Subclinical Leaflet Thrombosis and Clinical Outcomes after TAVR: A Systematic Review and Meta-Analysis

ABSTRACT

Background: Little is known about the influence of subclinical leaflet thrombosis (SCLT) on clinical outcomes after transcatheter aortic valve replacement (TAVR). Therefore, we sought to perform a systematic review and meta-analysis of studies that reported clinical outcomes in patients with or without SCLT after TAVR.

Methods: We searched Medline, PubMed, and Embase in September 2017 for studies reporting the clinical outcomes in patients with or without SCLT after TAVR. SCLT was defined as the presence of hypo-attenuated leaflet thickening (HALT) and/or hypo-attenuation affecting leaflet motion (HAM) shown on computed tomography. End-points studied included (1) mortality; (2) stroke; and (3) stroke and/or TIA. Odds ratio (OR) meta-analysis was conducted by the Peto method using a random effects model; results are presented at the 95% confidence level.

Results: A total of five studies (91 patients with SCLT; 672 patients without SCLT) met the inclusion criteria. Pooled incidence of SCLT was 15.2% (7.8–27.7%) in patients undergoing TAVR. There was no significant difference in mortality (OR:  0.86 [0.29–2.51]), stroke (OR: 1.3 [0.26–6.67]), or stroke and/or TIA (OR: 4.56 [0.35–58.8]) in patients with or without SCLT.

Conclusions: This study-level meta-analysis suggests a 15% incidence of SCLT post-TAVR, with no statistically significant associations with mortality and stroke/TIA, though with broad confidence intervals and limited statistical power. Given the lack of availability of patient-level data, as well as the relatively limited numbers of patients included across a handful of registries, ongoing surveillance as well as systematic attempts to understand better the clinical significance of SCLT will be required.

KEYWORDS:

• Hypo-attenuated leaflet thickening
• hypo-attenuation affecting leaflet motion
• leaflet thrombosis
• transcatheter aortic valve replacement
• valve thrombosis

Disclosure statements

Dr. Deepak L. Bhatt discloses the following relationships: Advisory Board: Cardax, Elsevier Practice Update Cardiology, Medscape Cardiology, Regado Biosciences; Board of Directors: Boston VA Research Institute, Society of Cardiovascular Patient Care; Chair: American Heart Association Quality Oversight Committee; Data Monitoring Committees: Cleveland Clinic, Duke Clinical Research Institute, Harvard Clinical Research Institute (including for the PORTICO trial funded by St. Jude), Mayo Clinic, Mount Sinai School of Medicine, Population Health Research Institute; Honoraria: American College of Cardiology (Senior Associate Editor, Clinical Trials and News, ACC.org), Belvoir Publications (Editor in Chief, Harvard Heart Letter), Duke Clinical Research Institute (clinical trial steering committees), Harvard Clinical Research Institute (clinical trial steering committee), HMP Communications (Editor in Chief, Journal of Invasive Cardiology), Journal of the American College of Cardiology (Guest Editor; Associate Editor), Population Health Research Institute (clinical trial steering committee), Slack Publications (Chief Medical Editor, Cardiology Today’s Intervention), Society of Cardiovascular Patient Care (Secretary/Treasurer), WebMD (CME steering committees); Other: Clinical Cardiology (Deputy Editor), NCDR-ACTION Registry Steering Committee (Chair), VA CART Research and Publications Committee (Chair); Research Funding: Abbott, Amarin, Amgen, AstraZeneca, Bristol-Myers Squibb, Chiesi, Eisai, Ethicon, Forest Laboratories, Ironwood, Ischemix, Lilly, Medtronic, Pfizer, Roche, Sanofi Aventis, The Medicines Company; Royalties: Elsevier (Editor, Cardiovascular Intervention: A Companion to Braunwald’s Heart Disease); Site Co-Investigator: Biotronik, Boston Scientific, St. Jude Medical (now Abbott); Trustee: American College of Cardiology; Unfunded Research: FlowCo, Merck, PLx Pharma, Takeda. Dr. Auffret received research grants from Edwards Lifesciences and Medtronic. Dr. Sabik discloses the following: North American principal investigator for the Abbott Laboratories–sponsored left main coronary disease randomized trial (EXCEL; NCT01205776). Society of Thoracic Surgeons board of Director; Scientific advisory board of Medtronic; Principal Investigator for PERIGON Pivotal Trial (NCT02088554) and The TRANSFORM trial (NCT01700439).