Ankle brachial index combined with Framingham Risk Score to predict cardiovascular events and mortality: a meta-analysis.

CONTEXT: Prediction models to identify healthy individuals at high risk of cardiovascular disease have limited accuracy. A low ankle brachial index (ABI) is an indicator of atherosclerosis and has the potential to improve prediction. OBJECTIVE: To determine if the ABI provides information on the risk of cardiovascular events and mortality independently of the Framingham risk score (FRS) and can improve risk prediction. DATA SOURCES: Relevant studies were identified. A search of MEDLINE (1950 to February 2008) and EMBASE (1980 to February 2008) was conducted using common text words for the term ankle brachial index combined with text words and Medical Subject Headings to capture prospective cohort designs. Review of reference lists and conference proceedings, and correspondence with experts was conducted to identify additional published and unpublished studies. STUDY SELECTION: Studies were included if participants were derived from a general population, ABI was measured at baseline, and individuals were followed up to detect total and cardiovascular mortality. DATA EXTRACTION: Prespecified data on individuals in each selected study were extracted into a combined data set and an individual participant data meta-analysis was conducted on individuals who had no previous history of coronary heart disease. RESULTS: Sixteen population cohort studies fulfilling the inclusion criteria were included. During 480,325 person-years of follow-up of 24,955 men and 23,339 women, the risk of death by ABI had a reverse J-shaped distribution with a normal (low risk) ABI of 1.11 to 1.40. The 10-year cardiovascular mortality in men with a low ABI (< or = 0.90) was 18.7% (95% confidence interval [CI], 13.3%-24.1%) and with normal ABI (1.11-1.40) was 4.4% (95% CI, 3.2%-5.7%) (hazard ratio [HR], 4.2; 95% CI, 3.3-5.4). Corresponding mortalities in women were 12.6% (95% CI, 6.2%-19.0%) and 4.1% (95% CI, 2.2%-6.1%) (HR, 3.5; 95% CI, 2.4-5.1). The HRs remained elevated after adjusting for FRS (2.9 [95% CI, 2.3-3.7] for men vs 3.0 [95% CI, 2.0-4.4] for women). A low ABI (< or = 0.90) was associated with approximately twice the 10-year total mortality, cardiovascular mortality, and major coronary event rate compared with the overall rate in each FRS category. Inclusion of the ABI in cardiovascular risk stratification using the FRS would result in reclassification of the risk category and modification of treatment recommendations in approximately 19% of men and 36% of women. CONCLUSION: Measurement of the ABI may improve the accuracy of cardiovascular risk prediction beyond the FRS.

Asymptomatic peripheral arterial occlusive disease predicted cardiovascular morbidity and mortality in a 7-year follow-up study.

OBJECTIVE: Asymptomatic peripheral arterial occlusive disease (PAOD) is a common atherosclerotic disorder among the elderly population. Scarce data are available on the risk of nonfatal and fatal cardiovascular diseases in these subjects. We investigated cardiovascular morbidity and mortality of asymptomatic PAOD subjects. STUDY DESIGN AND SETTING: A sample of 3649 subjects (40-78 years of age) was selected in collaboration with 18 general practice centers and followed up after the initial screening (mean follow-up time 7.2 years). Asymptomatic PAOD was determined by means of the ankle-brachial pressure index (ABPI). Main outcome measures were nonfatal cardiovascular events and mortality. RESULTS: Cox proportional hazard models showed that asymptomatic PAOD was significantly associated with cardiovascular morbidity (hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.3-2.1), total mortality (HR 1.4, 95% CI 1.1-1.8), and cardiovascular mortality (HR 1.5, 95% CI 1.1-2.1). CONCLUSION: Asymptomatic PAOD is a significant predictor of cardiovascular morbidity and mortality. In high-risk subjects, measurement of the ABPI provides valuable information on future cardiovascular events.

[Reported cases of Legionella pneumonia in the Netherlands, 1987-2000]. / Gemelde Legionella-pneumonie in Nederland, 1987-2000.

OBJECTIVE: To describe the incidence and mortality of legionnaires' disease (LD) in the Netherlands on the basis of registration, with a focus on possible sources of infection, and geographic and seasonal variations. DESIGN: Retrospective, descriptive. METHOD: The incidence and mortality rate of LD from July 1987 until December 2000 was described using registration data from the Dutch Health Inspectorate. Possible sources of infection were also listed (patients involved in the Bovenkarspel outbreak (1999) were excluded). Geographic variations in occurrence of LD were investigated by incidences computed per province. To gain insight into the possible existence of seasonal variations the mean numbers of patients per month were compared. RESULTS: During the period of interest a total of 806 persons with LD were reported, 36 of whom were excluded. The mean incidence rose from 0.27 cases per 100,000 inhabitants in the 1987-1998 period to 0.91 cases per 100,000 inhabitants in the 1999-2000 period. The male:female ratio was 2.6:1. A total of 96 persons (12.5%) died as a result of LD. There were more deaths in the group of patients with confirmed LD compared to the group of patients with probable LD. After 1998 the case fatality rate was lower than in the previous period (Fisher's exact test: p = 0.005). The potential source of infection was situated in the open population in 92.9% of cases. In 7.1% of cases the potential source was situated in a hospital. The incidence per province varied from 0.13 per 100,000 (Drente) to 0.66 per 100,000 (Limburg). During the summer months more patients were reported, most of whom had contracted the infection abroad. In contrast to the 1987-1998 period, after 1998 the incidence in the Netherlands was higher than the European mean and the incidence of confirmed LD was higher than in the United States.

Incidence of and risk factors for asymptomatic peripheral arterial occlusive disease: a longitudinal study.

The current study describes the age- and sex-specific incidence rates and risk factors for asymptomatic and symptomatic peripheral arterial occlusive disease (PAOD) among 2,327 subjects and the incidence of intermittent claudication in asymptomatic PAOD subjects. The study population was selected from 18 general practice centers in the Netherlands. PAOD was assessed with the ankle-brachial blood pressure index, and intermittent claudication was assessed with a modified version of the Rose questionnaire. After 7.2 years, the overall incidence rate for asymptomatic PAOD, using the person-years method, was 9.9 (95% confidence interval (CI): 7.3, 18.8) per 1,000 person-years at risk. The rate was 7.8 (95% CI: 4.9, 20.3) for men and 12.4 (95% CI: 7.7, 24.8) for women. For symptomatic PAOD, the incidence rate was 1.0 (95% CI: 0.7, 7.5) overall, 0.4 (95% CI: 0.3, 10.0) for men, and 1.8 (95% CI: 1.0, 10.3) for women. Multivariate analyses showed that increasing age, smoking, hypertension, and diabetes mellitus were the most important risk factors. The overall incidence rate for intermittent claudication among PAOD subjects who were asymptomatic at baseline was 90.5 per 1,000 person-years at risk (95% CI: 36.4, 378.3). The incidence of asymptomatic PAOD was higher than the incidence of symptomatic PAOD, with women developing PAOD more often than men. In the development of preventive strategies, modification of atherosclerotic risk factors, such as smoking, hypertension, and diabetes, should be the main goals.

The prognosis of non-critical limb ischaemia: a systematic review of population-based evidence.

BACKGROUND: Peripheral arterial occlusive disease (PAOD) is the most common peripheral vascular disorder in the elderly. A clear picture of the disease's course, especially in patients with non-critical limb ischaemia (Fontaine stages I and II), is essential for the general practitioner, who plays a key role in the diagnosis and management of PAOD. AIM: To evaluate the population-based evidence on the course and prognosis of PAOD. METHODS: An exhaustive literature search yielded 16 population-based studies on the prognosis of PAOD. The methodological qualities of the studies were assessed according to eight criteria. RESULTS: Thirteen studies of high methodological quality show that data on the course, cardiovascular morbidity, and mortality of asymptomatic PAOD are scarce. Only a small group of asymptomatic patients seem to develop intermittent claudication symptoms. However, asymptomatic patients appear to have the same increased risk for cardiovascular morbidity and mortality when compared with claudicants. No data were available on prognostic factors for intermittent claudication and cardiovascular morbidity in asymptomatic patients. The course, cardiovascular morbidity, and mortality of symptomatic PAOD are better documented. A small group of claudicants experience symptom progression. Smoking, hypertension, increasing age, and diabetes are the most relevant risk factors for intermittent claudication. Claudicants are at a higher risk for developing other cardiovascular diseases, resulting in a significantly increased mortality mainly owing to coronary heart disease. Intermittent claudication and a low ankle-brachial pressure index are significant predictors of mortality. Men had intermittent claudication and symptom progression more often than women. Cardiovascular (co-)morbidity was common in both male and female PAOD patients, but male PAOD patients had a higher mortality compared with female PAOD patients. CONCLUSION: Given the current knowledge on the prognosis of PAOD in the general population, an important task for (secondary) prevention is reserved for the general practitioner. Further research is required to document the course and prognosis of asymptomatic PAOD patients.

Risk factors and cardiovascular diseases associated with asymptomatic peripheral arterial occlusive disease. The Limburg PAOD Study. Peripheral Arterial Occlusive Disease.

OBJECTIVES: To describe the risk-factor profile and cardiovascular comorbidity of asymptomatic peripheral arterial occlusive disease (PAOD). DESIGN: A cross-sectional survey. Asymptomatic PAOD was defined as an ankle-brachial pressure index < 0.95, measured on two consecutive occasions, without intermittent claudication. Logistic regression analyses were performed to investigate independent associations between age, gender, smoking status, hypertension, obesity, diabetes, hypercholesterolaemia, physical activity, a family history of cardiovascular disease, the occurrence of ischaemic heart disease and cerebrovascular disease (CeVD) and asymptomatic PAOD. SETTING: 18 general practices in the province of Limburg, the Netherlands. SUBJECTS: A total of 3650 subjects, aged 40-78 years. MAIN RESULTS: Asymptomatic PAOD was present in 8.6% (n = 314) and symptomatic disease in 3.8% (n = 138) of the participants. Age, smoking status, hypertension, and diabetes were significantly associated with asymptomatic PAOD. The ratio of asymptomatic to symptomatic PAOD was higher among the younger age groups. Male gender, hypertension and smoking status were stronger associated with symptomatic PAOD compared with asymptomatic PAOD. Asymptomatic subjects had more IHD and CeVD comorbidity compared with the healthy population. CONCLUSION: Our findings suggest that the risk-factor profile and cardiovascular comorbidity of asymptomatic subjects is comparable to claudicants. Preventive efforts could be made to diminish the influence of especially smoking, diabetes and hypertension in asymptomatic subjects.