Study explores incidence of cardiac impairment a year after SARS-CoV-2 infection

In a recent study posted to the medRxiv* pre-print server, researchers used cardiac magnetic resonance (CMR) to show the one-year trajectory of cardiac impairment in long coronavirus disease (COVID) patients. Additionally, they examined the impact of acute hospitalizations for COVID 2019 (COVID-19) on cardiac impairment.

Background

Long COVID patients exhibit persistent symptoms, including dyspnoea, palpitations, and chest pain over 12 weeks following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Several cross-sectional studies have also reported cardiac impairment of varying degrees in long COVID patients using different methodologies; however, studies elucidating the association between long COVID and cardiac impairment are sparse.

About the study

In the present study, researchers invited 534 long COVID patients to participate in the CoverScan study for a multiparametric magnetic resonance imaging (MRI) assessment of the lungs, heart, liver, pancreas, kidneys, and spleen between May 2020 and August 2021. The test subjects who showed organ impairment in the baseline MRI scan in more than one of the following organs – lungs, heart, liver, spleen, pancreas, kidneys were followed up for six months.

The control group comprised sex and age-matched 92 healthy individuals; scanned twice on the same date as the test subjects with a 10-minute interval to assess the measurement repeatability. Using repeatability coefficients (RC) for each CMR metric in healthy controls, the researchers determined the smallest detectable difference between repeated scans. Likewise, they assessed baseline and follow-up metrics using reference ranges calculated in healthy controls.

On both the MRI scan dates, the researchers also collected two blood samples, of which one was sent for analysis immediately, and the other was fractionated and frozen for subsequent analysis.

The study definition of cardiac impairment encompassed ≥1 outside of reference range for left or right ventricular ejection fraction (LVEF or RVEF) or left or right ventricular end-diastolic volume (LVEDV or RVEDV), low 3D echocardiographic global longitudinal strain (GLS) or ≥3 quantitative T1 mapping segments. Similarly, multi-organ impairment was defined as ≥2 measurements outside reference ranges in an organ, excluding elevated kidney or liver volume.

Study findings

CMR data was available for 534 individuals at a six-months median after the appearance of the first COVID-19 symptoms. Only one of six individuals had abnormal CMR with low LVEF and RVEF; additionally, 62% of individuals with cardiac impairment had severe long COVID, based on questionnaires. 

Cardiac impairment was prevalent in 19% and 15% of long COVID patients at six and 12 months of follow-up, respectively. Although some of the patients had myocarditis, it was difficult to diagnose by routine echocardiography.

Over 43% of individuals had severe COVID-19 symptoms, including fatigue, shortness of breath, headache, chest pain, and cough. Interestingly, symptom prevalence was similar regardless of cardiac impairment in long COVID patients.

At the six-month-follow up, one of the five individuals suffered from a cardiac impairment, predominantly non-myocarditis. About 81% of individuals presenting with cardiac injury at baseline in this study did not require acute COVID-19 hospitalization.

Although MRI assessment showed a higher prevalence of cardiac T1 abnormalities and multi-organ involvement (renal) in those with cardiac impairment and acute COVID-19 hospitalization, blood biomarkers and symptoms did not differentiate between hospitalized and non-hospitalized groups.

Three months after infection, 26% of the 58 hospitalized long COVID patients had persistent abnormalities in cardiac T1, and 29% had increased cortical T1, a marker of kidney inflammation. After six months, 52% had persistent symptoms and cardiac impairment. While in 201 individuals, the authors observed 26% and 4% renal impairment, in 443 individuals, 10 months post-mild-to-moderate COVID-19, subclinical multi-organ impairment was associated with cardiac impairment. After a year of follow-up, 54% of individuals with cardiac impairment did not fully recover.

Importantly, CMR parameters, including LVEF, 3D GLS, and cardiac T1 were predictive of the quality of life and COVID-19 symptom severity at 12 months.

Conclusions

The study conducted CMR of the non-hospitalized, post-COVID-19 cohort in a non-acute setting for one year and reported several new findings.

Overall, 19% and 58% of long COVID patients presented cardiac impairment at baseline and had ongoing cardiac impairment at 12 months, respectively. Moreover, the patients most commonly suffered from T1, T2, and LGE abnormalities. At baseline, the authors noted that high RVEDV, low LVEF, and low GLS were associated with cardiac impairment, and low LVEF at baseline resulted in persistent cardiac impairment at 12 months.

The study data could be used for cardiac metrics and definition standardization and to scale up research, practice documentation, and cardiac monitoring.

*Important notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Written by

Neha Mathur

Neha is a digital marketing professional based in Gurugram, India. She has a Master’s degree from the University of Rajasthan with a specialization in Biotechnology in 2008. She has experience in pre-clinical research as part of her research project in The Department of Toxicology at the prestigious Central Drug Research Institute (CDRI), Lucknow, India. She also holds a certification in C++ programming.