Patient characteristics, by year of hospitalisation
| Variable | 2004–2013 n=2 32 353 (Total cohort) | 2004–2005 n=42,799 (18.4% of the cohort) | 2012–2013 n=37,081 (16.0% of cohort) | Difference between 2004–2005 and 2012–2013 (95% CI) | P value | |
| Age (years) | Median (IQR) | 64.6 (55.0–75.0) | 65.3 (55.8–74.9) | 64.0 (54.5–74.9) | 1.30 (1.04 to 1.56) | <0.001 |
| Sex (male) | N (%) | 166 690 (72.0) | 30 332 (71.2) | 26 590 (72.2) | 0.93 (0.30 to 1.56) | 0.004 |
| Deprivation (IMD score) | Median (IQR) | 18.4 (10.5–32.2) | 18.7 (10.6–32.6) | 18.4 (10.5–32.1) | 0.37 (0.08 to 0.66) | 0.012 |
| Systolic blood pressure (mm Hg) | Mean (SD) | 136.5 (28.2) | 139.9 (29.2) | 132.8 (26.9) | −7.18 (−7.61 to −6.74) | <0.001 |
| Heart rate (beats per min) | Mean (SD) | 77.9 (20.8) | 77.1 (21.4) | 77.9 (19.4) | 0.83 (0.51 to 1.14) | <0.001 |
| Total cholesterol (mg/dL) | Median (IQR) | 5.1 (4.2–6.0) | 5.4 (4.5–6.3) | 4.9 (4.0–5.8) | 0.50 (0.47 to 0.53) | <0.001 |
| Creatinine (mg/dL) | Median (IQR) | 87.0 (74.0–104.0) | 101.0 (90.0–116.0) | 82.0 (70.0–99.0) | 19.0 (17.3 to 20.7) | <0.001 |
| Ejection fraction <50% | N (%) | 38 634 (49.3) | 1753 (53.2) | 9598 (49.5) | −3.72 (−5.56 to −1.88) | <0.001 |
| Medical history | ||||||
| Previous diabetes | N (%) | 29 083 (12.5) | 5265 (12.3) | 5158 (13.9) | 1.61 (1.14 to 2.08) | <0.001 |
| Current or ex-smoker | N (%) | 143 508 (68.1) | 27 098 (69.9) | 22 338 (66.0) | 3.93 (−4.61 to 3.25) | <0.001 |
| Family history of CHD | N (%) | 59 709 (25.7) | 4633 (10.8) | 10 249 (27.6) | 16.8 1 (16.27 to 17.34) | <0.001 |
| Hypertension | N (%) | 87 990 (37.9) | 15 938 (37.2) | 13 960 (37.7) | 0.41 (−0.26 to 1.08) | 0.235 |
| Previous MI | N (%) | 26 892 (11.6) | 5525 (12.9) | 4012 (10.8) | −2.09 (−2.54 to −1.64) | <0.001 |
| Previous angina | N (%) | 31 060 (13.4) | 7050 (16.5) | 4036 (10.9) | −5.59 (−6.06 to −5.11) | <0.001 |
| Peripheral vascular disease | N (%) | 5868 (2.5) | 1168 (2.7) | 950 (2.7) | −0.17 (−0.39 to 0.06) | 0.143 |
| Cerebrovascular disease | N (%) | 10 415 (4.5) | 1896 (4.4) | 1612 (4.4) | −0.08 (−0.37 to 0.20) | 0.569 |
| COPD or asthma | N (%) | 23 404 (10.1) | 4444 (10.4) | 3745 (10.1) | −0.28 (−0.71 to 0.14) | 0.187 |
| Chronic renal failure | N (%) | 4410 (1.9) | 576 (1.4) | 793 (2.1) | 0.79 (0.61 to 0.98) | <0.001 |
| Congestive cardiac failure | N (%) | 3593 (1.6) | 762 (1.8) | 529 (1.4) | −0.35 (−0.53 to −0.18) | <0.001 |
| Previous PCI | N (%) | 12 006 (5.2) | 1488 (3.5) | 2318 (6.3) | 2.77 (2.47 to 3.08) | <0.001 |
| Previous CABG | N (%) | 5217 (2.3) | 921 (2.2) | 840 (2.3) | 0.11 (−0.09 to 0.32) | 0.276 |
| Admission diagnosis | ||||||
| ACS or probable MI | N (%) | 217 563 (93.6) | 40 231 (94.0) | 35 270 (95.1) | 1.12 (0.80 to 1.43) | <0.001 |
| Chest pain unknown cause | N (%) | 6810 (2.9) | 1313 (3.1) | 797 (2.2) | −0.92 (−1.14 to 0.70) | <0.001 |
| Other | N (%) | 7976 (3.4) | 1255 (2.9) | 1014 (2.7) | −0.20 (−0.43 to 0.03) | 0.093 |
| Preadmission medications* | ||||||
| Aspirin | N (%) | 146 742 (64.4) | 26 121 (62.9) | 25 229 (68.8) | 5.88 (5.22 to 6.55) | <0.001 |
| β-blocker | N (%) | 37 199 (22.3) | 4294 (32.2) | 6097 (20.3) | −11.94 (−12.85 to −11.0) | <0.001 |
| Statin | N (%) | 54 151 (31.2) | 5008 (37.7) | 9654 (30.2) | −7.47 (−8.44 to −6.50) | <0.001 |
| ACEi or ARBs | N (%) | 45 897 (27.5) | 4264 (32.2) | 8424 (28.0) | −4.20 (−5.14 to −3.25) | <0.001 |
| P2Y12 inhibitor | N (%) | 13 136 (14.2) | – | 4566 (14.8) | – | |
| Warfarin | N (%) | 6891 (3.7) | 1558 (4.6) | 1060 (3.6) | −1.00 (−1.31 to −0.69) | <0.001 |
| Discharge medications* | ||||||
| Aspirin | N (%) | 186 098 (98.8) | 35 753 (98.1) | 30 197 (99.2) | 1.13 (0.96 to 1.30) | <0.001 |
| β-blocker | N (%) | 165 472 (95.7) | 30 375 (94.1) | 28 207 (97.5) | 3.40 (3.09 to 3.72) | <0.001 |
| Statin | N (%) | 185 710 (98.1) | 35 708 (97.3) | 30 029 (98.8) | 1.46 (1.26 to 1.67) | <0.001 |
| ACEi or ARB | N (%) | 173 303 (95.3) | 32 616 (93.1) | 28 567 (97.3) | 4.16 (3.83 to 4.48) | <0.001 |
| P2Y12 inhibitor | N (%) | 89 676 (96.7) | 190 (94.5) | 28 694 (97.6) | 3.05 (−0.10 to 6.20) | 0.005 |
| Aldosterone antagonist | N (%) | 7296 (12.6) | 0 (0) | 3031 (15.8) | – | – |
| Reperfusion strategy* | ||||||
| PPCI | N (%) | 83 627 (39.6) | 148 (2.1) | 26 799 (80.2) | 78.15 (77.61 to 78.69) | <0.001 |
| Thrombolysis | N (%) | 83 800 (39.6) | 30 220 (81.1) | 1218 (15.6) | −65.54 (−66.44 to −64.65) | <0.001 |
| CABG | N (%) | 1638 (0.8) | 276 (3.8) | 247 (3.6) | 0.17 (−0.79 to 0.45) | 0.593 |
| None† | N (%) | 42 354 (20.0) | 6955 (18.6) | 6275 (18.2) | −0.40 (−1.00 to 0.13) | 0.129 |
| Cardiac rehabilitation | N (%) | 182 575 (92.4) | 33 933 (89.8) | 30 387 (94.3) | 4.44 (4.05 to 4.84) | <0.001 |
| GRACE risk score category | ||||||
| Lowest (<70) | N (%) | 5034 (5.0) | 30 (5.6) | 1099 (4.7) | −0.84 (−2.79 to 1.11) | 0.362 |
| Low (70-87) | N (%) | 11 541 (11.4) | 61 (11.3) | 2654 (11.4) | 0.08 (−2.61 to 2.78) | 0.952 |
| Intermediate to high (≥88) | N (%) | 84 509 (83.6) | 450 (83.2) | 19 612 (83.9) | 0.76 (−2.43 to 3.95) | 0.635 |
| Crude mortality | ||||||
| 30 days | N (%) | 5517 (2.4) | 1046 (2.4) | 836 (2.3) | −0.18 (−0.40 to 0.02) | 0.078 |
| 6 months | N (%) | 12 143 (5.2) | 2347 (5.5) | 1703 (4.6) | −0.89 (−1.19 to −0.59) | <0.001 |
| 1 year | N (%) | 16 239 (7.0) | 3221 (7.5) | 2090 (5.6) | −1.89 (−2.23 to −1.55) | <0.001 |
*Only patients eligible (eligibility criteria definition used given in online supplementary section 1) to receive treatments were included in the denominator of the complete cases.
†Reasons for non-receipt of PPCI/thrombolysis included: (1) ineligible ECG (25.2% (n=10,678)), (2) too late (32.8% (n=13,878)), (3) risk of haemorrhage (6.7% (n=2,837)), (4) uncontrolled hypertension (0.5% (n=209)), (5) administrative failure (1.7% (n=711)), (6) elective decision (15.4% (n=6,521)), (7) patient refused treatment (1.4% (n=570)) and (8) other (16.4% (n=6,950)).
ACEi, ACE inhibitor; ACS, acute coronary syndrome; ARBs, angiotensin receptor blocker; CABG, coronary artery bypass grafting; CHD, coronary heart disease; COPD, chronic obstructive pulmonary disease; GRACE, Global Registry of Acute Coronary Events; IMD, index of multiple deprivation; MI, myocardial infarction; PCI, percutaneous coronary intervention; PPCI, primary percutaneous coronary intervention.