Impaired cerebral circulation in patients with slow coronary flow

Establishment and verification of a nomogram that predicts the risk for coronary slow flow

Background

Coronary slow flow (CSF) has gained significance as a chronic coronary artery disease, but few studies have integrated both biological and anatomical factors for CSF assessment. This study aimed to develop and validate a simple-to-use nomogram for predicting CSF risk by combining biological and anatomical factors.

Methods

In this retrospective case-control study, 1042 patients (614 CSF cases and 428 controls) were randomly assigned to the development and validation cohorts at a 7:3 ratio. Potential predictive factors were identified using least absolute shrinkage and selection operator regression and subsequently utilized in multivariate logistic regression to construct the nomogram. Validation of the nomogram was assessed by discrimination and calibration.

Results

N-terminal pro brain natriuretic peptide, high density lipoprotein cholesterol, hemoglobin, left anterior descending artery diameter, left circumflex artery diameter, and right coronary artery diameter were independent predictors of CSF. The model displayed high discrimination in the development and validation cohorts (C-index 0.771, 95% CI: 0.737-0.805 and 0.805, 95% CI: 0.757-0.853, respectively). The calibration curves for both cohorts showed close alignment between predicted and actual risk estimates, demonstrating improved model calibration. Decision curve analysis suggested high clinical utility for the predictive nomogram.

Conclusion

The constructed nomogram accurately and individually predicts the risk of CSF for patients with suspected CSF and may be considered for use in clinical care.

Major Adverse Cardiovascular Events and Prognosis in Patients With Coronary Slow Flow

This study aimed to investigate its clinical implications, risk factors, prognosis, and overall long-term outcomes. Demographic profiles, various clinical characteristics, and clinical outcomes were compared between 614 patients with coronary slow flow (CSF) and 428 patients with normal coronary artery. The incidence of CSF was found to be 2.65%. Significant differences were observed between patients with CSF and control subjects in terms of sex, chest tightness, hyperlipidemia, smoking history, alcohol consumption, age, height, weight, body mass index, diastolic blood pressure, heart rate, and body surface area (P < 0.05). CSF (hazard ratio: 1.531; 95% confidence interval: 1.064-2.202; p = 0.022) proved to be independent prognostic predictors of major adverse cardiovascular events (MACEs). Kaplan-Meier survival evaluations for MACEs presented a worser outcome for patients with CSF. Patients with CSF are at high risk for cardiovascular events and experience generally poor clinical outcomes.

Non-Dipper Blood Pressure Impact on Coronary Slow Flow in Hypertensive Patients With Normal Coronary Arteries

OBJECTIVE

Coronary slow flow (CSF) is linked to myocardial ischemia, malignant arrhythmias, and cardiovascular mortality. On the other hand, hypertension (HTN) is an important risk factor for vascular disorders. There is limited research on the relationship between CSF and HTN. This study aimed to investigate TIMI frame count (TFC), which is an indicator of CSF, in dipper and non-dipper hypertensive individuals with normal coronary arteries.

METHODS

The study was conducted as a retrospective observational study. Patients diagnosed with CSF and dipper or non-dipper hypertension were included in this study. Blood tests were routinely conducted for all patients. ECG was conducted for each patient, and echocardiography was performed. Coronary artery images were obtained in the CAG laboratory. Blood pressure (BP) measurements were obtained from the ambulatory Holter records. The patients were separated into two groups based on ambulatory Holter monitoring. The relationship between CSF and HTN was also examined.

RESULTS

A total of 71 patients, comprising 25 women (37.2%) and 46 men (62.8%) with an average age of 52.75±9.42 years, were enrolled in the research. Based on ambulatory BP, the individuals were separated into two groups: non-dipper (n=36) and dipper (n=35). The pulse rate was significantly higher in the non-dipper group (p<0.001). In terms of mean systolic and diastolic blood pressure, there were no substantial differences across the groups (p = 0.326 and p = 0.654, respectively). The daytime mean systolic and diastolic BP did not significantly differ across the groups (p = 0.842 and p = 0.421). The dipper group had substantially lower nighttime systolic and diastolic BP values (p <0.001). The LAD, Cx, and RCA TIMI frame scores were significantly lower in the dipper group (p<0.001).

CONCLUSION

In this study, non-dipper patients had a greater CSF rate than dipper.

Microvascular Dysfunction as a Systemic Disease: A Review of the Evidence

Microvascular dysfunction describes a varied set of conditions that includes vessel destruction, abnormal vasoreactivity, in situ thrombosis, and fibrosis, which ultimately results in tissue damage and progressive organ failure. Microvascular dysfunction has a wide array of clinical presentations, ranging from ischemic heart disease to renal failure, stroke, blindness, pulmonary arterial hypertension, and dementia. An intriguing unifying hypothesis suggests that microvascular dysfunction of specific organs is an expression of a systemic illness that worsens with age and is accelerated by vascular risk factors. Studying relationships across a spectrum of microvascular diseases affecting the brain, retina, kidney, lung, and heart may uncover shared pathologic mechanisms that could inform novel treatment strategies. We review the evidence that supports the notion that microvascular dysfunction represents a global pathologic process. Our focus is on studies reporting concomitant microvascular dysfunction of the heart with that of the brain, kidney, retina, and lung.

Long-term outcomes of the modest stent expansion strategy for the culprit lesion of acute myocardial infarction

Slow flow during primary percutaneous coronary intervention (PCI) is a common complication. Our group showed that the stent (or post-balloon) diameter-to-vessel diameter ratio was inversely associated with slow flow phenomenon. We advocated the utility of modest stent expansion strategy, which was defined as the stent (or post-balloon) diameter-to-culprit vessel diameter ratio < 0.71, for prevention of slow flow phenomenon. This study aimed to compare the long-term outcomes in patients with acute myocardial infarction (AMI) between the modest stent expansion strategy and the aggressive stent expansion strategy (the stent diameter-to-culprit vessel diameter ratio ≥ 0.71). We included 584 AMI patients, which were divided 177 patients in the modest stent expansion group and 146 patients in the aggressive stent expansion group. The primary endpoint was major adverse cardiac events (MACE), which was defined as a composite of cardiac death, ischemia driven target vessel revascularization, and stent thrombosis. The slow flow after stent deployment was more frequently observed in the aggressive stent expansion group (24.0%) than in the modest stent expansion group (4.0%) (P < 0.001). The Kaplan-Meier curves revealed that MACE was comparable between the two groups (P = 0.64). The multivariate COX hazard model showed the non-significant association between the modest stent expansion strategy and MACE (vs. aggressive stent expansion: hazard ratio 1.005, 95% confidence interval 0.619-3.242, P = 0.41). In conclusion, the modest stent expansion strategy was not associated with long-term MACE. Therefore, the modest stent expansion strategy may be a good choice for the culprit lesion of AMI.

Carotid artery blood velocity decreases in patients with coronary slow flow: A manifestation of systemic arteriosclerosis

OBJECTIVES

Coronary slow flow phenomenon (CSFP) could be a manifestation of systemic arteriosclerosis, as coronary and carotid arteries have similar intimal thickening. However, as an initial cause of arteriosclerosis, hemodynamic changes in carotid arteries have rarely been studied.

METHODS

Twenty patients with angiography-proven CSFP and 39 patients with normal coronary flow (NCF) were enrolled. TIMI frame counts (CTFC) were investigated. Carotid intima-media thickness (CIMT), peak systolic velocity (PSV), and end-diastolic velocity (EDV) were measured by ultrasonography, and shear rate (SR) and resistance index (RI) were calculated.

RESULTS

The results showed that PSV, EDV, SR, and RI were significantly lower in patients with CSFP (p＜0.01), but CIMT was significantly increased (P ＜ 0.01). PSV, EDV, SR, and RI were negatively correlated with CTFC, while CIMT was positively correlated with CTFC. Logistic regression analysis revealed that PSV (OR = 0.95, P < 0.01) could be an independent protective factor against CSFP, but CIMT (OR = 1.10, P ＜ 0.05) and male gender (OR = 9.89, P ＜ 0.01) could be risk factors for CSFP.

CONCLUSIONS

The slow flow phenomenon was observed in both coronary and carotid arteries, which could be a characteristic manifestation of systemic arteriosclerosis in CSFP; the lower wall shear stress may be the underlying mechanism. Carotid ultrasound could be applied in the noninvasive diagnosis of CSFP in the future.

Relationship of serum salusin beta levels with coronary slow flow

OBJECTIVE

The pathophysiology of coronary slow flow (CSF) has not been clarified. Salusin-β is released predominantly from the atheroma plaques and influences the pathophysiologic processes of atherosclerosis. Therefore, this study aimed to determine serum salusin-β levels in CSF and its correlation with CSF.

METHODS

The study included 39 patients with CSF, and the control group (n=42) consisted of consecutive subjects with normal coronary arteriogram. We measured salusin-β and thrombolysis in myocardial infarction frame count (TFC).

RESULTS

Age, body mass index (BMI), systolic blood pressure, diabetes, hyperlipidemia, and smoking rates were similar (p values>0.05) in both groups. High sensitive C-reactive protein (2.80±1.2 vs. 2.21±1.2 mg/dL, p=0.011), salusin-β [1205 (330-2092) vs. 162 (29-676), pg/ml, p<0.001], corrected TFC of left anterior descending coronary artery (29±9 vs. 19.7±3.7, p<0.001), circumflex artery TFC (25±10 vs. 15±3.2, p<0.001), right coronary artery TFC (28±7.1 vs. 13±3.3, p<0.001), and mean TFC (28±4.4 vs. 16±3.7, p<0.001) were significantly higher in the CSF group. In univariate and multivariate regression analysis, only BMI (unstandardized β±SE=0.178±0.08, p=0.036) and salusin-β levels (unstandardized β±SE=0.006±0.01, p<0.001) were determined as predictors of CSF. There was a good correlation between serum salusin-β and mean TFC values (r=0.564; p<0.001).

CONCLUSION

There is an association between serum salusin-β levels and CSF.

The coronary slow flow phenomenon: characteristics, mechanisms and implications

The coronary slow flow phenomenon (CSFP) is an important, angiographic entity characterized by delayed progression of the injected contrast medium through the coronary tree. It is a frequent finding, typically observed in patients presenting with acute coronary syndromes. Although it is well known to interventional cardiologists for approximately four decades, the pathogenic mechanisms remain unclear. The clinical implications are significant, with over 80% of patients experiencing recurrent chest pain, resulting in considerable impairment in quality of life. This article will address in detail the characteristics, possible mechanisms, and clinical implications of this entity to provide further insight into its clinical significance and management strategies.