Research trends and hotspots in exercise rehabilitation for coronary heart disease: A bibliometric analysis

Exercise rehabilitation can improve the prognosis of patients with coronary heart disease. However, a bibliometric analysis of the global exercise rehabilitation for coronary heart disease (CHD) research topic is lacking. This study investigated the development trends and research hotspots in the field of coronary heart disease and exercise rehabilitation. CiteSpace software was used to analyze the literature on exercise therapy for CHD in the Web of Science Core Collection database. We analyzed the data of countries/institutions, journals, authors, keywords, and cited references. A total of 3485 peer-reviewed papers were found, and the number of publications on the topic has steadily increased. The most productive country is the USA (1125), followed by China (477) and England (399). The top 3 active academic institutions are Research Libraries UK (RLUK) (236), Harvard University (152), and the University of California System (118). The most commonly cited journals are Circulation (2596), The most commonly cited references are "Exercise-based cardiac rehabilitation for coronary heart disease" (75), Lavie CJ had published the most papers (48). World Health Organization was the most influential author (334 citations). The research frontier trends in this field are body composition, participation, and function. Research on the effects of physical activity or exercise on patients with CHD is a focus of continuous exploration in this field. This study provides a new scientific perspective for exercise rehabilitation and CHD research and gives researchers valuable information for detecting the current research status, hotspots, and emerging trends for further research.

Association of obesity and cardiovascular disease and progress in pharmacotherapy: what is next for obesity?

Obesity has recently emerged as one of the most severe health concerns. Obesity is a key autonomous risk factor for heart failure and contributes to cardiovascular disease (CVD) risk factors such as hypertension, type 2 diabetes, and metabolic abnormalities. Obesity is caused by a metabolic imbalance, which occurs when calories burnt are fewer than the number of calories consumed. There are several pathways accountable for the adverse impacts of obesity on the cardiovascular system. Inflammatory cell infiltration develops in the adipose tissue, the pancreas, and other issues similar to the progression of obesity. Inflammation is triggered by immune cells that invade dysfunctional adipose tissue. The atherosclerotic inflammation phase, related to obesity, induces coronary calcification. Obesity is linked to elevated levels of leptin and high blood pressure. Leptin causes systemic vasoconstriction, sodium retention, and increased blood pressure by influencing the synthesis of nitric oxide and activating the sympathetic nervous system. Obesity is a well-known risk factor for CVD and is one of the leading causes of the greater risk of diseases, including dyslipidemia, hypertension, depression, metabolic syndrome, atrial fibrillation, and heart failure in adults and children. When used with dietary improvements, antiobesity drugs improve the probability of experiencing clinically healthy (5%) weight loss. This review aimed to address the consequences of obesity on cardiac structure and function, risk factors, the impact of the obesity paradox, pharmacological treatment strategies for managing and recommended exercise and diet.

Updates on obesity and the obesity paradox in cardiovascular diseases

The prevalence of obesity has reached pandemic proportions worldwide and certainly in the United States. Obesity is a well-established independent risk factor for development of many cardiovascular diseases (CVD), including heart failure, coronary heart disease, atrial fibrillation, and hypertension. Therefore, it is logical to expect obesity would have a strong correlation with CVD mortality. However, a substantial body of literature demonstrates a paradox with improved prognosis of overweight and obese patients with established CVD compared to lean patients with the identical CVD. Surprisingly, similar data has also shown that cardiovascular fitness, rather than weight loss alone, influences the relationship between obesity and mortality in those with established CVD. The impact of fitness, exercise, physical activity (PA), and weight loss and their relationship to the obesity paradox are all reviewed here.

Change of Left Ventricular Geometric Pattern in Patients with Preserved Ejection Fraction Undergoing Coronary Artery Bypass Grafting

Left ventricular (LV) remodeling and geometric patterns are associated with variations in prognosis. Two hundred twenty-eight patients who underwent selective isolated coronary artery bypass grafting (CABG) were included, divided into normal geometry, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy at baseline. More than half participants with normal geometry at baseline remained in that category, and similar ratio of concentric remodeling reverted to normal geometry on follow-up. The concentric hypertrophy at baseline tended to progress to eccentric geometry rather than normal geometry, while changes from eccentric to concentric hypertrophy was uncommon. iLVEDD had a significant association with an increased risk of developing an abnormal geometric pattern from a normal or concentric remodeling pattern, and iLVESD and LAScd involved in the regression from an abnormal geometric pattern. Thus, dynamic changes in LV geometric pattern are common on 1-year follow-up after CABG and LA strain has an incremental role for early detection in this process.

Left Ventricular Abnormality and Covert Atrial Fibrillation in Embolic Stroke of Undetermined Source

AIMS

The relationship between left ventricular (LV) function and AF detection in embolic stroke of undetermined source (ESUS) patients with insertable cardiac monitors (ICMs) remains unclear. We investigated the association between LV function and AF detection in patients with ESUS after ICMs implantation.

METHODS

We enrolled patients with ESUS who underwent ICMs implantation from September 2016 to September 2020 using a single-center, prospective registry. LV systolic and diastolic functions were assessed on precordial echocardiography by LV fractional shortening (LVFS) and average E/e', respectively. Associations between characteristics of LV function and detection of AF by ICMs were analyzed.

RESULTS

Participants comprised 101 patients (median age, 74 years; male, 62%). During a median follow-up period of 442 days (interquartile range (IQR), 202-770 days), AF was detected in 24 patients (24%). Median duration from ICMs implantation to AF detection was 71 days (IQR, 13-150 days). When LVFS and E/e' were dichotomized by cutoff value, each of low LVFS (＜35.5%; adjusted hazard ratio (HR), 4.77; 95% confidence interval (CI), 1.77-12.9) and high E/e' (≥ 8.65; adjusted HR, 4.56; 95%CI, 1.17-17.7) were independently associated with AF detection after adjusting for age and sex. When patients were divided into four groups according to dichotomized LVFS and E/e', the combination of low LVFS and high E/e' was independently associated with AF.

CONCLUSIONS

In patients with ESUS after ICMs implantation, the LV characteristics of low LVFS and high E/e' were associated with AF detection.

The impact of left ventricular geometry on left atrium phasic function in obstructive sleep apnea syndrome: a multimodal echocardiography investigation

BACKGROUND

Left ventricular geometry and left atrium (LA) enlargement are risk factors for cardiovascular disease. However, reports on the relationship between left ventricular geometry and LA volume yielded contradictory findings, and LA phasic function remains unclear. Hence, this study aimed to investigate the influence of left ventricular geometry on LA volume and phasic function in patients with obstructive sleep apnea syndrome (OSAS) via a multimodal echocardiographic approach.

METHODS

In this cross-sectional study, 221 patients with OSAS (age 20-68 years, mean age 45.27 ± 12.50 years) underwent clinical evaluation, polysomnography, and multimodal echocardiographic examination with two-dimensional echocardiography (2DE), two-dimensional speckle-tracking echocardiography (2D-STE) and three-dimensional echocardiography (3DE). Based on conventional classification of left ventricular geometry, patients with OSAS were divided into four groups: normal geometry (NG), concentric remodeling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH).

RESULTS

Based on 2DE and 3DE, the LA volumes and indices gradually increased from NG to CH. Additionally, 2DE and 3DE LA maximum volume index (LAVImax) were higher in patients with CH and EH than in patients with NG and CR (P < 0.05). The reservoir function, estimated by LA total emptying fraction (LA TotEF) was lower in patients with CH than in patients with NG in 2DE and 3DE (both, P < 0.05). Also, LA conduit function, evaluated by LA passive emptying fraction (LA PassEF) was lower in patients with CH than in patients with NG and CR, and in patients with EH than in those with NG in 2DE and 3DE (all, P < 0.05). The LA booster pump function, evaluated by LA active emptying fraction (LA ActEF) showed no statistically significant difference in 2DE; however, it was greater in patients with CH than in those with NG in 3DE. Similar results were obtained by 2D-STE, and CH was significantly associated with LA strain during systole (LAS-S, β = - 0.546, 95%CI: - 6.371-(- 3.444); P < 0.001), early diastole (LAS-E, β = - 0.636, 95%CI: - 9.532-(- 5.710); P < 0.001), and late diastole (LAS-A, β = - 0.450, 95%CI: 1.518-3.909; P < 0.001) in multiple linear regression.

CONCLUSIONS

The LA phasic function changed with left ventricular geometry via multimodal echocardiography. CH had the most notable negative effect on the maximum volume and phasic function of the LA.

The clinical value of the apex beat as a marker of left atrial enlargement

BACKGROUND

The palpation of the apex beat, one of the most fundamental physical examinations, provides a clue to left ventricular (LV) dilatation and hypertrophy; however, its relation to left atrial (LA) volume has rarely been investigated.

METHODS

The clinical value of the apex beat, especially in relation to LA volume was studied in 138 consecutive patients. Patients were examined in the supine position for a palpable apex beat. When an apex beat was felt, the apex beat distance, defined as the distance from the mid-clavicular line to the lateral border of the apex beat, was measured. The LA and LV geometry were assessed using echocardiography.

RESULTS

Of the 138 patients, an apex beat was palpable in 52 (38%) patients and the apex distance of these 52 patients ranged from -2 to 8 cm. The parameters of LV dilatation or hypertrophy were significant according to univariate but not to multivariate analysis. Only LA volume index was significant both for the palpability of the apex beat (p=0.0042) and the apex distance (p=0.0017) by multivariate analysis. The best cut-off point for the apex distance was -1 cm for LA enlargement (sensitivity 61%, specificity 92%, p<0.0001).

CONCLUSIONS

The LA volume is the most significant factor for the palpability and leftward deviation of the apex beat. Palpation of the apex beat is a crucial diagnostic tool for the detection of not only LV dilatation or hypertrophy but also of LA enlargement.

[The «obesity paradox» and its degree of proof]

The article gives a critical assessment of the so-called obesity paradox. Methodological errors that occur in the organization of studies that studied the obesity paradox and the formation of comparison groups are highlighted. There are also examples of the disappearance of the obesity paradox when taking into account additional risk factors. The organization of prospective studies or more careful consideration of all currently known risk factors for cardiovascular diseases (CVD) will significantly improve the results of the study of the effect of overweight and obesity on mortality in patients with CVD. Thus, despite the biological possibility of the existence of a positive effect of adipose tissue in CVD, the presence of a large number of errors identified in the analysis of the work of researchers obesity paradox require to reconsider the existence of this phenomenon, it should be taken into account the possibility that the obesity paradox may be a consequence of improper design studies to investigate this phenomenon.

Association between atrial fibrillation, atrial enlargement, and left ventricular geometric remodeling

This study investigated the relationship between atrial fibrillation (AF) and left ventricular (LV) geometric patterns in a hospital-based population in Japan. We retrospectively analyzed 4444 patients who had undergone simultaneous scheduled transthoracic echocardiography (TTE) and electrocardiography during 2013. A total of 430 patients who had findings of previous myocardial infarctions (n = 419) and without the data on body surface area (n = 11) were excluded from the study. We calculated the LV mass index (LVMI) and relative wall (RWT) and categorized 4014 patients into four groups as follows: normal geometry (n = 3046); concentric remodeling (normal LVMI and high RWT, n = 437); concentric hypertrophy (high LVMI and high RWT, n = 149); and eccentric remodeling (high LVMI and normal RWT, n = 382). The mean left atrial volume indices (LAVI) were 22.5, 23.8, 33.3, and 37.0 mm/m² in patients with normal geometry, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy, respectively. The mean LV ejection fractions (LVEF) were 62.7, 62.6, 60.8, and 53.8%, respectively, whereas the prevalence of AF was 10.4%, 10.5%, 14.8%, and 16.8% in patients with normal geometry, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy, respectively. In conclusion, the prevalence of AF was increasing according to LV geometric remodeling patterns in association with LA size and LVEF.

Liver enzymes are not directly involved in atrial fibrillation: a prospective cohort study

BACKGROUND

Epidemiological evidence proposes the direct involvement of the liver enzymes in atrial fibrillation. These relationships are controversial and mechanistically unclear. As part of the British Regional Heart Study, we investigated whether change in liver enzymes over time associates with atrial fibrillation in men initially free of this heart condition.

MATERIALS AND METHODS

We prospectively investigated change (delta) in liver enzymes and new-onset atrial fibrillation in a representative sample of 1428 men aged 60-79 years.

RESULTS

Mean follow-up was 12·3 years, after which 108 new atrial fibrillation cases were identified. The liver enzymes did not differ at baseline or follow-up, except for gamma-glutamyl transferase which was higher at follow-up in men who developed atrial fibrillation compared to those who did not (P < 0·0001). Change in GGT was greater in men who developed AF than those who did not (+6·12 vs. -2·60 U/L, P = 0·036). N-terminal pro-brain natriuretic peptide (baseline and follow-up, P < 0·0001) and total bilirubin (follow-up only, P < 0·0001) were also higher in men who developed atrial fibrillation while serum haemoglobin was similar at baseline and follow-up (P ≥ 0·74). Atrial fibrillation was associated with change in gamma-glutamyl transferase (OR, 1·18; 95% CI, 1·01-1·37) after multiple adjustments and exclusions. However, after adjusting for baseline (P = 0·088) or change (P = 0·40) in N-terminal pro-brain natriuretic peptide, the association between atrial fibrillation and change in gamma-glutamyl transferase was lost.

CONCLUSION

The direct relationship between atrial fibrillation and liver enzymes is absent and depends, at least in part, on the progression of heart failure as captured by N-terminal pro-brain natriuretic peptide.

Management of cardiovascular diseases in patients with obesity

The management of cardiovascular diseases (CVD) in patients with obesity presents numerous challenges. Obesity has a negative effect on almost all of the major CVD risk factors, and adversely influences cardiovascular structure and function. Patients who are overweight or obese have a higher incidence of almost all CVDs compared with patients who are of normal weight. However, those who are overweight or obese seem to have a better short-term and medium-term prognosis after major CVD events and interventional procedures or cardiac surgeries than leaner patients, a phenomenon termed the 'obesity paradox'. In considering the mechanisms underlying this paradox, we review evidence of the deleterious consequences of obesity in patients with coronary heart disease, and the limited data on the benefits of weight loss in patients with CVD. Additional studies are needed on the efficacy of purposeful weight loss on cardiovascular outcomes to determine the ideal body composition for patients with CVD.

Investigating the differences of body mass index and waist circumference in the follow-up assessment of patients to cardiac rehabilitation with acute coronary syndrome

Obesity management is a key point during cardiac rehabilitation. The effect of new index, waist circumference (WC), in the obesity management of cardiac rehabilitation is not clear yet. Therefore, our study compared the WC index to the body mass index (BMI) in the evaluation of obesity management for the patients with acute coronary syndrome (ACS) in a well-designed cardiac rehabilitation program (CRP). Totally 61 patients were enrolled into our study between October 2013 and January 2014 in our hospital. All these patients were requested to participate in the CRP actively for 6 months. We collected the BMI, WC, vital signs, fasting blood levels, the results from a sub-maximal exercise treadmill test (ETT) and ultrasonic cardiogram (UCG) through a follow-up visit conducted every 1, 3, and 6 months. We used two-tailed Pearson's test and linear regression to analyze the data from our experiment. Our results show that the grouping of obese individuals based on the WC results in the WC being significantly associated with high-density lipoprotein cholesterol (HDL_C), inter-ventricular septal thickness at diastole (IVSd) and left ventricular posterior wall at diastole (LVPwd) after 1 and 3 months of the CRP (HDL_C after1 month of CRP: r = -0.292, P = 0.022; HDL_C after 3 months of CRP: r = -0.289, P = 0.024; IVSd after1 month of CRP: r = 0.451, P = 0.004; IVSd after 3 months of CRP: r = 0.304, P = 0.035; LVPwd after1 month of CRP: r = 0.468, P = 0.002; LVPwd after 3 months of CRP: r = 0.290, P = 0.045). However, no similar regular associations were found when obesity was stratified using the BMI. In other words, WC could be better than the BMI for reflecting the cardiac status. In conclusion, obesity management using WC can benefit the clinical evaluation, diagnosis, treatment, prevention, and prognosis of obese individuals of ACS when participating in the CRP.

Body habitus in heart failure: understanding the mechanisms and clinical significance of the obesity paradox

The prevalence of obesity among adults and children worldwide has reached epic proportions and has become a major independent risk factor for the development of heart failure (HF), in addition to a contributor of hypertension and cardiovascular disease. The implications of obesity in the development of HF involve adverse effects on cardiac structure and function. Despite all of this, in the setting of chronic HF, excess body mass is associated with improved clinical outcomes, demonstrating the presence of an obesity paradox. In this review, we will discuss the gender differences, global application, potential mechanisms and role of interventions based on fitness and purposeful weight loss as potential therapeutic strategies.

Obesity and Prevalence of Cardiovascular Diseases and Prognosis-The Obesity Paradox Updated

The prevalence and severity of obesity have increased in the United States and most of the Westernized World over recent decades, reaching worldwide epidemics. Since obesity worsens most of the cardiovascular disease (CVD) risk factors, not surprisingly, most CVDs, including hypertension, coronary heart disease, heart failure, and atrial fibrillation, are all increased in the setting of obesity. However, many studies and meta-analyses have demonstrated an obesity paradox with regards to prognosis in CVD patients, with often the overweight and mildly obese having a better prognosis than do their leaner counterparts with the same CVD. The implication for fitness to markedly alter the relationship between adiposity and prognosis and the potential impact of weight loss, in light of the obesity paradox, are all reviewed.

The influence of left ventricular geometry on left atrial phasic function in hypertensive patients

OBJECTIVE

We aimed to investigate left atrial (LA) phasic function in hypertensive patients with different geometric patterns using two-dimensional (2DE) and three-dimensional (3DE) echocardiography.

METHODS

This cross-sectional study included 213 hypertensive subjects who underwent a complete 2DE and 3DE examination. The new updated criteria for left ventricular (LV) geometry, which consider LV mass index, LV end-diastolic diameter and relative wall thickness, were applied. According to this classification, the subjects were divided into six groups: normal geometry, concentric remodeling, eccentric non-dilated left ventricular hypertrophy (LVH), concentric LVH, dilated LVH and concentric-dilated LVH.

RESULTS

2DE and 3DE LA volumes gradually increased from normal LV geometry to concentric and concentric-dilated LVH. LA reservoir and conduit functions, estimated by 2DE and 3DE LA total and passive emptying fractions, were decreased in subjects with concentric and concentric-dilated LVH. LA booster pump function was increased in patients with concentric, dilated and concentric-dilated LVH compared to subjects with normal LV geometry. The same results regarding LA phasic function were provided by 2DE strain analysis. Concentric, dilated and non-concentric dilated LVH were associated with LA enlargement independently of main demographic and clinical features.

CONCLUSION

LV geometric patterns significantly influence LA phasic function. Concentric and dilated LVH patterns have the most prominent negative effect on LA enlargement assessed by both 2DE and 3DE.

The Different Effects of BMI and WC on Organ Damage in Patients from a Cardiac Rehabilitation Program after Acute Coronary Syndrome

One of the purposes of cardiac rehabilitation (CR) after acute coronary syndrome (ACS) is to monitor and control weight of the patient. Our study is to compare the different obesity indexes, body mass index (BMI), and waist circumference (WC), through one well-designed CR program (CRP) with ACS in Guangzhou city of Guangdong Province, China, in order to identify different effects of BMI and WC on organ damage. In our work, sixty-one patients between October 2013 and January 2014 fulfilled our study. We collected the vital signs by medical records, the clinical variables of body-metabolic status by fasting blood test, and the organ damage variables by submaximal exercise treadmill test (ETT) and ultrasonic cardiogram (UCG) both on our inpatient and four-to-five weeks of outpatient part of CRP after ACS. We mainly used two-tailed Pearson's test and liner regression to evaluate the relationship of BMI/WC and organ damage. Our results confirmed that WC could be more accurate than BMI to evaluate the cardiac function through the changes of left ventricular structure on the CRP after ACS cases. It makes sense of early diagnosis, valid evaluation, and proper adjustment to ACS in CRP of the obesity individuals in the future.

Impact of echocardiographic left ventricular geometry on clinical prognosis

Abnormal left ventricular (LV) geometry, including LV hypertrophy (LVH), is associated with increased risk of major cardiovascular (CV) events and all-cause mortality and may be an independent predictor of morbid CV events. Patients with LVH have increased risk of congestive heart failure, coronary heart disease, sudden cardiac death and stroke. We review the risk factors for LVH and its consequences, as well as the risk imposed by concentric remodeling (CR). We also examine evidence supporting the benefits of LVH regression, as well as evidence regarding the risk of CR progressing to LVH, as opposed to normalization of CR. We also briefly review the association of abnormal LV geometry with left atrial enlargement and the combined effects of these structural cardiac abnormalities.

Obesity and cardiovascular diseases: implications regarding fitness, fatness, and severity in the obesity paradox

Obesity has been increasing in epidemic proportions, with a disproportionately higher increase in morbid or class III obesity, and obesity adversely affects cardiovascular (CV) hemodynamics, structure, and function, as well as increases the prevalence of most CV diseases. Progressive declines in physical activity over 5 decades have occurred and have primarily caused the obesity epidemic. Despite the potential adverse impact of overweight and obesity, recent epidemiological data have demonstrated an association of mild obesity and, particularly, overweight on improved survival. We review in detail the obesity paradox in CV diseases where overweight and at least mildly obese patients with most CV diseases seem to have a better prognosis than do their leaner counterparts. The implications of cardiorespiratory fitness with prognosis are discussed, along with the joint impact of fitness and adiposity on the obesity paradox. Finally, in light of the obesity paradox, the potential value of purposeful weight loss and increased physical activity to affect levels of fitness is reviewed.

Atrial fibrillation in the 21st century: a current understanding of risk factors and primary prevention strategies

Atrial fibrillation (AF) is the most common arrhythmia worldwide, and it has a significant effect on morbidity and mortality. It is a significant risk factor for stroke and peripheral embolization, and it has an effect on cardiac function. Despite widespread interest and extensive research on this topic, our understanding of the etiology and pathogenesis of this disease process is still incomplete. As a result, there are no set primary preventive strategies in place apart from general cardiology risk factor prevention goals. It seems intuitive that a better understanding of the risk factors for AF would better prepare medical professionals to initially prevent or subsequently treat these patients. In this article, we discuss widely established risk factors for AF and explore newer risk factors currently being investigated that may have implications in the primary prevention of AF. For this review, we conducted a search of PubMed and used the following search terms (or a combination of terms): atrial fibrillation, metabolic syndrome, obesity, dyslipidemia, hypertension, type 2 diabetes mellitus, omega-3 fatty acids, vitamin D, exercise toxicity, alcohol abuse, and treatment. We also used additional articles that were identified from the bibliographies of the retrieved articles to examine the published evidence for the risk factors of AF.