Table 1.

Study design and characteristics of included studies.

Study	Sample	Inclusion criteria	Primary outcomes	Secondary outcome	Length of stay	Revascularization & antiplatelets	Follow up	Risk ratio for early vs late discharge
								Mortality	Readmissions	MACE
Observational studies
Swaminathan 2015	33,920 Short LOS (n = 9135) Medium LOS (n = 15,704) Long LOS (n = 9081)	≥65 age PPCI for STEMI 2004–2009 NCDR Database	30-day mortality or MACE defined as composite of mortality, MI readmissions, unplanned revascularizations	30-day all-cause mortality, readmissions for MI, unplanned revascularization, bleeding events	Very short 1–2 days Short≤3 days Medium = 4–5 days Long ≥5 days	Femoral access 97.9% ED, 98% LD		ED ≤ 3 days Events = 82 Total = 9135 Risk Ratio ED = 82/9135 LD > 3 days Events = 475 Total = 24,785 Risk Ratio LD = 475/24785	ED ≤ 3 days Events = 91 Total = 9135 Risk Ratio for ED: 91/9135 LD > 3 days Events = 318 Total = 24,785 Risk Ratio LD: 318/24785	ED ≤ 3 days Events = 174 Total = 9135 Risk Ratio ED: 174/9135 LD > 3 days Events = 799 > Total = 24,785 Risk Ratio LD: 799/24785
Karabulut 2011	267 D/C in 1-day (90) D/C in 2 days (94) D/C in 3-days (46) D/C in >3 days (37)	PPCI for STEMI	1-year mortality or reinfarction or revascularization of infarct related artery.	Defining an optimal LOS according to demographic and clinical characteristics	1-day 2-days 3-days >3-days	Tirofiban 45.2% ED, 73% LD	1-year	ED ≤ 3 days Events = 1 Total = 230 Risk Ratio ED = 1/230 LD > 3 days Events = 3 Total = 37 Risk Ratio LD = 3/37		ED ≤ 3 days Events = 37 Total = 230 Risk Ratio ED = 37/230 LD > 3 days Events = 11 Totals = 37 Risk Ratio LD = 11/37
Jones 2012	2779 D/C in 2- days (1117) D/C in 3-days (620) D/C in >3-days (916)	PPCI for STEMI	30-day readmissions	MACE defined as composite of death, recurrent MI, revascularization, stroke, target vessel revascularization	2-days 3-days >3-days	Radial access 42.5% ED, 31.2% LD GP IIb/IIIa 90% ED, 87.6% LD	2.8 years (IQR 1.3–4.4) (median)		ED ≤ 3 days Events = 87 Total = 1737 Risk Ratio ED: 87/1737 LD > 3 days Events = 42 Total = 916 Risk Ratio LD: 42/916	ED ≤ 3 days Events = 160 Total = 1737 Risk Ratio ED: 160/1737 LD > 3 days Events = 284 Total = 916 Risk Ratio LD: 284/916
Noman 2013	2448 ED (1542) LD (906)	PPCI for STEMI	Mortality at 1, 7 and 30 days			Radial access 72.6% ED, 64.1% LD Aspiration thrombectomy 45.7% ED, 39.3% LD GP IIb/IIIa inhibitors 83.3% ED, 79.4% LD DES 59.5% ED, 53.6% LD	ED 584 days and 582 days in LD (mean)	ED Events = 11 Total = 1542 Risk Ratio ED: 11/1542 LD Events = 15 Total = 906 Risk Ratio LD: 15/906
Randomized controlled clinical trials
Satilmisoglu 2016 (EDAP-PCI)	769 ED (370) LD (363)	PPCI for STEMI within 12 h of onset, Uneventful 24 h f/u, Single epicardial vessel to be treated	30-day mortality	Readmission at 30 days due to reinfarction, unstable angina, arrhythmia, CHF, revascularization, stroke, major bleeding. Functional status Health related QOL	ED < 48 to 56 h.	Aspirin Clopidogrel	30-days	ED < 48 h to 56 h. Events = 2 Total = 370 Risk Ratio ED =2/370 LD > 48 h to 56 h. Events = 3 Total = 363 Risk Ratio LD = 3/363	ED < 48 h to 56 h. Events = 14 Total = 370 Risk Ratio ED = 14/370 LD > 48 h to 56 h. Events = 25 Total = 363 Risk Ratio LD = 25/363
Melberg 2015	215 ED (107) LD (108)	STEMI within 2 days of admission with Zwolle risk score ≤ 3	30-day mortality	30-day readmissions Health related QOL	ED ≤3-days	DES 60% ED, 62% LD GP IIb/IIIa inhibitors 61.7% ED, 71.3% LD Aspiration thrombectomy 48.6% ED, 55.6% LD Radial access 50.5% ED, 66.7% LD	30-days	ED ≤ 3 days Events = 0 Total = 107 Risk Ratio ED = 0/107 LD > 3 days Events = 0 Total = 108 Risk Ratio LD = 0/108	ED ≤ 3 days Events = 4 Total = 107 Risk Ratio ED = 4/107 LD > 3 days Events = 3, Total = 108 Risk Ratio LD = 3/108	ED ≤ 3 days Events = 1 Total = 107 Risk Ratio for ED = 1/107 LD > 3 days Events = 3 Total = 108 Risk Ratio for ED = 3/108
Azzalini 2015 (EDAMI)	100 ED (54) CDS (46)	PPC1 for STEMI within 12 h of onset, Zwolle risk score ≤ 3,symptoms	Feasibility of ED vs LD Strategy		ED ≤3-days	BMS 42% DES 56% POBA 2% Aspirin 99% Clopidogrel 88% Prasugrel 11% Ticagrelor 1%	ED ≤ 3 days Events = 0 Total = 54 LD > 3 days Events = 0 Total = 46
Kotowycz 2010 (SAFE-DEPART)	54 ED (27) LD (27)	PPCI or Rescue PCI for STEMI	Feasibility of ED vs LD Strategy		ED ≤ 2–3 days	Aspirin Clopidogrel			ED ≤ 3 days Events = 2 Total = 27 Risk Ratio ED = 2/27 LD > 3 days Event = 1 Total = 27 Risk Ratio LD = 1/27
Jirmar 2008 (PRAGUE-5)	56 ED (37) LD (19)	PPC1 for Uncomplicated STEMI TIMI-3 flow with <20% residual stenosis Single vessel disease EF >40% Age < 75	Feasibility and Safety of ED vs LD Strategy	30-day Death Reinfarction Stroke Unstable Angina Rehospitalization Repeat target vessel revascularization Local groin complications EF	ED ≤1 day	Aspirin Clopidogrel	30-days		ED ≤ 1 day Events = 1 Total = 37 Risk Ratio ED = 1/37 LD > 1 day Events = 0 Total = 19 Risk Ratio LD = 0/19
Grines 1998 (PAMI-II)	471 ED (237) LD (234)	PPCI for Low-risk STEMI Age ≤70 years LVEF >45% ≤ 2-Vessel disease Successful PPCI	Composite of death, reinfarction, unstable ischemia, stroke or CHF by 6-months	Death, reinfarction, unstable ischemia, stroke or CHF by 6-months	ED ≤3 days	Successful PTCA 96.1% TIMI Grade 3 flow 92.9% vessels	6-months	ED ≤ 3 days Events = 2 Total = 237 Risk Ratio ED = 2/237 LD > 3 days Events = 1 Total = 234 Risk Ratio LD = 1/234	ED ≤ 3 days Events = 10, Total = 237 Risk Ratio ED = 10/237 LD > 3 days Events = 9, Total = 234 Risk Ratio LD = 9/234	ED ≤ 3 days Events = 36 Total = 237 Risk Ratio ED = 36/237 LD > 3 days Events = 41 Total = 234 Risk Ratio LD = 41/234
Novobilsky 2018	151 ED (76) LD (75)	PPCI STEMI ≤ 12 h after onset Age ≤ 75 years EF >45% ≤ 2-Vessel disease Successful PPCI No arrhythmias or hemodynamic instability >2 h after PPCI	Composite of death, MI, UA, stroke, unplanned rehospitalization, repeat target vessel revascularization, stent thrombosis at 90-days post discharge.		ED ≤3 days	DES 84.2% ED, 93.3% LD GP IIb/IIIa inhibitors 14.5% ED, 16% LD Aspiration thrombectomy 46.1% ED, 46.7% LD Radial access 98.7% ED, 100% LD		ED ≤ 3 days Events = 0 Total = 76 Risk Ratio ED = 0/76 LD > 3 days Events = 0 Total = 75 Risk Ratio LD = 0/75	LD > 3 days Events = 5 Total = 76 Risk Ratio ED = 5/76 LD > 3 days Events = 6 Total = 75 Risk Ratio LD = 6/75

APN: Advanced practice nurse, BMS: Bare Metal Stent, CDS: Conventional discharge strategy, CHF: Congestive heart failure, D/C: Discharge, DES: Drug Eluting Stent, ED: Early discharge, EF: Ejection fraction, F/u: Follow up, GP: Glycoprotein, IQR: Interquartile range, LD: Late discharge, LOS: Length of stay, MACE: Major adverse cardiovascular events, MI: Myocardial infarction, NCDR: National cardiovascular disease registry, PPCI: Primary percutaneous coronary intervention, POBA: Percutaneous Old Balloon Angioplasty, QOL: Quality of life, STEMI: ST-Elevation myocardial infarction.