Assudation betw the of incr fi#Brino in S study Thirty-seven patients affected by spontaneous angina and 15 comparable control subjects were enrolled in a 12-month prospective study to evaluate the relatIonship between blood clotting activation (assessed by tlbtlnopeptlda A [WA] plasma concentration) and the occurfanca of myocardlal ischamk attacks. FPA measurements and cllnlcai axamhmtions In patients were performed every 2 weeks. In control sublects blood sampling was performed every 4 weeks. Data from 28 patients who completed the study and from the 15 control subjects were analyzed. The clinical activity of anglna was divided into three classes (asymptomatlo, mildly symptomatic, and severely symptomatic) on the basis of the number and time-concentration of the ischemic attacks and ECG changes during the 15 days preceding each cltnlcal axamtnatlon. In all but one patient, a cyclic pattern of activtty of coronary artery disease was observed. During follow-up studies, 824 FPA measurements were performed In pattents and 173 in control subjects. Mean values were 4.88 ? 4.53 and 1.32 f 0.80 rig/ml, respectively (p < 0.001). FPA levels dlffered markedly In relation to the activity of angina. A ralatlonship between FPA levels and activity of disease (r = 0.54, p < 0.01) was found in time course. Bohr8 heparhi admlnlstratton (100 IU/kg) during the active phase of angina sharply but incompletely lowered FPA plasma levels, indicating thrombin formation both intravascularly and extravascularly. Present results indkata that a marked blood clotting activation occurs simultaneously with the outbursts of clinical activity of spontaneous angina. (AM HEART J 1987;113:872.) Gian Gastone Neri Serneri, M.D., Gian Franc0 Gensini, M.D., Marino Carnovali, M.D., Domenico Prisco, M.D., Pier Giorgio Rogasi, M.D., Gian Carlo Casolo, M.D., Antonio Fazi, M.D., and Rosanna Abbate, M.D. Florence, Italy In patients with acute coronary insufficiency, a hypercoagulable state has been reported,1-3 and hep- arin4 and fibrinolytic therapy5 have been found to be effective in preventing myocardial infarction in patients with unstable angina. Moreover, in a pro- spective study, blood clotting activation was found to be strictly associated with increased risk of cardiovascular death.6s7 Measurement of fibrinopep- tide A (FPA) levels in plasma is considered a reliable index o! actual blwd clot& actkat:on,g-1” because FPA is a specific product of fibrinogen cleavage by thrombin and its half-life is about 3.5 minutes.l’ From the Clinica Medica I, University of Florence. Supported in part by grant No. 84.02443.56 from the Consiglio Nazionale delle Ricerche, Rome, Italy. Received for publication Feb. 7, 1986, accepted July 10, 1986. Reprint requests: G. G. Neri Serneri, M.D., Clinica Medica I, University of Florence, Viale Morgagni 83, 50134 Florence, Italy. 872 Patients with spontaneous angina in the active phase, that is, those who were having either symp- tomatic or asymptomatic ischemic attacks, had more elevated plasma levels of FPA than patients with stable coronary artery disease (CAD).‘+ 12, l3 Spontaneous angina frequently waxes and wanes spontaneously and during the active phase of the disease the risk of myocardial infarction or sudden death is increased.14e17The aim of the present inves- tlgatkm wae to asseee tlxe relat!on&p !n time between anginal activity and hypercoagulability in a prospective controlled study in a select group of patients who suffered from spontanaous angina. METHODS Patients investigated. Thirty-seven outpatients (28 men and nine women, ages39 to 68 years), affected by spontaneous angina but responding to medical therapy, were enrolled in the study after discharge from our institution. Spontaneous angina wasdefined as myocardi-