Patterns of myocardial injury in recovered troponin-positive COVID-19 patients assessed by cardiovascular magnetic resonance.

BACKGROUND: Troponin elevation is common in hospitalized COVID-19 patients, but underlying aetiologies are ill-defined. We used multi-parametric cardiovascular magnetic resonance (CMR) to assess myocardial injury in recovered COVID-19 patients. METHODS AND RESULTS: One hundred and forty-eight patients (64 ± 12 years, 70% male) with severe COVID-19 infection [all requiring hospital admission, 48 (32%) requiring ventilatory support] and troponin elevation discharged from six hospitals underwent convalescent CMR (including adenosine stress perfusion if indicated) at median 68 days. Left ventricular (LV) function was normal in 89% (ejection fraction 67% ± 11%). Late gadolinium enhancement and/or ischaemia was found in 54% (80/148). This comprised myocarditis-like scar in 26% (39/148), infarction and/or ischaemia in 22% (32/148) and dual pathology in 6% (9/148). Myocarditis-like injury was limited to three or less myocardial segments in 88% (35/40) of cases with no associated LV dysfunction; of these, 30% had active myocarditis. Myocardial infarction was found in 19% (28/148) and inducible ischaemia in 26% (20/76) of those undergoing stress perfusion (including 7 with both infarction and ischaemia). Of patients with ischaemic injury pattern, 66% (27/41) had no past history of coronary disease. There was no evidence of diffuse fibrosis or oedema in the remote myocardium (T1: COVID-19 patients 1033 ± 41 ms vs. matched controls 1028 ± 35 ms; T2: COVID-19 46 ± 3 ms vs. matched controls 47 ± 3 ms). CONCLUSIONS: During convalescence after severe COVID-19 infection with troponin elevation, myocarditis-like injury can be encountered, with limited extent and minimal functional consequence. In a proportion of patients, there is evidence of possible ongoing localized inflammation. A quarter of patients had ischaemic heart disease, of which two-thirds had no previous history. Whether these observed findings represent pre-existing clinically silent disease or de novo COVID-19-related changes remain undetermined. Diffuse oedema or fibrosis was not detected.

Temporal convolutional networks allow early prediction of events in critical care.

OBJECTIVE: Clinical interventions and death in the intensive care unit (ICU) depend on complex patterns in patients' longitudinal data. We aim to anticipate these events earlier and more consistently so that staff can consider preemptive action. MATERIALS AND METHODS: We use a temporal convolutional network to encode longitudinal data and a feedforward neural network to encode demographic data from 4713 ICU admissions in 2014-2018. For each hour of each admission, we predict events in the subsequent 1-6 hours. We compare performance with other models including a recurrent neural network. RESULTS: Our model performed similarly to the recurrent neural network for some events and outperformed it for others. This performance increase was more evident in a sensitivity analysis where the prediction timeframe was varied. Average positive predictive value (95% CI) was 0.786 (0.781-0.790) and 0.738 (0.732-0.743) for up- and down-titrating FiO2, 0.574 (0.519-0.625) for extubation, 0.139 (0.117-0.162) for intubation, 0.533 (0.492-0.572) for starting noradrenaline, 0.441 (0.433-0.448) for fluid challenge, and 0.315 (0.282-0.352) for death. DISCUSSION: Events were better predicted where their important determinants were captured in structured electronic health data, and where they occurred in homogeneous circumstances. We produce partial dependence plots that show our model learns clinically-plausible associations between its inputs and predictions. CONCLUSION: Temporal convolutional networks improve prediction of clinical events when used to represent longitudinal ICU data.

'Normal' serum sodium concentration among inpatients over 65 admitted to hospital: an observational study.

BACKGROUND: The usual reference range of serum sodium (typically 135-145 mmol/l) is derived from healthy populations but may not apply to hospital patients. OBJECTIVES: To describe the range of serum sodium in inpatients and outpatients of both sexes at different ages. To ascertain correlates of serum sodium among older inpatients. To describe the association between sodium and mortality. METHODS: We used routine hospital data on serum sodium in inpatients admitted between 1 January 2011 and 31 December 2014 and patients attending outpatient or community clinics with no record of admission to the same hospitals in the same period. We investigated the distribution of sodium values within these groups and explored the relationship between serum sodium and death using logistic regression. RESULTS: Levels among hospital inpatients were significantly lower than in outpatients of the same age. Emergency admissions had lower levels and those admitted from care homes higher levels, risk of inhospital death began to rise at 140 mmol/L, well within the 'normal' range. Patients with a serum sodium concentration of 145 mmol/L on admission have a risk of inhospital death 3.7 times higher than that of a patient with a concentration of 140 mmol/L. CONCLUSIONS: The range for serum sodium concentration on admission in inpatients is broader and lower than the commonly accepted reference range. The risk of mortality increases at sodium concentration >139 mmol/L, well within reference range currently considered normal.

Are patients admitted to hospitals from care homes dehydrated? A retrospective analysis of hypernatraemia and in-hospital mortality.

OBJECTIVES: To compare risks of hypernatraemia on admission to hospital in persons who were with those who were not identified as care home residents and evaluate the association of hypernatraemia with in-hospital mortality. DESIGN: Retrospective observational study. SETTING: A National Health Service Trust in London. PARTICIPANTS: A total of 21,610 patients aged over 65 years whose first admission to the Trust was between 1 January 2011 and 31 December 2013. MAIN OUTCOME MEASURES: Hypernatraemia on admission (plasma Na > 145 mmol/L) and in-hospital death. RESULTS: Patients admitted from care homes had 10-fold higher prevalence of hypernatraemia than those from their own homes (12.0% versus 1.3%, respectively; odds ratio [OR]: 10.5, 95% confidence interval [CI]: 8.43-13.0). Of those with hypernatraemia, nine in 10 cases were associated with nursing home ECOHOST residency (attributable fraction exposure: 90.5%), and the population attributable fraction of hypernatraemia on admission associated with care homes was 36.0%. After correcting for age, gender, mode of admission and dementia, care home residents were significantly more likely to be admitted with hypernatraemia than were own-home residents (adjusted odds ratio [AOR]: 5.32, 95% CI: 3.85-7.37). Compared with own-home residents, care home residents were also at about a two-fold higher risk of in-hospital mortality compared with non-care home residents (AOR: 1.97, 95% CI: 1.59-2.45). Consistent with evidence that hypernatraemia is implicated in higher mortality, the association of nursing homes with in-hospital mortality was attenuated after adjustment for it (AOR: 1.61, 95% CI: 1.26-2.06). CONCLUSIONS: Patients admitted to hospital from care homes are commonly dehydrated on admission and, as a result, appear to experience significantly greater risks of in-hospital mortality.

Combining patient administration and laboratory computer systems - a proposal to measure and improve the quality of care.

Several approaches to measuring the quality of hospital care have been suggested. We propose the simple and objective approach of using the health related data of the patient administration systems and the laboratory results that have been collected and stored electronically in hospitals for years. Imaginative manipulation of this data can give new insights into the quality of patient care.

Intensive care transfers.

The demand for intensive care has increased relentlessly over the past 30 years. It is now regarded as a necessity rather than a luxury. The provision of intensive care has lagged behind that demand. Thus, patients who are judged to need intensive care when a bed is unavailable are increasingly transferred to another hospital for such care. The present commentary discusses intensive care transfers and describes a website being trialled in the UK that helps with locating available intensive care beds.