ABSTRACT
BackgroundThe longitudinal trajectories of cardiopulmonary abnormalities and symptoms following infection with coronavirus disease (COVID-19) are unclear. We sought to describe their natural history in previously hospitalised patients, compare this with controls, and assess the relationship between symptoms and cardiopulmonary impairment at 6 months post-COVID-19. MethodsFifty-eight patients and thirty matched controls underwent symptom-questionnaires, cardiac and lung magnetic resonance imaging (CMR), cardiopulmonary exercise test (CPET), and spirometry at 3 months following COVID-19. Of them, forty-six patients returned for follow-up assessments at 6 months. FindingsAt 2-3 months, 83% of patients had at least one cardiopulmonary symptom versus 33% of controls. Patients and controls had comparable biventricular volumes and function. Native cardiac T1 (marker of inflammation) and late gadolinium enhancement (LGE, marker of focal fibrosis) were increased in patients. Sixty percent of patients had lung parenchymal abnormalities on CMR and 55% had reduced peak oxygen consumption (pVO2) on CPET. By 6 months, 53% of patients remained symptomatic. On CMR, indexed right ventricular (RV) end-diastolic volume (-4{middle dot}3 mls/m2, P=0{middle dot}005) decreased and RV ejection fraction (+3{middle dot}2%, P=0{middle dot}0003) increased. Native T1 and LGE improved and was comparable to controls. Lung parenchymal abnormalities and peak VO2, although better, were abnormal in patients versus controls. 31% had reduced pVO2 secondary to fatigue and submaximal tests. Cardiopulmonary symptoms in patients did not associate with CMR, lung function, or CPET measures. InterpretationIn patients, cardiopulmonary abnormalities improve over time, though some measures remain abnormal relative to controls. Persistent symptoms at 6 months post-COVID-19 did not associate with objective measures of cardiopulmonary health. FundingNIHR Oxford and Oxford Health BRC, Oxford BHF CRE, UKRI and Wellcome Trust.
ABSTRACT
BackgroundThe medium-term effects of Coronavirus disease (COVID-19) on multiple organ health, exercise capacity, cognition, quality of life and mental health are poorly understood. MethodsFifty-eight COVID-19 patients post-hospital discharge and 30 comorbidity-matched controls were prospectively enrolled for multiorgan (brain, lungs, heart, liver and kidneys) magnetic resonance imaging (MRI), spirometry, six-minute walk test, cardiopulmonary exercise test (CPET), quality of life, cognitive and mental health assessments. FindingsAt 2-3 months from disease-onset, 64% of patients experienced persistent breathlessness and 55% complained of significant fatigue. On MRI, tissue signal abnormalities were seen in the lungs (60%), heart (26%), liver (10%) and kidneys (29%) of patients. COVID-19 patients also exhibited tissue changes in the thalamus, posterior thalamic radiations and sagittal stratum on brain MRI and demonstrated impaired cognitive performance, specifically in the executive and visuospatial domain relative to controls. Exercise tolerance (maximal oxygen consumption and ventilatory efficiency on CPET) and six-minute walk distance (405{+/-}118m vs 517{+/-}106m in controls, p<0.0001) were significantly reduced in patients. The extent of extra-pulmonary MRI abnormalities and exercise tolerance correlated with serum markers of ongoing inflammation and severity of acute illness. Patients were more likely to report symptoms of moderate to severe anxiety (35% versus 10%, p=0.012) and depression (39% versus 17%, p=0.036) and a significant impairment in all domains of quality of life compared to controls. InterpretationA significant proportion of COVID-19 patients discharged from hospital experience ongoing symptoms of breathlessness, fatigue, anxiety, depression and exercise limitation at 2-3 months from disease-onset. Persistent lung and extra-pulmonary organ MRI findings are common. In COVID-19 survivors, chronic inflammation may underlie multiorgan abnormalities and contribute to impaired quality of life. FundingNIHR Oxford and Oxford Health Biomedical Research Centres, British Heart Foundation Centre for Research Excellence, UKRI, Wellcome Trust, British Heart Foundation.
ABSTRACT
Cardiovascular magnetic resonance (CMR) is the current gold standard for imaging cardiac anatomy, function, and advanced myocardial tissue characterization. After cine, late gadolinium enhancement (LGE), and perfusion imaging, parametric mapping is widely regarded as the 4th era of myocardial CMR development. In contrast to conventional CMR tissue characterization techniques, which rely on relative variations in image intensities to highlight abnormal tissues, parametric mapping provides direct visualization of tissue MR properties such as T1, T2 and T2* in absolute denominations (e.g. in milliseconds). Presentation as pixel-wise parametric maps adds spatial information for a more complete assessment of the myocardium. Advantages of parametric mapping include direct, quantitative comparisons inter- and within-individuals, as well as detection of diffuse disease not evident on conventional CMR imaging, without the need for contrast agents. CMR parametric mapping methods have matured over the past decade into clinical tools, demonstrating not only clinical utility but added value in a wide range of cardiac diseases. They are particularly useful for the evaluation of acute myocardial injury, suspected infiltration and heart failure of unclear etiology. This review discusses the background of parametric mapping, particularly T1-, T2- and ECV-mapping, general magnetic resonance physics principles, clinical applications (including imaging protocols, image analysis and reporting guidelines), current challenges and future directions. CMR parametric mapping is increasingly available on routine clinical scanners, and promises to deliver advanced myocardial tissue characterization beyond conventional CMR techniques, ultimately helping clinicians to benefit patients in their clinical management.
