Peripheral microvascular dysfunction is also present in patients with ischemia and no obstructive coronary artery disease (INOCA)

Understanding Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA): a comprehensive meta-analysis of clinical characteristics, management, and prognosis compared to MI with the Obstructive Coronary Artery (MIOCA)

BACKGROUND

MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) represents a unique subset of acute coronary syndrome, distinct from MIOCA (Myocardial Infarction with Obstructive Coronary Arteries) and a control group. This study systematically compares their prevalence, clinical characteristics, management strategies, and outcomes to improve understanding and treatment approaches.

METHODS

This systematic review and meta-analysis followed PRISMA guidelines across multiple databases up to 2024. STATA 17 was used for statistical analyses, and the Newcastle-Ottawa Scale was employed to assess study quality.

RESULTS

One-hundred and twelve studies, including 5,908,768 patients, were analyzed. The pooled prevalence of MINOCA among patients undergoing coronary angiography was 8.92% (95% CI: 8.90-8.94). MINOCA patients were generally younger, predominantly female, and more likely to present with atypical chest pain and dyspnea compared to MIOCA patients. Laboratory findings showed higher levels of CRP, BNP, and fibrinogen in MINOCA patients, suggesting inflammation and microvascular dysfunction as key mechanisms. In contrast, MIOCA patients had higher rates of diabetes and dyslipidemia, highlighting differences in pathophysiological processes. Medication use differed between the groups, with MINOCA patients more likely to be prescribed anticoagulants and β-blockers. Prognostically, MINOCA patients experienced significantly lower rates of adverse short- and long-term outcomes, including major adverse cardiac events (MACE) and cardiovascular death, compared to MIOCA patients.

CONCLUSIONS

This study demonstrated that patients with MINOCA have a better prognosis compared to those with MIOCA and are at a lower risk of serious cardiac events. Based on the findings of this study, we emphasize that microcirculation and vascular spasm are the main mechanisms involved in MINOCA. Considering these findings, it is suggested that a better management strategy for MINOCA patients can be established by precisely defining diagnostic criteria and focusing on anti-inflammatory treatments and risk factor control.

Nailfold videocapillaroscopy as a non-invasive tool for the assessment of peripheral microangiopathy in cardiovascular diseases

Cardiovascular disease (CVD) remains the main cause of morbidity and mortality worldwide. Accumulating evidence supports the presence of endothelial and microvascular dysfunction in CVD, which can be assessed using several methods in peripheral organs and tissues. Naifold videocapillaroscopy (NVC) is an established, noninvasive, easily applicable technique for the assessment of peripheral microcirculation. There is limited capillaroscopic data in the field of CVD, though, and the diagnostic or possible prognostic significance of the capillaroscopic alterations in this population is still a matter of research. This review aims to summarize the current knowledge on the capillaroscopic findings in patients with cardiovascular risk factors or established atherosclerotic and nonatherosclerotic CVD, focusing on the possible correlations of these alterations with clinical and laboratory markers of cardiac function.

Relationship between peripheral and intracoronary blood flow in patients with angina and nonobstructive coronary arteries

Coronary vasomotor dysfunction, an important underlying cause of angina and nonobstructive coronary arteries (ANOCA), encompassing coronary vasospasm, coronary endothelial dysfunction, and/or coronary microvascular dysfunction, is clinically assessed by invasive coronary function testing (ICFT). As ICFT imposes a high burden on patients and carries risks, developing noninvasive alternatives is important. We evaluated whether coronary vasomotor dysfunction is a component of systemic microvascular endothelial and smooth muscle dysfunction and can be detected using laser speckle contrast analysis (LASCA). Forty-three consecutive patients with ANOCA underwent ICFT, with intracoronary acetylcholine, adenosine, and flow measurements, to assess coronary vasomotor dysfunction. Cutaneous microvascular function was assessed using LASCA in the forearm, combined with vasodilators acetylcholine, sodium nitroprusside, and insulin and using EndoPAT, by measuring the reactive hyperemia index (RHI). Of the 43 included patients with ANOCA (79% women, 59 ± 9 yr old), 38 patients had coronary vasomotor dysfunction, including 28 with coronary vasospasm, 26 with coronary endothelial dysfunction, and 18 with coronary microvascular dysfunction, with overlapping endotypes. Patients with and without coronary vasomotor dysfunction had similar peripheral flow responses to acetylcholine, insulin, and RHI. In contrast, coronary vasomotor dysfunction was associated with lower peripheral flow responses to sodium nitroprusside (P < 0.001). An absolute flow response to sodium nitroprusside of 83.95 APU resulted in 86.1% sensitivity and 80.0% specificity for coronary vasomotor dysfunction (area under the ROC curve, 0.883; P = 0.006). In conclusion, this study provides evidence of systemic vascular smooth muscle dysfunction in patients with ANOCA with coronary vasomotor dysfunction and the diagnostic value of peripheral microvascular function testing as a noninvasive tool for detecting coronary vasomotor dysfunction.NEW & NOTEWORTHY This study provides proof of concept that assessment of the peripheral vasculature, particularly vascular smooth muscle cells measured using the LASCA technology holds potential as a noninvasive tool for detecting coronary vasomotor dysfunction. This finding highlights the potential of the LASCA technology in, for example, medication studies for coronary vasomotor dysfunction, especially when investigating whether medication improves vascular function, as repeated peripheral measurements are less invasive than invasive coronary function testing, the current gold standard.

The Relationship between TNF-a, IL-35, VEGF and Cutaneous Microvascular Dysfunction in Young Patients with Uncomplicated Type 1 Diabetes

The aim of this study was to analyze the relationship between immunological markers and the dysfunction of cutaneous microcirculation in young patients with type 1 diabetes. The study group consisted of 46 young patients with type 1 diabetes and no associated complications. Microvascular function was assessed with the use of nail fold capillaroscopy before and after implementing post-occlusive reactive hyperemia. This evaluation was then repeated after 12 months. Patients were divided into two subgroups according to their baseline median coverage (defined as the ratio of capillary surface area to surface area of the image area), which was established during the initial exam (coverageBASE). Additionally, the levels of several serum biomarkers, including VEGF, TNF-a and IL-35, were assessed at the time of the initial examination. HbA1c levels obtained at baseline and after a 12-month interval were also obtained. Mean HbA1c levels obtained during the first two years of the course of the disease were also analyzed. Patients with coverageBASE below 16.85% were found to have higher levels of VEGF and TNF-α, as well as higher levels of HbA1c during the first two years following diabetes diagnosis. Our results support the hypothesis that the development of diabetic complications is strongly influenced by metabolic memory and an imbalance of pro- and anti-inflammatory cytokines, regardless of achieving adequate glycemic control.

Impaired retinal microcirculation in patients with non-obstructive coronary artery disease

PURPOSE

To quantitatively investigate alterations of retinal microcirculation in patients with non-obstructive coronary artery disease (NOCAD) using optical coherence tomography angiography (OCTA), and to identify the ability of retinal microcirculation parameters in differentiating coronary artery disease (CAD) subtypes.

METHODS

All participants with angina pectoris underwent coronary computed tomography angiography. Patients with lumen diameter reduction of 20-50 % in all major coronary arteries were defined as NOCAD, while patients with at least one major coronary artery lumen diameter reduction ≥ 50 % were recruited as obstructive coronary artery disease (OCAD). Participants without a history of ophthalmic or systemic vascular disease were recruited as healthy controls. Retinal neural-vasculature was measured quantitatively by OCTA, including peripapillary retinal nerve fiber layer (RNFL) thickness and vessel density (VD) of the optic disc, superficial vessel plexus (SVP), deep vessel plexus (DVP), and foveal density (FD 300). p < 0.017 is considered significant in multiple comparisons.

RESULTS

A total of 185 participants (65 NOCAD, 62 OCAD, and 58 controls) were enrolled. Except for the DVP fovea (p = 0.069), significantly reduced VD in all other regions of SVP and DVP was detected in both the NOCAD and OCAD groups compared to control group (all p < 0.017), while a more significant decrease was found in OCAD compared to NOCAD. Multivariate regression analysis showed that lower VD in superior hemi part of whole SVP (OR: 0.582, 95 % CI: 0.451-0.752) was an independent risk factor for NOCAD compared to controls, while lower VD in the whole SVP (OR: 0.550, 95 % CI: 0.421-0.719) was an independent risk factor for OCAD compared to NOCAD. Using the integration of retinal microvascular parameters, the area under the receiver operating characteristic curve (AUC) for NOCAD versus control and OCAD versus NOCAD were 0.840 and 0.830, respectively.

CONCLUSION

Significant retinal microcirculation impairment, while milder than that in OCAD was observed in NOCAD patients, indicating retinal microvasculature assessment might provide a new systemic microcirculation observation window for NOCAD. Furthermore, retinal microvasculature may serve as a new indicator to assess the severity of CAD with good performance of retinal microvascular parameters in identifying different CAD subtypes.

Non-invasive techniques to access in vivo the skin microcirculation in patients

The microcirculation is composed of blood vessels with mean internal diameter smaller than 100 μm. This structure is responsible for survival of cells and in the last 50 years its study has become increasingly interesting because it often participates in the pathophysiology of several diseases or can determine better or worse prognosis for them. Due to the growing importance of knowing more about the microcirculation, several techniques have been developed and now it is possible to study its structure or function. In the last 25 years, the cutaneous microcirculation has emerged as an accessible and representative portion of generalized vascular bed allowing the examination of mechanisms of microcirculatory function and dysfunction. This mini review presents several techniques used for non-invasive access to skin microcirculation, such as Nailfold Videocapillaroscopy, Orthogonal Polarization Spectral Imaging, Sidestream Dark Field Imaging, Incident Dark field Illumination, Laser Doppler Flowmetry, and Laser Speckle Contrast Imaging applied. The techniques presented will describe which types of variables (structural or functional) can be evaluated, their limitations and potential uses.

Effectiveness of an online/offline mixed-mode Tai Chi cardiac rehabilitation program on microcirculation in patients with coronary artery disease: A randomized controlled study

OBJECTIVE

We explored the effectiveness of an online/offline mixed-mode Tai Chi cardiac rehabilitation program on the microcirculation of patients with coronary artery disease (CAD).

DESIGN

Prospective, randomized controlled study.

SETTING

It was conducted in a tertiary hospital.

SUBJECTS

Twenty-six patients who met the diagnostic criteria for coronary artery disease were recruited.

INTERVENTIONS

Patients were randomized divided into a 12-week Tai Chi cardiac rehabilitation program(TCCRP) or a conventional exercise rehabilitation program(CERP) in a 1:1 fashion, 4 weeks of in-hospital rehabilitation and 8 weeks of online rehabilitation at home (a total of 12 weeks of intervention).

MAIN OUTCOME MEASURES

Nailfold microcirculation (Morphological integrals, Blood flow integrals, Periphery capillary loop integrals, Overall integrals).

MAIN OUTCOME MEASURES

Twenty patients completed the study. The Morphological integrals (baseline: 2.875±1.171 vs 12weeks: 1.863±0.414, t = 2.432, P = 0.045 < 0.05) and Overall integrals (baseline: 5.563±2.001 vs 12weeks: 3.688±1.167, t = 3.358, P = 0.012 < 0.05) decreased significantly in the TCCRP, The nailfold microcirculation integra decreased not significantly in the CERP (P > 0.05). The nailfold microcirculation integra was not significantly different between the two groups after the intervention (P > 0.05).

CONCLUSIONS

The TCCRP improved the microcirculation of patients with CAD.

Microvascular tissue perfusion after postcatheterization pseudoaneurysm treatment

BACKGROUND

Femoral pseudoaneurysm (PSA) is a severe complication after endovascular procedures. Ultrasound-guided manual compression (MC) and percutaneous thrombin injection (TI) are frequently used treatments. MC is less effective, TI may cause thromboembolic events.

OBJECTIVE

Up to date, there is no data regarding impairment of microvascular tissue perfusion after PSA treatment.

METHODS

In this single-center, prospective study 22 patients with PSA were included. We compared macro- and microcirculatory perfusion in the treated and untreated leg at baseline before, after and one day after treatment. Leg perfusion was assessed with ultrasound and ankle-brachial index (ABI). Microcirculatory perfusion of the feet was measured with a near-infrared spectroscopy (NIRS) camera generating StO2-tissue-maps.

RESULTS

Successful PSA thrombosis was achieved in 16 (100%) patients in TI group and in 4 (66.7%) patients in MC group. There was no evidence of arterial thrombi on ultrasound and the ABI did not differ between groups. NIRS StO2-tissue-maps of the feet showed no significant difference in both groups concerning the treated (p = 0.121) or the untreated (p = 0.198) leg during follow up.

CONCLUSIONS

In this small exploratory study, there was no evidence of micro- and macrovascular tissue perfusion impairment after treatment of postcatheterization femoral pseudoaneurysm with thrombin injection underscoring the safety of this approach.

Coronary venous therapy to improve microvascular dysfunction

The coronary circulation is a complex system in which vascular resistances are determined by an interplay of forces in at least three compartments: the epicardial, the microvascular, and the venous district. Cardiologists, and particularly interventional cardiologists, normallly place the focus of their attention on diseases of the epicardial coronary circulation as possible causes of coronary syndromes and neglect the importance of the other two compartments of coronary circulation. The study of the coronary microcirculation, an increasingly recognized source of ischemia, has long been disregarded, but is witnessing a revival since the (re-)introduction of diagnostic tools in the better equipped catheterization laboratories. Unfortunately, to date our understanding of coronary microvascular disease remains incomplete and the numerous proposed classifications fail to reflect its complexity. Further, no specific therapy for these disorders is available. The coronary venous circulation is an even more neglected third vascular district. Its role in regulating coronary resistances is almost completely unexplored, but inital evidence suggests that the modulation of venous pressure might help improve coronary perfusion. Coronary sinus interventions are a group of invasive techniques (both surgical and catheter-based) that are designed to treat ischaemic heart disease by increasing coronary venous pressure and therefore redistributing coronary blood flow towards the endocardium. In this review paper, we revise the role of these interventions with particular focus on acute and chronic coronary microvascular disease.