Return-to-Play Guidelines for Athletes After COVID-19 Infection

To the Editor We read with interest the Viewpoint “A Game Plan for the Resumption of Sport and Exercise After COVID-19 Infection,” where Phelan et al¹ provide an expert opinion–based algorithm for resuming physical activity after recovering from coronavirus disease 2019 (COVID-19). They carefully state that the recommendations are not evidence based, suggesting the criteria will evolve as data emerge. However, several areas of laboratory testing listed in this article could be problematic.

One relates to high-sensitivity cardiac troponin (hs-cTn) assays. The 99th percentile is an appropriate cutoff for diagnosis of acute myocardial infarction. In nonacute situations, more modest increases within the hs-cTn normal range have been of prognostic signficance.² Thus, adopting the 99th percentile as a gatekeeper for return-to-sport activity after COVID-19 could lead to a false sense of security in some patients or unnecessary concern in others. We suggest that before embracing such an approach that reference intervals are established for the specific population. Athletes may have more left ventricular hypertrophy and/or dilation, which could change the interval. Similarly, professional athletes may have higher systemic hs-cTn levels compared with sedentary adults given they exercise so heavily and therefore could be penalized because of their athletic prowess.³

Even with implementation of a more appropriate reference interval, hs-cTn is best interpreted relative to baseline. This requires use of hs-cTn assays, but most hospitals and medical centers in the US are still using less sensitive or conventional cTn assays.⁴ These will not suffice.

Second, there are known differences in the hs-cTn concentrations between sexes that are unaccounted for in this algorithm.² Third, the lack of standardization between hs-cTn assays may cause inconsistencies in interpretation because their critical values are not harmonized.

Additionally, Phelan et al¹ refer to testing for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen. The vast majority of SARS-CoV-2 detection is accomplished by amplifying viral RNA. Detection of RNA, not antigen, is the preferred approach. Although detection of serum antibodies to SARS-CoV-2 infers a prior infection, there is no guarantee of immunity. Therefore, we agree on a limited role for serology in the return-to-play clearance.

We concur that data and trials are critical to guideline development, and their current absence is a limitation. One approach to consider may be to obtain baseline hs-cTn concentrations on all athletes so comparisons can be made. If the baseline samples are obtained in a consistent and careful manner and the same manufacturer assay is consistently used for hs-cTn quantification, confounding variables will be reduced and may allow a better paradigm to develop.⁵

Corresponding Author: Alan H. B. Wu, PhD, Zuckerberg San Francisco General Hospital and Trauma Center, 1001 Potrero Ave, San Francisco, CA 94110 (alan.wu@ucsf.edu).

Published Online: November 4, 2020. doi:10.1001/jamacardio.2020.5348

Conflict of Interest Disclosures: Dr Wu has received personal fees for consulting and research grants from ET Healthcare, Abbott Laboratories, Roche Diagnostics, Thermo Fisher Scientific, Siemens, Spingo Tec, Quidel Corporation, Brava Diagnostics, Babson Diagnostics, Osler Diagnostics, Konica Minolta Healthcare, and Instrumentation Laboratory. Dr Jaffe has received personal fees for consulting from Abbott Laboratories, Siemens, Beckman Coulter Diagnostics, Roche, ET Healthcare, SphingoTec, Quidel, Brava Diagnostics, Blade Therapeutics, Amgen, and Novartis. No other disclosures were reported.