Advances in Clinical Cardiology 2021: A Summary of Key Clinical Trials

Abstract

Introduction: Over the course of 2021, numerous key clinical trials with valuable contributions to clinical cardiology were published or presented at major international conferences. This review seeks to summarise these trials and reflect on their clinical context.

Methods: The authors reviewed clinical trials presented at major cardiology conferences during 2021 including the American College of Cardiology (ACC), European Association for Percutaneous Cardiovascular Interventions (EuroPCR), European Society of Cardiology (ESC), Transcatheter Cardiovascular Therapeutics (TCT), American Heart Association (AHA), European Heart Rhythm Association (EHRA), Society for Cardiovascular Angiography and Interventions (SCAI), TVT-The Heart Summit (TVT) and Cardiovascular Research Technologies (CRT). Trials with a broad relevance to the cardiology community and those with potential to change current practice were included.

Results: A total of 150 key cardiology clinical trials were identified for inclusion. Interventional cardiology data included trials evaluating the use of new generation novel stent technology and new intravascular physiology strategies such as quantitative flow ratio (QFR) to guide revascularisation in stable and unstable coronary artery disease. New trials in acute coronary syndromes focused on shock, out of hospital cardiac arrest (OOHCA), the impact of COVID-19 on ST-elevation myocardial infarction (STEMI) networks and optimal duration/type of antiplatelet treatment. Structural intervention trials included latest data on transcatheter aortic valve replacement (TAVR) and mitral, tricuspid and pulmonary valve interventions. Heart failure data included trials with sodium-glucose cotransporter 2 (SGLT2) inhibitors, sacubitril/valsartan and novel drugs such as mavacamten for hypertrophic cardiomyopathy (HCM). Prevention trials included new data on proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. In electrophysiology, new data regarding atrial fibrillation (AF) screening and new evidence for rhythm vs. rate control strategies were evaluated.

Conclusion: This article presents a summary of key clinical cardiology trials published and presented during the past year and should be of interest to both practising clinicians and researchers.

Keywords: Acute coronary syndrome; Antiplatelets; Atrial fibrillation; Cardiology; Coronary revascularisation; Heart failure; Left atrial appendage closure; Lipids; Mechanical support; Mitral clip; Shock; Transcatheter aortic valve implantation; Transcatheter tricuspid valve interventions.

Fig. 1

A summary of key findings of the NACMI Registry of acute myocardial infarction in patients with coronavirus disease 2019 [1]. COVID  coronavirus disease, MACE major adverse cardiac events, NACMI North American COVID-19 and STEMI. Reproduced with kind permission of the Journal of the American College of Cardiology (Garcia et al. [2])

Fig. 2

Figure demonstrating meta-regression of rate ratios for cardiac mortality with revascularisation plus medical therapy vs. medical therapy alone in relation to follow-up duration. The size of the data markers is proportional to the size of trial. Rate ratios lower than 1 indicate cardiac death reduction with revascularisation. The solid line represents the meta-regression slope of the change in cardiac death rate ratio for revascularisation plus medical therapy vs. medical therapy alone with increasing length of follow-up. Reproduced with permission from the European Heart Journal (Naverese et al. [19])

Fig. 3

Figure demonstrating definite or probable stent thrombosis at 2 years for Biomatrix Alpha vs. LEA[1]DERS with propensity-adjustment. Stent thrombosis was adjudicated using identical criteria in both studies. CoCr-BP-BES cobalt chromium biodegradable polymer Biolimus A9-eluting stent, MACE major cardiac adverse events, SS-BP-BES stainless steel biodegradable polymer Biolimus A9-eluting stent (Menown et al. [25])

Fig. 4

Central illustration from Zahr et al.’s paper demonstrating 30-day outcomes from the intrepid transcatheter mitral valve replacement early feasability study. A Image of the Intrepid transfemoral transcatheter replacement bioprothesis. B Delivery system. C Summary of 30-day results demonstrating improvement in mitral regurgitation. D Improvement in NYHA score. Reproduced with permission from the Journal of the American College Cardiology (Zahr et al. [53])

Fig. 5

Image of the EVOQUE™ transfemoral tricuspid valve replacement (Edwards Lifesciences LLC, Irvine, CA). Image supplied with permission from Edwards Lifesciences LLC

Fig. 6

The Medtronic Harmony™ Transcatheter Pulmonary Valve replacement system. Reproduced with permission from Medtronic, Inc

Fig. 7

Graphs showing the cumulative incidence of the primary (top left) and secondary safety (bottom left) endpoints according to eGFR, over 12 months. Figures to the right show the hazard ratio treatment effect (ticagrelor vs. prasugrel) according to eGFR (reproduced with the permission of Elsevier) [97]

Fig. 8

Illustration reproduced from Kaplan–Meier curve demonstrating time to first atrial arrhythmia recurrence in the cryoablation cohort and the antiarrhythmic drug cohort. At 12 months from index procedure there were significantly more patients who were free from arrhythmia in the cryoablation group compared with the control group: 82.2% vs. 67.6% (HR 0.48, 95% CI 0.26–0.86; p  =  0.013). Reproduced with permission from Oxford University Press (OUP) (Kuniss et al. [115])

Fig. 9

Clinical outcomes in participants randomised to a fixed-dose combination primary prevention pill versus a control group (Joseph et al. [146])