Myocardial Work Efficiency, A Novel Measure of Myocardial Dysfunction, Is Reduced in COVID-19 Patients and Associated With In-Hospital Mortality

Cardiac structure and function 1.5 years after COVID-19: results from the EPILOC study

PURPOSE

Impaired left and right ventricular (LV/RV) function during acute SARS-CoV-2 infection has been predominantly reported in hospitalized patients, but long-term cardiac sequelae in large, well-characterized cohorts remain inconclusive. This study evaluated cardiac structure and function in individuals with post-Coronavirus disease (COVID) syndrome (PCS) compared to recovered controls (CON), focusing on associations with cardiopulmonary symptoms and rapid physical exhaustion (RPE).

METHODS

This multicenter, population-based study included 1154 participants (679 PCS, 475 age- and sex matched CON; mean age 49 ± 12 years; 760 women) 1.5 years post-infection. Transthoracic echocardiography assessed LV global longitudinal strain (GLS), RV GLS and RV free wall strain (FWS), and other measures. Cardiopulmonary exercise testing (CPET) measured maximum respiratory oxygen uptake (VO2max) as a marker of cardiopulmonary fitness.

RESULTS

PCS participants exhibited significantly lower LV GLS (-20.25% [-21.28 - -19.22] vs. -20.73% [-21.74 - -19.72], p = 0.003), reduced diastolic function (E/A 1.16 [1.04-1.27] vs. 1.21 [1.1-1.32], p = 0.022) and decreased TAPSE (24.45 mm [22.14-26.77] vs. 25.05 mm [22.78-27.32], p = 0.022) compared to CON, even after adjusting for confounders. RV strain values were similar between groups. LV GLS correlated inversely with VO2max (p = 0.004) and positively with RPE (p = 0.050), though no associations were observed with other cardiopulmonary symptoms.

CONCLUSIONS

This study demonstrates subtle yet consistent reductions in LV function, specifically LV GLS and diastolic function, and exercise capacity in PCS compared to CON. While these changes are within reference ranges, their potential impact on clinical outcomes warrants further investigation. These findings highlight the need for cardiac assessments and long-term follow-up in symptomatic PCS patients.

Evaluation of myocardial work and exercise capacity in patients recovered from the severe form of COVID-19

Background

The impact of COVID-19 goes beyond its acute form and can lead to the persistence of symptoms and the emergence of systemic disorders, defined as long-term COVID.

Methods

We performed a cross-sectional study that included patients over 18 years of age who recovered from the severe form of COVID-19 at least 60 days after their discharge. Patients and controls were enrolled to undergo transthoracic echocardiography (TTE) using a more sensitive tool, myocardial work, in combination with cardiopulmonary exercise testing (CPET).

Results

A total of 52 patients and 31 controls were enrolled. Significant differences were observed in ejection fraction (LVEF; 62 ± 7 vs. 66 ± 6 %; p = 0.007), global longitudinal strain (LVGLS; -18.7 ± 2.6 vs. -20.4 ± 1.4 %; p = 0.001), myocardial wasted work (GWW; 152 ± 81 vs. 101 ± 54 mmHg; p = 0.003), and myocardial work efficiency (GWE; 93 ± 3 vs. 95 ± 2 %; p = 0.002). We found a significant difference in peak VO2 (24.4 ± 5.4 vs. 33.4 ± 8.8 mL/kg/min; p < 0.001), heart rate (160 ± 14 vs. 176 ± 11 bpm; p < 0.001), ventilation (84.6 ± 22.6 vs. 104.9 ± 27.0 L/min; p < 0.001), OUES% (89 ± 16 vs. 102 ± 22 %; p = 0.002), T ½ (120.3 ± 32 vs. 97.6 ± 27 s; p = 0.002) and HRR at 2 min (-36 ± 11 vs. -43 ± 13 bpm; p = 0.010).

Conclusion

Our findings revealed an increased wasted work, with lower myocardial efficiency, significantly reduced aerobic exercise capacity, and abnormal heart rate response during recovery, which may be related to previously described late symptoms. The reduction in functional capacity during physical exercise is partly associated with a decrease in resting myocardial work efficiency. These findings strongly indicate the need to determine whether these manifestations persist in the long term and their impact on cardiovascular health and quality of life in COVID-19 survivors.

Changes in Cardiopulmonary Capacity Parameters after Surgery: A Pilot Study Exploring the Link between Heart Function and Knee Surgery

Background: A knee injury in an athlete leads to periods of forced exercise interruption. Myocardial work (MW) assessed by echocardiographic and cardiopulmonary exercise testing (CPET) are two essential methods for evaluating athletes during the period following injury. However, compared to pre-surgery evaluations, the variations in cardiovascular parameters and functional capacity assessed by these methods after surgery remain unclear. Methods: We evaluated 22 non-professional athletes aged 18-52, involved in prevalently aerobic or alternate aerobic/anaerobic sports activities, who were affected by a knee pathology requiring surgical treatment. The evaluation was performed at rest using transthoracic echocardiography, including MW assessment, and during exercise using CPET. Each athlete underwent the following two evaluations: the first before surgery and the second after surgery (specifically at the end of the deconditioning period). Results: Resting heart rate (HR) increased significantly (from 63.3 ± 10.85 to 71.2 ± 12.52 beats per minute, p = 0.041), while resting diastolic and systolic blood pressure, forced vital capacity, and forced expiratory volume in the first second did not show significant changes. Regarding the echocardiographic data, global longitudinal strain decreased from -18.9 ± 1.8 to -19.3 ± 1.75; however, this reduction was not statistically significant (p = 0.161). However, the global work efficiency (GWE) increased significantly (from 93.0% ± 2.9 to 94.8% ± 2.6, p = 0.006) and global wasted work (GWW) reduced significantly (from 141.4 ± 74.07 to 98.0 ± 50.9, p = 0.007). Additionally, the patients were able to perform maximal CPET at both pre- and post-surgery evaluations, as demonstrated by the peak respiratory exchange ratio and HR. However, the improved myocardial contractility (increased GWE and decreased GWW) observed at rest did not translate into significant changes in exercise parameters, such as peak oxygen consumption and the mean ventilation/carbon dioxide slope. Conclusions: After surgery, the athletes were more deconditioned (as indicated by a higher resting HR) but exhibited better resting myocardial contractility (increased GWE and reduced GWW). Interestingly, no significant changes in exercise capacity parameters, as evaluated by CPET, were found after surgery, suggesting that the improved myocardial contractility was offset by a greater degree of muscular deconditioning.

Myocardial Work Indices in Patients Recently Recovered from Mild-to-Moderate COVID-19

Background/Objectives: Persistent cardiovascular issues are common in COVID-19 survivors, making the detection of subtle myocardial injuries critical. This study evaluates myocardial work (MW) indices in patients recently recovering from mild-to-moderate COVID-19. Methods: A total of 105 recently recovered COVID-19 patients (who had a mean age of 52 years) underwent comprehensive laboratory testing and advanced echocardiographic assessments. The median time since their COVID-19 infections was 56 days (IQR: 42-71). The cohort was stratified based on high-sensitive troponin I (hs-TnI) levels: undetectable versus detectable. The echocardiographic analysis utilized pressure-strain loops to evaluate MW indices. Results: Detectable hs-TnI levels were observed in 42% of patients. The median values of MW indices for the entire group were slightly below normal values: global work index (GWI)-1834 mmHg% (IQR 1168-2054 mmHg%), global constructive work (GCW)-2130 mmHg% (IQR 2010-2398 mmHg%), global wasted work (GWW)-119 mmHg% (IQR 78-175 mmHg%), and global work efficiency (GWE)-94% (IQR 92-96%). Patients with detectable hs-TnI had higher GWW (168 vs. 97 mmHg%, p < 0.005) and lower GWE (93% vs. 95%, p < 0.005). In multiple regression analysis, strain dispersion (PSD) was the sole predictor for GWW (β = 0.67, p < 0.001), while for GWE, PSD (β = -0.67, p < 0.001) and LVEF (β = 0.16, p = 0.05) were significant predictors. Conclusions: Among patients recently recovering from mild-to-moderate COVID-19, elevated hs-TnI levels are linked with a reduction in GWE and an increase in GWW. PSD is an important predictor of myocardial inefficiency and wasted work. In this group, disruptions in the timing and coordination of cardiac muscle contractions may play a key pathophysiological role in reducing the efficiency of the heart's performance.

Understanding long COVID myocarditis: A comprehensive review

Infectious diseases are a cause of major concern in this twenty-first century. There have been reports of various outbreaks like severe acute respiratory syndrome (SARS) in 2003, swine flu in 2009, Zika virus disease in 2015, and Middle East Respiratory Syndrome (MERS) in 2012, since the start of this millennium. In addition to these outbreaks, the latest infectious disease to result in an outbreak is the SARS-CoV-2 infection. A viral infection recognized as a respiratory illness at the time of emergence, SARS-CoV-2 has wreaked havoc worldwide because of its long-lasting implications like heart failure, sepsis, organ failure, etc., and its significant impact on the global economy. Besides the acute illness, it also leads to symptoms months later which is called long COVID or post-COVID-19 condition. Due to its ever-increasing prevalence, it has been a significant challenge to treat the affected individuals and manage the complications as well. Myocarditis, a long-term complication of coronavirus disease 2019 (COVID-19) is an inflammatory condition involving the myocardium of the heart, which could even be fatal in the long term in cases of progression to ventricular dysfunction and heart failure. Thus, it is imperative to diagnose early and treat this condition in the affected individuals. At present, there are numerous studies which are in progress, investigating patients with COVID-19-related myocarditis and the treatment strategies. This review focuses primarily on myocarditis, a life-threatening complication of COVID-19 illness, and endeavors to elucidate the pathogenesis, biomarkers, and management of long COVID myocarditis along with pipeline drugs in detail.

The inflammatory spectrum of cardiomyopathies

Infiltration of the myocardium with various cell types, cytokines and chemokines plays a crucial role in the pathogenesis of cardiomyopathies including inflammatory cardiomyopathies and myocarditis. A more comprehensive understanding of the precise immune mechanisms involved in acute and chronic myocarditis is essential to develop novel therapeutic approaches. This review offers a comprehensive overview of the current knowledge of the immune landscape in cardiomyopathies based on etiology. It identifies gaps in our knowledge about cardiac inflammation and emphasizes the need for new translational approaches to improve our understanding thus enabling development of novel early detection methods and more effective treatments.

Cardiovascular effects of the post-COVID-19 condition

Throughout the COVID-19 pandemic, the new clinical entity of the post-COVID-19 condition, defined as a multisystemic condition of persistent symptoms following resolution of an acute severe acute respiratory syndrome coronavirus 2 infection, has emerged as an important area of clinical focus. While this syndrome spans multiple organ systems, cardiovascular complications are often the most prominent features. These include, but are not limited to, myocardial injury, heart failure, arrhythmias, vascular injury/thrombosis and dysautonomia. As the number of individuals with the post-COVID-19 condition continues to climb and overwhelm medical systems, summarizing existing information and knowledge gaps in the complex cardiovascular effects of the post-COVID-19 condition has become critical for patient care. In this Review, we explore the current state of knowledge of the post-COVID-19 condition and identify areas where additional research is warranted. This will provide a framework for better understanding the cardiovascular manifestations of the post-COVID-19 condition with a focus on pathophysiology, diagnosis and management.

Longitudinal strain and myocardial work in symptomatic patients having recovered from COVID-19 and possible associations with the severity of the disease

COVID-19 may have residual consequences in multiple organs, including the cardiovascular system. The purpose of the present investigation is to quantify myocardial function in symptomatic individuals with long COVID and investigate the association between illness severity and myocardial function. A retrospective cross-sectional study was conducted in which symptomatic individuals with previous COVID-19 underwent echocardiographic analysis of left ventricle global longitudinal strain (LVGLS) and myocardial work (MW). Individuals also performed cardiopulmonary testing (CPX) to assess peak oxygen uptake (VO2peak). Differences between illness severity subgroups were analyzed by the Mann-Whitney test. Correlations were calculated using the Spearman correlation test. Multilinear regressions were performed to evaluate the influences of COVID-19 severity, body mass index, age, and sex on MW. Fifty-six individuals were included (critical subgroup: 17; moderate/severe subgroup: 39), 59% females; median age: 56 years (IQR: 43-63). CPX revealed a substantial reduction in VO2peak (median of 53% of predicted values). LVGLS were not statistically different between subgroups. Global wasted work (GWW) was higher in the critical subgroup [146 (104-212) versus 121 (74-163) mmHg%, p = 0.01], and global work efficiency (GWE) was lower in this subgroup [93 (91-95) versus 94 (93-96), p = 0.03]. Illness severity was the only independent predictor of GWW and GWE (GWW: r2 = 0.167; p = 0.009; GWE: r2 = 0.172; p = 0.005) in multilinear regressions. In our study with long COVID-19 individuals, despite having a similar LVGLS, patients had subclinical LV dysfunction, demonstrated only by an increase in GWW and a decrease in GWE.

Echocardiographic Myocardial Work: A Novel Method to Assess Left Ventricular Function in Patients with Coronary Artery Disease and Diabetes Mellitus

Myocardial ischemia caused by coronary artery disease (CAD) and the presence of metabolic abnormalities and microvascular impairments detected in patients with diabetes mellitus (DM) are a common cause of left ventricular (LV) dysfunction. Transthoracic echocardiography is the most-used, non-invasive imaging method for the assessment of myocardial contractility. The accurate evaluation of LV function is crucial for identifying patients who are at high risk or may have worse outcomes. Myocardial work (MW) is emerging as an alternative tool for the evaluation of LV systolic function, providing additional information on cardiac performance when compared to conventional parameters such as left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) because it incorporates deformation and load into its analysis. The potential of MW in various conditions is promising and it has gained increased attention. However, larger studies are necessary to further investigate its role and application before giving an answer to the question of whether it can have widespread implementation into clinical practice. The aim of this review is to summarize the actual knowledge of MW for the analysis of LV dysfunction caused by myocardial ischemia and hyperglycemia.

Unmasking Pandemic Echoes: An In-Depth Review of Long COVID's Unabated Cardiovascular Consequences beyond 2020

At the beginning of 2020, coronavirus disease 2019 (COVID-19) emerged as a new pandemic, leading to a worldwide health crisis and overwhelming healthcare systems due to high numbers of hospital admissions, insufficient resources, and a lack of standardized therapeutic protocols. Multiple genetic variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been detected since its first public declaration in 2020, some of them being considered variants of concern (VOCs) corresponding to several pandemic waves. Nevertheless, a growing number of COVID-19 patients are continuously discharged from hospitals, remaining symptomatic even months after their first episode of COVID-19 infection. Long COVID-19 or 'post-acute COVID-19 syndrome' emerged as the new pandemic, being characterized by a high variability of clinical manifestations ranging from cardiorespiratory and neurological symptoms such as chest pain, exertional dyspnoea or cognitive disturbance to psychological disturbances, e.g., depression, anxiety or sleep disturbance with a crucial impact on patients' quality of life. Moreover, Long COVID is viewed as a new cardiovascular risk factor capable of modifying the trajectory of current and future cardiovascular diseases, altering the patients' prognosis. Therefore, in this review we address the current definitions of Long COVID and its pathophysiology, with a focus on cardiovascular manifestations. Furthermore, we aim to review the mechanisms of acute and chronic cardiac injury and the variety of cardiovascular sequelae observed in recovered COVID-19 patients, in addition to the potential role of Long COVID clinics in the medical management of this new condition. We will further address the role of future research for a better understanding of the actual impact of Long COVID and future therapeutic directions.

Assessment of myocardial function and cardiac performance using left ventricular global longitudinal strain in athletes after COVID-19: a follow-up study

Background

It has not yet been conclusively determined whether reduced left ventricular global longitudinal strain (LV GLS) after COVID-19 contributes to a reduction in exercise capacity. Our own studies showed a possible mild myocardial involvement in the form of reduced LV GLS in athletes after COVID-19 compared with healthy athletes. The aims of this prospective follow-up study were to investigate the development of LV GLS over a 3-month period in athletes after COVID-19 and the possible relationship between LV GLS and physical performance.

Methods

LV GLS was determined in four-, two-, and three-chamber views and assessed offline by a blinded investigator in 96 recreational athletes (mean age 33.15 ± 12.40 years, 53 male, peak VO2 38.82 ± 11.14 ml/min/kg) at a median of two (t0) and five months (t1) after COVID-19. Cardiopulmonary exercise testing (CPET) was performed on a bicycle ergometer on both examination dates.

Results

LV GLS improved significantly between t0 and t1 (t0 -18.82 ± 2.02 vs. t1 -19.46 ± 2.05, p < 0.001). Echocardiographic and spiroergometric parameters were within the normal clinical reference range. Maximum power increased significantly from t0 to t1 (t0 283.17 ± 83.20 vs. t1 286.24 ± 85.22 Watt, p = 0.009) and there was a trend toward increased peak oxygen uptake (t0 36.82 ± 11.14 vs. t1 38.68 ± 10.26 ml/min/kg, p = 0.069). We found no correlation between LV GLS and performance parameters, except for the respiratory exchange ratio (RER) [ρ -0.316, (-0.501; -0.102), p < 0.050].

Conclusions

Significant improvement in LV GLS approximately five months after COVID-19 may be due to mild myocardial involvement during or shortly after COVID-19, which seems to recover. There was no correlation between LV GLS and performance parameters, except for an inverse correlation of LV GLS and RER, suggesting insufficient exercise intolerance at lower GLS values. Further studies on the development of GLS in athletes or in the general population with moderate and severe disease courses would be informative as well as the comparison of pre-COVID-19 with post-COVID-19 echocardiography to evaluate the effects of COVID-19 on cardiac function.

Sex differences in coronavirus disease 2019 myocarditis

Myocarditis is frequently caused by viral infections, but animal models that closely resemble human disease suggest that virus-triggered autoimmune disease is the most likely cause of myocarditis. Myocarditis is a rare condition that occurs primarily in men under age 50. The incidence of myocarditis rose at least 15x during the COVID-19 pandemic from 1-10 to 150-400 cases/100,000 individuals, with most cases occurring in men under age 50. COVID-19 vaccination was also associated with rare cases of myocarditis primarily in young men under 50 years of age with an incidence as high as 50 cases/100,000 individuals reported for some mRNA vaccines. Sex differences in the immune response to COVID-19 are virtually identical to the mechanisms known to drive sex differences in myocarditis pre-COVID based on clinical studies and animal models. The many similarities between COVID-19 vaccine-associated myocarditis to COVID-19 myocarditis and non-COVID myocarditis suggest common immune mechanisms drive disease.

COVID-19, Myocarditis and Pericarditis

Viral infections are a leading cause of myocarditis and pericarditis worldwide, conditions that frequently coexist. Myocarditis and pericarditis were some of the early comorbidities associated with SARS-CoV-2 infection and COVID-19. Many epidemiologic studies have been conducted since that time concluding that SARS-CoV-2 increased the incidence of myocarditis/pericarditis at least 15× over pre-COVID levels although the condition remains rare. The incidence of myocarditis pre-COVID was reported at 1 to 10 cases/100 000 individuals and with COVID ranging from 150 to 4000 cases/100 000 individuals. Before COVID-19, some vaccines were reported to cause myocarditis and pericarditis in rare cases, but the use of novel mRNA platforms led to a higher number of reported cases than with previous platforms providing new insight into potential pathogenic mechanisms. The incidence of COVID-19 vaccine-associated myocarditis/pericarditis covers a large range depending on the vaccine platform, age, and sex examined. Importantly, the findings highlight that myocarditis occurs predominantly in male patients aged 12 to 40 years regardless of whether the cause was due to a virus-like SARS-CoV-2 or associated with a vaccine-a demographic that has been reported before COVID-19. This review discusses findings from COVID-19 and COVID-19 vaccine-associated myocarditis and pericarditis considering the known symptoms, diagnosis, management, treatment, and pathogenesis of disease that has been gleaned from clinical research and animal models. Sex differences in the immune response to COVID-19 are discussed, and theories for how mRNA vaccines could lead to myocarditis/pericarditis are proposed. Additionally, gaps in our understanding that need further research are raised.

Left Ventricular Global Longitudinal Strain as a Parameter of Mild Myocardial Dysfunction in Athletes after COVID-19

Whether symptoms during COVID-19 contribute to impaired left ventricular (LV) function remains unclear. We determine LV global longitudinal strain (GLS) between athletes with a positive COVID-19 test (PCAt) and healthy control athletes (CON) and relate it to symptoms during COVID-19. GLS is determined in four-, two-, and three-chamber views and assessed offline by a blinded investigator in 88 PCAt (35% women) (training at least three times per week/>20 MET) and 52 CONs from the national or state squad (38% women) at a median of two months after COVID-19. The results show that the GLS is significantly lower (GLS -18.53 ± 1.94% vs. -19.94 ± 1.42%, p < 0.001) and diastolic function significantly reduces (E/A 1.54 ± 0.52 vs. 1.66 ± 0.43, p = 0.020; E/E'l 5.74 ± 1.74 vs. 5.22 ± 1.36, p = 0.024) in PCAt. There is no association between GLS and symptoms like resting or exertional dyspnea, palpitations, chest pain or increased resting heart rate. However, there is a trend toward a lower GLS in PCAt with subjectively perceived performance limitation (p =0.054). A significantly lower GLS and diastolic function in PCAt compared with healthy peers may indicate mild myocardial dysfunction after COVID-19. However, the changes are within the normal range, so that clinical relevance is questionable. Further studies on the effect of lower GLS on performance parameters are necessary.

Strain Echocardiography in Acute COVID-19 and Post-COVID Syndrome: More than Just a Snapshot

Speckle-tracking echocardiography (STE) has become an established, widely available diagnostic method in the past few years, making its value clear in cases of COVID-19 and the further course of the disease, including post-COVID syndrome. Since the beginning of the pandemic, many studies have been published on the use of STE in this condition, enabling, on the one hand, a better understanding of myocardial involvement in COVID-19 and, on the other, a better identification of risk to patients, although some questions remain unanswered in regard to specific pathomechanisms, especially in post-COVID patients. This review takes a closer look at current findings and potential future developments by summarising the extant data on the use of STE, with a focus on left and right ventricular longitudinal strain.

Myocardial Work in Echocardiography

Myocardial work is an emerging tool in echocardiography that incorporates left ventricular afterload into global longitudinal strain analysis. Myocardial work correlates with myocardial oxygen consumption, and work efficiency can also be assessed. Myocardial work has been evaluated in a variety of clinical conditions to assess the added value of myocardial work compared to left ventricular ejection fraction and global longitudinal strain. This review showcases the current use of myocardial work in adult echocardiography and its possible role in cardiac pathologies.

Echocardiography in Coronavirus Disease 2019 Era: A Single Tool for Diagnosis and Prognosis

Coronavirus disease 2019 (COVID-19) is characterized by multi-organ involvement, including respiratory and cardiac events. Echocardiography is widely considered the first-choice tool for the evaluation of cardiac structures and function because of its reproducibility, feasibility, easy to use at bedside, and for good cost-effectiveness. The aim of our literature review is to define the utility of echocardiography in the prediction of prognosis and mortality in COVID-19 patients with mild to critical respiratory illness, with or without known cardiovascular disease. Moreover, we focused our attention on classical echocardiographic parameters and the use of speckle tracking to predict the evolution of respiratory involvement. Finally, we tried to explore the possible relationship between pulmonary disease and cardiac manifestations.

2D speckle-tracking echocardiography as a prognostic imaging modality for COVID-19 adverse outcomes

2D speckle-tracking echocardiography (2D-STE) has been used to assess cardiac recovery during the COVID-19 patient follow-ups within the pandemic. The novel role of STE in predicting adverse outcomes of COVID-19 has received attention due to its high sensitivity in identifying subclinical myocardial dysfunction. We reviewed the studies on using 2D-STE to assess COVID-19 prognosis. A literature search was conducted on PubMed and Scopus for eligible articles, 24 of which discussed using prognostic 2D-STE for COVID-19 patients. 2D-STE predicts cardiovascular impairments more rapidly and precisely than conventional echocardiography. The 2D-STE technique presents an independent prognostic factor in COVID-19 infection. 2D-STE could be considered a time-efficient and accurate risk predictor of all-cause mortality in COVID-19 patients.

Current and novel echocardiographic assessment of left ventricular systolic function in aortic stenosis-A comprehensive review

Aortic stenosis (AS) is a complex and progressive condition that can significantly reduce the quality of life and increase the incidence of premature mortality. Transthoracic echocardiography (TTE) is the gold standard imaging modality for the assessment of AS severity. While left ventricular ejection fraction (LVEF) derived from TTE is a very well-understood parameter, limitations such as high inter and intra-observer variability, insensitivity to sub-clinical dysfunction, and influence of loading conditions make LVEF a complicated and unreliable parameter. Myocardial deformation imaging has been identified as a promising parameter for identifying subclinical left ventricular dysfunction, however, this parameter is still afterload dependent. Myocardial Work is a promising novel assessment technique that accounts for afterload by combining the use of myocardial deformation imaging and non-invasive blood pressure to provide a more comprehensive assessment of mechanics beyond LVEF. This review evaluates the evidence for various echocardiographic assessment parameters used to quantify left ventricular function including myocardial work in patients with AS.

Cardiac function in relation to functional status and fatigue in patients with post-COVID syndrome

Patients with Post-COVID syndrome (PCS) are frequently referred for cardiologic evaluation. We assessed cardiac function and biomarkers in relation to functional status and fatigue in patients with PCS. This prospective single-center cohort study included 227 patients with persisting symptoms after COVID-19 infection. Most frequent complaints were fatigue (70%), dyspnea (56%), neurocognitive symptoms (34%) and chest pain (28%). Standardized questionnaires were used to assess Post-COVID-Functional-Scale (PCFS) and fatigue (MFI-20). The fatigue severity was inversely related to age and did not correlate with cardiovascular diseases, echocardiographic findings, or biomarkers. Similarly, mild to moderate functional impairment (PCFS 1-3) did not correlate with cardiovascular alterations. However, the subgroup of patients with significant functional impairment (PCFS = 4) had more frequent cardiovascular comorbidities, biomarkers and impaired global longitudinal strain (GLS). Patients with elevated troponin T showed abnormal GLS, reduced left ventricular ejection fraction and impaired tricuspid annular plane systolic excursion. The majority of patients with PCS shows a normal cardiac function. Only the small subgroup of patients with severe functional impairment and patients with elevated troponin T is at risk for impaired cardiac function and likely to benefit from specialized care by a cardiologist.

Myocardial Work in Patients Hospitalized With COVID-19: Relation to Biomarkers, COVID-19 Severity, and All-Cause Mortality

Background COVID-19 infection has been hypothesized to affect left ventricular function; however, the underlying mechanisms and the association to clinical outcome are not understood. The global work index (GWI) is a novel echocardiographic measure of systolic function that may offer insights on cardiac dysfunction in COVID-19. We hypothesized that GWI was associated with disease severity and all-cause death in patients with COVID-19. Methods and Results In a multicenter study of patients admitted with COVID-19 (n=305), 249 underwent pressure-strain loop analyses to quantify GWI at a median time of 4 days after admission. We examined the association of GWI to cardiac biomarkers (troponin and NT-proBNP [N-terminal pro-B-type natriuretic peptide]), disease severity (oxygen requirement and CRP [C-reactive protein]), and all-cause death. Patients with elevated troponin (n=71) exhibited significantly reduced GWI (1508 versus 1707 mm Hg%; P=0.018). A curvilinear association to NT-proBNP was observed, with increasing NT-proBNP once GWI decreased below 1446 mm Hg%. Moreover, GWI was significantly associated with a higher oxygen requirement (relative increase of 6% per 100-mm Hg% decrease). No association was observed with CRP. Of the 249 patients, 37 died during follow-up (median, 58 days). In multivariable Cox regression, GWI was associated with all-cause death (hazard ratio, 1.08 [95% CI, 1.01-1.15], per 100-mm Hg% decrease), but did not increase C-statistics when added to clinical parameters. Conclusions In patients admitted with COVID-19, our findings indicate that NT-proBNP and troponin may be associated with lower GWI, whereas CRP is not. GWI was independently associated with all-cause death, but did not provide prognostic information beyond readily available clinical parameters. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04377035.

Screening for Myocardial Injury after Mild SARS-CoV-2 Infection with Advanced Transthoracic Echocardiography Modalities

Although the clinical manifestations of SARS-CoV-2 viral infection affect mainly the respiratory system, cardiac complications are common and are associated with increased morbidity and mortality. While echocardiographic alterations indicating myocardial involvement are widely reported in patients hospitalized for acute COVID-19 infection, much fewer data available in non-hospitalized, mildly symptomatic COVID-19 patients. In our work, we aimed to investigate subclinical cardiac alterations characterized by parameters provided by advanced echocardiographic techniques following mild SARS-CoV-2 viral infection. A total of 86 patients (30 males, age: 39.5 ± 13.0 yrs) were assessed 59 ± 33 days after mild SARS-CoV-2 viral infection (requiring no hospital or <5 days in-hospital treatment) by advanced echocardiographic examination including 2-dimensional (2D) speckle tracking echocardiography and non-invasive myocardial work analysis, and were compared to an age-and sex-matched control group. Altogether, variables from eleven echocardiographic categories representing morphological or functional echocardiographic parameters showed statistical difference between the post-COVID patient group and the control group. The magnitude of change was subtle or mild in the case of these parameters, ranging from 1−11.7% of relative change. Among the parameters, global longitudinal strain [−20.3 (−21.1−−19.0) vs. −19.1 (−20.4−−17.6) %; p = 0.0007], global myocardial work index [1975 (1789−2105) vs. 1829 (1656−2057) Hgmm%; p = 0.007] and right ventricular free wall strain values (−26.6 ± 3.80 vs. −23.8 ± 4.0%; p = 0.0003) showed the most significant differences between the two groups. Subclinical cardiac alterations are present following even mild SARS-CoV-2 viral infection. These more subtle alterations are difficult to detect by routine echocardiography. Extended protocols, involving speckle-tracking echocardiography, non-invasive measurement of cardiac hemodynamics, and possibly myocardial work are necessary for detection and adequate follow-up.

The Evolving Role of Echocardiography During the Coronavirus Disease 2019 Pandemic

Coronavirus disease 2019 (COVID-19) has been associated with a wide spectrum of cardiovascular manifestations. Since the beginning of the pandemic, echocardiography has served as a valuable tool for triaging, diagnosing and managing patients with COVID-19. More recently, speckle-tracking echocardiography has been shown to be effective in demonstrating subclinical myocardial dysfunction that is often not detected in standard echocardiography. Echocardiographic findings in COVID-19 patients include left or right ventricular dysfunction, including abnormal longitudinal strain and focal wall motion abnormalities, valvular dysfunction and pericardial effusion. Additionally, some of these echocardiographic abnormalities have been shown to correlate with biomarkers and adverse clinical outcomes, suggesting an additional prognostic value of echocardiography. With increasing evidence of cardiac sequelae of COVID-19, the use of echocardiography has expanded to patients with cardiopulmonary symptoms after recovery from initial infection. This article aims to highlight the available echocardiographic tools and to summarize the echocardiographic findings across the full spectrum of COVID-19 disease and their correlations with biomarkers and mortality.

COVID-19 and Myocarditis: Review of Clinical Presentations, Pathogenesis and Management

There are four main myocarditis presentations identified in the context of severe acute respiratory coronavirus 2 (SARS-CoV-2): myocarditis associated with acute coronavirus disease 2019 (COVID-19) infection, post-acute COVID-19 syndrome, multisystem inflammatory syndrome, and vaccination-associated myocarditis. This article reviews the clinical features and current management strategies for each of these presentations. The overall prevalence of myocarditis is considered to be rare, although accurate estimation is affected by heterogeneity in diagnostic criteria and reporting, as well as infrequent use of gold-standard diagnostic endomyocardial biopsy. Severity of disease can range from mild symptoms to fulminant myocarditis. Therapeutic interventions are typically supportive and extrapolated from treatment for non-COVID-19 viral myocarditis. Several pathogenic mechanisms for the development of myocarditis have been proposed, and ongoing research is critical for elucidating disease pathogenesis and potentially identifying therapeutic targets. The long-term cardiovascular sequelae of SARS-CoV-2 infections and associated myocarditis require further elucidation and understanding.

Comparison of Myocardial Layer-Specific Strain and Global Myocardial Work Efficiency During Treadmill Exercise Stress in Detecting Significant Coronary Artery Disease

Background

Myocardial layer-specific strain can identify myocardial ischemia. Global myocardial work efficiency (GWE) based on non-invasive left ventricular (LV) pressure-strain loops is a novel parameter to determine LV function considering afterload. The study aimed to compare the diagnostic value of GWE and myocardial layer-specific strain during treadmill exercise stress testing to detect significant coronary artery disease (CAD) with normal baseline wall motion.

Methods

Eighty-nine patients who referred for coronary angiography due to suspected of CAD were included. Forty patients with severe coronary artery stenosis were diagnosed with significant CAD, and 49 were defined as non-significant CAD. Stress echocardiography was performed 24 h before angiography. Layer-specific longitudinal strains were assessed from the endocardium, mid-myocardium, and epicardium by 2D speckle-tracking echocardiography. Binary logistic regression analyses were performed to evaluate the association between significant CAD and echocardiographic parameters. A receiver operating characteristic curve was used to assess the capability of layer-specific strain and GWE to diagnose significant CAD.

Results

Patients with significant CAD had the worse function in all three myocardial layers at peak exercise compared with those with non-significant CAD when assessed with global longitudinal strain (GLS). At the peak exercise and recovery periods, GWE was lower in patients with significant CAD than in patients with non-significant CAD. In multivariable binary logistic regression analysis, peak endocardial GLS (OR: 1.35, p = 0.006) and peak GWE (OR: 0.76, p = 0.001) were associated with significant CAD. Receiver operating characteristic curves showed peak GWE to be superior to mid-myocardial, epicardial, and endocardial GLS in identifying significant CAD. Further, adding peak GWE to endocardial GLS could improve diagnostic capabilities.

Conclusions

Both GWE and endocardial GLS contribute to improving the diagnostic performance of exercise stress echocardiography. Furthermore, adding peak GWE to peak endocardial GLS provides incremental diagnostic value during a non-invasive screening of significant CAD before radioactive or invasive examinations.

Improving Risk Prediction for Pulmonary Embolism in COVID‐19 Patients using Echocardiography

SARS‐CoV‐2 infection is associated with increased risk for pulmonary embolism (PE), a fatal complication that can cause right ventricular (RV) dysfunction. Serum D‐dimer levels are a sensitive test to suggest PE, however lacks specificity in COVID‐19 patients. The goal of this study was to identify a model that better predicts PE diagnosis in hospitalized COVID‐19 patients using clinical, laboratory, and echocardiographic imaging predictors. We performed a cross‐sectional study of 302 adult patients admitted to the Johns Hopkins Hospital (March 2020–February 2021) for COVID‐19 infection who underwent transthoracic echocardiography and D‐dimer testing; 204 patients had CT angiography. Clinical, laboratory and imaging predictors including, but not limited to, D‐dimer and RV dysfunction were used to build prediction models for PE using logistic regression. Model discrimination was assessed using area under the receiver operator curve (AUC) and calibration using Hosmer‐Lemeshow χ² statistic. Internal validation was performed. The prevalence of PE was 7.6%. The model with positive D‐dimer above 5 mg/L, RV dysfunction on echocardiography, and troponin had an AUC of 0.77, and cross‐validated AUC of 0.74. D‐dimer (>5 mg/L) had a positive association with PE (adj odds ratio = 4.40; 95% confidence interval: [1.80, 10.78]). We identified a model including clinical, imaging and laboratory variables that predicted PE in hospitalized COVID‐19 patients. Positive D‐dimer >5, RV dysfunction on echocardiography, and troponin were important predictors for calculating likelihood of PE diagnosis. This approach may be useful to aid in clinical decision‐making related to diagnostic imaging and treatment. Prospective studies are needed to evaluate impact on patient outcomes.

Subclinical Myocardial Dysfunction in Patients with Persistent Dyspnea One Year after COVID-19

Long coronavirus disease 2019 (COVID-19) was described in patients recovering from COVID-19, with dyspnea being a frequent symptom. Data regarding the potential mechanisms of long COVID remain scarce. We investigated the presence of subclinical cardiac dysfunction, assessed by transthoracic echocardiography (TTE), in recovered COVID-19 patients with or without dyspnea, after exclusion of previous cardiopulmonary diseases. A total of 310 consecutive COVID-19 patients were prospectively included. Of those, 66 patients (mean age 51.3 ± 11.1 years, almost 60% males) without known cardiopulmonary diseases underwent one-year follow-up consisting of clinical evaluation, spirometry, chest computed tomography, and TTE. From there, 23 (34.8%) patients reported dyspnea. Left ventricle (LV) ejection fraction was not significantly different between patients with or without dyspnea (55.7 ± 4.6 versus (vs.) 57.6 ± 4.5, p = 0.131). Patients with dyspnea presented lower LV global longitudinal strain, global constructive work (GCW), and global work index (GWI) compared to asymptomatic patients (−19.9 ± 2.1 vs. −21.3 ± 2.3 p = 0.039; 2183.7 ± 487.9 vs. 2483.1 ± 422.4, p = 0.024; 1960.0 ± 396.2 vs. 2221.1 ± 407.9, p = 0.030). GCW and GWI were inversely and independently associated with dyspnea (p = 0.035, OR 0.998, 95% CI 0.997–1.000; p = 0.040, OR 0.998, 95% CI 0.997–1.000). Persistent dyspnea one-year after COVID-19 was present in more than a third of the recovered patients. GCW and GWI were the only echocardiographic parameters independently associated with symptoms, suggesting a decrease in myocardial performance and subclinical cardiac dysfunction.