is less than 30%. In order to elucidate these questions in France we analysed a large population of 145,000 subjects examined at the Centre d'Investigations Préventives et Cliniques in Paris (IPC). Among those with high BP at the time of their IPC visit, only 20% received an antihypertensive treatment. Among those receiving an antihypertensive treatment, less than 27% (24% in men and 30% in women) presented with BP values less than 140 mmHg for SBP and less than 90 mmHg for DBP. This analysis also showed that 72% of hypertensive patients presented with at least one modifiable associated cardiovascular risk factor and that more than 30% of hypertensive men and more than 25% of hypertensive women presented with at least two associated risk factors. The use of combination therapies could help to increase the percentage of well-controlled hypertensive subjects. It has been shown that in order to reach this BP level, combination therapy should be used in more than two-thirds of the treated subjects. The trandolapril-verapamil combination is the first fixed combination of an angiotensin-converting enzyme inhibitor and a non-dihydropyridine calcium-channel blocker. Administered once daily, this combination reduces BP more than a classic monotherapy. The effects of the trandolapril-verapamil combination on risk factors are either neutral (metabolic parameters), or even beneficial (reduction in heart rate).

[Electrophysiological remodeling induced by atrial fibrillation. An experimental curiosity or major factor in atrial fibrillation in man?]

Atrial fibrillation usually progresses from a paroxysmal to a permanent arrhythmia, even in the absence of underlying cardiac disease. The treatment is more difficult when the arrhythmia is chronic. This progression may be explained by the aggravation of underlying cardiac disease with time. Another explanation is that the arrhythmia induces functional and structural changes of the atrial tissues (remodelling) which promote the perpetuation of the arrhythmia and which make treatment less effective. Although the electrophysiological changes predisposing to atrial fibrillation have been known for over 15 years, it was only in 1995 that experimental studies showed the presence of atrial electrophysiological remodelling induced by the arrhythmia. This process of long term adaptation of the atrial myocytes to the tachycardia comprises marked changes of the parameters which sustain the arrhythmia: changes in refractory period (decreased duration, inadaptation to the heart rate, increased dispersion), reduced conduction speed and sinus dysfunction. Atrial remodelling also affects the contractile function by the structural changes. The calcium currents play a major role in its development. This mechanism has not yet been completely defined in the clinical setting and its importance in sustaining the arrhythmia has not been clearly evaluated. Atrial fibrillation remains one of the most difficult arrhythmias to treat. A better understanding of cellular mechanisms of remodelling could open up new therapeutic approaches to limit the natural history of the arrhythmia with progression to chronicity and structural changes responsible for the degradation of atrial contractility.

Induction of apoptosis using sphingolipids activates a chloride current in Xenopus laevis oocytes

The purpose of this study was to investigate whether the cell shrinkage that occurs during apoptosis could be explained by a change of the activity in ion transport pathways. We tested whether sphingolipids, which are potent pro-apoptotic compounds, can activate ionic currents in Xenopus laevis oocytes. Apoptosis was characterized in our model by a decrease in cell volume, a loss of cell viability, and DNA cleavage. Oocytes were studied using voltage-clamp after injection with N,N-dimethyl-D-erythrosphingosine (DMS) or D-sphingosine (DS). DMS and DS activated a fast-activating, slowly inactivating, outwardly rectifying current, similar to I(Cl-swell), a swelling-induced chloride current. Lowering the extracellular chloride dramatically reduced the current, and the channel was more selective for thiocyanate and iodide (thiocyanate > iodide) than for chloride. The current was blocked by 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) and lanthanum but not by niflumic acid. Oocytes injected with a pseudosubstrate inhibitor of protein kinase C (PKC), PKC-(19-31), exhibited the same current. DMS-activated current was abolished by preexposure with phorbol myristate acetate. Our results suggest that induction of apoptosis in X. laevis oocytes, using sphingolipids or PKC inhibitors, activates a current similar to swelling-induced chloride current previously described in oocytes.

Temporal and geographical trends in indications for implantation of cardiac defibrillators in Europe 1993-1998. Medtronic ICD System Investigators

Despite the demonstrated efficacy of implantable cardioverter defibrillators (ICDs) in reducing sudden and total mortality in selected populations, their implantation rates vary greatly between countries. The aim of our study was to analyze temporal and geographical trends in ICD implantations in countries with similar health related expenditure in Western Europe. A total of 2,257 patients from ten European evaluation studies of Medtronic defibrillators and defibrillation electrodes, conducted between 1993 and 1998, representing 12 countries, was included in this analysis. Rates of implantation and clinical characteristics were compared between countries and years of implantation. Rates of implantation differed greatly between Western European countries and did not correlate with indices of health related expenditure (i.e., number of patients per physician and number of patients per hospital bed). However, there was a strong and statistically significant negative correlation between the use of amiodarone and the rates of implantation (r = -0.66, P = 0.02). Temporal trends showed a significant increase in the age of the patients receiving an ICD between 1993 and 1998 (57 +/- 14 vs 61 +/- 12 years, mean +/- SD, P < 0.001). There was also a temporal trend towards an increased incidence of coronary artery disease and a significant decrease in the incidence of cardiomyopathy. There was a temporal increase in implantations in patients with a history of ventricular tachycardia. Despite a general scientific agreement that ICDs are a first line treatment for patients at high risk of sudden cardiac death, their acceptance remains low in several developed countries. This low acceptance may not be entirely related to budget constraint but may also be related to their perceived efficacy by physicians and health authorities.

[Heart rate and mortality: review of the literature]

A great number of studies focussed on a wide variety of subjects have been concerned with the subject of morbi-mortality and the effect of heart rate. These studies show that there is a connection between high heart rate and arterial hypertension, and a significant coronary, cardiovascular, non-cardiovascular and overall mortality risk. Two explanations are possible for this. The increase in heart rate together with associated sympathetic hyperactivity can be considered a cardiovascular risk factor: or it could be viewed as an independent risk factor, associated with an increase in mechanical constraints.

[One-year follow-up of a population of patients with angina. Factors influencing mortality and occurrence of cardiovascular events. Results of the ELAN study]

The ELAN (Etude longitudinale dans l'angor) study was carried out both to acquire better knowledge of the occurrence of major cardiovascular events (myocardial infarction, revascularization surgery, death) in patients followed up for angina pectoris, and to determine the factors influencing such events. A cohort of angina patients was formed in January 1997, and 3,284 patients were followed up by 488 French cardiologists during a one-year period. Of these 3,284 patients, 96 (29/1000) died; causes of death included underlying coronary heart disease in 31, sudden death in 8, other cardiac aetiologies in 35, and noncardiac causes in 22. Sixty-nine (21/1000) patients developed myocardial infarction, 240 (73/1000) underwent PTCA, and 119 (36/1000) underwent coronary bypass surgery. Factors associated with an increased risk of death were age, diabetes mellitus, heart failure and angina type, mixed and rest angina being associated with poorer prognosis compared to exertional angina. Infarction risk increased with age and a history of previous infarction. Analysis of therapeutic factors after adjustment for the above risk factors showed a beneficial effect of betablockers on both cardiovascular and all-cause mortality and of aspirin on all-cause mortality.

A decrease in diastolic blood pressure combined with an increase in systolic blood pressure is associated with a higher cardiovascular mortality in men

OBJECTIVES

The study evaluated the risk of cardiovascular mortality according to combined spontaneous (non-treatment-related) changes in both systolic and diastolic blood pressure (BP).

BACKGROUND

Long-term longitudinal changes in blood pressure may be a more accurate determinant of cardiovascular risk since changes in systolic or diastolic blood pressure over a period of time reflect the evolution of arterial and arteriolar alterations.

METHODS

Two independent French male cohorts were studied: the IPC cohort (Investigations Préventives et Cliniques) composed of 15,561 men aged 20 to 82 years who had had two visits spaced four to 10 years apart, and the Paris Prospective Study composed of 6,246 men aged 42 to 53 years, examined annually for a period of four years. None of the subjects were taking antihypertensive medication. Annual changes in BP were estimated, and subjects were divided into groups according to the increase, lack of change, or decrease of systolic or diastolic BP. Nine groups were formed by combining the changes of systolic and diastolic BP. Cardiovascular mortality was assessed for a mean period of 13.5 years for the IPC Study and 17 years for the Paris Prospective Study.

RESULTS

In both cohorts, after adjustment for age and major risk factors, the group with an increase in systolic and a decrease in diastolic BP presented the highest relative risk of cardiovascular mortality compared to the group with no changes in either systolic or diastolic BP (relative risk: 2.07 [1.05 to 4.06] in the IPC Study and 2.16 [1.16 to 4.01] in the Paris Prospective Study).

CONCLUSIONS

Assessment of spontaneous changes of BP over a long period of time can contribute to the evaluation of cardiovascular risk. Subjects whose systolic BP increased while their diastolic BP decreased had the highest cardiovascular risk independently of absolute values of BP or other risk factors.

[Characteristics of a cohort of 4,000 French patients with angina. The ELAN study]

The ELAN (Etude Longitudinale dans l'ANgor) study was carried out to evaluate factors influencing the occurrence of death, myocardial infarction and revascularization procedures in patients with known angina pectoris. Analysis of baseline data collected in January 1997 involves 4,035 patients throughout France, which were recruited by 613 cardiologists practising on a private, hospital or mixed basis. The study population comprised 75% of men with a mean age of 65 years and 25% of women with a mean age of 70 years. Eighty eight percent of the patients had at least one cardiovascular risk factor, and nearly half of them had two or more factors; hypercholesterolemia and hypertension were the two most frequent ones. Reported cardiovascular past events included myocardial infarction in 47% of patients, PTCA in 33% and aorto-coronary bypass in 24%. Angina pectoris had been diagnosed within the previous year in 39% of patients. Exertional angina was the most common type (66%), with grade I/II angina being most frequently found (more than 70% of all cases). Management strategies are especially described for angina patients diagnosed within the previous year. More than half of the patients had undergone exercise testing within the previous 12 months, while scanning and coronary arteriography had been performed in 15% and 72%, respectively. Ninety five percent of patients were under antianginal drug therapy, with combined therapies being used in 58% of them. The most frequently prescribed drugs were betablockers (63%) and nitrates (53%). In 74% of patients, aspirin was given in addition to conventional antianginal agents. These data will be reviewed in a one-year cohort analysis as potential predictive factors for the occurrence of cardiovascular events.

Significant association of atrial vulnerability with atrial septal abnormalities in young patients with ischemic stroke of unknown cause

BACKGROUND AND PURPOSE

Atrial septal abnormalities have been associated with cryptogenic ischemic stroke in young patients, but the causal link has not yet been established. Paradoxical embolism is considered the most likely mechanism but is rarely proven. It can be hypothesized that, in those patients, paroxysmal atrial arrhythmias, potentially favored by the anatomic abnormalities, can be another cause of thrombus formation and subsequent embolism to the brain. In this study we assessed the relationship between atrial vulnerability, reflecting arrhythmogenic properties of the atria, and atrial septal abnormalities in young patients with cryptogenic ischemic stroke.

METHODS

We enrolled 62 consecutive patients aged <55 years who had ischemic stroke of unknown cause and transesophageal echocardiography to assess atrial septal aneurysm (ASA) or patent foramen ovale (PFO) (ie, atrial septal abnormalities). These patients underwent electrophysiological study to measure atrial refractoriness and conduction time defining a vulnerability index (ie, latent atrial vulnerability) and to assess the inducibility of sustained (lasting >60 seconds) atrial fibrillation with the use of programmed atrial stimulation. Actual atrial vulnerability was defined by the presence of both latent vulnerability and inducibility of sustained atrial fibrillation lasting >60 seconds.

RESULTS

We found atrial vulnerability in 58% of patients with atrial septal abnormalities and in 25% of patients without (odds ratio=4.1 [95% CI, 1.3 to 12.7; P<0.02]). The difference between patients with and without PFO or between patients with both PFO and ASA and those without were also significant. Patients with inducible sustained atrial fibrillation had more frequent past history of palpitations and syncope than patients without (P<0.02).

CONCLUSIONS

Atrial vulnerability is associated with atrial septal abnormalities in patients with cryptogenic stroke. This result raises the question of the potential role of transient atrial arrhythmias in thrombus formation in the presence of PFO or ASA.

Associations between heart rate and other risk factors in a large French population

OBJECTIVES

In a large general French population of 100,000 subjects, the relationship of resting heart rate with age, gender, demographic parameters, physical activity and classical risk factors was evaluated.

POPULATION AND METHODS

A population composed of all the subjects who had a free health check-up at the IPC Centre between 1992 and 1995 (62,353 men and 35,371 women) was analysed. Heart rate was considered either as a continuous parameter or as a qualitative parameter. The study population was divided into four heart rate classes: < 65, 65-74, 75-84 and > or = 85 beats/min.

RESULTS

Women had significantly higher heart rate values than men, and this gender difference was constant in the different age groups. In both genders, heart rate was positively associated with blood pressure, triglycerides, glycaemia and physical inactivity, and negatively with body height Heart rate was also correlated with total cholesterol but only in men. The only factor having opposite effects on heart rate in men and women was tobacco smoking (positive in men and negative in women). Among untreated hypertensive men, 21.3% had a heart rate > or = 85 beats/min compared with only 4.0% among normotensive men. In women, these percentages were 23.6 and 7.6%, respectively. Subjects with untreated mild hypertension or uncontrolled treated hypertension also showed increased rates of tachycardia compared to normotensives.

CONCLUSIONS

The present analysis, performed in a large French population, shows that high heart rate is associated with several other risk factors, especially hypertension, suggesting that tachycardic subjects have a high risk profile.