Biomedical subjects

Shozo Sueda

Publications and source records attributed to Shozo Sueda.

13 recordsLinked to original sources

PubMed2005

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.

Angina Pectoris, Variant↗

PubMed2004

Improvement of insulin resistance by troglitazone ameliorates cardiac sympathetic nervous dysfunction in patients with essential hypertension.

BACKGROUND: It was recently suggested that insulin resistance is significantly correlated with activation of the cardiac sympathetic nervous system in patients with essential hypertension. OBJECTIVES: To examine the effects of troglitazone, an agent used to treat insulin resistance, on cardiac sympathetic nervous dysfunction and insulin resistance in patients with essential hypertension. METHODS: The study participants included 34 patients (14 men, 20 women) with mild essential hypertension and 17 normal controls (group C, seven men). The patients were randomly divided into two groups, one treated with 400 mg troglitazone and antihypertensive drugs (group T, n = 17) and the other treated with antihypertensive drugs only (group N, n = 17). We evaluated insulin resistance and cardiac sympathetic nervous function before and after 6 months of treatment. Insulin resistance was evaluated using steady-state plasma glucose (SSPG; mg/dl) concentrations and cardiac sympathetic nervous function was evaluated using the heart-to-mediastinum ratio (H : M) and mean washout rate measured by 123I-meta-iodobenzylguanidine (MIBG) cardiac imaging. RESULTS: There were significant differences in SSPG (P < 0.01), early (P < 0.05) and delayed (P < 0.05) phases of H : M and washout rate (P < 0.05) between the hypertensive patients and group C. The SSPG concentration was significantly improved after treatment only in group T, from 153.3 to 123.7 mg/dl (P < 0.01). The early and delayed phases of H : M and washout rate also were significantly improved (P < 0.05) (from 2.59 to 2.63, from 2.12 to 2.27 and from 18.1 to 13.7%, respectively) in only group T.The change in SSPG was significantly correlated with the changes in H : M and washout rate (r = -0.639 and 0.577, respectively). CONCLUSION: Troglitazone had a beneficial effect on cardiac sympathetic nervous function through a decrease in insulin resistance in patients with essential hypertension.

Antihypertensive Agents↗

PubMed2004

Clinical impact of selective spasm provocation tests: comparisons between acetylcholine and ergonovine in 1508 examinations.

BACKGROUND: There are few reports regarding the concordance of coronary arterial response between acetylcholine (ACh) and ergonovine (ER) spasm provocation tests. OBJECTIVES: We attempted to perform selective spasm provocation tests to examine the incidence of provoked spasm in patients who had undergone first coronary angiography as much as possible and we compared the coronary arterial response and clinical usefulness between selective intracoronary injection of ACh and intracoronary administration of ER. METHODS: We performed 1508 selective spasm provocation tests, consisting of 873 ACh tests and 635 ER tests, from 1991 to 2002. We examined the frequency of provoked spasms of each agent retrospectively. ACh was injected in incremental doses of 20, 50 and 80 microg into the right coronary artery and 20, 50 and 100 microg into the left coronary artery. ER was administered as 10 microg/min over 4 min for a maximal dose of 40 microg in the right coronary artery and as 16 microg/min over 4 min for a total dose of 64 microg in the left coronary artery. Coronary spasm was defined as transient >99% luminal narrowing. RESULTS: Intracoronary ACh provoked spasms in 36.0% of patients and intracoronary ER induced spasms in 29.8% of patients. In patients with ischemic heart disease, the incidence of provoked spasms was not different between ACh tests (50.9%) and ER tests (43.8%). In contrast, the frequency of provoked spasms with ACh tests was significantly higher than that with ER tests (11.0% compared with 6.4%, P<0.05) in patients without ischemic heart disease. Moreover, ACh provoked more spasms in patients without fixed stenosis than ER (36.2% compared with 25.5%, P<0.01) and multiple spasms were frequently observed when performing ACh tests (40.0% compared with 27.0%, P<0.01). Major complications were observed in 1.4% of patients with ACh tests and in 0.2% of patients with ER tests. The need for intracoronary administration of isosorbide dinitrate to relieve coronary spasms during ER testing before performing another coronary artery test was more frequently observed in ACh tests (5.04% compared with 1.49%, P<0.01). However, no serious irreversible complications, such as death or acute myocardial infarction, were observed in this study. There was a significant difference in sex, history of smoking and hyperlipidemia between patients with and without spasms for both tests, whereas no difference in age or hypertension was observed in either test. CONCLUSION: Thus, both selective ACh and ER tests were useful as spasm provocation tests.

Acetylcholine↗

PubMed2003

Effect of cilostazol on vasomotor reactivity in patients with vasospastic angina pectoris.

We examined the effects of cilostazol on impaired coronary arterial responses in patients with vasospastic angina (VSA). Thirty patients who were diagnosed with VSA based on an acetylcholine provocation test and 10 subjects with normal coronary arteries were enrolled. The patients were divided into the following 3 groups: no antiplatelet agent treatment group, aspirin treatment, or cilostazol treatment groups. Coronary flow reserve (CFR), coronary flow volume at maximum hyperemia, and epicardial coronary artery diameter after administration of N(G)-monomethyl-L-arginine (L-NMMA) were examined using a Doppler flow wire before and 6 months after the start of this study. CFR, coronary flow volume at maximum hyperemia, and diameter changes by L-NMMA were significantly increased in the cilostazol treatment group compared with the other 2 groups. In conclusion, cilostazol increased CFR and flow-dependent coronary dilation; these changes were attributable to nitric oxide. Cilostazol may improve coronary vascular endothelial dysfunction and coronary hemodynamics in patients with VSA.

Angina Pectoris↗

PubMed2003

Beneficial effects of betaxolol, a selective antagonist of beta-1 adrenoceptors, on exercise-induced myocardial ischemia in patients with coronary vasospasm.

Although beta-blockers can not be used for the treatment of vasospastic angina, the effect of beta-blockers with vasorelaxant property on coronary vasospasm remains uncertain. In this study, we evaluated the effect of betaxolol, a new beta-blocker with calcium antagonistic property, as an additional therapy on vasospastic angina (VSA) with anginal attacks on effort. We enrolled 12 patients with VSA and anginal attacks with ST segment depression during exercise stress test. All patients received 1.25-5 mg of betaxolol for 3 months. Treadmill exercise stress test and adenosine triphosphate stress thallium-201 myocardial scintigraphy were performed before and 3 months after the onset of the betaxolol treatment. The other drugs including calcium antagonists, nitrates and nicorandil were continued. No patients experienced the exacerbation of angina during the betaxolol treatment. Exercise time to chest pain (317.5+/-72.1-454.2+/-75.5 s, P<0.01) and maximal ST segment depression (1.67+/-0.67-1.16+/-0.46 mm, P<0.01) obtained by exercise stress test, the defect score (8.6+/-2.7-5.3+/-2.1, P<0.01), the extent score (14.8+/-5.8-8.8+/-4.6%, P<0.01), the severity score (17.5+/-7.3-11.3+/-5.2, P<0.01) and washout rate (31.4+/-5.6-37.6+/-5.0%, P<0.01) obtained by the scintigraphy were improved by betaxolol. Our results suggest that betaxolol increases regional myocardial blood flow and improves exercise capacity in patients with VSA. Betaxolol may become a drug for a new potential therapy for VSA.

Adrenergic beta-1 Receptor Antagonists↗

PubMed2003

Coronary flow reserve in patients with vasospastic angina: correlation between coronary flow reserve and age or duration of angina.

OBJECTIVES: This study sought to assess the coronary flow reserve (CFR) in patients with pure vasospastic angina (VSA). METHODS AND RESULTS: The phasic flow velocities of both spasm-positive and spasm-negative coronary arteries of the left anterior descending artery (LAD) were recorded at rest and during hyperaemia (50 microg of adenosine triphosphate infusion intracoronary) using a 0.014 inch, 15 MHz Doppler guide wire in 42 patients with pure VSA and acetylcholine (ACh)-induced coronary artery spasms (20-100 microg), and 23 controls with normal coronary arteries without ACh-induced vasospasm. These 42 patients had 16 vessels with focal spasms (>99%), 17 vessels with diffuse spasms (>90%) in the LAD, and nine vessels with ACh-induced spasms in the right coronary artery, but not the LAD. Coronary flow reserve was obtained from the ratio of the hyperaemic/baseline time-averaged peak velocity. Coronary flow reserve did not differ between patients with VSA and the controls (2.9+/-0.8 versus 3.2+/-0.7, NS). Moreover, CFR did not differ among the four cases (focal: 2.8+/-0.7; diffuse: 3.0+/-0.9; non spasm: 2.9+/-0.7 versus controls: 3.2+/-0.7, respectively, NS). Coronary flow reserve in vessels with proximal spasms was significantly higher than that in vessels with mid or distal spasms (3.4+/-0.8 versus 2.6+/-0.6, 2.6+/-0.9, p<0.05). The only significant correlation was between CFR and age (p=0.0275) or the duration of angina before admission (p=0.0405). CONCLUSIONS: There was no difference in CFR in patients with ACh-induced spasms between the spasm-positive and spasm-negative vessels. Moreover, CFR was maintained normally in vessels with diffuse spasms, as in those with focal spasms. The most important determinant factors for CFR in patients with VSA were age and the duration of angina before admission.

Age Factors↗

PubMed2003

Induction of coronary artery spasm by two pharmacological agents: comparison between intracoronary injection of acetylcholine and ergonovine.

BACKGROUND AND OBJECTIVES: There have been few studies comparing the clinical usefulness for the induction of coronary artery spasm (CAS) between acetylcholine (ACh) and ergonovine (ER). This study is designed: (1) to examine the duration of effect after intracoronary injection of ACh on the responsible vessels using a 0.014 inch, 15 MHz Doppler guide wire, and (2) to evaluate the efficacy of two pharmacological agents, ACh and ER, for the induction of CAS in patients with <50% stenosis in the cardiac laboratory. METHODS: Phasic coronary flow velocity patterns were recorded at rest and during ACh tests in 22 patients with normal or near-normal coronary arteries. The tip of the guide wire was placed on the proximal right coronary artery (RCA) and mid-left anterior descending artery. We measured the time required to baseline level of average peak velocity after intracoronary injection of ACh. We performed selective intracoronary administration of both ER and ACh in the same 171 patients (106 men, 65 women, mean age of 62+/-10 years) with <50% stenosis. Under no medication, ACh was injected first in incremental doses of 20, 50, and 80 microg into the RCA and of 20, 50, and 100 microg into the left coronary artery (LCA). Ten minutes later, ER was administered at 10 microg/min for four minutes for a maximal dose of 40 microg on the RCA and at 16 microg/min over four minutes for a total dose of 64 microg on the LCA. Positive spasm was defined as > or =99% luminal narrowing. RESULTS: The time-averaged peak velocity returned to baseline after intracoronary injection of ACh within 10 minutes in all 120 procedures, consisted of 19 with positive spasm (RCA (n=10): 245+/-33 s; LCA (n=9): 351+/-187 s) and 101 with negative spasm (RCA (n=48): 155+/-62 s, LCA (n=53): 248+/-106 s). In the overall results, there was no difference concerning the incidence of provoked spasm between the two pharmacological agents (ACh: 33% versus ER: 32%, NS). Coronary spasms were induced by either pharmacological agent in 134 vessels. Concordance in this study was 94% in all vessels, whereas the remaining 6% of vessels were different from each other. The non-concordance rate of the right coronary artery was significantly higher than that of the left coronary artery (10% versus 4%, p<0.01). However, ER provoked more focal spasms, whereas ACh provoked more diffuse and distal spasms, compared with each other. Seventy-four (55%) of the 134 vessels had coronary spasms in the same coronary arteries. Concordance of both provoked spasm sites and spasm configurations in the same coronary artery was observed in only 18 (13%) vessels. No serious or irreversible complications were observed during the two sequential tests. CONCLUSIONS: As a spasm provocation test, there were no differences between ACh and ER. We recommend the supplementary use of these two pharmacological agents for the induction of CAS in the cardiac laboratory, if available.

Acetylcholine↗

PubMed2003

Limitations of medical therapy in patients with pure coronary spastic angina.

OBJECTIVES: To assess the efficacy of medication for the treatment of pure coronary spastic angina, 71 consecutive patients with this diagnosis who had undergone coronary arteriography in a hospital with a follow-up of at least 2 years were studied. METHODS AND RESULTS: All 71 patients without significant organic stenosis were treated with long-acting calcium antagonists. The disappearance of chest pain attacks while receiving medical therapy was observed in 27 patients (38%), whereas the remaining 44 patients (62%) had chest pain attacks. Of special interest, 30 patients had more than one attack per month irrespective of the administration of calcium antagonists or isosorbide dinitrate. Medical treatment showed a good response in female patients (63% vs 31%, respectively; p < 0.05) and those with ST-segment elevation during selective spasm provocation tests (63% vs 30%, respectively; p < 0.05). In contrast, patients with a longer history of chest pain attacks before hospital admission and those with diffuse spasms (77% vs 34%, respectively; p < 0.01) had poor responses to medical treatment. In this study, neither sudden death nor acute myocardial infarction was observed during the follow-up periods. CONCLUSION: The limitations of medical therapy, including the administration of long-acting calcium antagonists, were observed in 30 of 71 patients (42%) with pure coronary spastic angina. Medical treatment was effective in only 38% of patients with pure coronary spastic angina in Japan.

Acetylcholine↗

PubMed2003

Did the widespread use of long-acting calcium antagonists decrease the occurrence of variant angina?

BACKGROUND: We have not often encountered variant angina (VA) since the use of long-acting calcium antagonists (L-CAs) became widespread. OBJECTIVES: This study examined the frequency of VA retrospectively. METHODS: and results: We diagnosed angiographically confirmed coronary spastic angina (CSA) in 349 consecutive patients using selective spasm provocation tests from January 1991 to December 2002. During this period, 3,148 diagnostic cardiac catheterizations and 1,515 selective spasm provocation tests were performed. Seventy-four of these 349 patients (21.2%) had VA. Coronary spasms were defined as transient luminal narrowings of > 99%, and VA was defined as an ST elevation during spontaneous attacks or noninvasive stress tests. We classified the 12 years of the study into four periods of 3 years each. No tendency to decrease for the ratio of the number of patients with CSA and the number of selective spasm provocation tests was observed among the four time periods (18%, 24%, 32%, and 23%, respectively). However, the number of patients with VA (28, 33, 9, and 4) and the VA/CSA ratio (32%, 28%, 14%, and 5%, respectively) in the four group significantly decreased. The frequency of administration of calcium antagonists (CAs) before hospital admission (49% vs 33%, respectively; p < 0.05) was significantly higher in the last time period (from 2000 to 2002) than in the first period (from 1991 to 1993). L-CAs were administered in > 90% of CSA patients who had been medicated with CAs before hospital admission in the last period (from 2000 to 2002), while L-CAs were administered in only 20% in the former period (from 1991 to 1993). The administration of statins and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers before hospital admission gradually increased according to the period passed, but not significantly. CONCLUSION: The frequency of VA has decreased in Japan, possibly due to the widespread use of therapy with L-CAs.

Angina Pectoris, Variant↗

PubMed2002

Clinical and angiographical characteristics of acetylcholine- induced spasm: relationship to dose of intracoronary injection of acetylcholine.

OBJECTIVES: The purpose of this study was to clarify clinical and angiographical characteristics of acetylcholine (ACh)-induced spasm in the right and left coronary artery. METHODS AND RESULTS: We performed 557 consecutive procedures of spasm provocation tests of ACh from January 1991 to December 2000 in patients without significant stenosis. ACh was injected in incremental doses of 20, 50 and 80 microg into the right coronary artery and in incremental doses of 20, 50 and 100 microg into the left coronary artery if spasm had not been provoked. Coronary spasm was defined as positive with more than 99% transient luminal narrowing. Proximal spasm was defined as that of segments 1, 2, 5, 6, 7 and 11 and distal spasm as that of segments 3, 4, 8, 9, 12, 13 and 14. Low-ACh-dose-induced spasms showed the clinical findings and angiographical characteristics of higher incidence of variant angina, proximal spasms, focal spasms, more ST elevation and ischemic heart disease. In contrast, angiographical characteristics of high-Ach-dose-induced spasms were distal spasms and diffuse spasms and there was less variant angina and less ST elevation. CONCLUSIONS: Lower ACh doses induced spasms more proximally and focally in the coronary artery, while higher doses of ACh provoked spasms more distally and diffusely.

Acetylcholine↗

PubMed2002

Intracoronary administration of a thromboxane A2 synthase inhibitor relieves acetylcholine-induced coronary spasm.

This study sought to clarify the effectiveness of intracoronary administration of a thromboxane (TX) A2 synthase inhibitor, Ozagrel Na, to relieve coronary spasms induced by intracoronary injection of acetylcholine (ACh). An ACh spasm provocation test was performed in 92 consecutive patients with coronary spastic angina using incremental doses of 20, 50, and 80 microg into the right coronary artery, and 20, 50, and 100 microg into the left coronary artery within 20s. A coronary spasm was defined as TIMI 0 or 1 flow and an intracoronary injection of 20 mg Ozagrel Na was administered when it was provoked. Within 2 min of the administration of the TXA2 synthase inhibitor, ACh-induced coronary spasms were relieved (TIMI 3 flow) in 88.1% of procedures without complications. In only 4 cases (4.3%), it took more than 3 min to relieve the coronary spasms. Intracoronary administration of 20mg Ozagrel Na when ACh-induced spasms occurred, shortened the spasm relief time in all 7 patients (200 +/- 59s vs 111 +/- 23s, p < 0.01), improved the maximal ST segment elevation in 5 of them (3.9 +/- 3.7 mm vs 0.7 +/- 1.5 mm, p < 0.05), and stopped chest pain in 4 patients. In 4 patients who had ACh-induced coronary spasm of the left anterior descending artery, the TXB2 concentration in the coronary sinus decreased after intracoronary administration of Ozagrel Na into the left coronary artery (463 +/- 562 vs 96 +/- 45, p < 0.01). In conclusion, intracoronary administration of a TXA2 synthase inhibitor can relieve ACh-induced coronary spasms by inhibiting TXA2 synthesis in the local coronary circulation.

Acetylcholine↗

PubMed2002

New protocol to detect coronary spastic angina without fixed stenosis.

A new combined test, accelerated exercise following mild hyperventilation (HV), was examined to determine whether it is effective at detecting a positive response in patients with pharmacologically-induced coronary vasospasm and near normal coronary arteries. Fifty-eight consecutive patients who underwent both triple non-invasive spasm provocation tests and diagnostic coronary angiography were enrolled. They all had pharmacologically-induced coronary vasospasms and no significant organic stenosis. In these patients, an HV test was performed first, followed by a treadmill exercise test (TET), and finally the new combined test under no medication within 3 days. Of the 58 patients, positive responses were observed in 9 patients to the HV, in 15 to the TET, and in 35 to the newly combined test. The remaining 21 patients had negative responses although the triple sequential tests were perfomed. Thus, the sensitivities of the HV test, TET, and newly combined test were 16% (9/58), 26% (15/58), and 63% (35/56), respectively. Forty-six subjects with near normal coronary arteries and no ACh-provoked spasm served as controls. None of these subjects had positive responses to any of these three tests, and thus their specificity was all 100%. No serious or irreversible complications were seen in this study. We recommend this newly-combined protocol for the induction of coronary artery spasm in patients with vasospastic angina pectoris and without significant stenosis as a diagnostic tool.

Adult↗

PubMedDate not supplied

Frequency of provoked coronary spasms in patients undergoing coronary arteriography using a spasm provocation test via intracoronary administration of ergonovine.

There are no data concerning the incidence of provoked coronary arterial spasms via intracoronary administration of ergonovine (ER). This study sought to establish the incidence of spasms due to intracoronary injection of ER in Japanese patients who underwent coronary angiography. The subjects were 596 consecutive patients (369 men, mean age 64.2 +/- 10.3 years) who were studied with a selective ER test. ER was administered in total doses of 40 microg into the right coronary artery and 64 microg into the left coronary artery. A positive spasm was defined as a total or subtotal occlusion. Coronary vasospasms were determined in 173 patients (29.0%). Spasms occurred often in patients with ischemic heart disease (43.3%); during effort and rest in patients with angina (46.3%), exertional angina (27.7%), recent myocardial infarction (36.7%), healed myocardial infarction (34.1%), and especially in patients with rest angina (55.5%), but were relatively uncommon in patients with nonischemic heart disease (3.7%). The incidence of provoked coronary spasms in this study was 2.2-2.6 times higher than in previous reports with intravenous ER administration. More spasms were superimposed on significant atherosclerotic lesions than on nonfixed atherosclerotic lesions (42.8% vs 24.0%, p < 0.01). No serious or irreversible complications were observed in this study. In conclusion, intracoronary administration of ER was a safe and reliable test. Compared with Caucasian patients, in Japanese patients, coronary arterial spasms occurred 2-3 times more frequently with various cardiac disorders.

Aged↗