A total of 798 T2DM patients with ACS undergoing PCI were included in the present analysis. The mean age of these patients was 61 ± 10 years, and male patients accounted for 72.7%. The baseline clinical and laboratory characteristics of the study population according to the AIP quartiles are listed in Table 1. Patients with higher AIP values tended to be younger, were predominantly male, had higher rates of current smoking and dyslipidaemia, and had lower rates of never smoking and diagnosis with unstable angina pectoris. Patients with higher AIP values were more likely to have higher levels of BMI, serum creatinine (SCr), uric acid, TC, LDL-C, triglycerides, and FPG, while have lower levels of pulse pressure (PP) and HDL-C. Use of medications, agiographic findings, and procedural results of the study population according to the AIP quartiles are summarized in Table 2. With the exception of β-blockers, medications before admission did not differ across the different AIP groups. With the exception of P2Y12 inhibitors, angiotensin converting enzyme inhibitors/angiotensin II receptor blockers (ACEIs/ARBs), and oral antidiabetic agents, medications at discharge were similar among the different AIP groups. Patients who had higher AIP values were more likely to receive ACEIs/ARBs at discharge. The proportions of left main/three-vessel disease and two-vessel disease were different among the different AIP groups. Patients with higher AIP values tended to have a higher rate of chronic total occlusions, and a lower rate of heavy calcification lesions. The proportions of left circumflex artery and right coronary artery interventions were different among the different AIP groups. Patients with higher AIP values tended to have a lower rate of complete revascularization.
Table 1
Baseline clinical and laboratory characteristics of the study population according to the AIP quartiles
Variable | Q1 n = 199 | Q2 n = 200 | Q3 n = 200 | Q4 n = 199 | P value |
Demographics | | | | | |
Age (years) | 63 ± 8 | 63 ± 10 | 61 ± 9 | 58 ± 12 | < 0.001 |
Male sex, n (%) | 125 (62.8) | 146 (73.0) | 153 (76.5) | 156 (78.4) | 0.002 |
Clinical values (on admission) | | | | | |
BMI (kg/m2) | 25.3 ± 3.1 | 25.4 ± 2.8 | 26.1 ± 3.1 | 27.0 ± 3.5 | < 0.001 |
SBP (mm Hg) | 133 ± 18 | 133 ± 17 | 130 ± 16 | 131 ± 16 | 0.116 |
DBP (mm Hg) | 75 ± 11 | 76 ± 10 | 75 ± 10 | 77 ± 11 | 0.203 |
PP (mm Hg) | 58 ± 16 | 58 ± 15 | 55 ± 15 | 54 ± 14 | 0.015 |
Risk factors | | | | | |
Smoking status | | | | | |
Current smoking, n (%) | 60 (30.2) | 77 (38.5) | 76 (38.0) | 111 (55.8) | < 0.001 |
Former smoking, n (%) | 33 (16.6) | 33 (16.5) | 38 (19.0) | 26 (13.1) | 0.455 |
Never smoking, n (%) | 106 (53.3) | 90 (45.0) | 86 (43.0) | 62 (31.2) | < 0.001 |
Chronically daily drinking, n (%) | 14 (7.0) | 18 (9.0) | 26 (13.0) | 21 (10.6) | 0.234 |
Family history of CHD, n (%) | 54 (27.1) | 60 (30.0) | 69 (34.5) | 56 (28.1) | 0.386 |
Hypertension, n (%) | 138 (69.3) | 137 (68.5) | 141 (70.5) | 130 (65.3) | 0.715 |
Dyslipidaemia, n (%) | 107 (53.8) | 174 (87.0) | 192 (96.0) | 195 (98.0) | < 0.001 |
Previous MI, n (%) | 36 (18.1) | 43 (21.5) | 40 (20.0) | 51 (25.6) | 0.301 |
Past PCI, n (%) | 47 (23.6) | 50 (25.0) | 50 (25.0) | 44 (22.1) | 0.891 |
Previous ischemic stroke or TIA, n (%) | 13 (6.5) | 13 (6.5) | 17 (8.5) | 8 (4.0) | 0.338 |
PAD, n (%) | 27 (13.6) | 29 (14.5) | 31 (15.5) | 35 (17.6) | 0.713 |
Cardiac failure, n (%) | 12 (6.0) | 13 (6.5) | 23 (11.5) | 19 (9.5) | 0.156 |
LVEF (%) | 64 (60–67) | 64 (60–68) | 65 (60–68) | 65 (59–68) | 0.963 |
Clinical presentation | | | | | |
UAP, n (%) | 171 (85.9) | 153 (76.5) | 150 (75.0) | 153 (76.9) | 0.033 |
NSTEMI, n (%) | 19 (9.5) | 28 (14.0) | 28 (14.5) | 25 (12.6) | 0.493 |
STEMI, n (%) | 9 (4.5) | 19 (9.5) | 22 (11.0) | 21 (10.6) | 0.088 |
Laboratory measurements (fasting state) | | | | | |
BUN (mmol/L) | 5.2 (4.3–6.3) | 5.4 (4.5–6.5) | 5.4 (4.6–6.2) | 5.5 (4.6–6.7) | 0.173 |
SCr (µmol/L) | 66.5 (59.3–73.6) | 69.2 (61.9–80.3) | 70.3 (62.2–81.3) | 71.5 (63.2–82.2) | < 0.001 |
UA (µmol/L) | 303.2 (271.7-347.2) | 321.3 (279.6–373.0) | 323.8 (282.5–386.0) | 368.5 (307.0-410.3) | < 0.001 |
TC (mmol/L) | 3.90 ± 0.96 | 4.06 ± 1.01 | 4.10 ± 0.99 | 4.47 ± 1.03 | < 0.001 |
LDL-C (mmol/L) | 2.23 ± 0.85 | 2.48 ± 0.84 | 2.48 ± 0.77 | 2.53 ± 0.76 | 0.001 |
HDL-C (mmol/L) | 1.23 ± 0.22 | 1.04 ± 0.17 | 0.95 ± 0.17 | 0.87 ± 0.14 | < 0.001 |
Triglycerides (mg/dl) | 0.88 (0.72-1.00) | 1.31 (1.18–1.48) | 1.71 (1.51–1.99) | 2.66 (2.25–3.38) | < 0.001 |
FPG (mg/dl) | 6.80 (6.12–8.23) | 7.17 (6.32–8.25) | 6.80 (5.91–7.88) | 7.65 (6.61–8.49) | < 0.001 |
Glycated haemoglobin (%) | 7.0 (6.6–8.1) | 7.3 (6.7–8.2) | 7.2 (6.6–8.1) | 7.3 (6.7-8.0) | 0.409 |
AIP | -0.1581 ± 0.1373 | 0.1029 ± 0.0482 | 0.2631 ± 0.0504 | 0.5272 ± 0.1773 | < 0.001 |
AIP indicates atherogenic index of plasma; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; PP, pulse pressure; CHD, coronary heart disease; MI, myocardial infarction; PCI, percutaneous coronary intervention; TIA, transient ischemic attack; PAD, peripheral artery disease; LVEF, left ventricular ejection fraction; UAP, unstable angina pectoris; NSTEMI, non ST-segment elevation myocardial infarction; STEMI, ST-segment elevation myocardial infarction; BUN, blood urea nitrogen; SCr, serum creatinine; UA, uric acid; TC, total cholesterol; LDL-C, low-density lipoprotein-cholesterol; HDL-C, high-density lipoprotein-cholesterol; FPG, fasting plasma glucose. |
Table 2
Use of medications, agiographic findings, and procedural results of the study population according to the AIP quartiles
Variable | Q1 n = 199 | Q2 n = 200 | Q3 n = 200 | Q4 n = 199 | P value |
Medications before admission | | | | | |
Aspirin, n (%) | 145 (72.9) | 149 (74.5) | 154 (77.0) | 146 (73.4) | 0.784 |
P2Y12 inhibitors, n (%) | 81 (40.7) | 81 (40.5) | 74 (37.0) | 80 (40.2) | 0.858 |
Statins, n (%) | 150 (75.4) | 143 (71.5) | 155 (77.5) | 142 (71.4) | 0.418 |
ACEIs/ARBs, n (%) | 55 (27.6) | 65 (32.5) | 72 (36.0) | 69 (34.7) | 0.300 |
β-blockers, n (%) | 70 (35.2) | 79 (39.5) | 93 (46.5) | 63 (31.7) | 0.016 |
Insulin, n (%) | 75 (37.7) | 73 (36.5) | 79 (39.5) | 63 (31.7) | 0.406 |
Oral antidiabetic agents, n (%) | 89 (44.7) | 98 (49.0) | 110 (55.0) | 90 (45.2) | 0.145 |
Intraoperative anticoagulants | | | | | |
Unfractionated heparin, n (%) | 168 (84.4) | 170 (85.0) | 154 (77.0) | 156 (78.4) | 0.086 |
LMWH, n (%) | 6 (3.0) | 7 (3.5) | 16 (8.0) | 10 (5.0) | 0.089 |
Bivalirudin, n (%) | 25 (12.6) | 23 (11.5) | 30 (15.0) | 33 (16.6) | 0.448 |
Perioperative medications | | | | | |
Aspirin, n (%) | 196 (98.5) | 198 (99.0) | 200 (100.0) | 196 (98.5) | 0.308 |
P2Y12 inhibitors, n (%) | 199 (100.0) | 200 (100.0) | 200 (100.0) | 199 (100.0) | - |
GP Ⅱb/Ⅲa receptor antagonist, n (%) | 29 (14.6) | 38 (19.0) | 45 (22.5) | 37 (18.6) | 0.246 |
Medications at discharge | | | | | |
Aspirin, n (%) | 196 (98.5) | 198 (99.0) | 200 (100.0) | 196 (98.5) | 0.308 |
Cilostazol, n (%) | 3 (1.5) | 2 (1.0) | 1 (0.5) | 4 (2.0) | 0.473 |
Clopidogrel, n (%) | 174 (87.4) | 183 (91.5) | 178 (89.0) | 190 (95.5) | 0.031 |
Ticagrelor, n (%) | 25 (12.6) | 17 (8.5) | 22 (11.0) | 9 (4.5) | 0.031 |
Statins, n (%) | 199 (100.0) | 200 (100.0) | 200 (100.0) | 199 (100.0) | - |
ACEIs/ARBs, n (%) | 81 (40.7) | 93 (46.5) | 105 (52.5) | 121 (60.8) | 0.001 |
β-blockers, n (%) | 138 (69.3) | 147 (73.5) | 155 (77.5) | 136 (68.3) | 0.155 |
Insulin, n (%) | 65 (32.7) | 76 (38.0) | 72 (36.0) | 57 (28.6) | 0.213 |
Oral antidiabetic agents, n (%) | 87 (43.7) | 120 (60.0) | 119 (59.5) | 105 (52.8) | 0.003 |
Angiographic findings | | | | | |
One-vessel disease, n (%) | 22 (11.1) | 15 (7.5) | 18 (9.0) | 25 (12.6) | 0.347 |
Two-vessel disease, n (%) | 68 (34.2) | 41 (20.5) | 42 (21.0) | 46 (23.1) | 0.004 |
LM/three-vessel disease, n (%) | 109 (54.8) | 144 (72.0) | 140 (70.0) | 128 (64.3) | 0.001 |
Proximal LAD stenosis, n (%) | 94(47.2) | 110 (55.0) | 97 (48.5) | 100 (50.3) | 0.428 |
Restenotic lesions, n (%) | 26 (13.1) | 26 (13.0) | 30 (15.0) | 29 (14.6) | 0.913 |
Trifurcation or bifurcation lesions, n (%) | 155 (77.9) | 162 (81.0) | 151 (75.5) | 148 (74.4) | 0.403 |
Chronic total occlusions, n (%) | 36 (18.1) | 46 (23.0) | 44 (22.0) | 57 (28.6) | 0.093 |
Thrombus lesions, n (%) | 7 (3.5) | 14 (7.0) | 12 (6.0) | 12 (6.0) | 0.478 |
Heavy calcification lesions, n (%) | 75 (37.7) | 69 (34.5) | 73 (36.5) | 48 (24.1) | 0.016 |
Lesions > 20 mm long, n (%) | 108 (54.3) | 112 (56.0) | 122 (61.0) | 117 (58.8) | 0.537 |
Procedural results | | | | | |
Target vessel territory | | | | | |
LM, n (%) | 13 (6.5) | 16 (8.0) | 9 (4.5) | 18 (9.0) | 0.313 |
LAD, n (%) | 104 (52.3) | 97 (48.5) | 100 (50.0) | 99 (49.7) | 0.899 |
LCX, n (%) | 64 (32.2) | 69 (34.5) | 42 (21.0) | 48 (24.1) | 0.007 |
RCA, n (%) | 69 (34.7) | 82 (41.0) | 100 (50.0) | 74 (37.2) | 0.011 |
DES use, n (%) | 174 (87.4) | 172 (86.0) | 161 (80.5) | 159 (79.9) | 0.097 |
BRS use, n (%) | 6 (3.0) | 7 (3.5) | 8 (4.0) | 11 (5.5) | 0.607 |
DCB use, n (%) | 12 (6.0) | 11 (5.5) | 19 (9.5) | 14 (7.0) | 0.409 |
Complete revascularization, n (%) | 136 (68.3) | 115 (57.5) | 110 (55.0) | 107 (53.8) | 0.012 |
AIP indicates atherogenic index of plasma; ACEIs, angiotensin converting enzyme inhibitors; ARBs, angiotensin II receptor blockers; LM, left-main artery; LAD, left anterior descending artery; LCX, left circumflex artery; RCA; right coronary artery; DES, drug-eluting stent; BRS, bioresorbable scaffold; DCB, drug-coated balloon. |
Patients were followed up for a median of 927 days (interquartile range, 774 to 1109 days). During the period 198 patients developed at least one adverse CV event which was found in 33 (16.6%) patients from the Q1 group, 45 (22.5%) from the Q2 group, 54 (27.0%) from the Q3 group, and 66 (33.2%) from the Q4 group. Of the 198 patients with at least one adverse CV event, 20 died (18 died from CV causes, and 2 died from non-CV causes), 17 developed non-fatal ischemic stroke, 24 developed non-fatal MI, and 180 developed unplanned repeat revascularization; among these patients, 33 had two, 2 had three, and 2 had four adverse CV events. The baseline clinical and laboratory characteristics of the study population stratified by the primary endpoint are shown in Table 3. Patients who had at least one event had higher levels of AIP than those who had no events. Patients with at least one event had higher rates of previous MI, past PCI, peripheral arterial disease (PAD), and cardiac failure, higher levels of PP, SCr, triglycerides, and FPG, but lower levels of diastolic blood pressure, HDL-C, and LVEF. Use of medications, agiographic findings, and procedural results of the study population stratified by the primary endpoint are presented in Table 4. With the exception of ACEIs/ARBs, there was no difference in use of medications before admission between patients with and without events. With the exception of aspirin, use of perioperative medications was similar between patients with and without events. With the exception of aspirin, cilostazol, and insulin, patients with and without events received similar medications at discharge. Patients who had at least one event had higher proportions of left main/three-vessel disease, lesions > 20 mm long, and restenotic lesions, but lower proportions of one-vessel and two-vessel diseases, compared with those who had no events. In terms of procedural results, patients who had at least one event were more likely to use drug-coated balloons, while less likely to achieve complete revascularization.
Table 3
Baseline clinical and laboratory characteristics of the study population stratified by the primary endpoint
Variable | No such events n = 600 | Primary endpoint n = 198 | P value |
Demographics | | | |
Age (years) | 61 ± 10 | 62 ± 10 | 0.435 |
Male sex, n (%) | 436 (72.7) | 144 (72.7) | 0.987 |
Clinical values (on admission) | | | |
BMI (kg/m2) | 26.1 ± 3.2 | 25.6 ± 3.1 | 0.087 |
SBP (mm Hg) | 131 ± 17 | 133 ± 16 | 0.399 |
DBP (mm Hg) | 77 ± 10 | 72 ± 10 | < 0.001 |
PP (mm Hg) | 55 ± 15 | 60 ± 15 | < 0.001 |
Risk factors | | | |
Smoking status | | | |
Current smoking, n (%) | 244 (40.7) | 80 (40.4) | 0.948 |
Former smoking, n (%) | 93 (15.5) | 37 (18.7) | 0.292 |
Never smoking, n (%) | 263 (43.8) | 81 (40.9) | 0.471 |
Chronically daily drinking, n (%) | 61 (10.2) | 18 (9.1) | 0.660 |
Family history of CHD, n (%) | 173 (28.8) | 66 (33.3) | 0.231 |
Hypertension, n (%) | 408 (68.0) | 138 (69.7) | 0.656 |
Dyslipidaemia, n (%) | 496 (82.7) | 172 (86.9) | 0.165 |
Previous MI, n (%) | 114 (19.0) | 56 (28.3) | 0.006 |
Past PCI, n (%) | 123 (20.5) | 68 (34.3) | < 0.001 |
Previous ischemic stroke or TIA, n (%) | 39 (6.5) | 12 (6.1) | 0.827 |
PAD, n (%) | 66 (11.0) | 56 (28.3) | < 0.001 |
Cardiac failure, n (%) | 39 (6.5) | 28 (14.1) | 0.001 |
LVEF (%) | 65 (60–68) | 63 (57–67) | 0.002 |
Clinical presentation UAP, n (%) | 467 (77.8) | 160 (80.8) | 0.376 |
NSTEMI, n (%) | 82 (13.7) | 18 (9.1) | 0.092 |
STEMI, n (%) | 51 (8.5) | 20 (10.1) | 0.493 |
Laboratory measurements (fasting state) | | | |
BUN (mmol/L) | 5.4 (4.5–6.3) | 5.6 (4.5–6.7) | 0.179 |
SCr (µmol/L) | 68.5 (60.9–78.5) | 70.7 (63.1–83.5) | 0.010 |
UA (µmol/L) | 333.2 ± 77.2 | 344.4 ± 78.9 | 0.079 |
TC (mmol/L) | 4.10 ± 1.03 | 4.24 ± 0.98 | 0.093 |
LDL-C (mmol/L) | 2.41 ± 0.83 | 2.47 ± 0.74 | 0.382 |
HDL-C (mmol/L) | 1.04 ± 0.22 | 0.96 ± 0.20 | < 0.001 |
Triglycerides (mmol/L) | 1.46 (1.04-2.00) | 1.67 (1.12–2.31) | 0.003 |
FPG (mmol/L) | 6.88 (6.12–8.01) | 7.89 (6.70–9.23) | < 0.001 |
Glycated haemoglobin (%) | 7.2 (6.6–8.1) | 7.4 (6.8–8.3) | 0.079 |
AIP | 0.1608 ± 0.2653 | 0.2535 ± 0.2919 | < 0.001 |
AIP | | | 0.001 |
Q1, n (%) | 166 (27.7) | 33 (16.7) | - |
Q2, n (%) | 155 (25.8) | 45 (22.7) | - |
Q3, n (%) | 146 (24.3) | 54 (27.3) | - |
Q4, n (%) | 133 (22.2) | 66 (33.3) | - |
Abbreviations as in Tables 1 and 2. |
Table 4
Use of medications, agiographic findings, and procedural results of the study population stratified by the primary endpoint
Variable | No such events n = 600 | Primary endpoint n = 198 | P value |
Medications before admission | | | |
Aspirin, n (%) | 442 (73.7) | 152 (76.8) | 0.386 |
P2Y12 inhibitors, n (%) | 234 (39.0) | 82 (41.4) | 0.547 |
Statins, n (%) | 438 (73.0) | 152 (76.8) | 0.295 |
ACEIs/ARBs, n (%) | 183 (30.5) | 78 (39.4) | 0.021 |
β-blockers, n (%) | 233 (38.8) | 72 (36.4) | 0.535 |
Insulin, n (%) | 212 (35.3) | 78 (39.4) | 0.303 |
Oral antidiabetic agents, n (%) | 289 (48.2) | 98 (49.5) | 0.746 |
Intraoperative anticoagulants | | | |
Unfractionated heparin, n (%) | 486 (81.0) | 162 (81.8) | 0.798 |
LMWH, n (%) | 29 (4.8) | 10 (5.1) | 0.902 |
Bivalirudin, n (%) | 85 (14.2) | 26 (13.1) | 0.715 |
Perioperative medications | | | |
Aspirin, n (%) | 600 (100.0) | 190 (96.0) | < 0.001 |
P2Y12 inhibitors, n (%) | 600 (100.0) | 198 (100.0) | - |
GP Ⅱb/Ⅲa receptor antagonist, n (%) | 105 (17.5) | 44 (22.2) | 0.139 |
Medications at discharge | | | |
Aspirin, n (%) | 600 (100.0) | 190 (96.0) | < 0.001 |
Cilostazol, n (%) | 2 (0.3) | 8 (4.0) | < 0.001 |
Clopidogrel, n (%) | 545 (90.8) | 180 (90.9) | 0.974 |
Ticagrelor, n (%) | 55 (9.2) | 18 (9.1) | 0.974 |
Statins, n (%) | 600 (100.0) | 198 (100.0) | - |
ACEIs/ARBs, n (%) | 294 (49.0) | 106 (53.5) | 0.268 |
β-blockers, n (%) | 442 (73.7) | 134 (67.7) | 0.103 |
Insulin, n (%) | 190 (31.7) | 80 (40.4) | 0.024 |
Oral antidiabetic agents, n (%) | 324 (54.0) | 106 (53.5) | 0.909 |
Angiographic findings | | | |
One-vessel disease, n (%) | 72 (12.0) | 8 (4.0) | 0.001 |
Two-vessel disease, n (%) | 165 (27.5) | 32 (16.2) | 0.001 |
LM/three-vessel disease, n (%) | 363 (60.5) | 158 (79.8) | < 0.001 |
Proximal LAD stenosis, n (%) | 295 (49.2) | 106 (53.5) | 0.286 |
Restenotic lesions, n (%) | 62 (10.3) | 49 (24.7) | < 0.001 |
Trifurcation or bifurcation lesions, n (%) | 460 (76.7) | 156 (78.8) | 0.537 |
Chronic total occlusions, n (%) | 141 (23.5) | 42 (21.2) | 0.507 |
Thrombus lesions, n (%) | 38 (6.3) | 7 (3.5) | 0.139 |
Heavy calcification lesions, n (%) | 197 (32.8) | 68 (34.3) | 0.696 |
Lesions > 20 mm long, n (%) | 319 (53.2) | 140 (70.7) | < 0.001 |
Procedural results | | | |
Target vessel territory | | | |
LM, n (%) | 40 (6.7) | 16 (8.1) | 0.499 |
LAD, n (%) | 302 (50.3) | 98 (49.5) | 0.838 |
LCX, n (%) | 168 (28.6) | 52 (27.7) | 0.808 |
RCA, n (%) | 243 (40.5) | 82 (41.4) | 0.820 |
DES use, n (%) | 502 (83.7) | 164 (82.8) | 0.783 |
BRS use, n (%) | 27 (4.5) | 5 (2.5) | 0.219 |
DCB use, n (%) | 34 (5.7) | 22 (11.1) | 0.009 |
Complete revascularization, n (%) | 384 (64.0) | 84 (42.4) | < 0.001 |
Abbreviations as in Tables 1 and 2. |
Kaplan-Meier analyses revealed a significantly higher incidence of the primary endpoint (log-rank test, P = 0.001; Fig. 1a) and a marginally (but non-significantly) higher incidence of the key secondary endpoint (log-rank test, P = 0.114; Fig. 1b) in patients with higher AIP values. The difference in the incidence of the primary endpoint was mainly due to an increase in unplanned repeat revascularization (log-rank test, P = 0.005; Fig. 1f) across the AIP quartiles. However, the incidence of all-cause death (log-rank test, P = 0.168; Fig. 1c), CV death (log-rank test, P = 0.459), non-fatal ischemic stroke (log-rank test, P = 0.167; Fig. 1d), and non-fatal MI (log-rank test, P = 0.636; Fig. 1e) did not differ among the AIP quartiles at follow-up.
Table 5 shows univariate and multivariate Cox proportional hazards analyses for the primary endpoint at follow up, which includes AIP quartiles, age, BMI, PP, LVEF, SCr, LDL-C, FPG, glycosylated haemoglobin, sex, current smoking, hypertension, previous MI, past PCI, PAD, cardiac failure, clinical presentation, coronary artery disease (CAD) severity, lesions > 20 mm long, restenotic lesions, use of drug-coated balloon, complete revascularization, and use of insulin at discharge. A multivariate Cox proportional hazards analysis, with Q1 as a reference, showed that the AIP for Q2, Q3, and Q4 had increased HRs for the incidence of the primary endpoint (Q2: HR 1.164, 95% CI 0.728–1.860; Q3: HR 1.640, 95% CI 1.032–2.606; Q4: HR 2.153, 95% CI 1.355–3.421). Moreover, AIP used as a continuous variable was independently predictive of the primary endpoint (HR, 2.581; 95% CI, 1.499–4.444; P = 0.001). Table 6 shows univariate and multivariate Cox proportional hazards analyses for the key secondary endpoint at follow up, which includes AIP quartiles, age, BMI, PP, LVEF, blood urea nitrogen, SCr, LDL-C, FPG, glycosylated haemoglobin, current smoking, hypertension, past PCI, PAD, cardiac failure, clinical presentation, CAD severity, lesions > 20 mm long, complete revascularization, and use of ACEIs/ARBs at discharge. A multivariate Cox proportional hazards analysis, with Q1 as a reference, showed that the AIP for Q2, Q3, and Q4 had increased HRs for the incidence of the key secondary endpoint (Q2: HR 1.063, 95% CI 0.397–2.849; Q3: HR 1.762, 95% CI 0.690–4.497; Q4: HR 2.613, 95% CI 1.024–6.666). Moreover, AIP used as a continuous variable was independently predictive of the key secondary endpoint (HR, 3.412; 95% CI, 1.086–10.723; P = 0.036).
Table 5
Relationship between the incidence of the primary endpoint and the AIP expressed as a categorical variable
Variables | Univariate analysis HR (95% CI) | P-value | Multivariate analysis HR (95% CI) | P-value |
AIP quartiles | | | | |
Q1 | Reference | | Reference | |
Q2 | 1.376 (0.878–2.156) | 0.164 | 1.164 (0.728–1.860) | 0.525 |
Q3 | 1.710 (1.109–2.636) | 0.015 | 1.640 (1.032–2.606) | 0.036 |
Q4 | 2.265 (1.491–3.440) | < 0.001 | 2.153 (1.355–3.421) | 0.001 |
Age | 1.005 (0.991–1.019) | 0.472 | 0.989 (0.972–1.007) | 0.219 |
BMI | 0.959 (0.916–1.005) | 0.078 | 0.931 (0.884–0.982) | 0.008 |
PP | 1.021 (1.012–1.029) | < 0.001 | 1.019 (1.008–1.029) | < 0.001 |
LVEF | 0.974 (0.959–0.990) | 0.002 | 0.987 (0.965–1.009) | 0.242 |
SCr | 1.013 (1.006–1.021) | 0.001 | 1.011 (1.003–1.020) | 0.010 |
LDL-C | 1.078 (0.916–1.269) | 0.366 | 1.021 (0.842–1.239) | 0.832 |
FPG | 1.201 (1.132–1.274) | < 0.001 | 1.192 (1.108–1.281) | < 0.001 |
Glycosylated haemoglobin | 1.067 (0.955–1.193) | 0.252 | 0.861 (0.739–1.003) | 0.055 |
Male sex | 0.966 (0.706–1.320) | 0.827 | 0.834 (0.549–1.266) | 0.394 |
Current smoking | 1.003 (0.755–1.332) | 0.983 | 1.256 (0.874–1.805) | 0.219 |
Hypertension | 1.068 (0.789–1.447) | 0.669 | 1.040 (0.732–1.478) | 0.825 |
Previous MI | 1.492 (1.095–2.033) | 0.011 | 0.812 (0.549–1.202) | 0.299 |
Past PCI | 1.723 (1.285–2.310) | < 0.001 | 1.157 (0.687–1.949) | 0.583 |
PAD | 2.511 (1.836–3.435) | < 0.001 | 1.601 (1.096–2.338) | 0.015 |
Cardiac failure | 1.951 (1.308–2.909) | 0.001 | 1.167 (0.661–2.062) | 0.594 |
Clinical presentation | | | | |
UAP | Reference | | Reference | |
NSTEMI | 0.677 (0.416–1.102) | 0.117 | 0.531 (0.310–0.909) | 0.021 |
STEMI | 1.098 (0.690–1.747) | 0.695 | 1.114 (0.649–1.913) | 0.695 |
CAD severity | | | | |
One-vessel disease | Reference | | Reference | |
Two-vessel disease | 1.756 (0.809–3.810) | 0.154 | 1.324 (0.589–2.975) | 0.497 |
LM/three-vessel disease | 3.541 (1.740–7.205) | < 0.001 | 1.876 (0.882–3.990) | 0.103 |
Restenotic lesions | 2.290 (1.658–3.163) | < 0.001 | 1.724 (0.947–3.138) | 0.075 |
Lesions > 20 mm long | 1.984 (1.461–2.695) | < 0.001 | 1.574 (1.132–2.189) | 0.007 |
DCB use | 1.913 (1.228–2.980) | 0.004 | 1.025 (0.589–1.784) | 0.931 |
Complete revascularization | 0.467 (0.352–0.619) | < 0.001 | 0.736 (0.538–1.008) | 0.056 |
Insulin at discharge | 1.396 (1.051–1.854) | 0.021 | 1.135 (0.818–1.574) | 0.448 |
Abbreviations as in Tables 1 and 2. |
Table 6
Relationship between the incidence of the key secondary endpoint and the AIP expressed as a categorical variable
Variables | Univariate analysis HR (95% CI) | P-value | Multivariate analysis HR (95% CI) | P-value |
AIP quartiles | | | | |
Q1 | Reference | | Reference | |
Q2 | 1.380 (0.555–3.432) | 0.488 | 1.063 (0.397–2.849) | 0.903 |
Q3 | 2.020 (0.865–4.720) | 0.104 | 1.762 (0.690–4.497) | 0.236 |
Q4 | 2.477 (1.085–5.659) | 0.031 | 2.613 (1.024–6.666) | 0.044 |
Age | 1.042 (1.013–1.072) | 0.004 | 1.017 (0.982–1.053) | 0.343 |
BMI | 0.915 (0.834–1.004) | 0.062 | 0.844 (0.751–0.948) | 0.004 |
PP | 1.030 (1.014–1.046) | < 0.001 | 1.012 (0.991–1.034) | 0.265 |
LVEF | 0.924 (0.902–0.946) | < 0.001 | 0.945 (0.906–0.984) | 0.007 |
BUN | 1.166 (1.018–1.335) | 0.026 | 0.868 (0.724–1.041) | 0.127 |
SCr | 1.025 (1.014–1.036) | < 0.001 | 1.016 (1.001–1.030) | 0.031 |
LDL-C | 1.064 (0.774–1.463) | 0.702 | 1.081 (0.714–1.636) | 0.713 |
FPG | 1.097 (0.967–1.243) | 0.150 | 1.017 (0.880–1.176) | 0.818 |
Glycated haemoglobin | 1.090 (0.882–1.347) | 0.425 | 1.220 (0.932–1.597) | 0.148 |
Current smoking | 1.014 (0.589–1.746) | 0.959 | 1.534 (0.824–2.855) | 0.177 |
Hypertension | 1.333 (0.725–2.450) | 0.354 | 1.266 (0.608–2.636) | 0.528 |
Past PCI | 1.904 (1.096–3.309) | 0.022 | 2.247 (1.170–4.313) | 0.015 |
PAD | 5.804 (3.402–9.902) | < 0.001 | 2.888 (1.545–5.399) | 0.001 |
Cardiac failure | 6.939 (3.993–12.061) | < 0.001 | 1.888 (0.767–4.648) | 0.167 |
Clinical presentation | | | | |
UAP | Reference | | Reference | |
NSTEMI | 1.333 (0.622–2.857) | 0.460 | 0.501 (0.199–1.258) | 0.141 |
STEMI | 1.920 (0.896–4.115) | 0.094 | 1.056 (0.427–2.610) | 0.906 |
CAD severity | | | | |
One-vessel disease | Reference | | Reference | |
Two-vessel disease | 0.201 (0.037–1.096) | 0.064 | 0.059 (0.009–0.402) | 0.004 |
LM/three-vessel disease | 1.910 (0.689–5.296) | 0.214 | 0.418 (0.121–1.444) | 0.168 |
Lesions > 20 mm long | 2.681 (1.411–5.029) | 0.003 | 1.828 (0.882–3.789) | 0.105 |
Complete revascularization | 0.403 (0.232-0.700) | 0.001 | 0.684 (0.348–1.343) | 0.270 |
ACEIs/ARBs at discharge | 2.933 (1.596–5.391) | 0.001 | 1.782 (0.883–3.599) | 0.107 |
Abbreviations as in Tables 1 and 2. |
From the results of the multivariate Cox proportional hazards analysis, we calculated the Harrell’s C statistic for the primary endpoint. The Harrell’s C statistic of the variables, including BMI, PP, SCr, FPG, PAD, clinical presentation, and lesions > 20 mm long, was 0.697 versus 0.707 after the addition of AIP quartiles; the continuous NRI was 19.1% (7.9–35.6%; P < 0.001).
The predictive impacts of AIP as a continuous variable for the primary endpoint were further assessed in different subgroups of the study population. Increased AIP value (per 1-unit) was consistently associated with the primary endpoint in different subgroups, including age < 60 versus ≥ 60 years, BMI < 28 versus ≥ 28 kg/m2, LDL-C ≤ 1.8 versus > 1.8 mmol/L, female versus male, with versus without hypertension, and non-ST versus ST segment elevation ACS (Fig. 2).