Effect of direct intracoronary administration of methylergonovine in patients with and without variant angina

Current advances in the understanding of coronary vasospasm

Recent years have witnessed progress in our understanding of coronary vasospasm (CVS). It is evident that this is not only an East Asian but also a global disease associated with significant symptoms and possible lethal sequelae for afflicted individuals. A correct diagnosis depends on the understanding of pathogenesis and symptomatology of CVS. With the correct diagnosis, we can manage CVS patients effectively and promptly, providing optimal patient safety. Advances in our understanding of interactions between inflammation, endothelium, and smooth muscle cells have led to substantial progress in understanding the pathogenesis of symptoms in CVS and have provided some insights into the basic etiology of this disorder in some patient subpopulations. We look forward to a time when therapy will address pathophysiology and perhaps, even the primary etiology.

An increased monocyte count predicts coronary artery spasm in patients with resting chest pain and insignificant coronary artery stenosis

BACKGROUND

Coronary atherosclerosis with inflammation gives rise to coronary vasospasm in the patients with coronary vasospastic angina. We have postulated that the peripheral leukocyte count and the differential count are associated with vasospastic angina.

METHODS

144 patients who underwent intracoronary ergonovine provocation testing between January 2002 and December 2004 were divided into two groups: Group I (72 patients with provoked spasm, mean age: 54.8 +/- 10.7 years, males: 75%) and Group II (72 without spasm, mean age: 55.3 +/- 10.2 years, males: 35%). Blood sampling was done to measure the lipid profiles and inflammatory markers, including the high sensitive C-reactive protein (hsCRP) levels and the monocyte counts. We compared the angiographic findings and laboratory data between the two groups.

RESULTS

There were no significant differences in the levels of serum lipid and hsCRP between the two groups. The white blood cell count and the monocyte count were higher in Group I than with Group II (7496.4 +/- 2622.28 vs. 6703.2 +/- 1768.37/mm3, respectively, p = 0.035; 627.5 +/- 270.70 vs. 426.9 +/- 205.76/mm3, respectively, p < 0.001). Gensini's score was higher in Group I than in Group II (2.2 +/- 2.88 vs. 0.5 +/- 1.03, respectively, p < 0.001). Multivariate analysis showed that the monocyte count and Gensini's score were independent factors affecting coronary spasm (p = 0.047 and p = 0.018, respectively). According to a receiver operating characteristics curve analysis, the area under the curve of the monocyte count was 0.738, that of the neutrophil count was 0.577 and that of the WBC count was 0.572. The cut-off value of the monocyte count was 530/mm3; the sensitivity and specificity of this cut-off value were 64% and 76%, respectively.

CONCLUSIONS

The peripheral monocyte count is an independent marker for predicting vasospastic angina in the patients with resting chest pain and insignificant coronary artery stenosis.

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

BACKGROUND

Elevated lipoprotein(a) (Lp(a)) concentrations are reported to impair endothelium-dependent vasodilatation of the epicardial coronary artery. However, the effects on vasomotor abnormalities in coronary spastic angina (CSA) have not been thoroughly investigated.

METHODS AND RESULTS

In the present study 80 sites of spasm (spastic sites) without significant organic stenosis (% diameter stenosis <50%) were assessed in 80 patients with CSA diagnosed by intracoronary ergonovine (EM) test. Spastic sites were divided into 2 groups: Group 1 included 30 sites provoked by the full dose (=50 microg) of EM, and Group 2 included 50 sites provoked with less than 50 microg (34.7+/-8.2 microg). Control subjects (n=22) did not show coronary spasm with the EM test. Serum Lp(a) concentrations were measured in all patients. Group 2 had a significantly greater basal coronary artery tone in the spastic sites than Group 1 (p<0.001). Lp(a) level in Group 2 was significantly higher compared with both the control group and Group 1 (p<0.05 by analysis of variance). Multivariate analysis confirmed that only serum Lp(a) concentration was associated with low-dose EM spasm provocation.

CONCLUSIONS

Serum Lp(a) concentration could be a marker for high disease activity in CSA.

Predictors of adverse long-term outcome in acute myocardial infarction patients undergoing primary percutaneous transluminal coronary angioplasty: with special reference to the admission concentration of lipoprotein (a)

The predictive values for long-term outcome in 127 consecutive patients with acute myocardial infarction (AMI) after successful primary percutaneous transluminal coronary angioplasty (PTCA) were prospectively investigated in the present study. The primary endpoint was a composite of cardiac death, nonfatal AMI, and recurrent angina. Follow-up angiography was performed in 120 patients to assess restenosis. The primary endpoint occurred in 21 patients during a follow-up period of 35+/-24 months. These patients had a higher lipoprotein(a) [Lp(a)] concentration (p=0.0105) and more prevalence of multivessel disease (p=0.0028) than the other patients. The subjects were divided into 2 groups at the 75th percentile Lp(a) value: group A had an Lp(a) concentration >or=47 mg/dl and group B <47 mg/dl. Kaplan-Meier analysis showed a lower cardiac event-free survival rate in group A (p=0.0007) and in patients with multivessel disease (p=0.001). In Cox proportional hazards regression analysis, an Lp(a) level >or=47 mg/dl (relative risk[RR] 5.5, 95% confidence interval [CI] 2.0-15.0, p=0.0007) and multivessel disease (RR 5.3, 95% CI 2.0-13.7, p=0.0006) were independent predictors of the primary endpoint. An elevated Lp(a) concentration on admission and multivessel disease are significant predictors for long-term adverse outcome in AMI patients treated by primary PTCA.

Significance of asymmetric dimethylarginine (ADMA) concentrations during coronary circulation in patients with vasospastic angina

The basal activity of nitric oxide (NO) is reduced in spastic arteries of patients with vasospastic angina (VSA). Elevated concentrations of ADMA are associated with reduced NO production and impaired endothelium-dependent vasodilatation. The aim of this study was to elucidate the role of ADMA and its relationship to NO end-products (NOx; nitrate + nitrite) during coronary circulation in patients with VSA. The plasma ADMA and NOx concentrations during coronary circulation were evaluated in 16 VSA and 16 control patients. Blood samples were obtained from the coronary sinus (V) and the ostium of the left coronary artery (A), and the (V-A) differences of ADMA and NOx were determined. The coronary sinus plasma ADMA concentration in patients with VSA was higher than that in the control. The coronary sinus - arterial (V-A) difference of NOx was negative in the VSA group and approximately zero in the control group (VSA group =-1.4 micromol/L, control group =-0.1 micromol/L, p=0.0005). Furthermore, in the VSA patients, there was a negative correlation between the (V-A) difference of NOx and the basal coronary artery tone at the site of spasm (r=-0.60, p=0.015). A significant negative correlation between the (V-A) differences of NOx and ADMA was observed in patients with VSA (r=-0.52, p<0.05), but not in those of the control. Higher ADMA concentrations might cause the reduced formation of NO that underlies the pathophysiology of coronary vasospasm.

Decrease of nitric oxide end-products during coronary circulation reflects elevated basal coronary artery tone in patients with vasospastic angina

The aim of this study was to investigate the role of nitric oxide (NO) in the coronary circulation and its relation to basal coronary artery tone in patients with vasospastic angina (VSA). We evaluated the level of nitric oxide end-products (NOx; nitrite + nitrate) in coronary circulation blood using an HPLC-Griess system for nine patients with VSA and nine control patients. All of the patients with VSA experienced focal spasm in the proximal to middle segments of the left anterior descending coronary artery (LAD) in response to intracoronary injection of ergonovine maleate. The luminal diameter of the coronary artery was measured in each patient by quantitative coronary arteriography. Blood samples for NOx measurement were obtained from the coronary sinus (NOxV) and the ostium of the left coronary artery (NOxA). The NOx difference, calculated from the coronary venous-arterial difference in NOx, was close to zero for the control patients whereas it was clearly negative for the patients with VSA. In addition, the NOx difference in the patients with VSA showed a negative correlation with basal coronary artery tone (r = -0.91, p < 0.01) and a positive correlation with the dose of ergonovine required for spasm provocation (r = 0.77, p < 0.05). These results indicate that increased basal coronary artery tone and higher susceptibility to ergonovine in patients with VSA would be a consequence of coronary endothelial dysfunction as is indicated by NOx.

Influence of exercise on QT dispersion in hypertensive patients with left ventricular hypertrophy without coronary artery disease

In hypertensive patients with left ventricular hypertrophy (LVH), the influence of exercise on the regional variations in ventricular repolarization is not well understood. The present study compared dispersions of QT and QT apex (QTD and QTaD), which are indices of regional variations in ventricular repolarization, between hypertensive patients with echocardiographic evidence of LVH and those without LVH. Seventy essential hypertensive patients underwent a modified Bruce protocol exercise test, and QTD and QTaD were measured at rest and at peak exercise level. All subjects had undergone coronary angiography and did not have coronary artery disease. None of them showed ST-segment depression during or after exercise. There were 20 patients with LVH and 50 patients without LVH. The QTD and QTaD at rest were not different between the patients with LVH and those without LVH (56+/-32 vs 57+/-28 ms, 52+/-20 vs 49+/-23 ms). At peak exercise level, QTaD was significantly decreased compared with the baseline in hypertensive patients without LVH (49+/-23 to 42+/-16ms, p<0.05), whereas in patients with LVH QTaD increased (52+/-20 to 67+/-17ms, p<0.05). QTaD at peak exercise level was positively correlated with the left ventricular mass index (r=0.357, p=0.0024). These data were unchanged after correction for heart rate using Bazett's equation. In conclusion, QTaD increased after exercise in hypertensive patients with LVH. Inhomogeneity of repolarization is induced by exercise stress in hypertensives with LVH.

Significance of exercise QT dispersion in patients with coronary artery disease who do not have exercise-induced ischemic ST-segment changes

The poor sensitivity and the poor predictive value of ST-segment depression have limited the usefulness of the exercise electrocardiogram (ECG) in the diagnosis and evaluation of coronary artery disease (CAD). The QT dispersion (QTD), recorded as the difference between maximal and minimal QT intervals on a 12-lead exercise ECG, is sensitive to myocardial ischemia and may improve the accuracy of exercise testing in patients with CAD who do not show an ST-segment depression. Exercise ECGs were analyzed in 50 subjects who had undergone coronary angiography for clinical indications. None of them showed an ST-segment depression during or after exercise: There were 25 patients with significant coronary artery stenosis and 25 without significant stenosis. The QTD measured before, immediately after, and 1 min after exercise was similar in the 2 groups. The QTD at 3 and 5 min after exercise was significantly greater in patients with CAD than in the controls, and the most marked difference in QTD was observed at 3 min after exercise. A QTD at 3 min after exercise of >60 ms had a sensitivity of 80% and specificity of 88% regarding the diagnosis of CAD. When a deltaQTD (post-exercise QTD minus QTD at rest) at 3 min after exercise of >0 ms was added to a QTD of >60 ms as a condition for positivity, the specificity increased to 96%. QTD measured at 3 min after exercise increases the accuracy of exercise testing in patients with CAD who do not show an ST-segment depression.

Angiographic demonstration of inhibition of methyl-ergonovine-induced coronary vasospasm in a patient with sudden death

A case is presented illustrating the association of spontaneous coronary vasospasm with sudden death. Serial angiography and challenge with methyl-ergonovine were performed to document the effectiveness of medial therapy. The use and safety of ergonovine testing in patients with spasm-related sudden death are reviewed.