Patients undergoing coronary artery bypass grafting within 2 days of hospitalization for acute myocardial infarction experienced higher mortality rates than those undergoing coronary artery bypass grafting 3 or more days after acute myocardial infarction, independently of clinical acuity. This suggests that coronary artery bypass grafting may best be deferred for 3 or more days after admission for acute myocardial infarction in nonurgent cases.

Background: The FOXO3a (forkhead box O3a)-BNIP3 (B-cell lymphoma 2/adenovirus E1B 19kDa interacting protein 3) pathway modulates mitochondrial dynamics and function and contributes to myocardial remodeling in rodent models of heart failure. We sought to investigate the expression of this pathway along with the expression of mitochondrial biogenesis (PGC-1α [peroxisome proliferator-activated receptor-γ coactivator-1α]), dynamics (DRP-1 [dynamin-related protein 1], OPA-1 [optic atrophy 1], and MFN 2 [mitofusin 2]), and oxidative phosphorylation (citrate synthase and electron transport chain complexes) markers and COX IV (cytochrome C oxidase) activity in myocardium from patients with valvular or ischemic heart disease and heart failure with preserved ejection fraction (HFpEF) or heart failure with reduced ejection fraction (HFrEF). Methods and Results: Subepicardial left ventricular biopsies (10×1×1 mm 3 ) were obtained at aortic valve replacement (HFpEF AVR , n=5; and HFrEF AVR , n=4), coronary artery bypass grafting (HFpEF CABG , n=5; and HFrEF CABG , n=5), or left ventricular assist device implantation (HFrEF LVAD , n=4). Subepicardial biopsies from patients with normal left ventricular function (n=2) and from donor hearts (n=3) served as controls (normal). Relative to normal, mitochondrial fragmentation and cristae destruction were evident, and mitochondrial area was decreased in HFpEF; 1.00±0.09 versus 0.71±0.08; P =0.016. These mitochondrial morphological changes were more pronounced in HFrEF (0.54±0.06); P =0.002 HFpEF versus HFrEF. BNIP3 (monomer+dimer) expression was increased in HFpEF (3.99±2.44) and in HFrEF (5.19±1.70) relative to normal; P =0.004 and P <0.001, respectively. However, BNIP3 monomer was increased in HFrEF (4.32±1.43) compared with normal (0.99±0.06) and HFpEF (1.97±0.90); P =0.001 and 0.004, respectively. The HFrEF group uniquely showed increase in DRP-1 expression (1.94±0.38) and decreases in PGC-1α expression (0.61±0.07) and COX IV activity (0.70±0.10) relative to normal; P =0.013, P <0.001, and P <0.001, respectively, with no significant change in electron transport chain complexes expression. Conclusions: These findings in human myocardium confirm studies in rodents where contractile dysfunction is associated with activation of the FOXO3a-BNIP3 pathway and altered mitochondrial dynamics, biogenesis, and function.

Background: Right ventricular failure is an underrecognized consequence of COVID-19 pneumonia. Those with severe disease are treated with extracorporeal membrane oxygenation (ECMO) but with poor outcomes. Concomitant right ventricular assist device (RVAD) may be beneficial. Methods: A retrospective analysis of intensive care unit patients admitted with COVID-19 ARDS (Acute Respiratory Distress Syndrome) was performed. Non-intubated patients, those with acute kidney injury, and age > 75 were excluded. Patients who underwent RVAD/ECMO support were compared with those managed via invasive mechanical ventilation (IMV) alone. The primary outcome was in-hospital mortality. Secondary outcomes included 30-day mortality, acute kidney injury, length of ICU stay, and duration of mechanical ventilation. Results: A total of 145 patients were admitted to the ICU with COVID-19. Thirty-nine patients met inclusion criteria. Of these, 21 received IMV, and 18 received RVAD/ECMO. In-hospital (52.4 vs 11.1%, p=0.008) and 30-day mortality (42.9 vs 5.6%, p=0.011) were significantly lower in patients treated with RVAD/ECMO. Acute kidney injury occurred in 15 (71.4%) patients in the IMV group and zero RVAD/ECMO patients (p<0.001). ICU (11.5 vs 21 days, p=0.067) and hospital (14 vs 25.5 days, p=0.054) length of stay were not significantly different. There were no RVAD/ECMO device complications. The duration of mechanical ventilation was not significantly different (10 vs 5 days, p=0.44). Conclusions: RVAD support at the time of ECMO initiation resulted in the no secondary end-organ damage and higher in-hospital and 30-day survival versus IMV in specially selected patients with severe COVID-19 ARDS. Management of severe COVID-19 ARDS should prioritize right ventricular support.

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