Description of the SAVa project
Background
Cardiovascular disease is the most common cause of death in the world. In the Western world, these diseases account for nearly 20% of the total health care costs. Atherosclerosis is in most cases the underlying mechanism behind these disease conditions. Treatment of traditional risk factors (high blood pressure, diabetes, smoking, elevated blood lipids, and obesity) has played a central role in preventing the atherosclerosis-related diseases. However, a problem is that at least half of patients who develop cardiovascular disease lack or only have one of the traditional risk factors, indicating that there are other important underlying factors. There is a great need to improve the traditional risk assessment of the individual in order to make the preventive strategies more cost-effective and thereby reduce both new cases and relapses.
The project SAVa (Study of Atherosclerosis in Vastmanland) includes two large sub-projects: VaMIS (Vastmanland Myocardial Infarction Study) and PADVa (Peripheral Arterial Disease in Vastmanland). In these projects, during the period November 2005 – May 2011, patients (n = 1460) with different clinical manifestations of atherosclerosis, namely peripheral artery disease (PADVa) and acute myocardial infarction (VaMIS), were included. In addition, a large number of control subjects (n = 855), randomly included from the population and matched to the VaMIS patients on sex, age, and place of residence, were also examined.
Study populations
VaMIS (Vastmanland Myocardial Infarction Study)
In the VaMIS cohort, consecutive patients treated at the Cardiology Clinic at Västmanland Hospital Västerås, Sweden, were included if they met the following criteria:
- diagnosed acute myocardial infarction
- living in the catchment area for Västmanland County Hospital Västerås.
PADVa (Peripheral Artery Disease in Vastmanland)
The PADVa cohort included consecutive patients who were referred to the ultrasound laboratory at the Vascular Clinic at Västmanland County Hospital Västerås, Sweden, due to known or suspected vascular disease and who met at least one of the following criteria:
- symptoms of claudication and an ankle-brachial index of ≤ 0.9 in the symptomatic lower extremity
- symptoms of claudication and ultrasound findings in the form of stenotic arterial change in the symptomatic lower extremity, or
- at least mild stenosis or occlusion in any of the internal carotid arteries (regardless of symptoms).
Control subjects from the general population
For each patient included in the VaMIS cohort, one person from the general population was invited to participate. This person was randomly selected from the National Population Register among those with the same sex, age and place of residence as the VaMIS patient. If the invited person had previously had a myocardial infarction, a new person was invited for examination (as a control in the VaMIS study), but both control subjects still underwent the examinations according to the study protocol.