Table 2: Study design and patient population characteristics in studies with ≥20 patients undergoing Impella-supported high-risk percutaneous coronary intervention.
| Reference | Study design | Sample size (treatment dates) | Elective/urgent HR-PCI | Major bleeding definition* | Definition provided in Methods |
|---|---|---|---|---|---|
| Azzalini et al. (2020)16 | Retrospective, single-centre study (Germany) | 64 patients (2017–2018) | Elective or urgent (including STEMI) | 1 | N |
| Johannsen et al. (2019)27 | Retrospective, single-centre study (Germany) | 61 patients (2016–2018) | Elective or urgent (including STEMI; 46% ACS) | 2 | Y |
| Becher (2019)18 | Retrospective, single-centre study (Germany) | 54 patients (26 Impella; 2015–2016) | Elective or urgent (15% STEMI) | 3 | N |
| Riley et al. (2018)29 | Retrospective, multicentre CTO-PCI study (5 centres, USA) | 57 patients (2013–2017) | 100% elective | 2 | Y |
| Russo et al. (2019)30 | Retrospective, multicentre study (2 centres, Italy) | 37 patients (2013–2016) | 100% elective (no AMI within 24 hours) | 2 | N |
| Amponsah et al. (2017)14 | Retrospective, single-centre study (USA) | 40 patients (2013–2014) | NR | 1 | Y |
| Danek et al. (2018)22 | Retrospective, multicentre PROGRESS-CTO registry (12 centres, USA) | 1,598 patients (50 Impella 2.5/CP; 2012–2017) | 18% urgent (Impella initiated during PCI), 82% elective | 3 | Y |
| Doshi et al. (2019)24 | Retrospective, multicentre study (2 centres, USA) | 160 patients (2011–2016) | Elective or urgent (27% STEMI) | 2 | Y |
| Azzalini et al. (2020)16 | Retrospective, single-centre study (USA) | 250 patients (2009–2018) | Elective or urgent (no STEMI) | 2 | Y |
| Venugopal et al. 2015)32 | Retrospective, single-centre registry (UK) | 49 patients (45 HR-PCI; 2008–2014) | 62% urgent, 38% elective | 1 | N |
| Alasnag et al. (2011)11 | Retrospective, single-centre study (USA) | 60 patients (2008–2010) | 100% elective | 1 | N |
| Anusionwu et al. (2012)15 | Retrospective, single-centre study (USA) | 25 patients (2008–2009) | NR | 1 | N |
| Burzotta et al. (2019)19 | Retrospective, multicentre Roma-Verona registry (2 centres, Italy) | 86 patients (2007–2016) | 100% elective (no AMI within 24 hours) | 3 | Y |
| Alraies et al. (2019)12 | Retrospective, multicentre cVAD registry (USA, Canada and Europe) | 1,053 patients (2007–2015) | Elective or urgent | 3 | Y |
| Cohen et al. (2015)21 | Retrospective, multicentre USpella registry (49 centres, USA and Canada) | 637 patients (USpella patients; 2007–2013) | Elective or urgent | 3 | N |
| Cohen et al. (2015)21/O’Neill et al. (2012)7 | Multicentre PROTECT II RCT (112 centres, USA, Canada and Europe)† | 216 patients (Impella arm of PROTECT II, 2007–2010) | Elective or urgent (no recent MI) | 3 | N |
| Iliodromitis et al. (2011)26 | Retrospective, single-centre study (Germany) | 38 patients (2006–2009) | 100% urgent (unstable angina or NSTEMI) | 3 | Y |
| Ferreiro et al. (2010)25 | Retrospective, single-centre study (Spain) | 27 patients (2006–2008) | 100% elective | 3 | Y |
| Dixon et al. (2009)23 | Prospective, multicentre PROTECT I study (USA and Netherlands) | 20 patients (2006–2007) | Elective or urgent (no STEMI within 7 days or CA within 24 hours) | 1 | N |
| Kovacic et al. (2013)28 | Retrospective, single-centre study (USA) | 68 patients (36 Impella; 2005–2010) | 100% elective | 2 | Y |
| Chieffo et al. (2020)20 | Retrospective, multicentre IMP-IT registry (17 centres, Italy) | 406 patients (177 Impella HR-PCI; 2004–2018) | Elective or urgent (32% Impella placement during PCI, 0.5% after PCI) | 2 | y |
| Sjauw et al. (2009)31 | Retrospective, multicentre Europella registry (Europe) | 144 patients (2004–2007) | 100% elective (no STEMI within 48 hours) | 3 | Y |
| Baumann et al. (2020)17 | Retrospective, multicentre German Impella registry (6 centres, Germany) | 157 patients (unknown years) | Elective or ‘semi-elective’ | 1 | N |
*Major bleeding definitions in the included studies were considered to fall into three separate definition groups, identified with the numbers 1–3:
1) no major bleeding definition provided, or definition was incomplete, i.e. listing a variety of vascular complication event types and transfusion, but not specifying an interventional threshold for major bleeding
2) major bleeding defined as bleeding event requiring transfusion, surgery or any unplanned procedure
3) major bleeding defined as bleeding event requiring transfusion or surgery.
† Both Cohen (2015) and O’Neill (2012) publications are listed for the PROTECT II trial. The Cohen publication is the primary report of study outcomes; however, it did not detail bleeding and vascular complications, which were provided in the comparative analysis conducted by Cohen et al.
ACS = acute coronary syndrome; AMI = acute myocardial infarction; CA = cardiac arrest; HR-PCI = high-risk PCI; MI = myocardial infarction; NR = not reported; NSTEMI = Non-ST segment elevation myocardial infarction; PCI = percutaneous coronary intervention; STEMI = ST-segment elevation myocardial infarction.