Cardiovascular risk factors and autonomic indices in relation to fatal and non-fatal coronary events

Abstract

Objective: Mortality caused by coronary artery disease has markedly decreased in recent years. However, a substantial proportion of patients suffering a coronary event (CE) die within the first day, most of them out of hospital. We aimed to investigate how established cardiovascular (CV) risk factors and CV autonomic indices associate with fatal versus non-fatal CEs in the population.

Methods: 33 057 individuals (mean age; 45.6 years; 10 773 women) free of coronary artery disease at baseline were included. Baseline examination, including assessment of traditional CV risk factors and autonomic indices such as heart rate and orthostatic reaction, was performed during 1974-1992, after which the subjects were monitored for incident CV disease. The Lunn-McNeil competing risks approach with a prespecified multivariable model was used to assess differences in risks for fatal and non-fatal CEs in relation to baseline CV risk factors.

Results: During follow-up period of 29.7 years, 5494 subjects (6.10/1000 person-years) had first CE; 1554 of these were fatal. Age, male gender, smoking, body mass index (BMI), blood pressure, pulse pressure and resting heart rate had stronger relationships with fatal CE than with non-fatal events. The effects of diabetes, serum cholesterol, antihypertensive treatment and orthostatic blood pressure responses were similar for fatal and non-fatal CE.

Conclusions: Several cardiovascular risk factors, such as smoking, high BMI, blood pressure and high resting heart rate, were preferentially associated with fatal compared with non-fatal CEs. These observations may require special attention in the overall efforts to further reduce coronary artery disease mortality.

Keywords: acute coronary syndrome; coronary artery disease; risk factors.

Figure 1

The relationship between haemodynamic measurements and incidence of non-fatal and fatal coronary events (CEs). HRs (depicted by horizontal bars) and the 95% CI (vertical bars) for non-fatal (solid lines) and fatal (dashed lines) CEs in relation to resting heart rate, systolic blood pressure and pulse pressure at baseline. Mean (range) in mm Hg for the quartiles of systolic blood pressure were 110 (75–115), 122 (117–125), 132 (128–135), 149 (137–255) for quartile 1, 2, 3 and 4, respectively. Mean (range) in mm Hg for the quartiles of pulse pressure were 31 (0–35), 40 (37–40), 47 (41–50) and 61 (51–130) for quartiles 1, 2, 3 and 4, respectively.