Incidence of thrombotic complications and overall survival in hospitalized patients with COVID-19 in the second and first wave

Abstract

Introduction: In the first wave, thrombotic complications were common in COVID-19 patients. It is unknown whether state-of-the-art treatment has resulted in less thrombotic complications in the second wave.

Methods: We assessed the incidence of thrombotic complications and overall mortality in COVID-19 patients admitted to eight Dutch hospitals between September 1st and November 30th 2020. Follow-up ended at discharge, transfer to another hospital, when they died, or on November 30th 2020, whichever came first. Cumulative incidences were estimated, adjusted for competing risk of death. These were compared to those observed in 579 patients admitted in the first wave, between February 24th and April 26th 2020, by means of Cox regression techniques adjusted for age, sex and weight.

Results: In total 947 patients with COVID-19 were included in this analysis, of whom 358 patients were admitted to the ICU; 144 patients died (15%). The adjusted cumulative incidence of all thrombotic complications after 10, 20 and 30 days was 12% (95% confidence interval (CI) 9.8-15%), 16% (13-19%) and 21% (17-25%), respectively. Patient characteristics between the first and second wave were comparable. The adjusted hazard ratio (HR) for overall mortality in the second wave versus the first wave was 0.53 (95%CI 0.41-0.70). The adjusted HR for any thrombotic complication in the second versus the first wave was 0.89 (95%CI 0.65-1.2).

Conclusions: Mortality was reduced by 47% in the second wave, but the thrombotic complication rate remained high, and comparable to the first wave. Careful attention to provision of adequate thromboprophylaxis is invariably warranted.

Keywords: Anticoagulants; Blood coagulation disorders; COVID-19; Critical illness; Diagnostic imaging; Incidence; Venous thromboembolism.

Conflict of interest statement

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:

H ten Cate received research support from Bayer and Pfizer, reimbursements for Advisory boards from Leo and Portola, grant support from the Dutch Heart foundation (CVON RACE-5 and CONTRAST), REG-MED XB and the Dutch Thrombosis Foundation. He is adjunct professor with the Gutenberg University Medical center, Mainz, Germany.

MHJA Kruip reports unrestricted research grants from Bayer, Boehringer-Ingelheim, Daiichi Sankyo, Pfizer, Sobi, the Dutch Thrombosis association, and The Netherlands Organisation for Health Research and Development (ZonMW).

FA Klok reports research grants from Bayer, Bristol-Myers Squibb, Boehringer-Ingelheim, Daiichi-Sankyo, MSD, The Netherlands Organisation for Health Research and Development, Actelion, the Dutch Heart foundation and the Dutch Thrombosis association, all outside the submitted work.

MV Huisman reports unrestricted grant support from The Netherlands Organisation for Health Research and Development (ZonMW), and unrestricted grant support and fees for presentations from Boehringer-Ingelheim, Pfizer-BMS, Bayer Health Care, Aspen, Daiichi-Sankyo, all outside the submitted work.

All other authors report no disclosures.

The Dutch COVID & Thrombosis Coalition is supported by The Netherlands Organisation for Health Research and Development (ZonMw) and Dutch Thrombosis Association.

Copyright © 2021 The Author. Published by Elsevier Ltd.. All rights reserved.