Jan Heeringa

Efficacy of statins in familial hypercholesterolaemia: a long term cohort study

Objective To determine the efficacy of statin treatment on risk of coronary heart disease in patients with familial hypercholesterolaemia. Design Cohort study with a mean follow-up of 8.5 years. Setting 27 outpatient lipid clinics. Subjects 2146 patients with familial hypercholesterolaemia without prevalent coronary heart disease before 1 January 1990. Main outcome measures Risk of coronary heart disease in treated and “untreated” (delay in starting statin treatment) patients compared with a Cox regression model in which statin use was a time dependent variable. Results In January 1990, 413 (21%) of the patients had started statin treatment, and during follow-up another 1294 patients (66%) started after a mean delay of 4.3 years. Most patients received simvastatin (n=1167, 33 mg daily) or atorvastatin (n=211, 49 mg daily). We observed an overall risk reduction of 76% (hazard ratio 0.24 (95% confidence interval 0.18 to 0.30), P<0.001). In fact, the risk of myocardial infarction in these statin treated patients was not significantly greater than that in an age-matched sample from the general population (hazard ration 1.44 (0.80 to 2.60), P=0.23). Conclusion Lower statin doses than those currently advised reduced the risk of coronary heart disease to a greater extent than anticipated in patients with familial hypercholesterolaemia. With statin treatment, such patients no longer have a risk of myocardial infarction significantly different from that of the general population.

Variants in ZFHX3 are associated with atrial fibrillation in individuals of European ancestry

We conducted meta-analyses of genome-wide association studies for atrial fibrillation (AF) in participants from five community-based cohorts. Meta-analyses of 896 prevalent (15,768 referents) and 2,517 incident (21,337 referents) AF cases identified a new locus for AF (ZFHX3, rs2106261, risk ratio RR = 1.19; P = 2.3 × 10−7). We replicated this association in an independent cohort from the German AF Network (odds ratio = 1.44; P = 1.6 × 10−11; combined RR = 1.25; combined P = 1.8 × 10−15).

Projections on the number of individuals with atrial fibrillation in the European Union, from 2000 to 2060

AIMS Since atrial fibrillation (AF) is associated with increased risks of cardiovascular and cerebrovascular complications, estimations on the number of individuals with AF are relevant to healthcare planning. We aimed to project the number of individuals with AF in the Netherlands and in the European Union from 2000 to 2060. METHODS AND RESULTS Age- and sex-specific AF prevalence estimates were obtained from the prospective community-based Rotterdam Study. Population projections for the Netherlands and the European Union were obtained from the European Unions statistics office. In the age stratum of 55-59 years, the prevalence of AF was 1.3% in men (95% CI: 0.4-3.6%) and 1.7% in women (95% CI: 0.7-4.0%). The prevalence of AF increased to 24.2% in men (95% CI: 18.5-30.7%), and 16.1% in women (95% CI: 13.1-19.4%), for those >85 years of age. This age- and sex-specific prevalence remained stable during the years of follow-up. Furthermore, we estimate that in the European Union, 8.8 million adults over 55 years had AF in 2010 (95% CI: 6.5-12.3 million). We project that this number will double by 2060 to 17.9 million (95% CI: 13.6-23.7 million) if the age- and sex-specific prevalence remains stable. CONCLUSION We estimate that from 2010 to 2060, the number of adults 55 years and over with AF in the European Union will more than double. As AF is associated with significant morbidities and mortality, this increasing number of individuals with AF may have major public health implications.

Large scale replication and meta-analysis of variants on chromosome 4q25 associated with atrial fibrillation.

AIMS A recent genome-wide association study identified a haplotype block on chromosome 4q25 associated with atrial fibrillation (AF). We sought to replicate this association in four independent cohorts. METHODS AND RESULTS The Framingham Heart Study and Rotterdam Study are community-based longitudinal studies. The Vanderbilt AF Registry and German AF Network (AFNet) are case-control studies. Participants with AF (n = 3508) were more likely to be male and were older than referent participants (n = 12 173; Framingham 82 +/- 10 vs. 71 +/- 13 years; Rotterdam 73 +/- 8 vs. 69 +/- 9 years; Vanderbilt 54 +/- 14 vs. 57 +/- 14 years; AFNet 62 +/- 12 vs. 49 +/- 14 years). Single nucleotide polymorphism (SNP) rs2200733 was associated with AF in all four cohorts, with odds ratios (ORs) ranging from 1.37 in Rotterdam [95% confidence interval (CI) 1.18-1.59; P = 3.1 x 10(-5)] to 2.52 in AFNet (95% CI 2.22-2.8; P = 1.8 x 10(-49)). There also was a significant association between AF and rs10033464 in Framingham (OR 1.34; 95% CI 1.03-1.75; P = 0.031) and AFNet (OR 1.30; 95% CI 1.13-1.51; P = 0.0002), but not Vanderbilt (OR 1.16; 95% CI 0.86-1.56; P = 0.33). A meta-analysis of the current and prior AF studies revealed an OR of 1.90 (95% CI 1.60-2.26; P = 3.3 x 10(-13)) for rs2200733 and of 1.36 (95% CI 1.26-1.47; P = 6.7 x 10(-15)) for rs10033464. CONCLUSION The non-coding SNPs rs2200733 and rs10033464 are strongly associated with AF in four cohorts of European descent. These results confirm the significant relations between AF and intergenic variants on chromosome 4.

Methods of data collection and definitions of cardiac outcomes in the Rotterdam Study

The prevalence of cardiovascular diseases is rising. Therefore, adequate risk prediction and identification of its determinants is increasingly important. The Rotterdam Study is a prospective population-based cohort study ongoing since 1990 in the city of Rotterdam, The Netherlands. One of the main targets of the Rotterdam Study is to identify the determinants and prognosis of cardiovascular diseases. Case finding in epidemiological studies is strongly depending on various sources of follow-up and clear outcome definitions. The sources used for collection of data in the Rotterdam Study are diverse and the definitions of outcomes in the Rotterdam Study have changed due to the introduction of novel diagnostics and therapeutic interventions. This article gives the methods for data collection and the up-to-date definitions of the cardiac outcomes based on international guidelines, including the recently adopted cardiovascular disease mortality definitions. In all, detailed description of cardiac outcome definitions enhances the possibility to make comparisons with other studies in the field of cardiovascular research and may increase the strength of collaborations.

Cigarette smoking and risk of atrial fibrillation: the Rotterdam Study.

BACKGROUND Cigarette smoking is an important risk factor for cardiovascular disease, but it is unknown whether it also contributes to the risk of atrial fibrillation. METHODS AND RESULTS The study is part of the Rotterdam Study, a population-based cohort study among subjects aged > or =55 years. The association between cigarette smoking and the risk of atrial fibrillation was examined in 5,668 subjects without atrial fibrillation at baseline. During a median follow-up of 7.2 years, 371 cases of atrial fibrillation were identified. Relative risks (RR) were calculated with 95% CIs using the Cox proportional hazards model, adjusted for age, gender, body mass index, hypertension, systolic blood pressure, serum cholesterol level, diabetes mellitus, left ventricular hypertrophy on the electrocardiogram, prevalent and incident myocardial infarction, prevalent heart failure, and the use of pulmonary medication. After multivariate adjustment, current smokers and former smokers had increased risks of atrial fibrillation as compared to never smokers (RR 1.51, 95% CI 1.07-2.12; and RR 1.49, 95% CI 1.14-1.97, respectively). No differences were found between men and women. CONCLUSIONS The results of this prospective, population-based study show that current and former smoking of cigarettes are associated with increased risk of atrial fibrillation.

Orthostatic Hypotension and Risk of Cardiovascular Disease in Elderly People: The Rotterdam Study

OBJECTIVES: To determine the prognostic role of orthostatic hypotension for cardiovascular disease (CVD) and all‐cause mortality in elderly people.

Setting and registry characteristics affect the prevalence and nature of multimorbidity in the elderly

OBJECTIVE The aim of the study was to investigate how settings and registry characteristics affect the prevalence and nature of multimorbidity in elderly individuals. STUDY DESIGN AND SETTING We used data from three population-based studies, two general practitioner registries, one hospital discharge register, and one nursing home registry to estimate the prevalence of multimorbidity. Individuals aged 55 years and over were included. RESULTS Multimorbidity was most prevalent in nursing homes (82%), followed by the general population and general practitioner registries (56%-72%) and the hospital setting (22%). There were large differences in the nature of multimorbidity between settings. Combinations of hypertension, heart disease, and osteoarthritis were dominant in the population-based setting, whereas hypertension in combination with osteoarthritis, obesity, disorders of lipid metabolism, and diabetes dominated in the general practitioner setting. In the hospital setting, combinations of heart diseases had the highest prevalence. Combinations of dementia, hypertension, and stroke were dominant within the nursing home setting. CONCLUSION This study shows that setting and registry characteristics have an important influence on the outcome of multimorbidity studies. We recommend provision of at least information about the setting, the (list of) conditions included, the data collection method, and the time frame used, when reporting about the size and nature of multimorbidity.

High-Normal Thyroid Function and Risk of Atrial Fibrillation: The Rotterdam Study

BACKGROUND Overt and subclinical hyperthyroidism are both well-known independent risk factors for atrial fibrillation. We aimed to investigate the association of high-normal thyroid function with the development of atrial fibrillation in a prospective population-based study in the elderly. METHODS The association between thyroid-stimulating hormone (TSH) levels and atrial fibrillation was examined in 1426 subjects with TSH levels in the normal range (0.4-4.0 mU/L) and without atrial fibrillation at baseline. In 1177 of the 1426 persons in this group, we also examined the association between free thyroxine levels within the normal range (0.86-1.94 ng/dL [to convert to picomoles per liter, multiply by 12.871]) and atrial fibrillation. During a median follow-up of 8 years, 105 new cases of atrial fibrillation were identified. Hazard ratios (HRs) were calculated with 95% confidence intervals (CIs) using Cox proportional hazards models after adjustment for age, sex, current smoking, former smoking, body mass index, systolic blood pressure, hypertension, history of myocardial infarction, presence of heart failure, left ventricular hypertrophy on the electrocardiogram, diabetes mellitus, total cholesterol level, and time of the drawing of blood samples. RESULTS The risk of atrial fibrillation was associated with the TSH level. The multivariate adjusted HR was 1.94 (95% CI, 1.13-3.34, lowest vs highest quartile; P for trend, .02). The multivariate adjusted level of free thyroxine showed a graded association with risk of atrial fibrillation (HR, 1.62; 95% CI, 0.84-3.14, highest vs lowest quartile; P for trend, .06). CONCLUSION Within the normal range of thyroid parameters, persons with high-normal thyroid function are at an increased risk of atrial fibrillation.

Atrial Fibrillation and the Prothrombotic State in the Elderly The Rotterdam Study

Background and Purpose— Atrial fibrillation (AF) is a major cause of stroke among the elderly. Evidence for a prothrombotic state in AF is controversial, and there is a lack of studies among the elderly. We studied the relationships between AF and 3 prothrombotic plasma markers—von Willebrand factor (vWf; a marker of endothelial damage/dysfunction), soluble P-selectin (sP-sel; a marker of platelet activation), and fibrinogen—in a matched case-control study nested within a large community-based study of an elderly population. Methods— We identified 162 elderly participants (mean±SD age, 78±8 years; 51% male) in the Rotterdam Study with documented AF and matched each case by age and sex to 2 population controls. vWf and sP-sel were measured by enzyme-linked immunosorbent assay; fibrinogen was measured with the Clauss method. We used conditional logistic regression analysis to assess the relationships between the markers and AF, adjusting for potential confounders. Results— There were no significant relationships between either fibrinogen (P =0.8) or sP-sel (P =0.6) and AF. However, a positive linear relationship between vWf level and presence of AF remained significant after adjustment for potential confounders among women (odds ratio [OR], 1.17; 95% CI, 1.02 to 1.34) per 10-IU/dL increase in vWf but not among men (OR, 1.06; 95% CI, 0.96 to 1.17). Conclusions— We observed a positive relationship between AF and plasma vWf (or endothelial damage/dysfunction) in our elderly population, which was most apparent among women. Fibrinogen and sP-sel levels were unrelated to AF. The prothrombotic state of AF may be subject to sex differences, but longitudinal studies are needed to determine the relationship between these plasma markers and stroke risk.