Longitudinal trajectory of cardiac magnetic resonance and cardiopulmonary exercise testing findings in moderate to severe COVID-19 and association with symptoms

ABSTRACT

Background: Cardiac magnetic resonance (CMR) and cardiopulmonary exercise testing (CPET) have provided important insights into the prevalence of early cardiopulmonary abnormalities in COVID-19 patients. It is currently unknown whether such abnormalities persist over time and relate to ongoing symptoms. Purpose: To describe the longitudinal trajectory of cardiopulmonary abnormalities on CMR and CPET in moderate to severe COVID-19 patients and assess their relationship with ongoing symptoms. Methods: Fifty-eight previously hospitalised COVID-19 patients and 30 age, sex, body mass index, comorbidity-matched controls underwent CMR, CPET and a symptom-based questionnaire at 2-3 months (2-3m). Repeat assessments (including gas transfer) were performed in 46 patients at 6 months (6m). Results: During admission, 1/3rd of patients needed ventilation or intensive care (Table 1) and three (5%) had a raised troponin. On CMR, patients had preserved left (LV) and right ventricular (RV) volumes and function at 2-3m from infection. By 6m, LV function did not change but RV end diastolic volume decreased (mean difference -4.3 mls/m2, p=0.005) and RV function increased (mean difference +3.2%, p<0.001, Fig. 1A). Patients had higher native T1 (a marker of fibroinflammation) at 2-3m compared to controls (Table 1, Fig. 1B), which normalised by 6m. Extracellular volume was normal and improved by 6m. Native T2, a marker of myocardial oedema, did not differ between patients and controls on serial CMR. At 2- 3m, late gadolinium enhancement (LGE) was higher in patients (p=0.023) but became comparable to controls by 6m (p=0.62). Six (12%) patients had LGE in a myocarditis pattern and one (2%) had myocardial infarction. None had active myocarditis using the Modified Lake Louise Criteria. Lung imaging (T2-weighted) revealed parenchymal abnormalities in 2/3rds of patients at 2-3 and 6 months. The extent of abnormalities improved on serial imaging (Table 1). Gas transfer (DLco) was worse in those with lung abnormalities (77% vs 91% of predicted, p=0.009). CPET revealed reduced peak oxygen consumption (pVO2) in patients at 2-3m, which normalised by 6m (80.5% to 93.3% of predicted, p=0.001) (Table 1, Fig. 1C). At 2-3m, 49% of patients had submaximal tests (respiratory exchange ratio <1.1), reducing to 25% by 6m (p=0.057). VE/VCO2 slope, a marker of lung efficiency, was abnormal in patients but improved on serial CPET (Table 1, Fig. 1D). Cardiac symptoms (chest pain, dyspnoea, palpitations, dizziness or syncope) were present in 83% of patients at 2-3m, reducing to 52% by 6m (p<0.001). There was no significant association between CMR or CPET parameters and persistent cardiac symptoms at 6m (Fig. 1E). Conclusions: Cardiopulmonary parameters (on CMR and CPET) improved in moderate-severe COVID-19 patients from 2-3 to 6 months post infection. Despite this, patients continued to experience cardiac symptoms which had no relationship with measured parameters. (Figure Presented).