New-Onset Atrial Fibrillation in Patients Hospitalized With COVID-19: Results From the American Heart Association COVID-19 Cardiovascular Registry.

BACKGROUND: New-onset atrial fibrillation (AF) in patients hospitalized with COVID-19 has been reported and associated with poor clinical outcomes. We aimed to understand the incidence of and outcomes associated with new-onset AF in a diverse and representative US cohort of patients hospitalized with COVID-19. METHODS: We used data from the American Heart Association COVID-19 Cardiovascular Disease Registry. Patients were stratified by the presence versus absence of new-onset AF. The primary and secondary outcomes were in-hospital mortality and major adverse cardiovascular events (MACE; cardiovascular death, myocardial infarction, stroke, cardiogenic shock, and heart failure). The association of new-onset AF and the primary and secondary outcomes was evaluated using Cox proportional-hazards models for the primary time to event analyses. RESULTS: Of the first 30 999 patients from 120 institutions across the United States hospitalized with COVID-19, 27 851 had no history of AF. One thousand five hundred seventeen (5.4%) developed new-onset AF during their index hospitalization. New-onset AF was associated with higher rates of death (45.2% versus 11.9%) and MACE (23.8% versus 6.5%). The unadjusted hazard ratio for mortality was 1.99 (95% CI, 1.81-2.18) and for MACE was 2.23 (95% CI, 1.98-2.53) for patients with versus without new-onset AF. After adjusting for demographics, clinical comorbidities, and severity of disease, the associations with death (hazard ratio, 1.10 [95% CI, 0.99-1.23]) fully attenuated and MACE (hazard ratio, 1.31 [95% CI, 1.14-1.50]) partially attenuated. CONCLUSIONS: New-onset AF was common (5.4%) among patients hospitalized with COVID-19. Almost half of patients with new-onset AF died during their index hospitalization. After multivariable adjustment for comorbidities and disease severity, new-onset AF was not statistically significantly associated with death, suggesting that new-onset AF in these patients may primarily be a marker of other adverse clinical factors rather than an independent driver of mortality. Causality between the MACE composites and AF needs to be further evaluated.

Total Artificial Heart as Bridge to Cardiac Retransplantation.

Mechanical circulatory support has been performed as a bridge to cardiac retransplantation in selected patients with graft failure. However, there is limited published experience on the use and potential benefit of the total artificial heart (TAH) as a bridge to cardiac retransplantation. We report on our institutional experience with 3 patients that received TAH as a bridge to retransplant, with 1 patient surviving post-retransplantation. This case series demonstrates the high-risk nature of this undertaking in cardiac retransplant candidates and highlights the issue of sensitization portending greater risk for poor outcomes after TAH as bridge to retransplantation.

cBIN1 Score (CS) Identifies Ambulatory HFrEF Patients and Predicts Cardiovascular Events.

BACKGROUND: Cardiac Bridging Integrator 1 (cBIN1) is a membrane deformation protein that generates calcium microdomains at cardiomyocyte t-tubules, whose transcription is reduced in heart failure, and is released into blood. cBIN1 score (CS), an inverse index of plasma cBIN1, measures cellular myocardial remodeling. In patients with heart failure with preserved ejection fraction (HFpEF), CS diagnoses ambulatory heart failure and prognosticates hospitalization. The performance of CS has not been tested in patients with heart failure with reduced ejection fraction (HFrEF). METHODS AND RESULTS: CS was determined from plasma of patients recruited in a prospective study. Two comparative cohorts consisted of 158 ambulatory HFrEF patients (left ventricular ejection fraction (LVEF) ≤ 40%, 57 ± 10 years, 80% men) and 115 age and sex matched volunteers with no known history of HF. N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations were also analyzed for comparison. CS follows a normal distribution with a median of 0 in the controls, which increases to a median of 1.9 (p < 0.0001) in HFrEF patients. CS correlates with clinically assessed New York Heart Association Class (p = 0.007). During 1-year follow-up, a high CS (≥ 1.9) in patients predicts increased cardiovascular events (43% vs. 26%, p = 0.01, hazard ratio 1.9). Compared to a model with demographics, clinical risk factors, and NT-proBNP, adding CS to the model improved the overall continuous net reclassification improvement (NRI 0.64; 95% CI 0.18-1.10; p = 0.006). Although performance for diagnosis and prognosis was similar to CS, NT-proBNP did not prognosticate between patients whose NT-proBNP values were > 400 pg/ml. CONCLUSION: CS, which is mechanistically distinct from NT-proBNP, successfully differentiates myocardial health between patients with HFrEF and matched controls. A high CS reflects advanced NYHA stage, pathologic cardiac muscle remodeling, and predicts 1-year risk of cardiovascular events in ambulatory HFrEF patients. CS is a marker of myocardial remodeling in HFrEF patients, independent of volume status.

Left ventricular cavity obliteration: Mechanism of the intracavitary gradient and differentiation from hypertrophic obstructive cardiomyopathy.

BACKGROUND: Controversy surrounds the cause of the pressure gradient in patients with hypertrophic obstructive cardiomyopathy (HOCM). Left ventricular cavity obliteration (LVCO) was first described as the cause of the gradient but subsequently systolic anterior motion (SAM) of the mitral valve has been established as the cause. Nevertheless, the two gradients, though different in origin and significance, share similar characteristics. They both have a similar "dagger" profile, are obtained from the cardiac apex, are associated with a hyperdynamic left ventricle, and the gradients are worsened by Valsalva. The distinction has clinical relevance, because treating the intracavitary gradient (ICG) of LVCO as if it were a SAM-associated gradient associated with HOCM would be inappropriate and possibly harmful. MATERIALS AND METHODS: To clarify the cause and characteristics of the ICG in patients with LVCO in patients without HOCM, we assessed the extent and duration of cavity obliteration, and for differentiation, we compared the spectral profiles with patients with HOCM and severe aortic stenosis (AS). RESULTS: Higher ICG is associated with a greater extent and more prolonged apposition of LV walls, and smaller left ventricular cavity size. The spectral profile of patients with AS, HOCM, and LVCO is differentiated by the peak/mean gradient ratios of 2 or less, 2-3, and 3 or greater, respectively, in >90% of patients. Most patients with LVCO without HOCM or severe LVH have an ICG < 36 mm Hg. CONCLUSION: The magnitude of ICG is quantitatively associated with the extent and duration of LVCO. Spectral profiles of severe AS, HOCM, and LVCO can be differentiated by the peak/mean gradient ratio.