Left Ventricular Myocardial Deformation Parameters Are Affected by Coronary Slow Flow Phenomenon: A Study of Speckle Tracking Echocardiography

Evaluation of changes in the global longitudinal strain for left ventricular function before and after eight weeks of taking high dose of atorvastatin in patients with coronary slow flow phenomenon

BACKGROUND

Coronary Slow Flow Phenomenon (CSFP) is a well-recognized clinical entity characterized by delayed opacification of coronary arteries in the presence of a normal coronary angiogram. The objective of this study was determined and compared left ventricle (LV)strain in patients with CSFP before and after receiving a high-dose atorvastatin.

MATERIALS AND METHODS

This cross-sectional study was conducted on 51 patients with CSFP from the beginning of 2021 to the end of September 2022. Trans-thoracic Echocardiogram (TTE) was performed by an echocardiography specialist. Thereafter, the patient's basic information was entered into the researcher's checklist after treatment with atorvastatin 40 mg daily for eight consecutive weeks. After eight weeks, the patients were subjected again to TTE. The data were analyzed in SPSS statistical software.

RESULTS

The mean LV-GLS before taking atorvastatin was - 16.53%±3.63%. The mean LV-GLS after taking atorvastatin was 17.57%±3.53% (P.value = 0.01). The mean LV function before taking atorvastatin was 48.82%±9.19%. Meanwhile, the mean LV function after taking atorvastatin was 50.59%±7.91% (P = 0.01). There was no significantly change in left atrium volume (49.88 ± 0.68 vs. 49.9 + 0.67) after 8 weeks taking atorvastatin (P = 0.884).

CONCLUSION

The plasma ET-1 levels are elevated in CSFP patients, and atorvastatin improves coronary flow and endothelial function. As evidenced by the results of this study, the daily intake of 40 mg of oral atorvastatin during eight consecutive weeks in patients with CSFP significantly improved LV strain and LV function, however atorvastatin does not have a significant effect on improving the right ventricular function and pulmonary artery systolic pressure.

Coronary slow flow research: a bibliometric analysis

BACKGROUND

Studies on coronary slow flow are receiving increasing attention, but objective evaluations are still lacking. The purpose of this study was to visualize the current status and research hotspots of coronary slow flow through bibliometric analysis.

METHODS

All relevant publications on coronary slow flow from 2003 to 2022 were extracted from the Web of Science Core Collection database and analyzed by VOSviewer and CiteSpace visualization software. Year of publication, journal, country/region, institution, and first author of each paper, as well as research hotspots were identified.

RESULTS

A total of 913 publications were retrieved. The journal with the most publications was Coronary Artery Disease. The country/region with the most publications was Turkey, followed by China and the United States. The institution with the largest publication volume was Turkey Specialized Higher Education Research Hospital. The author with the largest publication volume was Chun-Yan Ma from China. Keyword analysis indicated that "treatment and prognosis", "pathogenesis and risk factors" and "diagnosis" were the clustering centers of coronary slow flow, and the research hotspots gradually changed with time, from pathogenesis to treatment and prognosis.

CONCLUSION

Future research will focus on the search for effective and non-invasive detection indicators and treatments of coronary slow flow. Collaboration needs to be enhanced between different institutions or countries/regions, which would improve clinical outcomes for patients with coronary slow flow.

Evaluation of cardiac chamber functions by speckle-tracking echocardiography in the presence of coronary artery flow disturbances other than stenosis: A review

Conditions other than stenosis also disturb the coronary flow. Such conditions include the coronary slow flow phenomenon, coronary artery ectasia, and coronary artery tortuosity. Evidence exists regarding myocardial dysfunction in these conditions. In this review, we present studies that have used speckle-tracking echocardiography to determine whether coronary flow disturbances are accompanied by myocardial dysfunction. Additionally, we seek to show the gaps in knowledge concerning this issue and the dimensions that future studies should consider.

Slow Coronary Blood Flow: Pathogenesis and Clinical Implications

Coronary slow flow (CSF) phenomenon, also known as cardiac syndrome Y, is defined as the delayed opacification of the coronary vasculature at the distal level. Different hypotheses and theories have been postulated about its substrate and mechanism, such as microvascular and endothelial dysfunction. Several studies have confirmed that CSF is a cause of ischaemia detected by non-invasive testing. Clinically, it can present as angina pectoris, acute coronary syndrome and sudden cardiac death. It has an incidence of 1–5% in patients undergoing coronary angiography and has been most frequently found in young men who are smokers with metabolic syndrome. There are no established treatments for CSF and further studies are still necessary.

Incremental Value of Three-dimensional Speckle-tracking Echocardiography for Evaluating Left Ventricular Systolic Function in Patients with Coronary Slow Flow

The purpose was to evaluate left ventricular (LV) systolic function in patients with coronary slow flow (CSF), and compared the incremental values of 3-dimensional (3D) speckle-tracking echocardiography (STE). Seventy-three patients with CSF and 60 control subjects were enrolled. CSF was diagnosed during coronary angiography. Two-dimensional (2D) and 3D global strain were measured using STE. Sex, mitral E, 2D GLS, and all 3D strain parameters were independent predictors of CSF. Combination of sex, mitral E, and 3D GTS had the highest area under the curve (AUC) for identifying CSF (AUC, 0.81; P < 0.001). Integrated discrimination index (IDI) improved adding 3D GTS to the combined sex and mitral E model (IDI = 0.12, P = 0.01) or 2D GLS model (IDI = 0.14, P < 0.001). LV systolic function was impaired in CSF patients. 3D GTS had an independent and incremental value for predicting CSF compared with 2D echocardiography.

The effect of coronary slow flow on left atrial structure and function

The coronary slow flow phenomenon (CSFP) is common in coronary angiography, however its impact on left atrial (LA) function is still controversial. This study aims to evaluate the LA structure and function of patients with CSFP using two-dimensional speckle tracking echocardiography (2D-STE). Consecutive patients scheduled for coronary angiography from January 2016 to September 2017 were enrolled in this study. Patients’ demographic data, clinical histories, laboratory and angiographic findings were collected and recorded. Diagnostic criteria for CSFP is based on Beltrame et al. proposed in 2012. Meanwhile 139 patients who have no significant stenosis (≤ 40%) and normal blood flow were selected as control. All patients received an echocardiographic examination 24 h before coronary angiography. LA structure and function were measured with echocardiography and 2D-STE. Our results showed that among the 1,954 patients who had received coronary angiography, 512 patients were included in the analysis after the exclusion criteria was implemented. Of those, 101 patients met the CSFP criteria (5.5%). CSFP is mainly seen in LAD (~ 70%). There was no statistical difference in baseline characteristics between the CSFP group and control group, except for a higher proportion of smokers in the CSFP group (P = 0.001). The percentage of monocytes is an independent risk factor for the occurrence of CSFP (P = 0.036) after binary logistic regression analysis. The LA global longitudinal strain (LA-GLS, represents reservoir functions) decreased and LA strain rate at late diastole (LA-SRa, represents booster function) increased in patients with CSFP compared to the control group (P < 0.05). Correlation test of continuous variables by Pearson test suggested that LA-GLS was negatively correlated with TIMI frame count (TFC). We concluded that the percentage of monocytes is an independent risk factor for the CSFP; the LA reservoir and booster functions were impaired in patients with CSFP; LA-GLS is negatively correlated with TFC.

Ventricular Dysfunction in Patients with Coronary Slow-Flow Phenomenon: A Single-center Case-control Study

Background:

Coronary slow-flow phenomenon (CSFP), characterized by delayed distal vessel opacification of contrast, in the absence of significant epicardial coronary stenosis, has effects on exercise capacity and clinical outcomes. The aim of this study was to explore the systolic and diastolic function of patients with CSFP and to compare it with a group of controls with normal coronary anatomy and flow.

Materials and Methods:

In this case–control study, 45 consecutive CSFP patients and 45 age-, body mass index-, and presentation season-matched controls with normal coronary arteries and normal coronary flows were enrolled from Seyyedoshohada Heart Center from March 2015 to March 2016. A transthoracic echocardiography was done by a blinded echocardiographer using both conventional and tissue Doppler imaging techniques.

Results:

Patients with CSFP were more likely to be male (P = 0.006) and smoker (P = 0.02) compared to controls. Other risk factors were not different between the two groups. There were no differences between groups in terms of the peak early (E) and late (A) diastolic velocities, deceleration time, early (E’) and late (A’) peak diastolic velocities at the mitral annulus, and the systolic mitral annular velocity (S’). Global longitudinal strain and peak systolic strain rates was lower in patients with CSFP compared to controls (−16.7% ±2.4% vs. −18.9% ±1.6%, P < 0.001 and 1.10 ± 0.1 vs. 1.24 ± 0.3, P = 0.008, respectively).

Conclusion:

Patients with CSFP showed signs of the left ventricular systolic dysfunction in tissue Doppler echocardiography, which underlines the importance of close follow-up in these patients. Patients with CSFP should be screened for ventricular function preferably by tissue Doppler echocardiography.

Two-dimensional speckle-tracking echocardiographic evaluation of the longitudinal deformation of the left ventricular myocardium in patients with severe coronary artery tortuosity

PURPOSE

Coronary artery tortuosity (CAT) is an anatomical condition in which epicardial coronary arteries have abnormal curves or spiral courses. Although correlated with higher rates of positive stress test, its effects on the myocardial function remain to be clearly defined.

METHODS

We included in this cross-sectional study and evaluated with 2D speckle-tracking echocardiography 40 consecutive patients admitted to our hospital for selective coronary angiography which showed severe CAT without significant epicardial coronary artery stenosis, and 40 consecutive subjects matched for age, hypertension, and diabetes in whom selective coronary angiography showed neither CAT nor significant epicardial coronary artery stenosis.

RESULTS

Systolic strain, strain rate, and early and late diastolic strain rates were not significantly different between the 2 groups, even after adjustment for potential confounding variables.

CONCLUSION

The 2D speckle-tracking echocardiography-derived indices of longitudinal deformation of the left ventricular myocardium were not significantly different between the patients with severe CAT and controls.

Clinical, demographic, risk factor and angiographic profile of coronary slow flow phenomenon: A single centre experience

Background

The coronary slow flow phenomenon (CSFP) is an angiographic finding characterized by delayed distal vessel opacification in the absence of significant epicardial coronary stenosis. Although it is well-known to interventional cardiologists for approximately four decades, the etiopathogenesis still remains unclear.

Aims and objectives

In this study, we aimed to determine the clinical, demographic, risk factor and angiographic profile of patients with CSFP.

Methods

Clinical, demographic, risk factor and angiographic profile were recorded in all consecutive patients who had undergone coronary angiography between September 2016 and March 2017 and showed features of CSFP and a control group who showed normal coronary flow (NCF). The CSFP was diagnosed on the basis of the corrected thrombolysis in myocardial infarction frame count.

Results

CSFP was significantly more prevalent in male patients. Among the traditional risk factors, there was significantly more prevalence of hypertension (31.25% versus 6.67%, p < 0.001), dyslipidemia (40% versus 7.5%, p < 0.001) and history of tobacco use (47.5% versus 10.0%, p < 0.001) in CSFP patients as compared to NCF patients. On multivariable regression analysis hypertension, dyslipidemia, history of smoking and tobacco chewing were found to have independent association with CSFP. Acute coronary syndrome (ACS) was the most common mode of presentation in CSFP patients.

Conclusion

CSFP was relatively common among patients who presented with ACS. Hypertension, dyslipidemia, smoking and tobacco chewing can be considered independent risk factors for this phenomenon. Therefore, CSFP should be considered as a pathological entity and not an entirely benign condition.