Trends in Modifiable Risk Factors Are Associated With Declining Incidence of Hospitalized and Nonhospitalized Acute Coronary Heart Disease in a Population

Abstract

Both changes in the rates of out-of-hospital CHD deaths and hospitalization rates and the outcome of myocardial infarction (MI) with ST-segment elevation (STEMI) and non-ST-segment elevation (non-STEMI) will affect mortality. Editorial see p 8 Clinical Perspective on p 81It has been suggested that 45% to 75% of the decrease in deaths from CHD can be attributed to decreases in smoking, blood pressure, and cholesterol. [4][5][6][7][8] These studies based their estimates on ecological data or mathematical modeling of aggregate data. Few studies used individual person data, 9,10 and the studies were limited to population subgroups and did not study out-of-hospital CHD or subtypes of MI.We used individual person data from repeated surveys of a general population to study the rates of out-of-hospital CHD; the incidence, treatment, and outcome of hospitalized STEMI and non-STEMI; and the impact of changes in coronary risk factor levels during the years 1995 to 2010. Methods Study PopulationThe Tromsø Study is a population-based, prospective study of various health issues and chronic diseases. It consists of 6 surveys of both sexes conducted in the municipality of Tromsø, Norway, from Background-Few studies have used individual person data to study whether contemporary trends in the incidence of coronary heart disease are associated with changes in modifiable coronary risk factors. Methods and Results-We identified 29 582 healthy men and women ≥25 years of age who participated in 3 population surveys conducted between 1994 and 2008 in Tromsø, Norway. Age-and sex-adjusted incidence rates were calculated for coronary heart disease overall, out-of-hospital sudden death, and hospitalized ST-segment-elevation and non-STsegment-elevation myocardial infarction. We measured coronary risk factors at each survey and estimated the relationship between changes in risk factors and changes in incidence trends. A total of 1845 participants had an incident acute coronary heart disease event during 375 064 person-years of follow-up from 1994 to 2010. The age-and sex-adjusted incidence of total coronary heart disease decreased by 3% (95% confidence interval, 2.0-4.0; P<0.001) each year. This decline was driven by decreases in out-of-hospital sudden death and hospitalized ST-segment-elevation myocardial infarction. Changes in coronary risk factors accounted for 66% (95% confidence interval, 48-97; P<0.001) of the decline in total coronary heart disease. Favorable changes in cholesterol contributed 32% to the decline, whereas blood pressure, smoking, and physical activity each contributed 14%, 13%, and 9%, respectively. Conclusions-We observed a substantial decline in the incidence of coronary heart disease that was driven by reductions in out-of-hospital sudden death and hospitalized ST-segment-elevation myocardial infarction. Changes in modifiable coronary risk factors accounted for 66% of the decline in coronary heart disease events.

The impact of changes in leisure time physical activity on changes in cardiovascular risk factors: results from The Finnmark 3 Study and SAMINOR 1, 1987–2003

“…Although the incidence of CVD in Norway has declined over the last decades [4], CVD is still a major cause of premature death and morbidity, and focus on preventive measures such as physical activity should continue [5–7]. …”

Nye retningslinjer for forebygging av hjerte- og karsykdom

“…Since the 1970s, cholesterol levels in the population have decreased by 1 -1.5 mmol/l (5,6,20), including in persons with an underlying genetic lipid disorder. Whereas total cholesterol ≥ 8.0 mmol/l was previously thought to indicate a familial lipid disorder, today anyone with total cholesterol ≥ 7.0 mmol/l and/or LDL cholesterol ≥ 5.0 mmol/l is highly likely to have such a disorder.…”

“…Risk factors for cardiovascular disease, and levels of morbidity and mortality due to cardiovascular disease, have changed considerably within the population over the past 5 -10 years, with reductions in cholesterol and blood pressure levels, and in the number of daily smokers (5,6). Clinical studies in primary prevention have helped clarify the effects of pharmacotherapy in cases of intermediate cardiovascular risk (7)(8)(9).…”

Misvisende om kosthold i ny nasjonal retningslinje for forebygging av hjerte- og karsykdommer

“…Én studie av 52 land viste at ni modifiserbare risikofaktorer forklarte 90 prosent av den globale variasjonen i hjerteinfarkt 23 . Mye av de siste 40 års nedgang i hjerte-og karsykdom og dødelighet av hjerte-og karsykdom har i mange land blitt forklart med forbedringer i de nevnte risikofaktorene, spesielt lavere gjennomsnittlige kolesterol nivåer [35][36][37][38][39] . I Tromsø-undersøkelsen kunne 2/3 av den lavere insidensen av hjerteinfarkt og plutselig hjertedød mellom 1995 og 2010 tilskrives bedring av risikofaktorer i befolkningen 36 .…”