Mechanisms of Coronary Artery Spasm.

Recent clinical trials have highlighted that percutaneous coronary intervention in patients with stable angina provides limited additional benefits on top of optimal medical therapy. This has led to much more attention being paid to coronary vasomotion abnormalities regardless of obstructive or non-obstructive arterial segments. Coronary vasomotion is regulated by multiple mechanisms that include the endothelium, vascular smooth muscle cells (VSMCs), myocardial metabolic demand, autonomic nervous system and inflammation. Over the years, several animal models have been developed to explore the central mechanism of coronary artery spasm. This review summarises the landmark studies on the mechanisms of coronary vasospasm demonstrating the central role of Rho-kinase as a molecular switch of VSMC hypercontraction and the important role of coronary adventitial inflammation for Rho-kinase upregulation in VSMCs.

Prediction of the development of delirium after transcatheter aortic valve implantation using preoperative brain perfusion SPECT.

OBJECTIVES: Delirium is an important prognostic factor in postoperative patients undergoing cardiovascular surgery and intervention, including transcatheter aortic valve implantation (TAVI). However, delirium after transcatheter aortic valve implantation (DAT) is difficult to predict and its pathophysiology is still unclear. We aimed to investigate whether preoperative cerebral blood flow (CBF) is associated with DAT and, if so, whether CBF measurement is useful for predicting DAT. METHODS: We evaluated CBF in 50 consecutive patients before TAVI (84.7±4.5 yrs., 36 females) using 99mTc ethyl cysteinate dimer single-photon emission computed tomography. Preoperative CBF of the DAT group (N = 12) was compared with that of the non-DAT group (N = 38) using whole brain voxel-wise analysis with SPM12 and region of interest-based analysis with the easy-Z score imaging system. Multivariable logistic regression analysis with the presence of DAT was used to create its prediction model. RESULTS: The whole brain analysis showed that preoperative CBF in the insula was lower in the DAT than in the non-DAT group (P<0.05, family-wise error correction). Decrease extent ratio in the insula of the DAT group (17.6±11.5%) was also greater relative to that of the non-DAT group (7.0±11.3%) in the region of interest-based analysis (P = 0.007). A model that included preoperative CBF in the insula and conventional indicators (frailty index, short physical performance battery and mini-mental state examination) showed the best predictive power for DAT (AUC 0.882). CONCLUSIONS: These results suggest that preoperative CBF in the insula is associated with DAT and may be useful for its prediction.

Diagnostic Performance of Dynamic Myocardial Perfusion Imaging Using Dual-Source Computed Tomography.

BACKGROUND: Single-center studies indicated a high diagnostic accuracy of dynamic computed tomography perfusion (CTP) imaging in the diagnosis of coronary artery disease (CAD). OBJECTIVES: This prospective multicenter study determined the diagnostic performance of combined coronary computed tomography angiography (CTA) and CTP for detecting hemodynamically significant CAD defined by invasive coronary angiography (ICA) with fractional flow reserve (FFR). METHODS: Seven centers enrolled 174 patients with suspected or known CAD who were clinically referred for ICA. CTA and dynamic CTP were performed using dual-source CT before ICA. FFR was done as part of ICA in the case of 26% to 90% coronary diameter stenosis. Hemodynamically significant stenosis was defined as FFR of <0.8 or >90% stenosis on ICA. RESULTS: The study protocol was completed in 157 participants, and hemodynamically significant stenosis was detected in 76 of 157 patients (48%) and 112 of 442 vessels (25%). According to receiver-operating characteristic curve analysis, adding dynamic CTP to CTA significantly increased the area under the curve from 0.65 (95% CI: 0.57-0.72) to 0.74 (95% CI: 0.66-0.81; P = 0.011) on the patient level, with decreased sensitivity (93% vs 72%; P < 0.001), improved specificity (36% vs 75%; P < 0.001), and improved overall accuracy (64% vs 74%; P < 0.001). CONCLUSIONS: In this prospective multicenter study on dynamic CTP, the combination of anatomic assessment with coronary CTA and functional evaluation with dynamic CTP allowed more accurate identification of hemodynamically significant CAD compared with CTA alone. However, the clinical significance of this approach needs to be further investigated, including its usefulness in improving prognosis. (Assessment of Myocardial Perfusion Linked to Infarction and Fibrosis Explored With Dual-Source CT [AMPLIFiED]; UMIN000016353).

Low-intensity pulsed ultrasound therapy suppresses coronary adventitial inflammatory changes and hyperconstricting responses after coronary stent implantation in pigs in vivo.

BACKGROUNDS: We demonstrated that coronary adventitial inflammation plays important roles in the pathogenesis of drug-eluting stent (DES)-induced coronary hyperconstricting responses in pigs in vivo. However, no therapy is yet available to treat coronary adventitial inflammation. We thus developed the low-intensity pulsed ultrasound (LIPUS) therapy that ameliorates myocardial ischemia by enhancing angiogenesis. AIMS: We aimed to examine whether our LIPUS therapy suppresses DES-induced coronary hyperconstricting responses in pigs in vivo, and if so, what mechanisms are involved. METHODS: Sixteen normal male pigs were randomly assigned to the LIPUS or the sham therapy groups after DES implantation into the left anterior descending (LAD) coronary artery. In the LIPUS group, LIPUS (32 cycles, 193 mW/cm2) was applied to the heart at 3 different levels (segments proximal and distal to the stent edges and middle of the stent) for 20 min at each level for every other day for 2 weeks. The sham therapy group was treated in the same manner but without LIPUS. At 4 weeks after stent implantation, we performed coronary angiography, followed by immunohistological analysis. RESULTS: Coronary vasoconstricting responses to serotonin in LAD at DES edges were significantly suppressed in the LIPUS group compared with the sham group. Furthermore, lymph transport speed in vivo was significantly faster in the LIPUS group than in the sham group. Histological analysis at DES edges showed that inflammatory changes and Rho-kinase activity were significantly suppressed in the LIPUS group, associated with eNOS up-regulation and enhanced lymph-angiogenesis. CONCLUSIONS: These results suggest that our non-invasive LIPUS therapy is useful to treat coronary functional abnormalities caused by coronary adventitial inflammation, indicating its potential for the novel and safe therapeutic approach of coronary artery disease.

Prognostic Links Between OCT-Delineated Coronary Morphologies and Coronary Functional Abnormalities in Patients With INOCA.

OBJECTIVES: Whether there are prognostic links between coronary morphologies and coronary functional abnormalities was examined in ischemia and nonobstructive coronary artery disease (INOCA) patients. BACKGROUND: Although INOCA has attracted much attention, little is known about the prognostic impact of coronary morphologies in this disorder. METHODS: A total of 329 consecutive INOCA patients were enrolled and underwent spasm provocation testing combined with lactate sampling for diagnosis of epicardial and microvascular spasm (MVS). On the basis of the functional tests, the patients were classified into 4 groups: a control group without epicardial spasm or MVS (n = 32), MVS alone (n = 51), diffuse spasm in ≥2 coronary segments (n = 204), and focal spasm in 1 segment (n = 42). In this population, optical coherence tomography imaging of the left anterior descending coronary artery was performed for evaluation of adventitial vasa vasorum (AVV) and intraplaque neovessels (IPN). Index of microcirculatory resistance was also measured. RESULTS: MVS frequently coexisted with diffuse (70%) and focal spasm (68%) with a good correlation between AVV and index of microcirculatory resistance (R = 0.353; p = 0.022). For a median follow-up of 1,043 days, focal spasm showed the worst prognosis (log rank p = 0.005), for which IPN was a significant prognostic factor. By contrast, diffuse spasm showed the greatest AVV with an intermediate prognosis. The prognostic value of INOCA was significantly enhanced by adding AVV and IPN to the physiological indices (area under the curve = 0.88 vs. 0.76; p = 0.048). CONCLUSIONS: These results provide the first evidence that there are important prognostic links between coronary morphologies (evaluated by optical coherence tomography) and coronary functional abnormalities in patients with INOCA, indicating the importance of both evaluations in this population.

Prognostic Impacts of Comorbid Significant Coronary Stenosis and Coronary Artery Spasm in Patients With Stable Coronary Artery Disease.

BACKGROUND Stable coronary artery disease is caused by a variable combination of organic coronary stenosis and functional coronary abnormalities, such as coronary artery spasm. Thus, we examined the clinical importance of comorbid significant coronary stenosis and coronary spasm. METHODS AND RESULTS We enrolled 236 consecutive patients with suspected angina who underwent acetylcholine provocation testing for coronary spasm and fractional flow reserve (FFR) measurement. Among them, 175 patients were diagnosed as having vasospastic angina (VSA), whereas the remaining 61 had no VSA (non-VSA group). The patients with VSA were further divided into the following 3 groups based on angiography and FFR: no organic stenosis (≤50% luminal stenosis; VSA-alone group, n=110), insignificant stenosis of FFR>0.80 (high-FFR group, n=36), and significant stenosis of FFR≤0.80 (low-FFR group, n=29). The incidence of major adverse cardiovascular events, including cardiovascular death, nonfatal myocardial infarction, urgent percutaneous coronary intervention, and hospitalization attributed to unstable angina was evaluated. All patients with VSA received calcium channel blockers, and 28 patients (95%) in the low-FFR group underwent a planned percutaneous coronary intervention. During a median follow-up period of 656 days, although the incidence of major adverse cardiovascular events was low and comparable among non-VSA, VSA-alone, and high-FFR groups, the low-FFR group had an extremely poor prognosis (non-VSA group, 1.6%; VSA-alone group, 3.6%; high-FFR group, 5.6%; low-FFR group, 27.6%) (P<0.001). Importantly, all 8 patients with major adverse cardiovascular events in the low-FFR group were appropriately treated with percutaneous coronary intervention and calcium channel blockers. CONCLUSIONS These results indicate that patients with VSA with significant coronary stenosis represent a high-risk population despite current guideline-recommended therapies, suggesting the importance of routine coronary functional testing in this population.

Beneficial effects of exercise training on physical performance in patients with vasospastic angina.

AIMS: In vasospastic angina (VSA), coronary vasomotion abnormalities could develop not only in epicardial coronary arteries but also in coronary microvessels, where calcium channel blockers (CCBs) have limited efficacy. However, efficacy of exercise training for VSA remains to be elucidated. We thus aimed to examine whether vasodilator capacity of coronary microvessels is impaired in VSA patients, and if so, whether exercise exerts beneficial effects on the top of CCBs. METHODS: We performed 2 clinical protocols. In the protocol 1, we measured myocardial blood flow (MBF) using adenosine-stress dynamic computed tomography perfusion (CTP) in 38 consecutive VSA patients and 17 non-VSA controls. In the protocol 2, we conducted randomized controlled trial, where 20 VSA patients were randomly assigned to either 3-month exercise training group (Exercise group) or Non-Exercise group (n= 10 each). RESULTS: In the protocol 1, MBF on CTP was significantly decreased in the VSA group compared with the Non-VSA group (138 ± 6 vs 166 ± 10 ml/100 g/min, P = 0.02). In the protocol 2, exercise capacity was significantly increased in the Exercise group than in the Non-Exercise group (11.5 ± 0.5 to 15.4 ± 1.8 vs 12.6 ± 0.7 to 14.0 ± 0.8 ml/min/kg, P < 0.01). MBF was also significantly improved after 3 months only in the Exercise group (Exercise group, 145 ± 12 to 172 ± 8 ml/100 g/min, P < 0.04; Non-Exercise group, 143 ± 14 to 167 ± 8 ml/100 g/min, P = 0.11), although there were no significant between-group differences. CONCLUSIONS: These results provide the first evidence that, in VSA patients, exercise training on the top of CCBs treatment may be useful to improve physical performance, although its effect on MBF may be minimal.

Recent Advances in Vascular Imaging.

Recent advances in vascular imaging have enabled us to uncover the underlying mechanisms of vascular diseases both ex vivo and in vivo. In the past decade, efforts have been made to establish various methodologies for evaluation of atherosclerotic plaque progression and vascular inflammatory changes in addition to biomarkers and clinical manifestations. Several recent publications in Arteriosclerosis, Thrombosis, and Vascular Biology highlighted the essential roles of in vivo and ex vivo vascular imaging, including magnetic resonance image, computed tomography, positron emission tomography/scintigraphy, ultrasonography, intravascular ultrasound, and most recently, optical coherence tomography, all of which can be used in bench and clinical studies at relative ease. With new methods proposed in several landmark studies, these clinically available imaging modalities will be used in the near future. Moreover, future development of intravascular imaging modalities, such as optical coherence tomography-intravascular ultrasound, optical coherence tomography-near-infrared autofluorescence, polarized-sensitive optical coherence tomography, and micro-optical coherence tomography, are anticipated for better management of patients with cardiovascular disease. In this review article, we will overview recent advances in vascular imaging and ongoing works for future developments.

Marked Impairment of Endothelium-Dependent Digital Vasodilatations in Patients With Microvascular Angina: Evidence for Systemic Small Artery Disease.

OBJECTIVE: It remains to be elucidated whether and how endothelial functions are impaired in peripheral circulation of patients with coronary functional disorders, such as vasospastic angina (VSA) and microvascular angina (MVA). We simultaneously examined endothelial functions of peripheral conduit and resistance arteries in patients with coronary functional disorders, with a special reference to NO and endothelium-dependent hyperpolarization factors. Approach and Results: Based on the results of invasive coronary acetylcholine testing and coronary physiological measurements, we divided 43 patients into 3 groups; VSA, MVA, and VSA+MVA. Endothelium-dependent vasodilatations of the brachial artery and fingertip arterioles to intra-arterial infusion of bradykinin were simultaneously evaluated by ultrasonography and peripheral arterial tonometry, respectively. To assess NO and endothelium-dependent hyperpolarization factors, measurements were repeated after oral aspirin and intra-arterial infusion of NG-monomethyl-L-arginine. Additionally, endothelium-independent vasodilatations to sublingual nitroglycerin and plasma levels of biomarkers for endothelial functions were measured. Surprisingly, digital vasodilatations to bradykinin were almost absent in patients with MVA alone and those with VSA+MVA compared with those with VSA alone. Mechanistically, both NO- and endothelium-dependent hyperpolarization-mediated digital vasodilatations were markedly impaired in patients with MVA alone. In contrast, endothelium-independent vasodilatations to nitroglycerin were comparable among the 3 groups. Plasma levels of soluble VCAM (vascular cell adhesion molecule)-1 were significantly higher in patients with MVA alone compared with those with VSA alone. CONCLUSIONS: These results provide the first evidence that both NO- and endothelium-dependent hyperpolarization-mediated digital vasodilatations are markedly impaired in MVA patients, suggesting that MVA is a cardiac manifestation of the systemic small artery disease.

Impacts of hippocampal blood flow on changes in left ventricular wall thickness in patients with chronic heart failure.

BACKGROUND: Although depressive symptoms increased mortality and hospitalization in chronic heart failure (CHF) patients, the underlying mechanism remains unclear. The aim of this study was to investigate whether an alteration in hippocampal perfusion, which is the neural substrate of depressive symptoms, is associated with changes in cardiac structures and/or functions in CHF patients. METHODS: We used baseline data of 70 CHF patients (66.8 ± 8.9 yrs, 32.5% women), including cerebral blood flow (CBF) in the hippocampus, geriatric depression scale (GDS) scores and echocardiographic parameters, in the Brain Assessment and Investigation in Heart Failure Trial (B-HeFT) (UMIN000008584). Echocardiography was repeated at 3.1 ± 0.5 years after the baseline evaluation. We first tested voxel-wise regression model with hippocampal CBF as dependent variable and each of echocardiographic parameter change as independent variable, adjusted for age and sex. Structural equation modeling was used to test a mediation effect of cognitive test scores on associations between hippocampal perfusion and changes in cardiac structures and/or functions. RESULTS: Baseline anterior hippocampal CBF was negatively correlated with changes in left ventricular posterior wall thickness (PWT) (P < 0.05 with family-wise error corrections). An existence of depressive symptoms was positively correlated with the baseline anterior CBF and negatively with the PWT changes (P < 0.05, both). There were both direct effects of the baseline anterior hippocampal CBF on PWT thinning and effects mediated through the depressive symptoms (P < 0.05, both). CONCLUSIONS: This study provides the first evidence that the alteration in hippocampal perfusion may lead to changes in cardiac structures via increase in depressive symptoms in CHF patients.

Transcatheter aortic valve implantation and cognitive function in elderly patients with severe aortic stenosis.

AIMS: The aim of this study was to examine the mechanisms of cognitive impairment and reversibility in elderly patients with severe aortic stenosis (AS) after transcatheter aortic valve implantation (TAVI) with special reference to cerebral blood flow (CBF). METHODS AND RESULTS: We examined 15 elderly patients with severe AS (mean age 83.2±4.5 years, 12 female) who underwent TAVI. Before and three months after TAVI, we evaluated cognitive function with the Logical Memory II test (LM II), cardiac output (CO) with echocardiography, and CBF with 99mTc single-photon emission computed tomography (SPECT). LM II score and CO were significantly increased after TAVI compared with baseline (p<0.01 for LM II, p<0.005 for CO). Notably, CBF in the local regions, including that in the right hippocampus, was significantly increased after TAVI (p<0.005 at each voxel). The patients with increased CO after TAVI also showed significantly increased CBF in the right hippocampus compared with those without it (p<0.01). Importantly, CBF in the right hippocampus was positively correlated with LM II scores (p<0.05). CONCLUSIONS: These results provide the first evidence that TAVI may improve cognitive functions associated with increased cerebral perfusion especially in the hippocampus in elderly patients with severe AS.

Clinical implication of myocardial FDG uptake pattern in oncologic PET: retrospective comparison study with stress myocardial perfusion imaging as the reference standard.

OBJECTIVE: The purpose of this study was to determine the clinical implication of the myocardial FDG uptake patterns by comparing with the results of stress myocardial perfusion imaging (MPI) as the reference standard. METHODS: By reviewing the medical records, 86 pairs of stress MPI and FDG PET/CT of 84 patients who underwent stress MPI and oncologic FDG PET/CT in 1 month were included in this study. The patterns of the myocardial FDG uptake were classified into five patterns such as 'low', 'diffuse', 'basal ring', 'focal high', and 'focal defect on diffuse high'. MPI was evaluated using a 5-point scoring model ranging from 0 (normal uptake) to 4 (uptake absent) based on the 17-segment model. The summed stress score of 4 or higher was defined as 'abnormal MPI'. Factors predictive of abnormal MPI were analyzed using a log-rank multivariate test and p < 0.05 was set as significant. RESULTS: Abnormal MPI was observed in only 16 of 36 (44%) patients with 'low' pattern, 10 of 23 (43%) patients with 'diffuse high' pattern, and 1 of 9 (11%) patients with 'basal ring' pattern, but in 8 of 9 (89%) patients with 'focal high' pattern, and 8 of 9 (89%) patients with 'focal defect on diffuse high' pattern. The log-rank multivariate test revealed that 'focal high' and 'focal defect on diffuse high' pattern were correlated with an abnormal MPI. CONCLUSIONS: These results indicate that further cardiac work-up might be helpful in the patients with 'focal high' pattern or 'focal defect on diffuse high' pattern of myocardial FDG at oncologic PET. A prospective study should be needed to further support this conclusion.

Disappearance of Angiodysplasia Following Transcatheter Aortic Valve Implantation in a Patient with Heyde's Syndrome: A Case Report and Review of the Literature.

An 83-year-old woman with severe aortic stenosis was admitted to our hospital due to heart failure with refractory anemia requiring blood transfusions. She had repetitive bleeding episodes from endoscopically proven angiodysplasia in the stomach. Moreover, she repeatedly underwent endoscopic argon plasma coagulation for hemostasis. Importantly, she had a deficiency of the high-molecular-weight (HMW) multimers of von Willebrand factor (VWF), and she was diagnosed with Heyde's syndrome.After she underwent transcatheter aortic valve implantation (TAVI), aortic valve area and mean left ventricular aorta pressure gradient improved. Notably, endoscopy showed cessation of bleeding at 10 days after TAVI and the disappearance of angiodysplasia at 4 months after TAVI. Even at 2 years after TAVI, follow-up endoscopy showed remaining free of angiodysplasia in the stomach. She experienced no episodes of anemia since TAVI procedure. Additionally, analysis of HMW multimers demonstrated immediate and lasting recovery after TAVI.Recovery of HMW multimers of VWF with cessation of gastrointestinal bleeding following aortic valve replacement has been previously reported in a patient diagnosed with Heyde's syndrome. To the best our knowledge, this is the first case to demonstrate that angiodysplasia disappears after TAVI for a long term with endoscopic images in a patient with Heyde's syndrome. Here, we summarized case reports of patients with Heyde's syndrome that required aortic valve intervention. Cessation of gastrointestinal bleeding and anemia after aortic valve intervention for severe aortic stenosis may be attributed not only to recovery of HMW multimers of VWF but also to the disappearance of angiodysplasia.

Treadmill exercise prevents reduction of bone mineral density after myocardial infarction in apolipoprotein E-deficient mice.

AIMS: Recent clinical studies demonstrated the association between myocardial infarction (MI) and osteoporotic fractures. We examined whether MI causes bone loss and the effects of exercise training on bone in mice after MI. METHODS: We created a MI model in 16-week-old male apolipoprotein E-deficient mice (n = 42), which were randomly assigned to exercise group (MI-Ex) and sedentary group (MI-Sed). We also performed sham operations in other mice (n = 10). Treadmill exercise training was performed from one week after operation to eight weeks. At eight weeks, the bone parameters of the femur were measured by quantitative computed tomography, followed by histological analysis (n = 10-17). RESULTS: Bone mineral density (BMD) of the femur was significantly decreased in the MI-Sed group as compared with the sham group (P < 0.001), whereas the BMD was significantly increased in the MI-Ex group as compared with the MI-Sed group (P < 0.05). In histological analysis, Rho-associated coiled-coil kinase 2 and tartrate-resistant acid phosphate positive (bone resorptive) area in distal femur were significantly increased in the MI-Sed group as compared with the sham group (P < 0.05), whereas those parameters were significantly decreased in the MI-Ex group as compared with the MI-Sed group (P < 0.05). In contrast, alkaline phosphatase (ALP)-positive (bone-forming) area was significantly decreased in the MI-Sed group as compared with the sham group (P < 0.05), whereas ALP-positive area was significantly increased in the MI-Ex group as compared with the MI-Sed group (P < 0.05). CONCLUSIONS: The present study demonstrates that MI reduces BMD and treadmill exercise training prevents the reduction of BMD in apolipoprotein E-deficient mice.

Temporal trends in the prevalence and outcomes of geriatric patients with acute myocardial infarction in Japan-A report from the Miyagi AMI Registry Study.

BACKGROUND: Along with the global aging, the number of geriatric patients with acute myocardial infarction (AMI) has been increasing. However, temporal trends in the prevalence and outcomes of geriatric patients with AMI, with a special reference to heart failure (HF) on admission, remain to be elucidated. METHODS: The Miyagi AMI Registry is a prospective, multicenter, and observational study. This registry was established in 1979 and has been continued for 40 years. We examined a total of 6,596 AMI patients aged ≥70 years (male/female 4,141/2,455) registered in this registry from 2005 to 2016 and divided them into 3 groups according to age [70-79 (n = 3,485), 80-89 (n = 2,601), and ≥90 years (n = 510)]. RESULTS: Of those, 17.6% had HF (Killip class ≥ II) on admission, for which age, female sex, diabetes, and previous MI were identified as independent predictors. Importantly, the prevalence of HF on admission significantly increased in all ages during the study period (all p for trend <0.01). Despite the presence of HF on admission, primary percutaneous coronary intervention (PCI) was performed in about 70% of patients aged in their 80 s and about half of those aged ≥90 years. In each group, performance rate of primary PCI also progressively increased (all p < 0.05) irrespective of concomitant HF. However, in-hospital mortality remained unchanged. Multivariable analysis demonstrated that, even for patients with HF on admission, primary PCI was associated with improved in-hospital mortality in the younger 2 groups [adjusted odds ratios (ORs), 95% confidence intervals (CI) 0.58 (0.36-0.93) for 70s, 0.64 (0.43-0.95) for 80s, and 0.99 (0.44-2.21) for ≥90s], whereas PCI was ineffective to reduce long-term hospitalization ≥30 days in all groups [adjusted ORs (95%CI) 0.90 (0.52-1.54), 0.66 (0.38-1.14), and 0.38 (0.07-2.10)]. CONCLUSIONS: These results demonstrate that increasing prevalence of HF on admission and increasing performance of primary PCI counteract each other with resultant unchanged in-hospital outcomes in geriatric AMI patients in Japan.

Coronary Functional Abnormalities in Patients With Angina and Nonobstructive Coronary Artery Disease.

BACKGROUND: Approximately one-half of patients undergoing diagnostic coronary angiography for angina have no significant coronary stenosis, in whom coronary functional abnormalities could be involved. OBJECTIVES: This study examined the significance of coronary functional abnormalities in a comprehensive manner for both epicardial and microvascular coronary arteries in patients with angina and nonobstructive coronary artery disease (CAD). METHODS: This study prospectively enrolled 187 consecutive patients (male/female 113/74, 63.2 ± 12.3 years), who underwent acetylcholine provocation test for coronary spasm and measurement of index of microcirculatory resistance (IMR) to evaluate coronary microvascular function, and followed them for a median of 893 days. RESULTS: Of all subjects, acetylcholine test identified 128 patients with vasospastic angina (VSA) (68%), and cardiac events occurred in 10 patients (5.3%) during the follow-up. Multivariable analysis revealed that IMR correlated with the incidence of cardiac events (hazard ratio: 1.05; 95% confidence interval: 1.02 to 1.09; p = 0.002) and receiver-operating characteristics (ROC) curve analysis identified IMR of 18.0 as the optimal cut-off value. Among the 4 groups based on the cut-off value of IMR and the presence of VSA, the Kaplan-Meier survival analysis showed a significantly worse prognosis in the group with high IMR (≥18.0) and VSA compared with other groups (log rank, p = 0.002). Importantly, intracoronary administration of fasudil, a Rho-kinase inhibitor, significantly ameliorated IMR in the VSA patients with increased IMR (p < 0.0001). CONCLUSIONS: These results indicate that in patients with angina and nonobstructive CAD, coexistence of epicardial coronary spasm and increased microvascular resistance is associated with worse prognosis, for which Rho-kinase activation may be involved.

Usefulness of intracoronary administration of fasudil, a selective Rho-kinase inhibitor, for PCI-related refractory myocardial ischemia.

BACKGROUND: Intra-procedural myocardial ischemia as an iatrogenic complication still remains a critical issue in contemporary interventional cardiology. The aim of this study was to examine the usefulness of fasudil, a selective Rho-kinase inhibitor, for percutaneous coronary intervention (PCI)-related myocardial ischemia. METHODS: Among 448 PCI sessions performed between October 2015 and December 2017, we retrospectively examined 36 patients (69.0 ±â€¯9.1 [SD] yrs., M/F 26/10) who underwent intracoronary administration of fasudil during a procedure to resolve myocardial ischemia that was resistant to intracoronary nitrate administration. RESULTS: The refractory myocardial ischemia was caused by distal embolization (69%), enhanced vasoconstriction at distal site of chronic total occlusion (11%), coronary spasm (11%), and coronary dissection (8%), most of which occurred immediately after balloon or stent dilatation. Intracoronary fasudil significantly improved corrected TIMI frame count (from 37 [30-56] to 24 [12-36]) and TIMI flow grade (from 2 [1-2.5] to 3 [2-3]) (both P < 0.001). Finally, 86% of all subjects successfully obtained TIMI flow grade 3 at the end of the procedure. Intracoronary fasudil tended to be more effective in patients with an attenuated plaque detected by intravascular ultrasound. Importantly, among the 19 elective cases, fasudil successfully prevented 17 patients from developing post-procedure myocardial infarction. Although fasudil-induced transient hypotension requiring a vasopressor was noted in 22% of the subjects, no other adverse effects were noted. CONCLUSIONS: These results indicate that fasudil is a useful and safe therapeutic option for PCI-related myocardial ischemia refractory intracoronary nitrate.

Coronary Artery Spasm and Perivascular Adipose Tissue Inflammation: Insights From Translational Imaging Research.

Perivascular adipose tissue, which constitutes perivascular components along with the adventitial vasa vasorum, plays an important role as a source of various inflammatory mediators in cardiovascular disease. Inflammatory changes in the coronary adventitia are thought to be involved in the pathogenesis of coronary artery spasm and vasospastic angina. Recent advances in translational research using non-invasive imaging modalities, including 18F-fluorodeoxyglucose PET and cardiac CT, have enabled us to visualise perivascular inflammation in the pathogenesis of coronary artery spasm. These modality approaches appear to be clinically useful as a non-invasive tool for examining the presence and severity of vasospastic angina.

Cardiac Lymphatic Dysfunction Causes Drug-Eluting Stent-Induced Coronary Hyperconstricting Responses in Pigs In Vivo.

Objective- We have previously demonstrated that coronary adventitial inflammation plays important roles in the pathogenesis of coronary vasomotion abnormalities, including drug-eluting stent (DES)-induced coronary hyperconstricting responses. Importantly, the adventitia also harbors lymphatic vessels, which may prevent inflammation by transporting extravasated fluid and inflammatory cells. We thus aimed to examine the roles of coronary adventitial lymphatic vessels in the pathogenesis of DES-induced coronary hyperconstricting responses in a porcine model in vivo. Approach and Results- We performed 2 experimental studies. In protocol 1, 15 pigs were divided into 3 groups with or without DES and with bare metal stent. Nonstented sites 20 mm apart from stent implantation also were examined. In the protocol 2, 12 pigs were divided into 2 groups with or without lymphatic vessels ligation followed by DES implantation at 2 weeks later (n=6 each). We performed coronary angiography 4 weeks after DES implantation, followed by immunohistological analysis. In protocol 1, the number and the caliber of lymphatic vessels were greater at only the DES edges after 4 more weeks. In protocol 2, coronary hyperconstricting responses were further enhanced in the lymphatic vessels ligation group associated with adventitial inflammation, Rho-kinase activation, and less adventitial lymphatic vessels formation. Importantly, there were significant correlations among these inflammation-related changes and enhanced coronary vasoconstricting responses. Conclusions- These results provide evidence that cardiac lymphatic vessel dysfunction plays important roles in the pathogenesis of coronary vasoconstrictive responses in pigs in vivo.

A multicenter trial of extracorporeal cardiac shock wave therapy for refractory angina pectoris: report of the highly advanced medical treatment in Japan.

We have previously demonstrated that cardiac shock wave therapy (CSWT) effectively improves myocardial ischemia through coronary neovascularization both in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris (AP). In this study, we further addressed the efficacy and safety of CSWT in a single-arm multicenter study approved as a highly advanced medical treatment by the Japanese Ministry of Health, Labour and Welfare. Fifty patients with refractory AP [mean age 70.9 ± 12.6 (SD) years, M/F 38/12] without the indications of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) were enrolled in 4 institutes in Japan. Ischemic myocardial regions in the left ventricle (LV) were identified by drug-induced stress myocardial perfusion imaging (MPI). Shock waves (200 shots/spot at 0.09 mJ/mm2) were applied to 40-60 spots in the ischemic myocardium 3 times in the first week. The patients were followed up for 3 months thereafter. Forty-one patients underwent CSWT and completed the follow-up at 3 months. CSWT markedly improved weekly nitroglycerin use [from 3.5 (IQR 2 to 6) to 0 (IQR 0 to 1)] and the symptoms [Canadian Cardiovascular Society functional class score, from 2 (IQR 2 to 3) to 1 (IQR 1 to 2)] (both P < 0.001). CSWT also significantly improved 6-min walking distance (from 384 ± 91 to 435 ± 122 m, P < 0.05). There were no significant changes in LV ejection fraction evaluated by echocardiography and LV stroke volume evaluated by cardiac magnetic resonance imaging (from 56.3 ± 14.7 to 58.8 ± 12.8%, P = 0.10, and from 52.3 ± 17.4 to 55.6 ± 15.7 mL, P = 0.15, respectively). Percent myocardium ischemia assessed by drug-induced stress MPI tended to be improved only in the treated segments (from 16.0 ± 11.1 to 12.1 ± 16.2%, P = 0.06), although no change was noted in the whole LV. No procedural complications or adverse effects related to the CSWT were noted. These results of the multicenter trial further indicate that CSWT is a useful and safe non-invasive strategy for patients with refractory AP with no options of PCI or CABG.