Coronary microvascular function in patients with angina with no obstructive coronary artery disease-What factors affect it clinically or angiographically?

Background

In the clinical setting, we have often experienced patients with angina with no obstructive coronary artery disease (ANOCA), and it has been proposed that the presence of coronary microvascular dysfunction (CMD) play a pivotal role in the pathogenesis of ANOCA. Thus, it is important to assess coronary microvascular function (CMF). However, it has not been clarified what clinical factors or lesion characteristics on coronary angiography (CAG) affect CMF. Thus, we investigated the relationship between CMF and clinical factors or lesion characteristics on CAG in patients with ANOCA.

Methods

Thirty-four patients with chest pain, who underwent CAG, spasm provocation test (SPT) and CMF test, were enrolled. We excluded patients who had moderate coronary stenosis (% stenosis >30%). In the SPT with acetylcholine for left coronary artery and right coronary artery (RCA), the coronary spasm was defined as >90% narrowing of coronary artery on CAG accompanied with chest symptoms and/or ST-T changes on ECG during SPT, and coronary microvascular spasm (MVS) was defined as ≤90% narrowing of coronary artery on CAG with accompanied with chest pain and ST-T changes during SPT. In each coronary artery, the presences of atherosclerosis (20%≤%stenosis≤30%), focal spasm (spasm occurred within one segment of AHA classification), diffuse spasm (spasm occurred over two segments of AHA classification) and MVS, were checked. In the CMF test with a pressure-wire during adenosine triphosphate infusion, the index of microvascular resistance (IMR) was measured. IMR values were obtained in 34 of the left anterior descending coronary artery (LAD) and 12 in RCA. In each patient, conventional coronary risk factors, blood chemical parameters, peripheral endothelial function such as flow-mediated dilation (FMD) of brachial artery and left ventricular mass index (LVMI) were checked.

Results

In 34 patients, clinical factors including blood chemical parameters, FMD and LVMI, except for smoking status did not affect IMR values on LAD. Only the smoking status was associated with IMR values as follows: median IMR values were 44, 22 and 25 in current smokers (n=5), past smokers (n=8) and never smokers (n=21, p=0.03), respectively. In 46 coronary arteries, the presence of atherosclerosis, the type of the coronary spasm, such as focal and diffuse spasm and MVS, did not affect the IMR values, however, it was significantly higher in the RCA (median 38) than that in the LAD (median 26, p=0.02).

Conclusion

These results suggest that smoking status affected CMF in patients with ANOCA, suggesting the possibility of improvement of CMF by stop smoking in such patients. In addition, in the assessment of CMF, it may be important to take into account which coronary artery being evaluated.

Funding Acknowledgement

Type of funding sources: None.

Clinical characteristics and prognosis in patients with multi-vessel coronary spasm – comparison with those in patients with single-vessel coronary spasm

Background

We have sometimes experienced patients with vasospastic angina (VSA), who showed multi-vessel spasm (MVS) on coronary angiography (CAG) and spasm provocation test (SPT). However, it has not been clarified what clinical characteristics VSA patients with MVS have or whether such patients have poor prognosis. Therefore, we compared the clinical characteristics and prognosis in VSA patients with MVS with those in VSA patients with single-vessel spasm (SVS).

Methods

One hundred and fifty-two patients (mean age: 67 yrs, 74 men and 78 women) with VSA, in which presence of coronary spasm was assessed in both left coronary artery (LCA) and right coronary artery (RCA) on SPT, were subjected. We defined VSA as the presence of more than 90% narrowing of the epicardial coronary artery on angiograms, accompanied by the usual chest symptoms and/or ischemic ST-T changes on electrocardiogram. On SPT, MVS was defined as the presence of spasm on ≥ two major coronary arteries. Base on the presence of MVS, patients were divided into the following 2 groups: MVS group and SVS group. The frequencies of conventional coronary risk factors, the average times of anginal attack (per month), the findings of SPT such as spasm provocation induced by low dose of acetylcholine (LDA) and total occlusion due to coronary spasm (TOC), the number of coronary vasodilators at discharge, and the major cardiovascular events (MACE) including death of any cause and readmission due to heart failure, acute coronary syndrome and unstable angina, were compared in the two groups.

Results

There were 98 patients (64%) in the MVS group and 54 patients (36%) in the SVS groups. The frequencies of conventional coronary risk factors and the average times of anginal attacks (4/month in both groups) were not different in the two groups. The frequencies of LDA (33% in MVS and 17% in SVS, p<0.05) and TOC (12% in MVS, 0% in SVS, p<0.01) were higher in the MVS group than in the SVS group. The average numbers of coronary vasodilators was higher in the MVS group (1.1±0.4) than in the SVS group (0.9±0.4, p<0.01). The frequency of MACE did not differ in the two groups as follows (figure).

Conclusions

These findings suggest that there was no clinical characteristic, suggesting the presence of MVS in VSA patients. Such patients may have higher VSA activity on SPT and have more aggressive medications, leading to the similar prognosis in VSA patient with SVS.

Funding Acknowledgement

Type of funding sources: None.

Perfusion-metabolic mismatch in myocardial scintigraphy in patients with vasospastic angina: what does it mean clinically?

Background

It has been reported that perfusion-metabolic mismatch (PMM) in thallium-201 (Tl) and 123I-βmethyl-p-iodophenyl-pentadecanoic acid (BMIPP) shows important information regarding myocardial ischemia in the clinical setting. Such findings have been frequently obtained, even in patients with vasospastic angina (VSA). However, it has not been fully clarified what such findings mean clinically in patients with VSA. There, we investigated the frequency of PMM in patients with VSA as well as clinical characteristics of patients with VSA who have PMM.

Methods

Seventy-eight patients (mean age: 70 yrs, 29 men and 49 women) were diagnosed with VSA by coronary angiography and spasm-provocation test (SPT). We defined VSA as the presence of more than 90% narrowing of the epicardial coronary artery on angiograms, accompanied by the usual chest symptoms and/or ischemic ST-T changes on electrocardiogram. On SPT, multi-vessel spasm was defined as the presence of spasm on ≥ two major coronary arteries. Dual myocardial scintigraphy with Tl and BMIPP was performed, and the presence of PMM was defined as the summed rest score (SRS) in BMIPP scintigraphy ≥4 and difference in SRS in BMIPP and Tl-201 ≥4. Patients were divided into two groups according to the presence of PMM: Group I (+PMM, n=30) and Group II (−PMM, n=48). Each patient with VSA was assessed for conventional coronary risk factors, numbers of angina attacks per month, and taking vasodilators.

Results

Age, gender distribution, and conventional risk factors were not different between the groups. The median number of angina attacks was higher in the Group I than in the Group II (Group I: 4.5 vs. Group II: 0.1, p<0.01), and fewer patients were taking vasodilators in Group I (Group I: 1.1±1.0 vs. Group II: 1.5±1.1, p<0.05). On SPT, the presence of multi-vessels spasm was significantly higher in Group I (76%) than Group II (44%, p<0.05). Logistic regression analysis showed that the presence of multi-vessels spasm (p<0.05) and taking a smaller amount of vasodilators (p<0.05) were associated with PMM.

Conclusions

These findings suggest that PMM in Tl and BMIPP scintigraphy are associated with multi-vessels spasm and a smaller amount of vasodilator medication. This imaging data may provide important information regarding activity of VSA and sufficient medication.

Funding Acknowledgement

Type of funding source: None

P3579Clinical characteristics of an intracoronary erosion and thrombus in patients with vasospastic angina

Background

Intracoronary erosion and thrombus are sometimes detected in patients with vasospastic angina (VSA) through intracoronary imaging modalities. However, the clinical characteristics of these intracoronary findings remain unclear. Therefore, we assessed the clinical and lesion characteristics of these intracoronary abnormalities in patients with VSA.

Methods

We included 48 patients with VSA who underwent coronary angiography (CAG), spasm provocation test (SPT), and coronary angioscopy (CAS). In all patients, acetylcholine was infused in the left and right coronary arteries. The vessels were classified into spastic vessels (SVs) and non-spastic vessels (NSVs) based on SPT results. SVs that could not be observed using CAS were excluded from the study. CAG and SPT findings were evaluated for the presence of atherosclerotic lesions (%stenosis <30%) and types of spasm (segmental or diffuse). Two experts examined the presence of an intracoronary erosion and thrombus on CAS. Other serious symptoms such as cold sweating or syncope were also assessed.

Results

Among the 48 patients, intracoronary erosion and thrombus were detected in 11 (23%) and 10 (21%) patients, respectively, and total intracoronary abnormalities were observed in 17 (35%) patients. Male sex (p<0.05), smoking (p<0.05), and presence of other serious symptoms (p<0.01) were associated with the presence of intracoronary abnormalities. The logistic regression analysis showed the presence of other serious symptoms to be the only factor associated with the presence of intracoronary abnormalities (p<0.05). In the lesion analyses, among the 72 vessels, intracoronary abnormalities were observed only in SVs (17/53, 33%) but not in NSVs (0/19, 0%, p<0.01). Among the 53 SVs, the presence of atherosclerotic lesions (p<0.05) and segmental spasm type (p<0.05) were found to be associated with the presence of intracoronary abnormalities.

Conclusions

Intracoronary erosion and thrombus were observed in approximately 35% of patients with VSA. Such intracoronary abnormalities may be partly affected by the forms of the coronary artery and coronary spasm, leading to the onset of serious symptoms of VSA.