The Impact of Myocardial Bridging on the Coronary Functional Test in Patients with Ischaemia with Non-Obstructive Coronary Artery Disease

The evolving role of cardiopulmonary exercise testing in ischemic heart disease - state of the art review

PURPOSE OF REVIEW

Cardiopulmonary exercise testing (CPET) is the gold standard for directly assessing cardiorespiratory fitness (CRF) and has a relatively new and evolving role in evaluating atherosclerotic heart disease, particularly in detecting cardiac dysfunction caused by ischemic heart disease. The purpose of this review is to assess the current literature on the link between cardiovascular (CV) risk factors, cardiac dysfunction and CRF assessed by CPET.

RECENT FINDINGS

We summarize the basics of exercise physiology and the key determinants of CRF. Prognostically, several studies have been published relating directly measured CRF by CPET and outcomes allowing for more precise risk assessment. Diagnostically, this review describes in detail what is considered healthy and abnormal cardiac function assessed by CPET. New studies demonstrate that cardiac dysfunction on CPET is a common finding in asymptomatic individuals and is associated with CV risk factors and lower CRF. This review covers how key CPET parameters change as individuals transition from the asymptomatic to the symptomatic stage with progressively decreasing CRF. Finally, a supplement with case studies with long-term longitudinal data demonstrating how CPET can be used in daily clinical decision making is presented.

SUMMARY

In summary, CPET is a powerful tool to provide individualized CV risk assessment, monitor the effectiveness of therapeutic interventions, and provide meaningful feedback to help patients guide their path to improve CRF when routinely used in the outpatient setting.

Which Coronary Artery Should Be Preferred for Starting the Coronary Spasm Provocation Test?

BACKGROUND

The spasm provocation test (SPT) is a critical test for diagnosing vasospastic angina (VSA). However, the choice of vessel to be preferred for initiating the SPT-the right coronary artery (RCA) or the left coronary artery (LCA)-is unclear. This study aimed to assess SPT results including SPT-related complications while initiating the SPT in the RCA and LCA.

METHODS

We enrolled 225 patients who underwent coronary angiography and SPTs. The SPT was first performed in the RCA in 133 patients (RCA group) and the LCA in 92 patients (LCA group). We defined VSA as >90% narrowing of the coronary artery during the SPT, accompanied by chest pain and/or ST-T changes on the electrocardiogram. When coronary spasm occurs in two or more major coronary arteries, it is referred to as a multivessel spasm (MVS). SPT-related complications comprised atrial fibrillation, ventricular fibrillation, and unstable hemodynamics following catecholamine use. Analyses using propensity score matching (PSM) were performed in 120 patients.

RESULTS

No significant differences in the frequencies of VSA and complications were observed between the two groups (RCA: 79% and 19%, respectively; LCA: 85% and 22%, respectively). In both groups, spasms were most frequently provoked in the left anterior descending coronary artery (both p < 0.001) whereas spasms in the left circumflex coronary artery (LCX) were higher in the LCA group than in the RCA group (p = 0.015). Furthermore, no significant difference in the frequency of MVS was observed between both groups (RCA: 50%, LCA: 62%; p = 0.122). After PSM, no significant difference in the frequencies of VSA and complications were observed between the two groups (RCA: 82% and 15%, respectively; LCA: 88% and 18%, respectively). The frequencies of LCX spasms (RCA: 8%, LCA: 23%; p = 0.022) and MVS (RCA: 40%, LCA: 62%; p = 0.020) were higher in the LCA group than in the RCA group.

CONCLUSIONS

Although the diagnostic rate of VSA and frequency of SPT-related complications were similar in the two groups, the frequency of MVS was higher in the LCA group than in the RCA group because of the increase in the number of LCX spasms. A routine SPT may be started from the LCA.

Frequency and Clinical Impact of Family History of Coronary Artery Disease in Patients with Vasospastic Angina

BACKGROUND

Family history (FH) of coronary artery disease (CAD) [FH-CAD] is a well-known risk factor for atherosclerotic CAD. However, FH-CAD frequency in patients with vasospastic angina (VSA) remains unknown, and the clinical characteristics and prognosis of VSA patients with FH-CAD are unclear. Therefore, this study compared FH-CAD frequency between patients with atherosclerotic CAD and those with VSA and examined the clinical characteristics and prognosis of VSA patients with FH-CAD.

METHODS

Coronary angiography and spasm provocation tests (SPT) were used to investigate chest pain of coronary artery origin in patients classified into atherosclerotic CAD (362 cases), VSA (221 cases; positive for SPT) and non-VSA (73 cases; negative for SPT) groups, with FH-CAD being defined. In the VSA group, flow-mediated vasodilation (FMD) and nitroglycerin-independent vasodilation (NID) via brachial artery echocardiography and clinical symptoms in the groups with and without FH-CAD were checked, with Kaplan-Meier curves revealing major adverse cardiovascular events (cardiac death and rehospitalisation for cardiovascular disease) between the two groups.

RESULTS

The atherosclerotic CAD group had a significantly lower FH-CAD frequency (12%, p = 0.029) than the VSA (19%) and non-VSA groups (19%). FH-CAD was more common in females in the VSA and non-VSA groups than in the atherosclerotic CAD group (p < 0.001). Nonpharmacological treatment for CAD in FH-CAD was more common in the atherosclerotic CAD group (p = 0.017). In the VSA group, FH-CAD tended to be more common in females (p = 0.052). Although no differences in FMD of the brachial artery were observed between the groups, the FH-CAD (+) group had significantly higher NID than the FH-CAD (-) group (p = 0.023). Kaplan-Meier's analysis revealed a similar prognosis between the two groups, and other clinical characteristics did not differ.

CONCLUSION

Patients with VSA have a higher FH-CAD frequency than those with atherosclerotic CAD, especially in females. Although FH-CAD may affect vascular function in patients with VSA, its effect on the severity and prognosis of VSA appears to be minimal. FH-CAD and its confirmation may assist in CAD diagnosis, especially in female patients.

Vasospastic angina in women: Clinical backgrounds and prognoses of patients younger than and older than 60 years

BACKGROUND

We frequently encounter cases of women with vasospastic angina (VSA). Additionally, some women with VSA are younger than 60 years old. However, it is unknown whether the characteristics of VSA in women aged < 60 years are different from those in women aged ≥ 60 years.

AIM

To investigate and compare the clinical characteristics and prognosis of VSA in women aged < 60 years from those in women aged ≥ 60 years.

METHODS

We enrolled 94 women with VSA who were diagnosed using the spasm provocation test. According to the age at diagnosis, the patients were divided into two groups: Group Y (age < 60 years, n = 17) and Group O (age ≥ 60 years, n = 77). Flow-mediated dilation (FMD) and nitroglycerin (NTG)-induced dilation (NID) of the brachial artery were performed and assessed using brachial ultrasonography. Moreover, conventional coronary risk factors, such as atherosclerotic lesions (stenosis > 20%) detected using coronary angiography and focal spasms (coronary spasm within one segment of one coronary artery), and major cardiovascular adverse events (MACE) were assessed in both groups.

RESULTS

Smoking was more prevalent in Group Y than in Group O (P = 0.04). FMD was similar in both groups (Group O: 4.3% ± 3.2%, Group Y: 4.5% ± 3.3%; P = 0.75), whereas NID was higher in Group Y (20.5% ± 8.6%) than in Group O (13.6% ± 5.3%, P < 0.01). Atherosclerosis was not detected in Group Y but was detected in Group O (61%, P < 0.01). Focal spasms were less frequent in Group Y (12%) than in Group O (38%, P = 0.04). The incidence of major adverse cardiac events did not differ between the two groups (P = 0.40).

CONCLUSION

Women aged < 60 years with VSA have less atherosclerotic lesions and focal spasms. These characteristics may be affected by smoking habits and vascular smooth muscle dysfunction.

Does the intracoronary pressure differ according to two types (diffuse or focal) of coronary spasm?

BACKGROUND

Several reports show that two types of coronary vasospasm (diffuse and focal spasm) are associated with the severity or prognosis of coronary spasm in patients with vasospastic angina (VSA). It is unclear whether intracoronary pressure differs between the two spasm types.

AIM

To investigate such relationships using a pressure wire during the spasm provocation test (SPT) in patients with VSA.

METHODS

Eighty-seven patients with VSA (average age: 67 years; 50 men, 37 women) underwent SPT. During the SPT, a pressure wire was advanced into the distal portion of the right coronary artery and left anterior descending coronary artery, and the ratio of the intracoronary pressure to the aortic pressure (Pd/Pa) was continuously monitored. An SPT was performed using acetylcholine (ACh), and the presence of coronary spasm was defined as the presence of > 90% arterial narrowing in response to an ACh infusion, with the usual chest symptoms and/or ischemic ECG changes. Focal spasm was defined as total or subtotal spasm within one segment of the AHA classification, while diffuse spasm was defined as > 90% spasm with two or more segments.

RESULTS

Among 87 patients, the frequencies of metabolic syndrome and having coronary atherosclerosis were higher in the focal group (n = 33) than in the diffuse spasm group (n = 54, P < 0.05). In the vessel analyses, in these 134 spastic segments, diffuse and focal spasms were detected in 100 and 34 vessels, respectively. The Pd/Pa at baseline was similar in both groups (diffuse: 0.96 ± 0.05, focal: 0.95 ± 0.05, P = 0.35); however, the Pd/Pa during coronary spasm was lower in focal spastic vessels (0.66 ± 0.20) than in diffuse spastic vessels (0.76 ± 0.11, P < 0.01), and the reduction in Pd/Pa during an SPT was also lower in focal spastic vessels (-0.29 ± 0.20) than in diffuse spastic vessels (-0.18 ± 0.11, P < 0.01). The presence of focal spasm was a significant factor responsible for reduction in Pd/Pa during SPT.

CONCLUSION

These findings suggest that focal spasm may be more severe than diffuse spasm, judging from the intracoronary pressure during coronary spasm.

Clinical Characteristics and Prognosis of Patients with Vasospastic Angina Subjected to the Spasm Provocation Test and the Unavoidable Use of Nitroglycerin

Background: Multi-vessel spasm (MVS) has a prognostic impact in patients with vasospastic angina (VSA). Thus, the presence of coronary spasm in both the left coronary artery (LCA) and right coronary artery (RCA) should be assessed through the spasm provocation test (SPT). Nitroglycerin (NTG) is used to avoid SPT-related complications; however, this unavoidable use of NTG may decrease the detection of MVS. Therefore, we investigated the frequency of the unavoidable use of NTG during SPT and clarified the clinical characteristics in patients with VSA who underwent the unavoidable use of NTG during STP. Methods: A total of 141 patients with positive SPT were evaluated. A positive SPT was defined as > 90% constriction in epicardial coronary arteries in response to acetylcholine, accompanied by the usual chest symptoms and/or ischaemic ST-T changes on electrocardiography. When a coronary spasm occurred, we usually wait for the spontaneous relief of the coronary spasm. However, if a prolonged coronary spasm or unstable haemodynamics occurred, 0.3 mg NTG was administered intracoronarily to promptly relieve the coronary spasm and this was defined as the unavoidable use of NTG. Even when the unavoidable use of NTG was administered in one coronary artery, an additional SPT was performed on another coronary artery. If a coronary spasm occurred in another coronary artery, a positive SPT was diagnosed. In contrast, if a coronary spasm was not induced after the unavoidable use of NTG, the judgement was classified as undiagnosed. The patients were divided into two groups according to the unavoidable use of NTG: U-NTG (n = 42) and the final use of NTG: F-NTG (n = 99). The clinical characteristics and frequencies of MVS (≥2 major coronary arteries in which a coronary spasm was provoked) and complications (malignant arrhythmia and unstable haemodynamics requiring catecholamines) during the SPT were compared between the groups. Results: Except for smoking status, all other clinical characteristics did not differ significantly between the groups. More current smokers were observed in the U-NTG group (29%) than in the F-NTG group (12%, p = 0.02). The frequency of MVS did not vary significantly between the groups (p = 0.28), with 64% for U-NTG and 55% for F-NTG. No significant difference was found between the groups in the frequency of severe complications during SPT (p = 0.83), with 2% for U-NTG and 3% for F-NTG. In the U-NTG group, the positive induction rate of coronary spasm in another coronary artery was 40% (17/42). Conclusions: The unavoidable use of NTG occurred in ~30% of patients with VSA, most of whom were current smokers. It did not decrease the detection of MVS and potentially prevented severe complications during SPT. Therefore, the unavoidable use of NTG is acceptable during SPT. However, an additional test may need to be performed to assess the presence of MVS.