Characteristics of studies included in the systematic review.
| Study | O'Keefe (1992)11 | Deftereos (2013)12 | CISR (2019)13 | COLCOT (2019)14 | LoDoCo-MI (2019)15 | Colchicine-CI (2020)16 | COPS (2020)17 |
| Design | Double blinded RCT | Double blinded RCT | Unblinded RCT | Double blinded RCT | Double blinded RCT | Double blinded RCT | Double blinded RCT |
| Population | Patients who had undergone successful coronary angioplasty. Premenopausal women excluded. | Patients undergoing PCI with a BMS who are of 40–80 years of age, with DM and a contraindication to DES. | Patients above the age of 40 who underwent PCI with BMS or DES for treatment of stable IHD or ACS. Women of childbearing potential excluded. A: BMS +Colchicine B: BMS only C: DES | Patients who had an MI within 30 days before enrolment and had completed any planned percutaneous revascularisation procedures. Excluded if had stroke within previous 3 months, type two index MI, recent or planned CABG. | Patients who sustained a type one acute MI within the prior 7 days. Pregnant, lactating or women of childbearing age not on contraception excluded. | Patients aged above 18 years with suspected ischaemic heart disease or ACS referred for clinically indicated coronary angiography and PCI. | Patients presented with ACS and had evidence of CAD on coronary angiography, managed with either PCI or medical therapy. Excluded if needing surgical revascularisation. |
| No (T/C) | 197 (130/67) | 196 (100/96) | 90 (30/30/30) | 4745 (2366/2379) | 237 (119/118) | 400 (206/194) | 795 (396/399) |
| Mean age, yrs ±SD | 60.0 T: 59 C: 62 | 63.6±7.0 T: 63.7±6.9 C: 63.5±7.2 | 60.03±7.3 A: 57.5±6.7 B: 62.6±3 C: 61.8±7 | 60.5±10.7 T: 60.6±10.7 C: 60.5±10.6 | 61 ±13.0 T: 61±13.6 C: 61±12.5 | 66.2±11.4 T: 65.9±9.9 C: 66.6±10.2 | 59.8±10.3 T: 59.7±10.2 C:60.0±10.4 |
| Males, n (%) | 169 (85.8) | 128 (65.3) | 75 (83.3) A: 228 (93.3) B: 21 (70.0) C: 26 (86.7) | 3836 (80.8) | 182 (76.8) | 374 (93.5) | 632 (79.5) |
| HTN, n (%) | N/A | 95 (48.5) | 42 (47.8) A: 18 (60.0) B: 11 (36.7) 14 (46.7) | 2421 (51.0) | 112 (47.3) | 367 (91.8) | 400 (50.3) |
| DM, n (%) | 24 (8.08) | 196 (100) | 39 (43.3) A: 15 (50.0) B: 10 (33.3) C: 14 (46.7) | 959 (20.2) | 52 (21.9) | 231 (57.8) | 151 (20.0) |
| Smoking history, n (%) | N/A | 74 (37.8) | 32 (35.6) A: 9 (30.0) B: 12 (40.0) C: 10 (33.3) | 1416 (29.8) | 143 (60.3) | 282 (70.5) | 277 (34.8) |
| PCI, n (%) | 100 (angioplasty) | 196 (100) | 90 (100) A: 30 (100) B: 30 (100) C: 30 (100) | 4408 (92.9) | 237 (100) | 400 (100) | 691 (86.9) |
| Antiplatelet, n (%) | N/A | N/A | 89 (98.9) A: 30 (100) B: 29 (97.0) C: 30 (100) | 4686 (98.8) | 237 (100) | 362 (90.5) | 784 (98.6) |
| Statin, n (%) | N/A | N/A | 90 (100) A: 30 (100) B: 28 (93.3) C: 30 (100) | 4696 (99.0) | 233 (98.3) | 362 (90.5) | 786 (98.9) |
| Colchicine dose | 0.6 mg BD | 0.5 mg BD | 0.5 mg BD | 0.5 mg OD | 0.5 mg OD | One off 1.2 mg, followed by 0.6 mg | 0.5 mg BD for first month, followed by 0.5 mg OD for 11 months |
| Time of colchicine initiation | Before angioplasty or within 24 hours after angioplasty. | From day of index PCI (within 24 hours). | After BMS implantation. | After assignment to group. | Within 7 days post-MI. | 1.2 mg given 1 to 2 hours before coronary angiography, followed by 0.6 mg immediately before PCI. | After assignment to group. |
| Median follow-up | 5.5 months | 6 months | 6 months | 22.6 months | 30 days | 30 days | 12 months |
| Primary outcome | Angiographic ISR measured by electronic callipers. | Angiographic ISR and IVUS-ISR (defined as in-stent minimum lumen area of <4 mmˆtwo at follow-up). | Clinical ISR at 6 months, defined as recurrence of angina pectoris or evidence of MI (>50% restenosis). | Composite of death from CV causes, resuscitated cardiac arrest, MI, stroke, or urgent hospitalisation for angina leading to coronary revascularisation in a time-to-event analysis. | Proportion of patients with a residual hs-CRP level ≥2 mg/L at 30 days. | PCI-related myocardial injury, according to Troponin I measurements. | Composite of death from any cause, ACS, ischaemia-driven urgent revascularisation and non-cardioembolic ischaemic stroke. |
| Secondary outcome | Adverse drug effects in placebo or colchicine. | Angiographic and IVUS parameters of lumen loss and in-stent neointimal hyperplasia, including late lumen loss (angiography), lumen area loss, percentage of neointima volume, and normalised neointima volume (IVUS). | Target-vessel revascularisation and stent thrombosis within 6 months. | Secondary end points consisted of the components of the primary efficacy end point; a composite of death from CV causes, resuscitated cardiac arrest, MI or stroke; and total mortality in time-to-event analyses. Coronary revascularisation, hospitalisation for heart failure, atrial fibrillation, and deep vein thrombosis or pulmonary embolus were prespecified as exploratory end points in the protocol. | Actual levels of hs-CRP at 30 days and the relative and absolute change in hs-CRP levels from baseline to 30 days. Others: proportion of recruited patients completing the study, adverse events, participant-reported compliance with study medications, and death and major CV events at 30 days. | Occurrence of 30-day MACE, a composite of the earliest occurrence of death from any cause, nonfatal MI, or target vessel revascularisation, PCI-related MI. Nonfatal MI defined as PCI-related or type 1 MI. | Components of the primary endpoint, as well as hospitalisation for chest pain. Post hoc analysis performed after unblinding of trial using cardiovascular death as an outcome measure. |
ACS, acute coronary syndrome; BD, two times per day; BMS, bare metal stent; C, control; CABG, coronary artery bypass graft surgery; CAD, coronary artery disease; CRP, C reactive protein; CV, cardiovascular; DES, drug-eluting stent; DM, diabetes mellitus; hs-CRP, high-sentivity C reactive protein; HTN, hypertension; ISR, in-stent restenosis; IVUS, intravascular ultrasound; MI, myocardial infarction; N/A, not available; OD, once daily; PCI, percutaneous coronary intervention; RCT, randomised controlled trial; T, treatment; TvC, treatment versus control; UA, unstable angina.