Relationship between serum lipoprotein(a) concentrations and coronary vasomotion in coronary spastic angina

Prevalence of Coronary Microvascular Disease and Coronary Vasospasm in Patients With Nonobstructive Coronary Artery Disease: Systematic Review and Meta-Analysis

Background

A relevant proportion of patients with suspected coronary artery disease undergo invasive coronary angiography showing normal or nonobstructive coronary arteries. However, the prevalence of coronary microvascular disease (CMD) and coronary spasm in patients with nonobstructive coronary artery disease remains to be determined. The objective of this study was to determine the prevalence of coronary CMD and coronary vasospastic angina in patients with no obstructive coronary artery disease.

Methods and Results

A systematic review and meta‐analysis of studies assessing the prevalence of CMD and vasospastic angina in patients with no obstructive coronary artery disease was performed. Random‐effects models were used to determine the prevalence of these 2 disease entities. Fifty‐six studies comprising 14 427 patients were included. The pooled prevalence of CMD was 0.41 (95% CI, 0.36–0.47), epicardial vasospasm 0.40 (95% CI, 0.34–0.46) and microvascular spasm 24% (95% CI, 0.21–0.28). The prevalence of combined CMD and vasospastic angina was 0.23 (95% CI, 0.17–0.31). Female patients had a higher risk of presenting with CMD compared with male patients (risk ratio, 1.45 [95% CI, 1.11–1.90]). CMD prevalence was similar when assessed using noninvasive or invasive diagnostic methods.

Conclusions

In patients with no obstructive coronary artery disease, approximately half of the cases were reported to have CMD and/or coronary spasm. CMD was more prevalent among female patients. Greater awareness among physicians of ischemia with no obstructive coronary arteries is urgently needed for accurate diagnosis and patient‐tailored management.

The Biochemical Markers Associated with the Occurrence of Coronary Spasm

Coronary artery spasm (CAS) is one of the mechanisms of angina pectoris. Unlike the diagnosis of acute myocardial infarction which is based on the elevation of cardiac markers, the diagnosis of CAS is difficult and sometimes requires sophisticated and risky provocative test which is not widely accepted in China. There is no well-established biomarker for the diagnosis or prediction of CAS. However, there are some biomarkers proven to be associated with the occurrence of CAS. For example, inflammatory factors including C-reactive protein and cytokines, lipoprotein (a), and cystatin-C might be precipitating factor for CAS. Rho-kinase as a mediator involved in multiple mechanisms of CAS, serotonin, and endothelin-1 as powerful vasoconstrictors leading to vasospasm were all observed being elevated in patients with CAS. Thioredoxin and nitrotyrosine reflected the oxidative status and could be observed to be elevated after the occurrence of CAS. In some cases doubted to be CAS without the evidence of provocative test, the blood test for the biomarkers mentioned above could be useful for the diagnosis of CAS.

Higher serum uric acid and lipoprotein(a) are correlated with coronary spasm

It has been reported that a major cause of coronary vasospastic angina (VSA) is endothelial dysfunction of the coronary artery. On the other hand, some studies showed that serum uric acid and lipoprotein(a) are correlated with endothelial dysfunction. Thus, we examined whether uric acid and lipoprotein(a), are correlated with VSA. Four hundred forty-one patients with suspected VSA who underwent a coronary angiogram with acetylcholine provocation (ACh test) during an 8-year period were enrolled. We divided them into a VSA group, who showed coronary spasm by the ACh test, and an atypical chest pain (ACP) group, who showed negative ACh test. We compared serum markers between the two groups, including low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, high-sensitivity C-reactive protein (hs-CRP), lipoprotein(a), fibrinogen, total plasminogen activator inhibitor-1, and uric acid. Uric acid, hs-CRP, and lipoprotein(a) were significantly higher in the VSA group than in the ACP group (all P < 0.05) while there were no significant differences in the other parameters. Multivariate analyses identified uric acid and lipoprotein(a) as significant independent markers for VSA. Uric acid and lipoprotein(a) are correlated with VSA, and medical intervention to decrease uric acid and lipoprotein(a) might be effective in controlling VSA.

Coronary vasospasm-induced acute coronary syndrome complicated by life-threatening cardiac arrhythmias in patients without hemodynamically significant coronary artery disease

BACKGROUND

Coronary vasospasm-induced electrical and mechanical complications in patients with acute coronary syndrome and no hemodynamically significant coronary artery disease are rarely reported.

METHODS

A total of 733 consecutive patients with acute coronary syndrome admitted to our hospital who subsequently underwent coronary angiography at our institution were enrolled. Patients who had documented complete atrioventricular block or ventricular fibrillation, no evidence of hemodynamically significant coronary artery disease on coronary angiogram, and no other (non-coronary) cardiac abnormalities were included. Patients were followed for subsequent cardiac events and mortality.

RESULTS

Over a 6-year period at our institution, acute coronary syndrome complicated by life-threatening cardiac arrhythmias developed in six patients who had no hemodynamically significant coronary artery disease with corresponding intra-coronary ergonovine provocative coronary vasospasm. Acute myocardial infarction was diagnosed in five of these patients and variant angina pectoris in one. Complete atrioventricular block was the most common complication in these cases, followed by cardiogenic shock with or without right ventricular infarction, ventricular fibrillation, and severe sinus arrest. These complications were corrected with intravenous fluid, intravenous atropine or cardiac defibrillation. During a median follow-up period of 26 months, none of the patients expired or suffered nonfatal reinfarction. Two individuals who did not stop smoking during follow-up developed recurrent angina after self-discontinuation of calcium antagonists.

CONCLUSIONS

Coronary vasospasm can be a cause of life-threatening cardiac arrhythmias in patients with acute coronary syndrome and no hemodynamically significant coronary artery disease. Coronary angiography with/without intra-coronary ergonovine testing is necessary in acute coronary syndrome patients to identify the underlying pathology and establish appropriate treatment in these cases.

Clinical characteristics of patients with exercise-induced ST-segment elevation without prior myocardial infarction

BACKGROUND

Exercise-induced ST-segment elevation is a relatively uncommon problem and occurs more frequently in patients who have had a myocardial infarction. Data is limited on the characteristics of Taiwanese patients without prior myocardial infarction who develop exercise-induced ST-segment elevation.

METHODS AND RESULTS

Exercise-induced ST-segment elevation developed in 9 of 6,147 consecutive patients without myocardial infarction who underwent treadmill exercise testing at out institution over a 4-year period. The clinical and angiographic characteristics of these patients were studied. Angiographically normal coronary arteries with coronary vasospasm were found in 5 patients, hemodynamically significant coronary stenosis was found in 3 patients, and coexisting spasm in angiographically normal coronary arteries combined with hemodynamically significant coronary stenosis in the different vessel was found in 1 patient. During a median follow-up of 71 months, 2 patients with coronary vasospasm developed recurrent angina after self-discontinuation of calcium antagonists and 2 patients (1 with coronary vasospasm and 1 with hemodynamically significant coronary stenosis) died of cardiac causes before arrival at the emergency department.

CONCLUSION

Coronary vasospasm was a more common underlying pathology of exercise-induced ST-segment elevation in this Taiwanese cohort. Coronary angiography +/- intracoronary ergonovine provocation testing is necessary in these patients to identify the underlying pathology and appropriate treatment.

Need for documentation of guidelines for coronary artery spasm: an investigation by questionnaire in Japan

BACKGROUND

Because there are no guidelines concerning coronary spasm in Japan, the present study examined the current status of the spasm provocation test.

METHODS AND RESULTS

Questionnaires concerning the number of cases of coronary angiography, percutaneous coronary intervention, and invasive/non-invasive spasm provocation tests over 3 years (2001-2003) and the status of spasm provocation tests were sent to members of the Japanese Circulation Society in 120 cardiology hospitals in the Chugoku and Shikoku areas. Completed surveys were returned from 45 hospitals, giving a collection rate of 38%. As a spasm provocation agent, acetylcholine tests were performed in 29 hospitals, and ergonovine tests in 18 hospitals. Non-invasive spasm provocation tests were performed in only 9 hospitals (20%). In total, 5,267 patients underwent acetylcholine spasm provocation test (2,387 patients) or ergonovine spasm provocation test (2,880 patients) and vasospastic angina was diagnosed in 1,663 (2.4%) patients. Invasive spasm provocation tests were performed in 7.8% of patients with diagnostic catheterization and the spasm-positive rate was 31.6%. The difference among hospitals concerning the number of invasive spasm provocation tests was remarkable, and the angiographic spasm-positive standard and acetylcholine/ergonovine dose varied among the hospitals.

CONCLUSIONS

Guidelines on coronary spasm in Japan are essential to overcome the current differences between institutions.