Microcirculation function assessed by adenosine triphosphate stress myocardial contrast echocardiography and prognosis in patients with nonobstructive coronary artery disease

Impact of Isolated Coronary Microvascular Disease Diagnosed Using Various Measurement Modalities on Prognosis: An Updated Systematic Review and Meta-Analysis

INTRODUCTION

The main aim of this study was to investigate the impact of isolated coronary microvascular disease (CMD) as diagnosed via various modalities on prognosis.

METHODS

A systematic literature review of PubMed, Embase, and Cochrane Library databases was conducted to identify relevant studies published up to March 2023. Included studies were required to measure coronary microvascular function and report outcomes in patients without obstructive coronary artery disease (CAD) or any other cardiac pathological characteristics. The primary endpoint was all-cause mortality, and the secondary endpoint was a major adverse cardiac event (MACE). Pooled effects were calculated using random effects models.

RESULTS

A total of 27 studies comprising 18,204 subjects were included in the meta-analysis. Indices of coronary microvascular function measurement included coronary angiography-derived index of microcirculatory resistance (caIMR), hyperemic microcirculatory resistance (HMR), coronary flow reserve (CFR), and so on. Patients with isolated CMD exhibited a significantly higher risk of mortality (OR: 2.97, 95% CI, 1.91-4.60, p < 0.0001; HR: 3.38, 95% CI, 1.77-6.47, p = 0.0002) and MACE (OR: 5.82, 95% CI, 3.65-9.29, p < 0.00001; HR: 4.01, 95% CI, 2.59-6.20, p < 0.00001) compared to those without CMD. Subgroup analysis by measurement modality demonstrated consistent and robust pooled effect estimates in various subgroups.

CONCLUSION

CMD is significantly associated with an elevated risk of mortality and MACE in patients without obstructive CAD or any other identifiable cardiac pathologies. The utilization of various measurement techniques may have potential advantages in the management of isolated CMD.

Evaluation of left ventricular function in ischemia with non-obstructive coronary arteries: a research based on adenosine stress myocardial contrast echocardiography

Patients with ischemia with non-obstructive coronary arteries (INOCA) have an increased risk of adverse cardiovascular events in the future, which is widespread but underdiagnosed. The purpose of this study is to explore the application value of adenosine stress myocardial contrast echocardiography (ASMCE) in INOCA disease, so that clinicians can early identify and intervene patients with left ventricular function subclinical impairment in INOCA. We enrolled 118 patients with INOCA by ASMCE and invasive coronary angiography (ICA), 97 of whom had complete data. The study population was divided into two subgroups depending on coronary flow velocity reserve (CFVR): impaired CFVR group (n = 34) and normal CFVR group (n = 63). Global longitudinal strain endocardial myocardial (GLSendo), mid-myocardial (GLSmid) and epicardial myocardial (GLSepi) increased after stress in both groups; transmural strain, wall motion scored index (WMSI) and myocardial perfusion scored index (MPSI) increased and FORCE decreased in impaired CFVR group after stress, but there was no difference in normal group before and after stress. There was no significant difference in left ventricular myocardial mechanical parameters, including ΔGLSendo, ΔGLSmid, ΔGLSepi, GLSendo-epi Reserve, Δpeak strain dispersion (PSD), PSD Reserve between the two groups, but ΔEF, strain reserve and left ventricular contractile reserve (LVCR) in the impaired CFVR group were lower than those in the normal CFVR group, while ΔWMSI and ΔMPSI were increased. CFVR can be a clinically valuable indicator in the ASMCE diagnosis of patients with microvascular angina pectoris in INOCA. In the evaluation of left ventricular function in INOCA patients, attention should be paid not only to myocardial deformation, but also to the dynamic changes of LVCR and myocardial perfusion during peak hyperemia.

The association between heart rate reserve and impaired coronary flow velocity reserve: a study based on adenosine stress echocardiography

This study was to explore the correlation between heart rate reserve (HRR) to coronary flow velocity reserve (CFVR), using adenosine stress echocardiography (SE), in patients with angina and no obstructive coronary artery disease (ANOCA). 111 ANOCA patients underwent adenosine SE were enrolled, which were divided into two groups, impaired CFVR group (CFVR < 2) and control groups (CFVR ≥ 2). The relationships between HRR and impaired CFVR were explored in total and subgroup to sex. A reduced HRR during adenosine infusion was seen in ANOCA patients with impaired CFVR (25.73 ± 8.39 vs. 34.30 ± 19.93, P < 0.001). Compared to respective controls, the blunted HRR to adenosine was more pronounced in female patients (women: 27.21 ± 8.01 vs. 39.48 ± 10.57, P < 0.001; men: 24.05 ± 8.70 vs. 29.12 ± 8.69, P = 0.041). A strong association between CFVR and a blunted HRR was observed in women (r = 0.46, P < 0.001), while no association in men (r = 0.18, P = 0.199). In female, a multivariate logistic regression identified HRR as the strongest negative predictor of impaired CFVR [HR (95% CI) = 0.854 (0.764-0.956), P = 0.006]. Based on the ROC curve, HRR < 35% was a strong indicator of impaired CFVR, with AUC of 0.838, sensitivity of 70%, and specificity of 87% in females. A blunted HRR was seen in patients with impaired CFVR, with a most pronounced effect being seen in female patients. The blunted HRR < 35% is intricately linked to impaired CFVR in women with ANOCA beyond the value of traditional risk factors, which could ultimately contribute to risk stratification of impaired CFVR in such patients.

Correlation Between Retinopathy and Coronary Microcirculation Dysfunction in Patients with Type 2 Diabetes Mellitus

Purpose

The aim of this study is to evaluate the correlation between retinopathy and coronary microcirculation dysfunction (CMD) in type 2 diabetes mellitus (T2DM) patients.

Methods

198 T2DM patients with left ventricular ejection fraction (LVEF)>50%, no epicardial coronary artery stenosis diagnosis by coronary angiography (CAG) and successfully completed coronary blood flow reserve (CFR) test and laboratory examination were enrolled, and fundus examination was performed on all participants. Two groups were divided according to CFR value, including 86 patients with CMD (CFR≤2.5) in study group and 112 patients without CMD (CFR>2.5) in control group. The composition of various retinopathy in two groups was observed, and the correlation between retinopathy and CMD was analyzed using ordered logistic regression.

Results

There were 13 cases with arteriovenous (A/V) nicking, 4 cases with proliferative diabetic retinopathy (PDR), 14 cases with non-proliferative diabetic retinopathy (NPDR), 17 cases with diabetic retinopathy (DR) with A/V nicking, 38 cases without retinopathy in study group, and 18 cases, 7 cases, 20 cases, 4 cases and 63 cases for each in control group. After adjustment for age, gender, hypertension, diabetes duration, dyslipidemia, glycosylated hemoglobin (HbA1c), body mass index (BMI), A/V nicking, PDR and NPDR, the diference of DR with A/V nicking between study and control group remained statistically signifcant (OR 2.0, 95% CI 0.79 to 3.21, p = 0.001).

Conclusion

DR with A/V nicking could be used as an independent predictor of T2DM patients with CMD. CFR testing should be performed on patients with this kind of eye sign, even if they do not have any symptoms of heart disease. Meanwhile, DR with A/V nicking might be served as a reference indicator of CMD in T2DM patients with chest pain who were unable to be tested for CFR.

Research Progress of Imaging Methods for Detection of Microvascular Angina Pectoris in Diabetic Patients

Diabetes is a complex metabolic disease characterized by hyperglycemia. Its complications are various, often involving the heart, brain, kidney, and other essential organs. At present, the number of diabetic patients in the world is growing day by day. The cardiovascular disease caused by diabetes has dramatically affected the quality of life of diabetic patients. It is the leading cause of death of diabetic patients. Diabetic patients often suffer from microvascular angina pectoris without obstructive coronary artery disease. Still, there are typical ECG ischemia and angina pectoris, that is, chest pain and dyspnea under exercise. Unlike obstructive coronary diseases, nitrate does not affect chest pain caused by coronary microvascular angina in most cases. With the increasing emphasis on diabetic microvascular angina, the need for accurate diagnosis of the disease is also increasing. We can use SPECT, PET, CMR, MCE, and other methods to evaluate coronary microvascular function. SPECT is commonly used in clinical practice, and PET is considered the gold standard for non-invasive detection of myocardial blood flow. This article mainly introduces the research progress of these imaging methods in detecting microvascular angina in diabetic patients.

Neutrophil-to-lymphocyte ratio is associated with coronary microvascular dysfunction in type 2 diabetes mellitus patients

AIMS

Our study is aimed to investigate the relationship between neutrophil-to-lymphocyte ratio (NLR) and coronary microvascular dysfunction (CMD) in type 2 diabetes mellitus (T2DM) patients.

METHODS

We retrospect the consecutive medical files of 160 T2DM patients and recorded their clinical information and laboratory findings. Patients were divided into CMD group (n = 87) and non-CMD group (n = 73). We compared the NLR values of the two groups. Meanwhile we also observed the prevalence of CMD at different NLR levels. Then, logistic regression and ROC analysis were performed.

RESULTS

NLR value of CMD group was significantly lower than non-CMD group (2.01 ± 0.74 vs 2.53 ± 0.69, P＜0.001). Prevalence of CMD in low (NLR ≤ 1.53, n = 30), medium (1.53 < NLR ≤ 2.20, n = 53) and high (NLR > 2.20, n = 77) group were 90%, 61.1%, and 39.2% respectively. The prevalence of CMD significantly increased as NLR level decreased. After adjusting potential related factors, NLR was still significantly correlated with CMD (OR = 0.295, 95 %CI:0.162-0.539, P < 0.001). The area under ROC curve (AUC) was 0.707 (95 %CI:0.627-0.786, P < 0.001).

CONCLUSIONS

Our results showed that NLR is associated with CMD in T2DM patients, and the prevalence of CMD may increase as NLR level decrease.

Effects of Oral Drugs on Coronary Microvascular Function in Patients Without Significant Stenosis of Epicardial Coronary Arteries: A Systematic Review and Meta-Analysis of Coronary Flow Reserve

Objective: This study aims to investigate the impact of cardiovascular medications on the coronary flow reserve (CFR) in patients without obstructive coronary artery disease (CAD).

Methods: We searched PubMed, EMBASE, and Cochrane databases from inception to 15 November 2019. Studies were included if they reported CFR from baseline to follow-up after oral drug therapy of patients without obstructive CAD. Data was pooled using random-effects modeling. The primary outcome was change in CFR from baseline to follow-up after oral drug therapy.

Results: A total of 46 studies including 845 subjects were included in this study. Relative to baseline, the CFR was improved by angiotensin-converting enzymes (ACEIs), aldosterone receptor antagonists (ARBs) [standard mean difference (SMD): 1.12; 95% CI: 0.77–1.47], and statins treatments (SMD: 0.61; 95%CI: 0.36–0.85). Six to 12 months of calcium channel blocker (CCB) treatments improved CFR (SMD: 1.04; 95% CI: 0.51–1.58). Beta-blocker (SMD: 0.24; 95% CI: −0.39–0.88) and ranolazine treatment (SMD: 0.31; 95% CI: −0.39–1.01) were not associated with improved CFR.

Conclusions: Therapy with ACEIs, ARBs, and statins was associated with improved CFR in patients with confirmed or suspicious CMD. CCBs also improved CFR among patients followed for 6–12 months. Beta-blocker and ranolazine had no impact on CFR.

The value of coronary computed tomography angiography in assessing the cardiac circulation of an outpatient-based population

To evaluate the perfusion of coronary circulation and its related factors and the difference in the peak filling times in aortic sinus and coronary sinus by coronary computed tomography angiography (CCTA).From January 1 to August 1, 2018, 61 outpatients with angina pectoris were recruited, completed a questionnaire about risk factors and underwent CCTA, which was also used to assess the stenosis of different coronary artery segments.The duration of circulation was 9.50 ± 2.43 seconds in patients with flat T wave, which was shorter than the duration in normal subjects (P = .021). However, other cardiovascular risk factors showed no effect on the duration of circulation. In addition, the duration of circulation was closely related to the peak filling time of coronary sinus [r(s) = 0.681]. We further divided the circulation time difference (delta) values into 3 levels (<6, 6-12, and ≥12 seconds).It showed that the circulation duration (Y) was associated with:Therefore, the cardiac circulation duration was negatively related to the degree of stenosis in the 1 diagonal and proximal LCA.It compensates for the inability of CCTA to assess circulation at rest simply by determining the peak filling time in the aortic sinus and the coronary sinus. Moderate cardiac microcirculation duration was related to a low incidence of clinical symptoms and electrocardiogram disorders, which was determined mainly by the diagonal and left circumflex branch 1 of LCA.