No study has described the burden to a health service of the complete spectrum of possible acute coronary syndromes (ACS). The objective of this study was to describe the changing burden of suspected ACS on the hospital sector of the National Health Service in Scotland over the period 1990–2000.
METHODS
The record linkage system for discharges from Scottish hospitals and deaths has been described previously.1 We identified all emergency hospitalisations of patients ⩾ 18 years old in Scotland between January 1990 and December 2000 where acute myocardial infarction (AMI; International classification of diseases, (ICD), ninth revision, code 410, ICD‐10 I21, 22), angina (ICD‐9 411, 413, ICD‐10 I20, I249), or chest pain (ICD‐9 786.5, ICD‐10 R07) was coded as the principal diagnosis on discharge. Numbers and age and sex specific rates of discharges (and patients discharged), length of stay, revascularisation procedures, and deaths were studied. We used linear regression to examine trends in population hospitalisation rates, hospitalisation numbers, and length of stay.
RESULTS
Between 1990 and 2000, a total of 263 917 people (55% men) were hospitalised with one or more suspected ACS: 117 479 for AMI, 71 927 for angina, and 123 123 for chest pain (a person may have had more than one ACS). The number of patients with a discharge diagnosis of any suspected ACS increased steadily between 1990 and 2000, rising by about 41% (51% in women and 34% in men) due to an increase in hospitalisations for angina and chest pain (table 1).
Table 1 Hospitalisation for suspected acute coronary syndromes (ACS) in Scotland, 1990–2000.
| ACS | AMI | Angina | Chest pain | |||||
|---|---|---|---|---|---|---|---|---|
| 1990 | 2000 | 1990 | 2000 | 1990 | 2000 | 1990 | 2000 | |
| Number of patients hospitalised | 25643 | 36187 | 13105 | 9153 | 5226 | 10593 | 8693 | 18933 |
| Population rates per 100000 | ||||||||
| Both sexes | 653 | 915 | 334 | 231 | 133 | 268 | 221 | 479 |
| Men | 800 | 1 065 | 421 | 294 | 155 | 311 | 270 | 539 |
| Women | 522 | 781 | 225 | 157 | 113 | 229 | 178 | 425 |
| <65 years | 417 | 606 | 162 | 102 | 89 | 142 | 191 | 400 |
| ⩾65 years | 1631 | 2136 | 1044 | 742 | 315 | 765 | 346 | 791 |
| Total bed days | 300304 | 225033 | 203398 | 96422 | 46173 | 62292 | 50733 | 66319 |
| Bed days/1000 population | 76.5 | 56.9 | 51.8 | 24.4 | 11.8 | 15.8 | 12.9 | 16.8 |
| Proportion of medical bed days | 16.6% | 12.4% | 11.3% | 5.3% | 2.6% | 3.4% | 2.8% | 3.7% |
| Proportion of all medical emergency admissions | 20.2% | 19.2% | 9.4% | 4.2% | 4.1% | 5.6% | 6.6% | 9.4% |
| Median length of stay (days) | 6 | 3 | 8 | 6 | 4 | 3 | 3 | 1 |
| Number of patients undergoing revascularisation within calendar year | 451 (1.8%) | 1 723 (4.8%) | 171 (1.3%) | 682 (7.5%) | 262 (5.0%) | 1 025 (9.7%) | 96 (1.1%) | 277 (1.5%) |
| 30 day case fatality | 11.9% | 5.5% | 22.2% | 19.4% | 1.5% | 1.5% | 1.6% | 0.7% |
The number of men and women hospitalised with angina almost doubled, although hospitalisations for angina appeared to plateau over the last 3–4 years of the study period (table 1).
The number of patients hospitalised with chest pain rose, year on year, whereas the number of people admitted with AMI declined substantially (by about 30%).
Rates of AMI among men and women declined similarly across age groups and the greatest reductions were seen in middle aged patients (55–74 years). The increase in angina was larger in men than in women across all age groups and was greatest in the oldest age category (75 years or older). Hospitalisation rates for chest pain increased more for women than for men overall; among women the greatest increase was in those aged 55 years or younger (whereas these discharges rose more in older than in younger men).
The proportion of hospitalisations in different age groups changed over the period of study with patients generally getting older (most notable in those with angina, less so in AMI with little change in age of those with chest pain).
In 1990, 10% of men and 9% of women had two or more hospitalisations within the same calendar year. By 2000, this proportion had increased to 14% and 12%, respectively.
Suspected ACS accounted for 20.2% of emergency hospitalisations in 1990 and 19.2% in 2000.
For AMI, the median length of stay decreased from eight to six days between 1990 and 2000, for angina from four to three days, and for chest pain from three to one day. Total bed days for any suspected ACS declined 25% from 300 304 days in 1990 to 225 033 days in 2000 because of the reduction in AMI bed days. Suspected ACS accounted for 16.6% of medical bed days in 1990 and only 12.4% in 2000.
In 1990, 1.6% of men and 0.9% women hospitalised with AMI subsequently underwent revascularisation within the same calendar year. By 2000, the rate had increased sixfold for men and fivefold for women.
In 1990, 6.4% of men and 3.3% of women hospitalised for angina underwent revascularisation. The rate increased 1.9‐fold for both men and women by 2000.
DISCUSSION
The number of patients discharged with suspected ACS increased by 50% over the past decade due to a doubling of hospitalisations for angina and chest pain and despite a 30% decline in hospitalisations for AMI. Though the overall number of hospitalisations has increased, the extra burden placed on the hospital sector was ameliorated by a fall in length of stay.
The rise in hospitalisations for angina and chest pain and the changing clinical practice led to a three‐ to fourfold increase in coronary revascularisation procedures.
The increase in rates of hospitalisation was particularly large for angina and, to a smaller extent, for chest pain in older age groups. Proportionally, these age groups are going to increase in number as the population ages.
The rise in hospitalisations for chest pain, not thought to reflect coronary disease, in younger people, especially women, is a puzzling and unexplained phenomenon and supports the development of services to prevent these mainly unnecessary admissions or to expedite exclusion of coronary disease and early discharge.2,3,4,5
ACKNOWLEDGEMENTS
NM is funded by the British Heart Foundation.
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