Defining Coronary Slow Flow

Relationship between quantitative epicardial adipose tissue based on coronary computed tomography angiography and coronary slow flow

BACKGROUND

The purpose of this study was to explore the relationship between quantitative epicardial adipose tissue (EAT) based on coronary computed tomography angiography (CCTA) and coronary slow flow (CSF).

METHODS

A total of 85 patients with < 40% coronary stenosis on diagnostic coronary angiography were included in this retrospective study between January 2020 and December 2021. A semi-automatic method was developed for EAT quantification on CCTA images. According to the thrombolysis in myocardial infarction flow grade, the patients were divided into CSF group (n = 39) and normal coronary flow group (n = 46). Multivariate logistic regression was used to explore the relationship between EAT and CSF. Receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of EAT in CSF.

RESULTS

EAT volume in the CSF group was significantly higher than that of the normal coronary flow group (128.83± 21.59 mL vs. 101.87± 18.56 mL, P < 0.001). There was no significant difference in epicardial fat attenuation index between the two groups (P > 0.05). Multivariate logistic regression analysis showed that EAT volume was independently related to CSF [odds ratio (OR) = 4.82, 95% confidence interval (CI): 3.06-7.27, P < 0.001]. The area under ROC curve for EAT volume in identifying CSF was 0.86 (95% CI: 0.77-0.95). The optimal cutoff value of 118.46 mL yielded a sensitivity of 0.80 and a specificity of 0.94.

CONCLUSIONS

Increased EAT volume based on CCTA is strongly associated with CSF. This preliminary finding paves the way for future and larger studies aimed to definitively recognize the diagnostic value of EAT in CSF.

Long-Term Change in Flow Rates in Patients with Coronary Slow Flow

INTRODUCTION

Coronary slow flow (CSF) is a condition characterized by impaired blood flow rates in the coronary arteries. It can result in severe cardiovascular outcomes. There is no sufficient evidence regarding the certain etiology and reversibility of slow flow patterns and changes in frame counts with long-term management.

METHODS

We retrospectively enrolled 48 patients with chronic coronary syndrome and CSF who underwent a second angiography. A corrected coronary frame rate (CFR) >27 was defined as CSF. We created 3 groups according to the change in CSF status as the improved, not changed, and worsened groups. We compared the CFR and CSF status of the patients between the first and second angiographies within a median of 2.6 years.

RESULTS

We determined a nonsignificant change in cCFR in left anterior descending (LAD) artery (34.4 [18.9] vs. 31.59 [10.3], p = 0.35), circumflex (Cx) artery (42.84 [12.56] vs. 40.66 [13.2], p = 0.35), and right coronary artery (RCA) (57.80 [30.13] vs. 50.32 [19.5], p = 0.11). In the comparison of CSF status of LAD (75% vs. 63%, p = 0.27), Cx (96% vs. 83%, p = 0.09), RCA (94% vs. 94%, p = 1.0) between first and second angiographies, there was no significant change. In the comparison of the 3 groups according to the improvement of CSF status, there was no significant difference in demographic features, change in laboratory parameters, and time between the groups.

CONCLUSION

There was no significant change in the median CFR and CSF status in the overall group between the two angiographies after 3 years.

Meta-analysis and trial sequential analysis of shexiang baoxin pill for coronary slow flow

Background: Coronary slow flow (CSF) is a common cardiovascular phenomenon with no effective treatment in conventional Western medicine (CWM). Shexiang Baoxin Pill (SXBXP) is a widely used Chinese medicine for cardiovascular disease in China, and clinical studies have shown that it has good efficacy for CSF.

Objective: To systematically evaluate the efficacy and safety of SXBXP for CSF.

Methods: Seven databases were searched to identify related randomized controlled trials (RCTs). The Meta-analysis, trial sequential analysis (TSA), and Grades of Recommendation, Assessment, Development and Evaluation (GRADE) were performed using Stata 14.1, TSA 0.9.5.10 Beta and GRADE profiler 3.2.2 software respectively.

Results: A total of 10 RCTs were included. Meta-analysis showed that compared with CWM treatment alone, SXBXP combined with CWM further improved the angina pectoris efficacy [RR = 1.37, 95% CI (1.23, 1.52), p < 0.000 01] and nitric oxide (NO) level [WMD = 11.32, 95% CI (0.04, 22.59), p = 0.049], decreased the mean corrected TIMI frame count (CTFC) [WMD = −4.23, 95% CI (−5.51, −2.95), p < 0.000 01], CTFC of the left anterior descending artery (LAD) [WMD = −6.36, 95% CI (−12.07, −0.65), p = 0.029], left circumflex artery (LCX) [WMD = -5.73, 95% CI (−8.79, −2.67), p < 0.000 01], and right coronary artery (RCA) [WMD = −6.72, 95% CI (−10.60, −2.84), p = 0.001], decreased the positive rate of treadmill exercise test [RR = 0.45, 95% CI (0.25, 0.83), p = 0.010], endothelin-1 (ET-1) level [WMD = -11.03, 95% CI (−13.92, −8.14), p < 0.000 01], high-sensitivity C-reactive protein (hs-CRP) [WMD = −1.95, 95% CI (−2.57, −1.34), p < 0.000 01], and adverse reactions [RR = 0.20, 95% CI (0.05, 0.85), p = 0.030]. The GRADE evidence quality rating presented with moderate, low or very low quality of evidence. TSA further affirmed the clinical efficacy.

Conclusion: Although some results suggest that there may be a positive effect of SXBXP for CSF, the quality of the primary study including the reporting is too poor and therefore, no benefits could be demonstrated. More high-quality studies are still needed to further confirm the efficacy and safety.

Systematic review registration:https://www.crd.york.ac.uk/PROSPERO/, identifier (CRD42022329469).