Cumulative steroid dose in hospitalized patients and COVID-19-associated pulmonary aspergillosis

BACKGROUND

Severe COVID-19 elicits a hyperimmune response frequently amenable to steroids, which in turn increase the risk for opportunistic infections. COVID-19 associated pulmonary aspergillosis (CAPA) is a complication known to be associated with immunomodulatory treatment. The role of cumulative steroid dose in the development of CAPA is unclear. This study evaluates the relationship between cumulative steroid dose in hospitalized individuals with COVID-19 pneumonia and the risk for CAPA.

METHODS

This retrospective cohort study includes 135 hospitalized patients with PCR-confirmed COVID-19 pneumonia at a tertiary centre in north Mexico. Patients who developed CAPA were matched by age and gender to two controls with COVID-19 pneumonia who did not develop CAPA defined and classified as possible, probable, or proven according to 2020 ECMM/ISHAM criteria. Cumulative steroid dose in dexamethasone equivalents was obtained from admission until death, discharge, or diagnosis of CAPA (whichever occurred first). The risk of CAPA by the continuous cumulative steroid dose was assessed using a logistic regression model.

RESULTS

Forty-five patients were diagnosed with CAPA and matched to 90 controls. Mean age was 61 ± 14 years, and 72% were male. Mean cumulative steroid dose was 66 ± 75 mg in patients without CAPA vs 195 ± 226 mg in patients with CAPA (P<0.001). The risk for CAPA increased with higher cumulative dose of steroids (OR 1.0075, 95% CI: 1.0033-1.0116).

CONCLUSIONS

Patients who developed CAPA had a history of higher cumulative steroid dose during hospitalization. The risk for CAPA increases ∼8% for every 10 mg of dexamethasone used.

Stratifying risk outcomes among adult COVID-19 inpatients with high flow oxygen: The R4 score

Background

High flow oxygen therapy (HFO) is a widely used intervention for pulmonary complications. Amid the coronavirus infectious disease 2019 (COVID-19) pandemic, HFO became a popular alternative to conventional oxygen supplementation therapies. Risk stratification tools have been repurposed –and new ones developed– to estimate outcome risks among COVID-19 patients. This study aims to provide a simple risk stratification system to predict invasive mechanical ventilation (IMV) or death among COVID-19 inpatients on HFO.

Methods

Among 529 adult inpatients with COVID-19 pneumonia, we selected unadjusted clinical risk factors for developing the composite endpoint of IMV or death. The risk for the primary outcome by each category was estimated using a Cox proportional hazards model. Bootstrapping was used to validate the results.

Results

Age above 62, eGFR under 60 ml/min, room air SpO2 ≤89 % upon admission, history of hypertension, history of diabetes, and any comorbidity (cancer, cardiovascular disease, COPD/ asthma, hypothyroidism, or autoimmune disease) were considered for the score. Each of the six criteria scored 1 point. The score was further simplified into 4 categories: 1) 0 criteria, 2) 1 criterion, 3) 2-3 criteria, and 4) ≥4 criteria. Taking the first category as the reference, risk estimates for the primary endpoint were HR; 2.94 [1.67 – 5.26], 4.08 [2.63 – 7.05], and 6.63 [3.74 – 11.77], respectively. In ROC analysis, the AUC for the model was 0.72.

Conclusions

Our score uses simple criteria to estimate the risk for IMV or death among COVID-19 inpatients with HFO. Higher category reflects consistent increases in risk for the endpoint.

Cardiac responses to β-adrenoceptor stimulation is partly dependent on mitochondrial calcium uniporter activity

BACKGROUND AND PURPOSE

Despite the importance of mitochondrial Ca(2+) to metabolic regulation and cell physiology, little is known about the mechanisms that regulate Ca(2+) entry into the mitochondria. Accordingly, we established a system to determine the role of the mitochondrial Ca(2+) uniporter in an isolated heart model, at baseline and during increased workload following β-adrenoceptor stimulation.

EXPERIMENTAL APPROACH

Cardiac contractility, oxygen consumption and intracellular Ca(2+) transients were measured in ex vivo perfused murine hearts. Ru360 and spermine were used to modify mitochondrial Ca(2+) uniporter activity. Changes in mitochondrial Ca(2+) content and energetic phosphate metabolite levels were determined.

KEY RESULTS

The addition of Ru360 , a selective inhibitor of the mitochondrial Ca(2+) uniporter, induced progressively and sustained negative inotropic effects that were dose-dependent with an EC50 of 7 μM. Treatment with spermine, a uniporter agonist, showed a positive inotropic effect that was blocked by Ru360 . Inotropic stimulation with isoprenaline elevated oxygen consumption (2.7-fold), Ca(2+) -dependent activation of pyruvate dehydrogenase (5-fold) and mitochondrial Ca(2+) content (2.5-fold). However, in Ru360 -treated hearts, this parameter was attenuated. In addition, β-adrenoceptor stimulation in the presence of Ru360 did not affect intracellular Ca(2+) handling, PKA or Ca(2+) /calmodulin-dependent PK signalling.

CONCLUSIONS AND IMPLICATIONS

Inhibition of the mitochondrial Ca(2+) uniporter decreases β-adrenoceptor response, uncoupling between workload and production of energetic metabolites. Our results support the hypothesis that the coupling of workload and energy supply is partly dependent on mitochondrial Ca(2+) uniporter activity.

Surgical considerations on the use of the percutaneous ventricular assist device TandemHeart in critical aortic valve stenosis

Decompensated aortic valve stenosis is a life-threatening condition. Aortic valve replacement in patients with cardiogenic shock due to critical aortic stenosis is a high-risk procedure and is associated with increased operative mortality. We describe the clinical course of a patient who was transferred to our institution in cardiogenic shock and with multiple organ failure, due to decompensated aortic valve stenosis. The patient received the percutaneous left ventricular assist device TandemHeart which has been developed for short-term cardiac support. After hemodynamic improvement the patient underwent successful aortic valve replacement. The device was left in place until the patient had recovered from surgery. The excellent outcome suggests that a perioperative mechanical support might greatly improve the safety of aortic valve replacement in the presence of cardiogenic shock.

HSP60 in heart failure: abnormal distribution and role in cardiac myocyte apoptosis

Heat shock protein (HSP) 60 is a mitochondrial and cytosolic protein. Previously, we reported that HSP60 doubled in end-stage heart failure, even though levels of the protective HSP72 were unchanged. Furthermore, we observed that acute injury in adult cardiac myocytes resulted in movement of HSP60 to the plasma membrane. We hypothesized that the inflammatory state of heart failure would cause translocation of HSP60 to the plasma membrane and that this would provide a pathway for cardiac injury. Two models were used to test this hypothesis: 1) a rat model of heart failure and 2) human explanted failing hearts. We found that HSP60 localized to the plasma membrane and was also found in the plasma early in heart failure. Plasma membrane HSP60 localized to lipid rafts and was detectable on the cell surface with the use of both flow cytometry and confocal microscopy. Localization of HSP60 to the cell surface correlated with increased apoptosis. In heart failure, HSP60 is in the plasma membrane fraction, on the cell surface, and in the plasma. Membrane HSP60 correlated with increased apoptosis. Release of HSP60 may activate the innate immune system, promoting a proinflammatory state, including an increase in TNF-alpha. Thus abnormal trafficking of HSP60 to the cell surface may be an early trigger for myocyte loss and the progression of heart failure.