Inflammatory markers and extent and progression of early atherosclerosis: Meta-analysis of individual-participant-data from 20 prospective studies of the PROG-IMT collaboration

BACKGROUND

Large-scale epidemiological evidence on the role of inflammation in early atherosclerosis, assessed by carotid ultrasound, is lacking. We aimed to quantify cross-sectional and longitudinal associations of inflammatory markers with common-carotid-artery intima-media thickness (CCA-IMT) in the general population.

METHODS

Information on high-sensitivity C-reactive protein, fibrinogen, leucocyte count and CCA-IMT was available in 20 prospective cohort studies of the PROG-IMT collaboration involving 49,097 participants free of pre-existing cardiovascular disease. Estimates of associations were calculated within each study and then combined using random-effects meta-analyses.

RESULTS

Mean baseline CCA-IMT amounted to 0.74 mm (SD = 0.18) and mean CCA-IMT progression over a mean of 3.9 years to 0.011 mm/year (SD = 0.039). Cross-sectional analyses showed positive linear associations between inflammatory markers and baseline CCA-IMT. After adjustment for traditional cardiovascular risk factors, mean differences in baseline CCA-IMT per one-SD higher inflammatory marker were: 0.0082 mm for high-sensitivity C-reactive protein (p < 0.001); 0.0072 mm for fibrinogen (p < 0.001); and 0.0025 mm for leucocyte count (p = 0.033). 'Inflammatory load', defined as the number of elevated inflammatory markers (i.e. in upper two quintiles), showed a positive linear association with baseline CCA-IMT (p < 0.001). Longitudinal associations of baseline inflammatory markers and changes therein with CCA-IMT progression were null or at most weak. Participants with the highest 'inflammatory load' had a greater CCA-IMT progression (p = 0.015).

CONCLUSION

Inflammation was independently associated with CCA-IMT cross-sectionally. The lack of clear associations with CCA-IMT progression may be explained by imprecision in its assessment within a limited time period. Our findings for 'inflammatory load' suggest important combined effects of the three inflammatory markers on early atherosclerosis.

MicroRNAs as non-invasive biomarkers of heart transplant rejection

AIM

Rejection is one of the major causes of late cardiac allograft failure and at present can only be diagnosed by invasive endomyocardial biopsies. We sought to determine whether microRNA profiling could serve as a non-invasive biomarker of cardiac allograft rejection.

METHODS

We included 113 heart transplant recipients from four referral French institutions (test cohort, n = 60, validation cohort, n = 53). In the test cohort, we compared patients with acute biopsy-proven allograft rejection (n = 30) to matched control patients without rejection (n = 30), by assessing microRNAs expression in the heart allograft tissue and patients concomitant serum using RNA extraction and qPCR analysis. Fourteen miRNAs were selected on the basis of their implication in allograft rejection, endothelial activation, and inflammation and tissue specificity.

RESULTS

We identified seven miRNAs that were differentially expressed between normal and rejecting heart allografts: miR-10a, miR-21, miR-31, miR-92a, miR-142-3p miR-155, and miR-451 (P < 0.0001 for all comparisons). Four out of seven miRNAs also showed differential serological expression (miR-10a, miR-31, miR-92a, and miR-155) with strong correlation with their tissular expression. The receiver-operating characteristic analysis showed that these four circulating miRNAs strongly discriminated patients with allograft rejection from patients without rejection: miR-10a (AUC = 0.975), miR-31 (AUC = 0.932), miR-92a (AUC = 0.989), and miR-155 (AUC = 0.998, P < 0.0001 for all comparisons). We confirmed in the external validation set that these four miRNAs highly discriminated patients with rejection from those without. The discrimination capability of the four miRNAs remained significant when stratified by rejection diagnosis (T-cell-mediated rejection or antibody-mediated rejection) and time post-transplant.

CONCLUSION

This study demonstrates that a differential expression of miRNA occurs in rejecting allograft patients, not only at the tissue level but also in the serum, suggesting their potential relevance as non-invasive biomarkers in heart transplant rejection.

Microparticles and sudden cardiac death due to coronary occlusion. The TIDE (Thrombus and Inflammation in sudden DEath) study

AIMS

The pattern of coronary occlusion might contribute to the onset of ventricular arrhythmia and sudden cardiac death (SCD). We hypothesized that the concentrations of microparticles might differ between SCD and ST-elevation myocardial infarction (STEMI) patients without rhythmic disturbances.

METHODS AND RESULTS

The study sample includes consecutive patients hospitalized in two French tertiary centres between 2006 and 2011 for SCD with angiographically-proven acute coronary occlusion (n=23), for STEMI (n=61) and for a planned percutaneous coronary angioplasty (PCI) (n=35, controls). During PCI blood was collected in the arch of aorta (systemic blood) before and after the procedure and in the culprit coronary lesion with an aspiration catheter. Microparticles were analysed by flow cytometry in a blinded manner to quantify endothelial (CD144+), platelet (CD41+), leucocyte (CD11a+) and erythrocyte (CD235a+) derived microparticles. After multivariate analysis, intracoronary concentrations of endothelial-derived microparticles were significantly higher in SCD than in STEMI patients (129 (74-185) vs. 50 (21-118) nb/µl; p < 0.01). Intracoronary and systemic blood concentrations of platelet-derived microparticles were not different between SCD and controls, suggesting limited impact of cardiac massage and electric defibrillation in microparticle concentrations.

CONCLUSION

The higher concentrations of endothelial-derived microparticles in SCD due to acute coronary occlusion compared with STEMI without rhythmic disturbances suggests different patterns of acute coronary occlusion.

Characteristics and Outcomes of Sudden Cardiac Arrest During Sports in Women

Background—

No specific data are available on characteristics and outcome of sudden cardiac death (SCD) during sport activities among women in the general population.

Methods and Results—

From a prospective 5-year national survey, involving 820 subjects 10 to 75 years old who presented with SCD (resuscitated or not) during competitive or recreational sport activities, 43 (5.2%) such events occurred in women, principally during jogging, cycling, and swimming. The level of activity at the time of SCD was moderate to vigorous in 35 cases (81.4%). The overall incidence of sport-related SCD, among 15- to 75-year-old women, was estimated as 0.59 (95% confidence interval [CI], 0.39–0.79) to 2.17 (95% CI, 1.38–2.96) per year per million female sports participants for the 80th and 20th percentiles of reporting districts, respectively. Compared with men, the incidence of SCDs in women was dramatically lower, particularly in the 45- to 54-year range (relative risk, 0.033; 95% CI, 0.015–0.075). Despite similar circumstances of occurrence, survival at hospital admission (46.5%; 95% CI, 31.0–60.0) was significantly higher than that for men (30.0%; 95% CI, 26.8–33.2; P =0.02), although this did not reach statistical significance for hospital discharge. Favorable neurological outcomes were similar (80%). Cause of death seemed less likely to be associated with structural heart disease in women compared with men (58.3% versus 95.8%; P =0.003).

Conclusions—

Sports-related SCDs in women participants seems dramatically less common (up to 30-fold less frequent) compared with men. Our results also suggest a higher likelihood of successful resuscitation as well as less frequency of structural heart disease in women compared with men.

Complement-binding anti-HLA antibodies and kidney-allograft survival

BACKGROUND

Anti-HLA antibodies hamper successful transplantation, and activation of the complement cascade is involved in antibody-mediated rejection. We investigated whether the complement-binding capacity of anti-HLA antibodies plays a role in kidney-allograft failure.

METHODS

We enrolled patients who received kidney allografts at two transplantation centers in Paris between January 1, 2005, and January 1, 2011, in a population-based study. Patients were screened for the presence of circulating donor-specific anti-HLA antibodies and their complement-binding capacity. Graft injury phenotype and the time to kidney-allograft loss were assessed.

RESULTS

The primary analysis included 1016 patients. Patients with complement-binding donor-specific anti-HLA antibodies after transplantation had the lowest 5-year rate of graft survival (54%), as compared with patients with non-complement-binding donor-specific anti-HLA antibodies (93%) and patients without donor-specific anti-HLA antibodies (94%) (P<0.001 for both comparisons). The presence of complement-binding donor-specific anti-HLA antibodies after transplantation was associated with a risk of graft loss that was more than quadrupled (hazard ratio, 4.78; 95% confidence interval [CI], 2.69 to 8.49) when adjusted for clinical, functional, histologic, and immunologic factors. These antibodies were also associated with an increased rate of antibody-mediated rejection, a more severe graft injury phenotype with more extensive microvascular inflammation, and increased deposition of complement fraction C4d within graft capillaries. Adding complement-binding donor-specific anti-HLA antibodies to a traditional risk model improved the stratification of patients at risk for graft failure (continuous net reclassification improvement, 0.75; 95% CI, 0.54 to 0.97).

CONCLUSIONS

Assessment of the complement-binding capacity of donor-specific anti-HLA antibodies appears to be useful in identifying patients at high risk for kidney-allograft loss.

Mortality of French participants in the Tour de France (1947-2012)

AIMS

In the context of recent concerns regarding performance enhancing techniques and potential negative health effects of high-level physical activity, data on the long-term outcomes and causes of death in elite endurance cyclists are of particular interest.

METHODS AND RESULTS

Characteristics and vital status of all French participants in the Tour de France were collected for the 1947-2012 period. Causes of death were obtained from 1968. Overall and disease-specific mortalities were compared with the French male population using overall and specific standardized mortality ratios (SMRs) with their 95% confidence intervals (CIs). Among the 786 French cyclists who participated at least once between 1947 and 2012, 208 (26%) died by 1 September 2012. Neoplasms and cardiovascular diseases accounted for 61% of deaths. We observed a 41% lower mortality in French cyclists (SMR: 0.59, 95% CI: 0.51-0.68, P < 0.0001), which did not change over time (P = 0.70). It was observed for main mortality causes: for neoplasms (SMR: 0.56; 95% CI: 0.42-0.72, P < 0.0001) and for cardiovascular death (SMR: 0.67; 95% CI: 0.50-0.88, P = 0.004), except mortality related to external causes (SMR: 1.06, 95% CI: 0.71-1.53, P = 0.80).

CONCLUSION

We observed a substantially and significantly lower mortality in participants in the Tour de France, compared with the general male population. However, our results do not allow us to assess in detail the balance between positive effects of high-level sports activity and selection of healthy elite athletes, vs. any potential deleterious effects of excessive physical exercise or alleged doping.

External validation of the 2008 Framingham cardiovascular risk equation for CHD and stroke events in a European population of middle-aged men. The PRIME study

OBJECTIVE

To test the applicability of the sex-specific 2008 Framingham general cardiovascular risk equation for coronary heart disease (CHD) and stroke in European middle-aged men from Ireland and France.

METHODS

In the PRIME study, 9638 healthy middle-aged men recruited in France and Ireland were surveyed for 10 years for the occurrence of first CHD and stroke events. The original Framingham equation, the partially calibrated Framingham equation (using the PRIME baseline survival at 10 years), and the completely calibrated Framingham equation (additionally using risk factor means calculated in PRIME) were assessed. Model fit (expected versus observed events) and discrimination ability were assessed using a modified Hosmer-Lemeshow Chi-square statistic and Harrell's c-index respectively.

RESULTS

The original (uncalibrated) Framingham equation overestimated by 1.94-fold the risk of CHD and stroke combined in PRIME, and by 2.23 and 1.42-fold in PRIME-France and PRIME-Ireland respectively. Adequate fit was found after complete calibration. However, discrimination ability of the Framingham equation was poor as shown by Harrell's c-index lower than 0.70.

CONCLUSION

The (completely) calibrated 2008 Framingham equation predicted accurate number of CHD and stroke events but discriminated poorly individuals at higher from those at lower event risk in a European population of middle-aged men.

Insomnia, daytime sleepiness and cardio-cerebrovascular diseases in the elderly: a 6-year prospective study

OBJECTIVE

To examine 1) the associations between history of cardio-cerebrovascular diseases (CVD) and insomnia complaints and excessive daytime sleepiness (EDS), and 2) the relationships between sleep complaints and future CVD in persons over 65.

METHODS

CVD was assessed at baseline and during two, four, and six-year follow-up in 5494 non-demented subjects. Self-reported insomnia complaints (poor sleep quality, difficulty in initiating sleep, difficulty in maintening sleep, and early morning awakening), EDS and sleep medication use were evaluated at baseline. Logistic regression models and Cox proportional hazard models, with delayed entry and age of participants as the time scale, were adjusted for socio-demographic, lifestyle and clinical variables.

RESULTS

At baseline, 748 participants had a past-history of CVD. A past-history of CVD was associated with EDS (OR = 1.28 95%CI = [1.05-1.57]) and the number of insomnia complaints (OR = 1.26 95%CI = [1.03-1.55] for 1-2 insomnia complaints; OR = 1.32 95%CI = [1.03-1.71] for ≥3 complaints). In longitudinal analyses, neither the four components of insomnia nor the number of insomnia complaints were significantly associated with first or recurrent CVD events (n = 391 events). EDS was independently associated with future CVD events even after adjusting for prescribed sleep medication and past-history of CVD (HR = 1.35 95%CI = [1.06-1.71]).

CONCLUSION

Our results suggest that the relationships between sleep complaints and CVD could be complex. Insomnia complaints are more likely a consequence of CVD, whereas EDS appears to be a determinant of CVD independently of past-history of CVD. EDS screening may thus constitute a means of detecting persons at high risk of CVD.

Antibody-mediated vascular rejection of kidney allografts: a population-based study

BACKGROUND

Rejection of allografts has always been the major obstacle to transplantation success. We aimed to improve characterisation of different kidney-allograft rejection phenotypes, identify how each one is associated with anti-HLA antibodies, and investigate their distinct prognoses.

METHODS

Patients who underwent ABO-compatible kidney transplantations in Necker Hospital and Saint-Louis Hospital (Paris, France) between Jan 1, 1998, and Dec 31, 2008, were included in our population-based study. We assessed patients who provided biopsy samples for acute allograft rejection, which was defined as the association of deterioration in function and histopathological lesions. The main outcome was kidney allograft loss-ie, return to dialysis. To investigate distinct rejection patterns, we retrospectively assessed rejection episodes with review of graft histology, C4d in allograft biopsies, and donor-specific anti-HLA antibodies.

FINDINGS

2079 patients were included in the main analyses, of whom 302 (15%) had acute biopsy-proven rejection. We identified four distinct patterns of kidney allograft rejection: T cell-mediated vascular rejection (26 patients [9%]), antibody-mediated vascular rejection (64 [21%]), T cell-mediated rejection without vasculitis (139 [46%]), and antibody-mediated rejection without vasculitis (73 [24%]). Risk of graft loss was 9·07 times (95 CI 3·62-19·7) higher in antibody-mediated vascular rejection than in T cell-mediated rejection without vasculitis (p<0·0001), compared with an increase of 2·93 times (1·1-7·9; P=0·0237) in antibody-mediated rejection without vasculitis and no significant rise in T cell-mediated vascular rejection (hazard ratio [HR] 1·5, 95% CI 0·33-7·6; p=0·60).

INTERPRETATION

We have identified a type of kidney rejection not presently included in classifications: antibody-mediated vascular rejection. Recognition of this distinct phenotype could lead to the development of new treatment strategies that could salvage many kidney allografts.

FUNDING

None.

Depressive symptoms, antidepressants and disability and future coronary heart disease and stroke events in older adults: the Three City Study

To investigate the association between baseline depressive symptoms and first fatal and non fatal coronary heart disease (CHD) and stroke in older adults, taking antidepressants and disability into account. In the Three City Study, a community-based prospective multicentric observational study cohort, 7,308 non-institutionalized men and women aged ≥65 years with no reported history of CHD, stroke or dementia, completed the 20-item Center for Epidemiologic Studies depression scale (CESD) questionnaire. First CHD and stroke events during follow-up were adjudicated by an independent expert committee. Hazard ratios (HRs) were estimated by Cox proportional hazard model. After a median follow-up of 5.3 years, 338 subjects had suffered a first non-fatal CHD or stroke event, and 82 had died from a CHD or stroke. After adjustment for study center, baseline socio-demographic characteristics, and conventional risk factors, depressive symptoms (CESD ≥ 16) were associated with fatal events only: fatal CHD plus stroke (HR = 2.50; 95% CI 1.57-3.97), fatal CHD alone (n = 57; HR = 2.21 ; 95%CI 1.27-3.87), and fatal stroke alone (n = 25; HR = 3.27; 95% CI 1.42-7.52). These associations were even stronger in depressed subjects receiving antidepressants (HR = 4.17; 95% CI 1.84-9.46) and in depressed subjects with impaired Instrumental Activities of Daily Living (HR = 8.93; 95% CI 4.60-17.34). By contrast, there was no significant association with non fatal events (HR for non-fatal CHD or stroke = 0.94; 95% CI 0.66-1.33). In non-institutionalized elderly subjects without overt CHD, stroke or dementia, depressive symptoms were selectively and robustly associated with first fatal CHD or stroke events.

Multiple biomarkers for the prediction of ischemic stroke: the PRIME study

OBJECTIVE

To simultaneously evaluate 14 biomarkers from distinct biological pathways for risk prediction of ischemic stroke, including biomarkers of hemostasis, inflammation, and endothelial activation as well as chemokines and adipocytokines.

METHODS AND RESULTS

The Prospective Epidemiological Study on Myocardial Infarction (PRIME) is a cohort of 9771 healthy men 50 to 59 years of age who were followed up over 10 years. In a nested case-control study, 95 ischemic stroke cases were matched with 190 controls. After multivariable adjustment for traditional risk factors, fibrinogen (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.03-2.28), E-selectin (OR, 1.76; 95% CI, 1.06-2.93), interferon-γ-inducible-protein-10 (OR, 1.72; 95% CI, 1.06-2.78), resistin (OR, 2.86; 95% CI, 1.30-6.27), and total adiponectin (OR, 1.82; 95% CI, 1.04-3.19) were significantly associated with ischemic stroke. Adding E-selectin and resistin to a traditional risk factor model significantly increased the area under the receiver-operating characteristic curve from 0.679 (95% CI, 0.612-0.745) to 0.785 and 0.788, respectively, and yielded a categorical net reclassification improvement of 29.9% (P=0.001) and 28.4% (P=0.002), respectively. Their simultaneous inclusion in the traditional risk factor model increased the area under the receiver-operating characteristic curve to 0.824 (95% CI, 0.770-0.877) and resulted in an net reclassification improvement of 41.4% (P<0.001). Results were confirmed when using continuous net reclassification improvement.

CONCLUSIONS

Among multiple biomarkers from distinct biological pathways, E-selectin and resistin provided incremental and additive value to traditional risk factors in predicting ischemic stroke.

Clinical usefulness of the metabolic syndrome for the risk of coronary heart disease does not exceed the sum of its individual components in older men and women. The Three-City (3C) Study

Objectives

To investigate the respective associations and clinical usefulness of the metabolic syndrome (MetS) and its individual components to predict the risk of first coronary heart disease (CHD) events in elderly.

Design

The Three-City is a French prospective multisite community-based cohort.

Setting

Three large French cities: Bordeaux, Dijon and Montpellier.

Participants

7612 subjects aged 65 and over who were free of CHD at baseline.

Main outcome measures

The MetS was defined by the 2005 National Cholesterol Education Program Adult Treatment Panel III criteria.

Results

During a median follow-up of 5.2 years, 275 first CHD events were adjudicated. The MetS was associated with increased risks of total (adjusted HR: 1.78; 95% CI 1.39 to 2.28), fatal (HR: 2.40; 95% CI 1.41 to 4.09) and non-fatal (HR: 1.64; 95% CI 1.24 to 2.17) CHD events. The association with total CHD was significant in women (HR: 2.56; 95% CI 1.75 to 3.75) but not in men (HR: 1.39; 95% CI 0.99 to 1.94; p for interaction=0.012). When in the same multivariable model, hyperglycemia and abdominal adiposity in women, hyperglycemia, lower HDL cholesterol and abdominal adiposity (inverse association) in men were the components significantly associated with CHD. The components of the MetS but not the MetS itself improved risk prediction beyond traditional risk factors (NRI= 9.35%, p<0;001).

Conclusion

The MetS is a risk marker for CHD in community-dwelling elderly subjects but may not be useful for CHD risk prediction purposes compared to its individual components.

Adipocytokines and the risk of ischemic stroke: the PRIME Study

OBJECTIVE

Adipocytokines are hormones secreted from adipose tissue that possibly link adiposity and the risk of cardiovascular disease, but limited prospective data exist on plasma adipocytokines and ischemic stroke risk. We investigated associations and predictive properties of 4 plasma adipocytokines, namely resistin, adipsin, leptin, and total adiponectin, with regard to incident ischemic stroke in the PRIME Study.

METHODS

A cohort of 9,771 healthy men 50 to 59 years of age at baseline was followed up over a period of 10 years. In a nested case-control study, 95 ischemic stroke cases were matched with 190 controls on age, study center, and date of examination. Hazard ratios (HRs) per standard deviation increase in plasma adipocytokine levels were estimated using conditional logistic regression analysis. The additive value of adipocytokines in stroke risk prediction was evaluated by discrimination and reclassification metrics.

RESULTS

Resistin (HR, 1.88; 95% confidence interval [CI], 1.16-3.03), adipsin (HR, 2.01; 95% CI, 1.33-3.04), and total adiponectin (HR, 1.53; 95% CI, 1.01-2.34), but not leptin, were independent predictors of ischemic stroke. The performance of a traditional risk factor model predicting ischemic stroke was significantly improved by the simultaneous inclusion of resistin, adipsin, and total adiponectin (c-statistic: 0.673 [95% CI, 0.631-0.766] vs 0.826 [95% CI, 0.792-0.892], p < 0.001; net reclassification improvement: 38.1%, p < 0.001).

INTERPRETATION

Higher plasma levels of resistin, adipsin, and total adiponectin were associated with an increased 10-year risk of ischemic stroke among healthy middle-aged men. Resistin, adipsin, and total adiponectin provided incremental value over traditional risk factors for the prediction of ischemic stroke risk.

Low plasma testosterone and elevated carotid intima-media thickness: importance of low-grade inflammation in elderly men

CONTEXT AND OBJECTIVE

An inverse correlation between plasma testosterone levels and carotid intima-media thickness (IMT) has been reported in men. We investigated whether this association could be mediated or modified by traditional cardiovascular risk factors as well as inflammatory status.

METHODS

In the Three-City population-based cohort study, 354 men aged 65 and over had available baseline data on hormones levels and carotid ultrasonography. Plasma concentrations of testosterone (total and bioavailable), estradiol and sex hormone-binding globulin (SHBG), together with cardiovascular risk factors were measured. IMT in plaque-free site and atherosclerotic plaques in the extracranial carotid arteries were determined using a standardized protocol. Multiple linear regression models were used to analyze this association and interaction study.

RESULTS

Analyses with and without adjustment for cardiovascular risk factors showed that carotid IMT was inversely and significantly correlated with total and bioavailable testosterone levels but not with SHBG and estradiol levels. This association depended on C-reactive protein (CRP) levels (p for interaction <0.05). Among men with low-grade inflammation (CRP ≥2 mg/L), mean IMT was higher in subjects with bioavailable testosterone ≤ 3.2 ng/mL than in those with bioavailable testosterone > 3.2 ng/mL (0.76 mm and 0.70 mm respectively, p < 0.01). By contrast, among men with CRP ≤ 2 mg/L, mean IMT was similar in both groups (0.72 mm and 0.71 mm respectively, p = 0.77). Similar results were found for total testosterone although not significant. No association was found between plasma hormones levels and atherosclerotic plaques.

CONCLUSION

In elderly men, low plasma testosterone is associated with elevated carotid intima-media thickness only in those with low-grade inflammation. Traditional risk factors have no mediator role.

Depressive symptoms, a time-dependent risk factor for coronary heart disease and stroke in middle-aged men: the PRIME Study

BACKGROUND AND PURPOSE

To date, the association between depressive symptoms and the risk of cardiovascular diseases remains controversial. We investigated prospectively, within the same population, the time course of the association between baseline depressive symptoms and first stroke or coronary heart disease event.

METHODS

In the Prospective Epidemiological Study of Myocardial Infarction (PRIME) Study, a multicenter, observational, prospective cohort, 9601 men from France and Northern Ireland were surveyed for the occurrence of first coronary heart disease (n=647) and stroke events (n=136) over 10 years. At baseline, the fourth quartile of a 13-item modified Center for Epidemiological Studies questionnaire was used to define the presence of depressive symptoms. We sought the best time-dependent function to assess the association between depressive symptoms and outcomes. Thus, the hazard ratios were estimated by a Cox proportional hazard model after splitting the follow-up before and after 5 years of follow-up time periods.

RESULTS

Depressive symptoms at baseline were associated with coronary heart disease in the first 5 years of follow-up (hazard ratio, 1.43; 1.10-1.87) and with stroke in the second 5 years of follow up (hazard ratio, 1.96; 1.21-3.19) after adjustment for age, study centers, baseline socioeconomic factors, traditional vascular risk factors, and antidepressant treatment. The association was even stronger for ischemic stroke (n=108; hazard ratio, 2.48; 1.45-4.25).

CONCLUSIONS

The current study suggests that in healthy, European, middle-aged men, baseline depressive symptoms are associated with an increased risk of coronary heart disease in the short-term, and for stroke in the long-term.

Main air pollutants and myocardial infarction: a systematic review and meta-analysis

CONTEXT

Short-term exposure to high levels of air pollution may trigger myocardial infarction (MI), but this association remains unclear.

OBJECTIVE

To assess and quantify the association between short-term exposure to major air pollutants (ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter ≤10 μm [PM(10)] and ≤2.5 μm [PM(2.5)] in diameter) on MI risk.

DATA SOURCES

EMBASE, Ovid MEDLINE in-process and other nonindexed citations, and Ovid MEDLINE (between 1948 and November 28, 2011), and EBM Reviews-Cochrane Central Register of Controlled Trials and EBM Reviews-Cochrane Database of Systematic Reviews (between 2005 and November 28, 2011) were searched for a combination of keywords related to the type of exposure (air pollution, ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, PM(10), and PM(2.5)) and to the type of outcome (MI, heart attack, acute coronary syndrome).

STUDY SELECTION

Two independent reviewers selected studies of any study design and in any language, using original data and investigating the association between short-term exposure (for up to 7 days) to 1 or more air pollutants and subsequent MI risk. Selection was performed from abstracts and titles and pursued by reviewing the full text of potentially eligible studies.

DATA EXTRACTION

Descriptive and quantitative information was extracted from each selected study. Using a random effects model, relative risks (RRs) and 95% CIs were calculated for each increment of 10 μg/m(3) in pollutant concentration, with the exception of carbon monoxide, for which an increase of 1 mg/m(3) was considered.

DATA SYNTHESIS

After a detailed screening of 117 studies, 34 studies were identified. All the main air pollutants, with the exception of ozone, were significantly associated with an increase in MI risk (carbon monoxide: 1.048; 95% CI, 1.026-1.070; nitrogen dioxide: 1.011; 95% CI, 1.006-1.016; sulfur dioxide: 1.010; 95% CI, 1.003-1.017; PM(10): 1.006; 95% CI, 1.002-1.009; and PM(2.5): 1.025; 95% CI, 1.015-1.036). For ozone, the RR was 1.003 (95% CI, 0.997-1.010; P = .36). Subgroup analyses provided results comparable with those of the overall analyses. Population attributable fractions ranged between 0.6% and 4.5%, depending on the air pollutant.

CONCLUSION

All the main air pollutants, with the exception of ozone, were significantly associated with a near-term increase in MI risk.

Gender-specific trends in heart rate in the general population from 1992-2007: a study of 226,288 French adults

OBJECTIVES

Heart rate (HR) has been associated with cardiovascular (CV) risk factors and with CV mortality. Trends in CV risk factors have been described in recent decades, but HR changes over time have been less studied. We thus aimed to examine the secular trends in HR and interrelationships between HR and traditional CV risk factors and mortality.

METHODS

We studied 226,288 consecutive participants (141,533 men and 84,755 women) aged 44.7 ± 12.7 years who had a free standard health check up, between 1992 and 2007. Each had resting HR measured systematically on a 10-cycle electrocardiogram, and assessment of lipoproteins, blood pressure, smoking, glycemic status, body mass index, and physical activity. Sex-specific trends in mean HR were estimated by a general linear model adjusted for traditional CV risk factors and CV treatment. In that model, year was considered as a continuous variable.

RESULTS

Crude mean HR decreased over the study period (from 68.9 ± 10.4 to 63.7 ± 9.0 beats/min in men; from 72.2 ± 10.3 to 65.2 ± 9.0 beats/min in women; p < 0.001 for both). The amplitude of the HR decrease was similar after full adjustment and across the pre-cited risk factors categories. On multivariate analysis, higher HR (≥ 80 beats/min vs. <60 beats/min) was associated with higher mortality rate over 5 years in men (hazard ratio 2.11, 95% CI 1.79-2.49) and women (hazard ratio 1.58, 95% CI 1.16-2.15).

CONCLUSION

In this large population-based study of 226,288 middle-aged participants, heart rate declined over 16 years independently of traditional CV risk factors.

Paris Prospective Study III: a study of novel heart rate parameters, baroreflex sensitivity and risk of sudden death

Resting heart rate has been related to the risk of cardiovascular disease and sudden death in several large prospective studies. To investigate prospectively the association of novel heart rate parameters and of carotid artery stiffness with sudden death and other cardiovascular disease. The Paris Prospective Study III (PPS3) is a new, ongoing French prospective study. From June 2008 to December 2011, 10,000 men and women aged 50-75 years who will have a preventive medical check-up at the Centre d'Investigations Préventives et Cliniques in Paris (France), will be enrolled in the study, after signing an informed consent. In addition to the general health examination, each subject's heart rhythm will be recorded during the course of the health check-up (approximately 2(1/2) h) and an echo-tracking of the right carotid bulb will be performed by trained technicians. A bio bank and DNA bank will be established for further biomarker and genetic analyses. The occurrence of cardiovascular disease including acute coronary syndrome, stroke, peripheral artery disease and sudden death, and of mortality, of the participants will be followed up during 20 years. With an estimated mean annual rate of sudden death of 0.1% and its increasing incidence rate with age, between 250 and 300 sudden deaths are expected. This unique study should provide new insights into the regulation of heart rate and blood pressure and should enable to identify novel heart rate parameters that are associated with sudden death.

Combined effects of depressive symptoms and resting heart rate on mortality: the Whitehall II prospective cohort study

OBJECTIVE

To examine the combined effects of depressive symptoms and resting heart rate on mortality risk.

METHOD

Analysis was performed on data from 5,936 participants in the Whitehall II study with a mean ± SD age of 61 ± 6 years. Depressive symptoms were assessed from 2002 to 2004 using the Center for Epidemiologic Studies Depression Scale (cutoff score for depression at ≥ 16). Resting heart rate was measured at the same study phase via electrocardiogram. Participants were assigned to 1 of 6 risk-factor groups on the basis of depression status (yes/no) and resting heart rate categories (< 60, 60-80, and > 80 beats/minute [bpm]). All-cause mortality was the main outcome in our analysis. Mean follow-up for mortality was 5.6 years.

RESULTS

In mutually adjusted Cox regression models, depression (hazard ratio = 1.93, P < .001) and resting heart rate > 80 bpm (hazard ratio = 1.67, P < .001) were independent predictors of mortality. After adjustment for potential confounding and mediating variables, participants with both depression and high resting heart rate had a 3-fold higher (P < .001) risk of death compared to depression-free participants with resting heart rates ranging from 60 to 80 bpm. This risk is particularly marked in participants with prevalent coronary heart disease.

CONCLUSIONS

This study provides evidence that the coexistence of depressive symptoms and elevated resting heart rate is associated with substantially increased risk of death compared to those without these 2 factors. This finding suggests the possibility that treatments that improve both depression and resting heart rate might improve survival.

Heart rate and risk of cancer death in healthy men

Background

Data from several previous studies examining heart-rate and cardiovascular risk have hinted at a possible relationship between heart-rate and non-cardiac mortality. We thus systematically examined the predictive value of heart-rate variables on the subsequent risk of death from cancer.

Methods

In the Paris Prospective Study I, 6101 asymptomatic French working men aged 42 to 53 years, free of clinically detectable cardiovascular disease and cancer, underwent a standardized graded exercise test between 1967 and 1972. Resting heart-rate, heart-rate increase during exercise, and decrease during recovery were measured. Change in resting heart-rate over 5 years was also available in 5139 men. Mortality including 758 cancer deaths was assessed over the 25 years of follow-up.

Findings

There were strong, graded and significant relationships between all heart-rate parameters and subsequent cancer deaths. After adjustment for age and tobacco consumption and, compared with the lowest quartile, those with the highest quartile for resting heart-rate had a relative risk of 2.4 for cancer deaths (95% confidence interval: 1.9–2.9, p<0.0001) This was similar after adjustment for traditional cardiovascular risk factors and was observed for the commonest malignancies (respiratory and gastrointestinal). Similarly, significant relationships with cancer death were observed between poor heart rate increase during exercise, poor decrease during recovery and greater heart-rate increase over time (p<0.0001 for all).

Interpretation

Resting and exercise heart rate had consistent, graded and highly significant associations with subsequent cancer mortality in men.

Sports-related sudden death in the general population

BACKGROUND

Although such data are available for young competitive athletes, the prevalence, characteristics, and outcome of sports-related sudden death have not been assessed previously in the general population.

METHODS AND RESULTS

A prospective and comprehensive national survey was performed throughout France from 2005 to 2010, involving subjects 10 to 75 years of age. Case detection for sports-related sudden death, including resuscitated cardiac arrest, was undertaken via national ambulance service reporting and Web-based screening of media releases. The overall burden of sports-related sudden death was 4.6 cases per million population per year, with 6% of cases occurring in young competitive athletes. Sensitivity analyses used to address suspected underreporting demonstrated an incidence ranging from 5 to 17 new cases per million population per year. More than 90% of cases occurred in the context of recreational sports. The age of subjects was relatively young (mean ± SD 46 ± 15 years), with a predominance of men (95%). Although most cases were witnessed (93%), bystander cardiopulmonary resuscitation was only commenced in 30.7% of cases. Bystander cardiopulmonary resuscitation (odds ratio 3.73, 95% confidence interval 2.19 to 6.39, P<0.0001) and initial use of cardiac defibrillation (odds ratio 3.71, 95% confidence interval 2.07 to 6.64, P<0.0001) were the strongest independent predictors for survival to hospital discharge (15.7%, 95% confidence interval 13.2% to 18.2%).

CONCLUSIONS

Sports-related sudden death in the general population is considerably more common than previously suspected. Most cases are witnessed, yet bystander cardiopulmonary resuscitation was only initiated in one third of cases. Given the often predictable setting of sports-related sudden death and that prompt interventions were significantly associated with improved survival, these data have implications for health services planning.