Differential transmyocardial platelet behavior in response to pacing and ergonovine-induced myocardial ischemia

Vasotonic Angina as a Cause of Myocardial Ischemia in Women

The frequency, presentation, prognosis, and treatment of myocardial ischemia differ in men and women. A large proportion of women who have "normal" coronary arteries on angiography without any significant evidence of flow-limiting disease also have biochemical or imaging evidence of myocardial ischemia. In these women it is believed to be a dysfunction of coronary microcirculation and/or macrocirculation, or vasotonic angina (VA), that leads to abnormal vasoconstriction, and potentially to myocardial infarction, ventricular arrhythmias, and sudden death. Despite having a "normal" or near normal coronary angiography, these women should therefore undergo additional testing with acetylcholine to assess endothelial function. Long-term survival is believed to be relatively good. Predictors of poorer prognosis include documentation of severe endothelial dysfunction and presence of concurrent angiographycally visible coronary atherosclerosis. Because atherosclerosis is common in patients with VA, medical and lifestyle interventions for preventing or treating atherosclerosis should be implemented when appropriate. Angiotensin converting enzyme inhibitors are the mainstays of medical therapy for VA. Other agents have been tried with variable success, including beta-blockers. There are no available data on any specific treatment of VA in women (versus men).

Characteristics of vasospastic angina with exercised-induced ischemia--analysis of parameters of hemostasis and fibrinolysis

To characterize the vasospastic angina patients with exercise-induced ischemia, we measured hemostasis (platelet factor 4; PF4, fibrinopeptide A; FPA) and fibrinolytic parameters (tissue plasminogen activator antigen; t-PA, free plasminogen activator inhibitor-1 antigen; free PAI-1) in 15 normal subjects and 33 vasospastic angina patients without significant coronary artery stenosis (less than 50% stenosis). All of the vasospastic angina patients began to feel chest pain within 3 months before diagnostic coronary angiography. Blood samples were obtained from all of the study patients at 8:30-9:30 am before exercise 201Tl emission computed tomography. Vasospastic angina patients were divided into 2 groups; 15 patients with exercise-induced ischemia (group 1) and 18 patients without exercise-induced ischemia (group 2). On coronary angiography, the severity of coronary artery stenosis at the site of spasm in group 1 (34 +/- 5%) was greater than that in group 2 (18 +/- 3%). Plasma FPA and PF 4 levels in group 1 were also significantly higher than those in normal subjects and group 2. Plasma t-PA and free PAI-1 levels in group 1 were significantly higher than those in normal subjects and group 2. Plasma levels of free PAI-1 group 2 were also significantly higher than those in normal subjects. The present study demonstrated that all of the patients with vasospastic angina had impaired fibrinolysis, and these patients with exercise-induced ischemia showed enhanced platelet activation, an enhanced coagulation system, and advanced atherosclerotic lesions. These results suggest that vasospastic angina with exercise-induced ischemia puts patients at increased risk for thrombus formation.

Prognostic significance of silent myocardial ischemia in variant angina pectoris

The present study investigates the prognostic significance of silent myocardial ischemia in variant angina. Forty-eight-hour Holter monitoring and coronary angiography were performed in 54 patients with transient ST elevation and no history of myocardial infarction admitted to the coronary care unit for worsening of symptoms. Coronary artery spasm was documented in most of these patients. Over the subsequent month, 20 patients (group 1) had a major coronary event (2 died, 6 had nonfatal myocardial infarction and 12 had urgent coronary revascularization), and the remaining 34 patients (group 2) had a good clinical outcome. From 2,578 hours of recording, 547 ischemic episodes were identified of which only 9% were associated with angina. The mean daily number of ST elevation in group 1 was similar to that in group 2 (4.8 +/- 5.1 vs 4.1 +/- 4.6; p = not significant). Conversely, the mean daily duration of such ischemic episodes was consistently greater in group 1 than in 2 (79 +/- 36 vs 37 +/- 25 minutes; p less than 0.005). The occurrence of greater than or equal to 1 long-lasting (greater than or equal to 10 minutes) episode of ST elevation was observed in 18 of 20 patients in group 1 (sensitivity 90%), but only in 4 of 34 in group 2 (specificity 88%). Significant coronary atherosclerosis (greater than 50% stenoses) was found at angiography in 18 of 20 patients in group 1, and in 18 of 34 in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)