Assessment of coronary vasomotor responses to acetylcholine in German and Japanese patients with epicardial coronary spasm-more similarities than differences?

Coronary spasm is an established cause for angina pectoris. Ethnic differences have been suggested among Asian compared to Caucasian patients regarding prevalence, gender distribution, and angiographic patterns of coronary spasm. The aim of this study was to compare contemporary German and Japanese patients with coronary spasm. Between 2011 and 2015, 149 patients with resting angina and unobstructed coronary arteries with acetylcholine-induced epicardial spasm were enrolled in Stuttgart, Germany (n = 69) and Sendai, Japan (n = 80). All patients underwent intracoronary acetylcholine testing according to a standardized protocol. Comprehensive analysis included type of spasm (focal/diffuse), dose of acetylcholine leading to spasm, and frequency of multivessel spasm. Patients in this study were 61 ± 11 years old, predominantly female (54%), and had normal left ventricular ejection fraction (73 ± 9%). Diffuse spasm was the most prevalent type of spasm (85%) whereas focal spasm was found in the remaining 15% of patients. 31% of patients had multivessel spasm. Comparing the German with the Japanese patients, distribution of spasm type (focal/diffuse, p = 0.19) and frequency of multivessel spasm (p = 0.22) were comparable. Moreover, when Japanese patients were compared with German patients and diffuse spasm with focal spasm patients, respectively, no significant differences were observed regarding the acetylcholine dose required to induce spasm (p = 0.078 and p = 0.46, respectively). In conclusion, diffuse epicardial coronary spasm is the most frequent finding among German and Japanese patients with resting angina, unobstructed coronary arteries, and epicardial spasm on acetylcholine testing. Japanese and German patients share several similarities including comparable types of spasm and frequency of multivessel spasm.

Clinical characteristics and long-term prognosis of contemporary patients with vasospastic angina: Ethnic differences detected in an international comparative study.

BACKGROUND: Possible ethnic differences in clinical characteristics and long-term prognosis of contemporary patients with vasospastic angina (VSA) remain to be elucidated. METHODS AND RESULTS: The Japanese Coronary Spasm Association (JCSA) conducted an international, prospective, and multicenter registry study for VSA patients. A total of 1457 VSA patients (Japanese/Caucasians, 1339/118) were enrolled based on the same diagnostic criteria. Compared with Caucasian patients, Japanese patients were characterized by higher proportions of males (68 vs. 51%) and smoking history (60 vs. 49%). Japanese patients more often had angina especially during the night and early morning hours, compared with Caucasians. Ninety-five percent of Japanese and 84% of Caucasian patients underwent pharmacological provocation test. Importantly, no significant differences in the patterns of coronary spasm were apparent, with diffuse spasm most frequently noted in both ethnicities. The prescription rate of calcium-channel blockers was higher in Japanese (96 vs. 86%), whereas the uses of nitrates (46 vs. 59%), statins (43 vs. 65%), renin-angiotensin-system inhibitors (27 vs. 51%), and ß-blockers (10 vs. 24%) were more common in Caucasian patients. Survival rate free from major adverse cardiac events (MACE) was slightly but significantly higher in Japanese than in Caucasians (86.7 vs. 76.6% at 5 years, P < 0.001). Notably, multivariable analysis revealed that the JCSA risk score correlated with MACE rates not only in Japanese but also in Caucasian patients. CONCLUSION: These results indicate that there are ethnic differences in clinical profiles and long-term prognosis of contemporary VSA patients.

Prognostic impacts of Rho-kinase activity in circulating leucocytes in patients with vasospastic angina.

Aims: Rho-kinase activity in circulating leucocytes is a useful biomarker for diagnosis and disease activity assessment of vasospastic angina (VSA). The present study aimed to examine the long-term prognostic impact of Rho-kinase activity in circulating leucocytes in VSA patients. Methods and results: We prospectively enrolled 174 consecutive patients with VSA and 50 non-VSA patients, in whom we measured Rho-kinase activity in circulating leucocytes, and they were followed for a median of 16 months. The primary endpoint was cardiac events including cardiac death, non-fatal myocardial infarction, and hospitalization for unstable angina. During the follow-up period, cardiac events occurred in 10 VSA patients (5.7%) but in none of the non-VSA patients. When we divided VSA patients into two groups by a median value of their Rho-kinase activity, the Kaplan-Meier survival analysis showed a significantly worse prognosis in VSA patients with high Rho-kinase activity compared with those with low activity or non-VSA patients (log-rank; P < 0.05, respectively). Receiver-operating characteristic curve analysis showed that Rho-kinase activity value of 1.24 was the best cut-off level to predict cardiac events in VSA patients, and multivariable analysis showed that a value above the cut-off point had the largest hazard ratio to predict poor outcome in VSA patients [hazard ratio (95% confidence interval) 11.19 (1.41-88.95); P = 0.022]. Importantly, combination of the Japanese Coronary Spasm Association risk score and Rho-kinase activity significantly improved the prognostic impact in VSA patients as compared with either alone. Conclusion: Rho-kinase activity in circulating leucocytes is useful for prognostic stratification of VSA patients.

Plasma concentration of serotonin is a novel biomarker for coronary microvascular dysfunction in patients with suspected angina and unobstructive coronary arteries.

AIMS: Although the importance of coronary microvascular dysfunction (CMD) has been emerging, reliable biomarkers for CMD remain to be developed. We examined the potential usefulness of plasma concentration of serotonin to diagnose CMD in patients with suspected angina and unobstructive coronary arteries. METHODS AND RESULTS: We enrolled 198 consecutive patients (M/F 116/82, 60.2 ± 13.3 years old) who underwent acetylcholine provocation test and measured plasma serotonin concentration. Coronary microvascular dysfunction was defined as myocardial lactate production without or prior to the occurrence of epicardial coronary spasm during acetylcholine provocation test. Although no statistical difference in plasma concentration of serotonin [median (inter-quartile range) nmol/L] was noted between the vasospastic angina (VSA) and non-VSA groups [6.8 (3.8, 10.9) vs. 5.1 (3.7, 8.4), P = 0.135], it was significantly higher in patients with CMD compared with those without it [7.7 (4.5, 14.2) vs. 5.6 (3.7, 9.3), P = 0.008]. Among the four groups classified according to the presence or absence of VSA and CMD, serotonin concentration was highest in the VSA with CMD group. Importantly, there was a positive correlation between plasma serotonin concentration and baseline thrombolysis in myocardial infarction frame count (P = 0.001), a marker of coronary vascular resistance. The classification and regression trees analysis showed that plasma serotonin concentration of 9.55 nmol/L was the first discriminator to stratify the risk for the presence of CMD. In multivariable analysis, serotonin concentration greater than the cut-off value had the largest odds ratio in the prediction of CMD [odds ratio (95% confidence interval) 2.63 (1.28-5.49), P = 0.009]. CONCLUSIONS: Plasma concentration of serotonin may be a novel biomarker for CMD in patients with angina and unobstructive coronary arteries.

Prognostic impact of chronic nitrate therapy in patients with vasospastic angina: multicentre registry study of the Japanese coronary spasm association.

AIMS: Although nitrates are widely used as a concomitant therapy with calcium channel blockers (CCBs) for vasospastic angina (VSA), their prognostic contribution remains unclear. The present study aimed to examine the prognostic impact of chronic nitrate therapy in patients with VSA. METHODS AND RESULTS: A total of 1429 VSA patients (median 66 years; male/female, 1090/339) were enrolled. The primary endpoint was defined as major adverse cardiac events (MACE). The propensity score matching and multivariable Cox proportional hazard model were used to adjust for selection bias for treatment and potential confounding factors. Among the study patients, 695 (49%) were treated with nitrates, including conventional nitrates [e.g. nitroglycerin (GTN), isosorbide mono- and dinitrate] in 551 and nicorandil in 306. Calcium channel blockers were used in >90% of patients. During the median follow-up period of 32 months, 85 patients (5.9%) reached the primary endpoint. Propensity score-matched analysis demonstrated that the cumulative incidence of MACE was comparable between the patients with and those without nitrates [11 vs. 8% at 5 years; hazard ratio (HR): 1.28; 95% confidence interval (CI): 0.72-2.28, P = 0.40]. Although nicorandil itself had a neutral prognostic effect on VSA (HR: 0.80; 95% CI: 0.28-2.27, P = 0.67), multivariable Cox model revealed the potential harm of concomitant use of conventional nitrates and nicorandil (HR: 2.14; 95% CI: 1.02-4.47; P = 0.044), particularly when GTN and nicorandil were simultaneously administered. CONCLUSIONS: Chronic nitrate therapy did not improve the long-term prognosis of VSA patients when combined with CCBs. Furthermore, the VSA patients with multiple nitrates would have increased risk for cardiac events.