Association of coronary microvascular dysfunction with restenosis of left anterior descending coronary artery disease treated by percutaneous intervention

Global trends and frontiers in research on coronary microvascular dysfunction: a bibliometric analysis from 2002 to 2022

BACKGROUND

Coronary microvascular dysfunction (CMD) is a leading cause of ischemic heart disease. Over the past few decades, considerable progress has been made with respect to research on CMD. The present study summarized the current research hotspots and trends on CMD by applying a bibliometric approach.

METHODS

Relevant publications between 2002 and 2022 were extracted from the Web of Science Core Collection. Visualization network maps of countries, institutions, authors, and co-cited authors were built using VOSviewer. CiteSpace was used for keyword analysis and the construction of a dual-map overlay of journals and a timeline view of co-cited references.

RESULTS

1539 CMD-related publications were extracted for bibliometric analysis. The annual publications generally showed an upward trend. The United States of America was the most prolific country, with 515 publications (33.5%). Camici P. G. was the most influential author, whereas the European Heart Journal, Circulation, and Journal of the American College of Cardiology were the most authoritative journals. Research hotspot analysis revealed that endothelial dysfunction as well as reduced nitric oxide production or bioavailability played critical roles in CMD development. Positron emission tomography was the most widely used imaging method for diagnosis. In addition, microvascular angina, hypertrophic cardiomyopathy, and heart failure have attracted much attention as the main clinical implications. Furthermore, international standards for CMD diagnosis and management may be the future research directions.

CONCLUSIONS

This study offers a comprehensive view about the hotspots and development trends of CMD, which can assist subsequent researchers and guide future directions.

Coronary microvascular dysfunction in stable ischaemic heart disease (non-obstructive coronary artery disease and obstructive coronary artery disease)

Diffuse and focal epicardial coronary disease and coronary microvascular abnormalities may exist side-by-side. Identifying the contributions of each of these three players in the coronary circulation is a difficult task. Yet identifying coronary microvascular dysfunction (CMD) as an additional player in patients with coronary artery disease (CAD) may provide explanations of why symptoms may persist frequently following and why global coronary flow reserve may be more prognostically important than fractional flow reserve measured in a single vessel before percutaneous coronary intervention. This review focuses on the challenges of identifying the presence of CMD in the context of diffuse non-obstructive CAD and obstructive CAD. Furthermore, it is going to discuss the pathophysiology in this complex situation, examine the clinical context in which the interaction of the three components of disease takes place and finally look at non-invasive diagnostic methods relevant for addressing this question.

Mechanisms and diagnostic evaluation of persistent or recurrent angina following percutaneous coronary revascularization

Persistence or recurrence of angina after a percutaneous coronary intervention (PCI) may affect about 20-40% of patients during short-medium-term follow-up. This appears to be true even when PCI is 'optimized' using physiology-guided approaches and drug-eluting stents. Importantly, persistent or recurrent angina post-PCI is associated with a significant economic burden. Healthcare costs may be almost two-fold higher among patients with persistent or recurrent angina post-PCI vs. those who become symptom-free. However, practice guideline recommendations regarding the management of patients with angina post-PCI are unclear. Gaps in evidence into the mechanisms of post-PCI angina are relevant, and more research seems warranted. The purpose of this document is to review potential mechanisms for the persistence or recurrence of angina post-PCI, propose a practical diagnostic algorithm, and summarize current knowledge gaps.

Changes in Index of Microcirculatory Resistance during PCI in the Left Anterior Descending Coronary Artery in Relation to Total Length of Implanted Stents

Aim

To investigate the relationship between stent length and changes in microvascular resistance during PCI in stable coronary artery disease (CAD).

Methods and Results

We measured fractional flow reserve (FFR), index of microcirculatory resistance (IMR), and coronary flow reserve (CFR) before and after stenting in 42 consecutive subjects with stable coronary artery undergoing PCI with stent in the LAD. Patients that had very long stent length (38–78 mm) had lower FFR before stenting than patients that had long (23–37 mm) and moderate (12–22 mm) stent length (0.59 (±0.16), 0.70 (±0.12), and 0.75 (±0.07); p=0.002). FFR improved after stenting and more so in subjects with very long stent length compared to long and moderate stent length (0.27 (s.d ± 16), 0.15 (s.d ± 0.12), and 0.12 (s.d ± 0.07); p for interaction = 0.013). Corrected IMR (IMR_corr) increased after stenting in subjects who had very long stent length, whereas IMR_corr was lower after stenting in subjects who had long or moderate stent length (4.6 (s.d. ± 10.7), −1.4 (s.d. ± 9,9), and −4.2 (s.d. ± 7.8); p for interaction = 0.009).

Conclusions

Changes in IMR during PCI in the LAD in stable CAD seem to be related to total length of stents implanted, possibly influencing post-PCI FFR. Larger studies are needed to confirm the relationship.

Predictive model for quality of life in patients with recurrent coronary artery disease

Background:

The aims of this study were to construct and verify a model that explains the quality of life in patients with recurrent coronary artery disease.

Methods:

Participants were 212 patients with recurrent coronary artery disease undergoing percutaneous coronary intervention. Data were collected through structured questionnaires from 21 December 2016–30 April 2017, and were analyzed using SPSS 23.0 and AMOS 23.0.

Results:

The model’s fit indices were adequate. Type D personality, symptom experience, and resilience had a direct effect on quality of life, while type D personality, cardiac function status, social support, and resilience had an indirect effect on quality of life. Type D personality, cardiac function status, social support, symptom experience, and resilience explained 55% of the total variance in quality of life. Thus, type D personality, cardiac function status, social support, symptom experience, and resilience affected the quality of life in patients with recurrent coronary artery disease.

Conclusions:

Systematic and integrated intervention programs considering factors related to quality of life may be useful for improving quality of life for patients with recurrent coronary artery disease.

Effects of Catheterization on Artery Function and Health: When Should Patients Start Exercising Following Their Coronary Intervention?

Coronary artery disease (CAD) is a leading cause of death worldwide, and percutaneous transluminal coronary angiography (PTCA) and/or percutaneous coronary intervention (PCI; angioplasty) are commonly used to diagnose and/or treat the obstructed coronaries. Exercise-based rehabilitation is recommended for all CAD patients; however, most guidelines do not specify when exercise training should commence following PTCA and/or PCI. Catheterization can result in arterial dysfunction and acute injury, and given the fact that exercise, particularly at higher intensities, is associated with elevated inflammatory and oxidative stress, endothelial dysfunction and a pro-thrombotic milieu, performing exercise post-PTCA/PCI may transiently elevate the risk of cardiac events. This review aims to summarize extant literature relating to the impacts of coronary interventions on arterial function, including the time-course of recovery and the potential deleterious and/or beneficial impacts of acute versus long-term exercise. The current literature suggests that arterial dysfunction induced by catheterization recovers 4-12 weeks following catheterization. This review proposes that a period of relative arterial vulnerability may exist and exercise during this period may contribute to elevated event susceptibility. We therefore suggest that CAD patients start an exercise training programme between 2 and 4 weeks post-PCI, recognizing that the literature suggest there is a 'grey area' for functional recovery between 2 and 12 weeks post-catheterization. The timing of exercise onset should take into consideration the individual characteristics of patients (age, severity of disease, comorbidities) and the intensity, frequency and duration of the exercise prescription.

Intraoperative transit-time flowmetry in patients undergoing coronary surgery to determine relationships between graft flow and patency and prior coronary interventions and flow demand: a retrospective study

Background

The aim of this study was to delineate impacts of percutaneous coronary intervention (PCI), flow demand, and status of myocardium on graft flow.

Methods

We retrospectively assessed 736 individual coronary artery bypass grafts that had been created as the sole bypass graft for a vascular region in 405 patients. The grafts comprised 334 internal thoracic artery (ITA) to left anterior descending (LAD), 129 ITA and 65 saphenous vein grafts (SVG) to left circumflex (LCX), and 142 gastroepiploic artery (GEA) and 66 SVG to right coronary artery (RCA). Minimal luminal diameter, size of revascularized area, history of myocardial infarction, and PCI in the relevant area were examined to determine whether these factors are associated with flow insufficiency (FI), which was defined as ≤ 20 mL/min.

Results

FI developed in 123/736 grafts (16.7%) and correlated significantly with stenosis in the distal portion (23.0% vs. 12.8%, p = 0.0003). Prior myocardial infarction significantly correlated with FI in GEA–RCA (p = 0.002) and ITA–LCX grafts (p = 0.04). There was a history of PCI to the LAD (PCI group) in 54 ITA to LAD bypass grafts (16.2%), whereas the remaining 280 had no history of PCI to the LAD (no-PCI group). Graft flow was significantly greater in the no-PCI than in the PCI group (53 ± 29 vs. 42 ± 27; p = 0.006). The incidences of FI and graft failure were significantly higher in the PCI than the no-PCI group (22.2%, vs. 8.2%; p = 0.003; 9.2% vs. 1.8%; p = 0.003, respectively).

Conclusions

Prior PCI has a negative impact on graft flow. The influences of small revascularized area, myocardial infarction, and PCI are greater, necessitating consideration of factors associated with flow demand or microvasculature when planning revascularization.

Endothelial dysfunction as predictor of angina recurrence after successful percutaneous coronary intervention using second generation drug eluting stents

Background The role of endothelial dysfunction in predicting angina recurrence after percutaneous coronary intervention is unknown. Design We assessed the role of peripheral endothelial dysfunction measured by reactive-hyperaemia peripheral-artery tonometry (RH-PAT) in predicting recurrence of angina after percutaneous coronary intervention. Methods We enrolled consecutive patients undergoing percutaneous coronary intervention with second-generation drug-eluting stents. RH-PAT was measured at discharge. The endpoint was repeated coronary angiography for angina recurrence and/or evidence of myocardial ischaemia at follow-up. Patients with in-stent restenosis and/or significant de novo stenosis were defined as having angina with obstructed coronary arteries (AOCA); all other patients as having angina with non-obstructed coronary arteries (ANOCA). Results Among 100 patients (mean age 66.7 ± 10.4 years, 80 (80.0%) male, median follow-up 16 (3-20) months), AOCA occurred in 14 patients (14%), ANOCA in nine patients (9%). Repeated coronary angiography occurred more frequently among patients in the lower RH-PAT index tertile compared with middle and upper tertiles (14 (41.2%) vs. 6 (18.2%) vs. 3 (9.1%), p = 0.006, respectively). ANOCA was more frequent in the lower RH-PAT index tertile compared with middle and upper tertiles. In the multivariate regression analysis, the RH-PAT index only predicted angina recurrence. The receiver operating characteristic curve of the RH-PAT index to predict the angina recurrence demonstrated an area under the curve of 0.79 (95% confidence interval: 0.69-0.89; p < 0.001), with a cut-off value of 1.705, having sensitivity 74% and specificity 70%. Conclusions Non-invasive assessment of peripheral endothelial dysfunction using RH-PAT might help in the prediction of recurrent angina after percutaneous coronary intervention, thus identifying patients who may need more intense pharmacological treatment and risk factor control.

Angina after percutaneous coronary intervention: The need for precision medicine

Persistence or recurrence of angina after successful percutaneous coronary intervention (PCI) represent an important clinical issue involving from one fifth to one third of patients undergoing myocardial revascularization at one-year follow-up. A systematic approach to this syndrome is strongly needed. Precision medicine is particularly important in addressing angina after successful PCI because of the multiple underlying causes. Restenosis or coronary atherosclerosis progression explain symptom recurrence after successful PCI in some patients, while functional causes, including vasomotor abnormalities of epicardial coronary arteries and/or coronary microvascular dysfunction, explain symptoms in the remaining patients. In this review, we summarize the mechanisms of persistent or recurrent angina after PCI, proposing a diagnostic algorithm and a systematic therapeutic approach.