Reduced cardiac function is associated with cardiac injury and mortality risk in hospitalized COVID-19 Patients.

BACKGROUND: Cardiac injury is common in COVID-19 patients and is associated with increased mortality. However, it remains unclear if reduced cardiac function is associated with cardiac injury, and additionally if mortality risk is increased among those with reduced cardiac function in COVID-19 patients. HYPOTHESIS: The aim of this study was to assess cardiac function among COVID-19 patients with and without biomarkers of cardiac injury and to determine the mortality risk associated with reduced cardiac function. METHODS/RESULTS: This retrospective cohort study analyzed 143 consecutive COVID-19 patients who had an echocardiogram during hospitalization between March 1, 2020 and May 5, 2020. The mean age was 67 ± 16 years. Cardiac troponin-I was available in 131 patients and an increased value (>0.03 ng/dL) was found in 59 patients (45%). Reduced cardiac function, which included reduced left or right ventricular systolic function, was found in 40 patients (28%). Reduced cardiac function was found in 18% of patients without troponin-I elevation, 42% with mild troponin increase (0.04-5.00 ng/dL) and 67% with significant troponin increase (>5 ng/dL). Reduced cardiac function was also present in more than half of the patients on mechanical ventilation or those deceased. The in-hospital mortality of this cohort was 28% (N = 40). Using logistic regression analysis, we found that reduced cardiac function was associated with increased mortality with adjusted odds ratio (95% confidence interval) of 2.65 (1.18 to 5.96). CONCLUSIONS: Reduced cardiac function is highly prevalent among hospitalized COVID-19 patients with biomarkers of myocardial injury and is independently associated with mortality.

Relationship of phasic left atrial volume and emptying function to left ventricular filling pressure: a cardiovascular magnetic resonance study.

BACKGROUND: Left atrial volume (LAV) and emptying fraction (LAEF) are phasic during cardiac cycle. Their relationships to left ventricular end diastolic pressure (LVEDP) have not been fully defined. METHODS: Forty one patients undergoing clinically indicated left heart catheterization were recruited for same day cardiovascular magnetic resonance (CMR). LAV and LAEF were assessed in cine images using biplane area and length method. Three phasic LAV was assessed at LV end systole (LAV(max)), LV end diastole (LAV(min)) and late LV diastole prior to LA contraction (LAV(ac)). LAEF was assessed as global LAEF (LAEF(Total)), passive (LAEF(Passive)) and active LAEF (LAEF(Contractile)). The relationships of phasic LAV and LAEF to LVEDP were assessed using Receiver operating characteristic comparing areas under the curves (AUC). RESULTS: The mean age of the patients was 59 years. A history of heart failure was present in 16 (39%) with NYHA functional class III or IV in 8 (20%) patients. Average LV ejection fraction was 49 ± 16% ranging from 10% to 74% and LVEDP by catheterization 14 ± 8 mmHg ranging from 4 mmHg to 32 mmHg. LAV(min) had the strongest association with LVEDP elevation (>12 mmHg) (AUC 0.765, p = 0.002), as compared to LAV(max) (AUC 0.677, p = 0.074) and LAV(ac) (AUC 0.735, p = 0.008). Among three phasic LAEF assessed, LAEF(Total) had the closest association with LVEDP elevation (AUC 0.780, p = 0.001), followed by LAEF(Contractile) (AUC 0.698, p = 0.022) and LAEF(Passive) (AUC 0.656, p = 0.077). CONCLUSIONS: Increased LAV(min) and decreased LAEF(Total) have the best performance in identifying elevated LVEDP among three phasic LAV and LAEF analyzed. Future studies should further characterize LA phasic indices in clinical outcomes.

Effects of hemodynamics on global and regional lung perfusion: a quantitative lung perfusion study by magnetic resonance imaging.

BACKGROUND: Cardiac hemodynamics affect pulmonary vascular pressure and flow, but little is known of the effects of hemodynamics on lung perfusion at the tissue level. We sought to investigate the relationship between hemodynamic abnormalities in patients with left heart failure and global and regional lung perfusion using lung perfusion quantification by magnetic resonance imaging. METHODS AND RESULTS: Lung perfusion was quantified in 10 normal subjects and 28 patients undergoing clinically indicated left and right heart catheterization and same day research cardiac magnetic resonance imaging. A total of 228 lung slices were evaluated. Global lung perfusion, determined as the average of 6 coronal lung slices through the anterior, mid, and posterior left and right lungs, was significantly lower in patients with reduced cardiac index (<2.5 L/min per m(2)): 94±30 mL/100 mL per minute versus 132±40 mL/100 mL per minute in those with preserved cardiac index (≥2.5 L/min per m(2); P=0.003). The gravitational anterior to posterior perfusion gradient was inversely associated with left ventricular end-diastolic pressure (r=-0.728; P<0.001), resulting in a blunted perfusion gradient in patients with elevated left ventricular end-diastolic pressure, a finding largely attributed to the perfusion reduction in posterior lung regions. In a multivariate regression analysis adjusting for all hemodynamic variables, altered lung perfusion gradient was most closely associated with increased mean pulmonary arterial pressure (P=0.016). CONCLUSIONS: Increased left ventricular filling pressure and the resultant increase in pulmonary arterial pressure are associated with disruption of the normal gravitational lung perfusion gradient. Our findings underscore the complexity of heart-lung interaction in determining pulmonary hemodynamics in left heart failure.