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PubMed1994

[Problem of false positives in dipyridamole-echocardiography test. Description of a case and review of the literature].

Dipyridamole-echocardiography may be considered, at this time, an useful test not only in post-infarction risk stratification, but also in diagnosis and functional evaluation of coronary artery disease, having a satisfying sensibility (67%) and a very high specificity (96%). We report a particular case of "false positive" with a review of the literature. The patient, male, aged 45, without important risk factors for coronary artery disease, experimented recurrent events of spontaneous chest pain, typical per angina pectoris. Physical examination, chest roentgenogram and blood samples were normal. Slight signs of subendocardial ischemia, lateral, were present at ECG. Forced hyperpnea resulted in onset of chest pain, with increase of ECgraphic signs of ischemia; resolution of both was obtained with sublingual nitrate administration. A stress test with myocardial flow scintigraphic assessment using sestaMIBI, was performed: ECG showed significant ST downsloping at low workload (1-11 steps of Bruce protocol) and radionuclide tomography showed reversible hypoperfusion in anterior and septal regions. High dose dipyridamole-echocardiography test (a first bolus of 0.56 mg/kg in 4', followed after 4' by a second bolus of 0.28 mg/kg) gave these results: basal echocardiogram was normal; after first bolus of dipyridamole apical hypokinesia appeared; after second bolus complete akinesia was observed. ECG showed subendocardial injury wave and the patient experimented typical anginal pain. Clinical, electrocardiographic and echocardiographic changes were immediately reversed after intravenous bolus of aminophylline, 240 mgs. Coronary arteriography was performed: coronary arteries were angiographically normal, without even any marginal irregularity: left ventricle was normal in volume, wall kinesis and ejection fraction. Dipyridamole is a powerful ischemic stressor.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗
PubMed1994

Left ventricular function and myocardial perfusion during dipyridamole infusion assessed by a single injection of 99Tcm-sestamibi in patients unable to exercise.

First-pass radionuclide ventriculography followed by myocardial single photon emission computed tomography (SPECT) with 99Tcm-methoxyisobutyl isonitrile (sestamibi) was performed at rest and during dipyridamole infusion in 42 patients with suspected coronary artery disease. The presence of coronary stenoses of > or = 50% diameter was compared with the presence of rest or dipyridamole-induced abnormalities in perfusion or left ventricular function. Radionuclide-determined left ventricular ejection fraction (LVEF) was highly reproducible and correlated well with LVEF derived from contrast left ventriculography. Left ventricular ejection fraction decreased significantly after dipyridamole infusion in patients with multivessel disease (58 +/- 10% versus 52 +/- 11%, P < 0.01). The sensitivity and specificity for the detection of patients with coronary artery disease were 85 and 75% by myocardial SPECT, and 47 (P < 0.01 versus SPECT) and 75% by LVEF, respectively. However, in patients with multivessel disease, the sensitivity of LVEF was not different from that of SPECT (72% versus 89%, P = ns). The sensitivity of LVEF was higher in patients with multivessel disease than in those with single-vessel disease (19% versus 72%, P < 0.01). Radionuclide ventriculography followed by myocardial SPECT with 99Tcm-sestamibi allows simultaneous evaluation of ventricular contractile function associated with perfusion abnormality during dipyridamole infusion and may enhance the functional description of myocardial ischaemia.

Adult↗
PubMed1994

Detection of viable myocardium by dobutamine and dipyridamole stress echocardiography.

The basic aspect of cell behaviour that is the clue for viability recognition by stress echo is regional function. By definition, the function is depressed both in viable and in necrotic segments. However, only viable segments retain a contractile reserve; which can be evoked by an inotropic challenge, either cathecolaminic or flow-mediated, as consistently shown by several experimental studies. This is the basis of viability recognition by pharmacological stress echocardiography. Both dobutamine and dipyridamole exploit the same pathophysiological principle: viable tissue has a residual contractile reserve, which can be elicited by an appropriate inotropic stimulus. With dobutamine, the stimulus is a beta-receptor mediated effect on myocardial cell, which is later matched by an increase in flow. With dipyridamole, the primary stimulus is an adenosine A2-receptor mediated effect on the coronary arteriole smooth muscle cell, leading to an increase in flow. At that point, the increase in function is to be expected on the basis of the known relationship between myocardial contractility and coronary perfusion. From the technical point of view, the "viability window" is dose-related with dobutamine, and time-related with dipyridamole--where the same dose is associated to an early inotropic phase followed by a later ischemic response. In spite of the different pathophysiological background and technical modalities, dobutamine and and dipyridamole have shown a similar sensitivity and specificity for prediction of viability, with an overall accuracy only marginally lower than resting thallium. The practical, clinical impact of these observations is still blunted by relatively small numbers of observations in highly selected populations including a limited number of patients and studies in very few centers.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Circulation↗
PubMed1994

Evaluation of coronary artery disease using technetium-99m-sestamibi first-pass and perfusion imaging with dipyridamole infusion.

UNLABELLED: The aims of this study were: (1) to test whether first-pass radionuclide angiocardiography (FPRNA) adds useful information to perfusion scintigraphy; and (2) to assess the relative accuracy of perfusion and functional imaging in combination with dipyridamole for the evaluation of CAD. METHODS: Thirty patients with angiographically proven CAD (17 with prior infarction) were studied on separate days at rest and with dipyridamole infusion (0.7 mg/kg over 4 min). Tomographic images were evaluated using an uptake score. Dipyridamole FPRNA was considered positive in case of stress-induced wall motion abnormality or ejection fraction decrease. RESULTS: The CAD detection rate of perfusion imaging was 100%, while that of FPRNA was 70% using wall motion criteria, 63% using ejection fraction response and 77% considering any abnormality. For CAD localization, perfusion imaging showed 76% sensitivity, 96% specificity and 82% accuracy. FPRNA results were 50%, 100% and 60%, respectively. Perfusion imaging was significantly superior to FPRNA also excluding from the analysis the infarct-related vessels. FPRNA did not identify multivessel CAD, which was correctly detected by perfusion imaging in most cases. Both techniques were more sensitive in case of > or = 90% stenosis, but the difference was more remarkable for FPRNA (sensitivity 65% versus 14%, p < 0.0005). CONCLUSIONS: Dipyridamole FPRNA did not add noteworthy clinical information to perfusion imaging regarding CAD detection and evaluation of disease extent. The main contribution of a positive FPRNA was its relation with coronary obstruction severity. These results confirm the superiority of perfusion over functional imaging in combination with coronary vasodilators.

Coronary Angiography↗
PubMed1993

[Noninvasive identification of left main and triple vessel coronary artery disease using dipyridamole thallium scintigraphy].

The diagnostic value of dipyridamole thallium scintigraphy for the noninvasive identification of left main (LM) and triple vessel (TV) coronary artery disease (CAD) was evaluated in 615 consecutive patients with known or suspected CAD. One hundred thirty-nine patients had LM or TVCAD; the remaining 476 patients had limited CAD (double vessel CAD in 112, single vessel CAD in 235, insignificant lesions in 129). Patients with LM or TVCAD, compared to those with limited CAD, had a higher incidence of diffuse slow washout (58 vs 20%, p < 0.0001), extensive fixed defects (21 vs 6%, p < 0.0001) and extensive reversible defects (32 vs 8%, p < 0.0001). During dipyridamole loading, the incidence of chest pain was higher (65 vs 41%, p < 0.0001), and the magnitude of ST depression was greater (0.16 +/- 0.14 vs 0.04 +/- 0.07 mV, p < 0.001) in patients with LM or TVCAD than in those with limited CAD. Stepwise discriminant analysis using scintigraphic imaging achieved a sensitivity of 69%, a specificity of 79%, and an accuracy of 77% for diagnosing patients with LM or TVCAD. After including clinical markers of ischemia during dipyridamole loading, multivariate analysis revealed an improved diagnosis with a sensitivity of 71%, a specificity of 85%, and an accuracy of 82%. These results clearly show the usefulness of scintigraphic imaging as well as the significance of careful assessment of clinical markers of ischemia during dipyridamole loading for the noninvasive identification of LM and TVCAD.

Adult↗
PubMed1994

[Thallium-dipyridamole in acute myocardial infarction treated by thrombolysis: diagnostic and prognostic value].

BACKGROUND: The management of patients who received thrombolytic therapy for acute myocardial infarction is still controversial. It is not clear if the strategies usually followed after myocardial infarction for risk stratification have the same value when applied to patients treated with thrombolysis. METHODS: To assess the diagnostic and prognostic value of dipyridamole thallium-201 scintigraphy in the "thrombolytic era", we studied 110 consecutive patients younger than 75 recovering from first uncomplicated acute myocardial infarction treated with thrombolytic agents. Patients with early angina, recurrent acute myocardial infarction, heart failure, life-threatening arrhythmias, non Q wave myocardial infarction were excluded. Ninety patients were treated with streptokinase, 14 with rtPA, 6 with APSAC: All patients underwent dipyridamole thallium scintigraphy with standard dose and coronary angiography before discharge (10-20 days). Ninety-nine patients underwent exercise test. All patients were followed-up for 22 +/- 9 months (range 8-42). Perfusion abnormalities were classified as reversible (totally or partially) defects or persistent defects and within or outside the infarct zone. RESULTS: Fifty-eight patients developed anterior and 52 inferior acute myocardial infarction. Coronary angiography showed single vessel coronary artery disease in 66 patients, multivessel disease in 34, and normal coronary arteries or sub-critical stenosis in 10. No major complications (death, myocardial infarction, threatening arrhythmias, prolonged severe hypotension) occurred after dipyridamole infusion. Sixty-two patients had reversible perfusion defects at thallium scanning (34 within the infarct zone, 21 within and outside the infarct zone, 7 outside); 38 patients had persistent defects; 10 patients had a normal scintigraphic pattern. The diagnostic value of homozonal perfusion reversible defects for identifying a patent infarct-related vessel was poor (sensitivity 69.7%, specificity 64.7%). The diagnostic values of the same scintigraphic pattern improved in detecting patent infarct-related artery with residual critical stenosis (sensibility 75.4%, specificity 77.3%); in all the false positive cases (reversible defects within the infarct zone and occluded infarct-related artery) a good collateral flow was present. The sensitivity of reversible defects outside the infarct zone in detecting multivessel disease was 64.7% vs 56.3% of exercise test; the specificity was 92% vs 64%; the positive predictive value 78.6% vs 44%; the negative predictive value 85.3% vs 74.5%; the diagnostic accuracy 83.6% vs 61.4%. During the follow-up 2 deaths, 7 recurrent myocardial infarction, 1 sustained ventricular tachycardia, 1 heart failure, 13 recurrence of unstable angina and 9 revascularization procedures occurred among patients with reversible defects (either within or outside the infarct zone) at thallium scanning. One recurrent myocardial infarction, 4 recurrence of unstable angina and 2 revascularization procedures were the events among patients with persistent defects or normal scintigraphic pattern (p < 0.001). Ischemic events occurred with similar frequency in patients with reversible perfusion defects within the outside the infarct zone (55% vs 50%, NS). CONCLUSIONS: Dipyridamole thallium-201 scintigraphy performed after uncomplicated myocardial infarction treated with thrombolytic agents is a valuable diagnostic tool in identifying viable jeopardized myocardium within the infarct zone perfused by a patent but critically narrowed vessel; it shows better diagnostic accuracy in detecting multivessel disease than does the exercise test and is able to identify a subset of patients at risk for future ischemic events after thrombolytic therapy.

Adult↗
PubMed1993

Dipyridamole thallium imaging: use in preoperative cardiac risk assessment in vascular surgical patients.

BACKGROUND: The objective of this study was to determine whether routine performance of dipyridamole thallium imaging adds to the power of a careful clinical evaluation in the risk stratification of patients undergoing major vascular surgery. METHODS: In this retrospective study, 115 cases evaluated by dipyridamole thallium imaging before major vascular surgery were reviewed. Patients were assigned to a high-risk cohort if they had a history of congestive heart failure or evidence of previous myocardial infarction. RESULTS: Six (8%) patients from the high-risk cohort developed major cardiovascular complications. Reversible perfusion defects, present in 67% of the high-risk patients, did not predict complications. None of the patients in the low-risk cohort developed complications despite the presence of reversible perfusion defects in 33%. Patients in the high-risk cohort who underwent cardiac catheterization and selective coronary bypass grafting were uniformly free of perioperative complications. The extent and severity of fixed or reversible thallium perfusion did not predict the occurrence of cardiovascular complications. However, three patients were denied surgery following an unacceptable cardiovascular risk assessment based on clinical findings and multiple reversible thallium perfusion defects. CONCLUSION: In low-risk patients, screening with dipyridamole thallium can identify patients with redistribution defects whose risk of perioperative ischemic events can be reduced by intensifying perioperative anti-ischemic management. If the patient is in the high-clinical-risk subgroup, screening with dipyridamole thallium does not identify a cohort with negligible perioperative risk; thus, further evaluation of these patients by cardiac catheterization should be considered.

Aged↗
PubMed1993

[The role of the echo-dipyridamole test in the differential diagnosis of chest pain].

We have verified the utility of echo-dipyridamole test in the diagnosis of chest pain of unsure origin, especially in patients who cannot be quickly submitted to exercise stress test because of permanent abnormalities at basal ECG or because of clinical reasons. 17 patients with chest pain, abnormalities at basal ECG not evolutive and insignificant for myocardial ischemia, absence of enzymatic curve, were admitted to our hospital from September 1988 to January 1990. All these patients were submitted before the ninth and fifteenth day of hospitalization to the echo-dipyridamole test. Drugs were discontinued 3 days before the test. Dipyridamole was administered intravenously in 4 minutes at dosage of 0.56 mg/kg during ECG and echocardiographic monitoring. If no ECG or echocardiographic changes were observed, a second intravenous bolus of dipyridamole at a dosage of 0.28 mg/kg in 2 minutes was made. After the end of infusion continuous ECG and echocardiographic monitoring was performed for 20 minutes at least. Blood pressure was controlled every 3 minutes. Only the major changes in segmental wall motion were considered for analysis to minimize possible errors. Moreover a second physician not present during the test, revised in following the wall motion changes of all the tests. The test was positive in 5 patients (29%) (positive group) and negative in 12 (71%) (negative group). The changes in the heart rate and blood pressure observed during the test were not significantly different in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Evaluation of left ventricular early diastolic function by first pass radionuclide angiocardiography after dipyridamole infusion in patients with coronary artery disease--comparison with exercise test].

To evaluate the left ventricular early diastolic function after dipyridamole infusion or during exercise, the first pass radionuclide angiocardiography (FPRA) by a multicrystal gamma camera (SIM-400) was performed in 32 patients with coronary artery disease (CAD) and 14 normal subjects. Dipyridamole was administered intravenously (0.56 mg/kg in 4 min). The first third filling fraction (FF 1/3) and the first third mean filling rate (MFR 1/3) were calculated from the time-activity curve. FF 1/3 decreased and MFR 1/3 increased in both normal subjects and patients with CAD during exercise. After dipyridamole infusion, FF 1/3 and MFR 1/3 unchanged in normal subjects, in contrast, FF 1/3 and MFR 1/3 decreased in patients with CAD. Thus, dipyridamole infusion FPRA is more sensitive method to detect early diastolic dysfunction in patients with CAD than FPRA during exercise.

Aged↗
PubMed1993

Effect of dipyridamole on kidney function in cirrhosis.

Adenosine is a potent endogenous renal vasoconstrictor. To investigate the sensitivity of the renal circulation to adenosine in cirrhosis, we evaluated kidney function and vasoactive hormones in 20 patients with cirrhosis before and after administration of dipyridamole (0.4 mg/kg, intravenously), a drug that increases extracellular levels of adenosine. In patients with ascites and increased plasma renin activity (6.9 +/- 4.0 ng/ml.hr [mean +/- S.D.]) (n = 7), dipyridamole induced marked reductions in renal plasma flow (from 623 +/- 294 to 374 +/- 188 ml/min, p = 0.03), glomerular filtration rate (from 89 +/- 22 to 48 +/- 16 ml/min, p = 0.009), urine volume (from 7.1 +/- 2.1 to 1.5 +/- 1.1 ml/min, p = 0.0001), free water clearance (from 4.0 +/- 1.7 to 0.4 +/- 0.6 ml/min, p = 0.001) and sodium excretion (from 28 +/- 36 to 7 +/- 15 mu Eq/min, p = 0.05) in the absence of changes in arterial pressure, plasma renin activity and levels of aldosterone, norepinephrine and antidiuretic hormone. In patients without ascites (n = 5) and in patients with ascites and normal plasma renin activity (0.9 +/- 0.5 ng/ml.hr) (n = 8), renal plasma flow and glomerular filtration rate did not change significantly after dipyridamole administration, whereas excretion of sodium and free water was reduced. These results indicate that in cirrhotic patients with ascites and overactivity of the renin-angiotensin system, dipyridamole induces renal vasoconstriction in the absence of changes in systemic hemodynamics, suggesting that these patients are particularly sensitive to the renal vasoconstrictor effect of endogenous adenosine.

Ascites↗
PubMed1993

[Bronchospasm, apnea and heart arrest following dipyridamole perfusion scintigraphy].

The occurrence of fatal respiratory insufficiency following dipyridamole-thallium imaging is described. The patient, a 67-year-old man, had a history of chronic obstructive lung disease. Since patients with a history of chronic obstructive lung disease have an increased risk of developing bronchospasm after dipyridamole infusion, it is advised to be cautious in performing dipyridamole-thallium imaging in these patients. Dobutamine may be an acceptable alternative to dipyridamole in these patients.

Aged↗
PubMed1977

The synergistic effect of aspirin and dipyridamole upon platelet thrombi in living blood vessels.

In rabbits previously injected i.v. with alloxan, serial observations of platelet thrombus formation in response to topical adenosine diphosphate (ADP) at sites of electrical injuries in pial arteries have been made. Using this model we have studied the effects of oral daily doses of dipyridamole (Persantin) and acetyl salicylic acid (ASA) upon platelet thrombus formation. Oral daily doses of 42 mg of ASA and 6 mg dipyridamole given separately in alloxan-treated rabbits are without effect. When given together orally, 42 mg and 6 mg respectively reduced the level of sensitivity to ADP for producing platelet thrombi to that established for the rabbits before the injection of alloxan. But withdrawal of these combined doses of dipyridamole and ASA caused the sensitivity of ADP for platelet thrombus formation to be raised to the much increased level present in rabbits soon after they are given i.v. alloxan. This apparent synergistic behaviour displayed by dipyridamole and ASA in these rabbits results in antithrombotic effects which are clearly absent when these two agents are given separately. It is of interest that the dose levels used here are equivalent, an a body weight ratio, to those being used in man in the current Persantin-Aspirin Reinfarction Study.

Adenosine Diphosphate↗
PubMed1996

Hemodynamic indices of myocardial dysfunction correlate with dipyridamole thallium-201 SPECT.

UNLABELLED: Important differences in hemodynamics and tracer kinetics occur with dipyridamole compared to exercise scintigraphy. To better understand the clinical significance of dipyridamole SPECT 201Tl scintigraphy, we examined the relationships between scintigraphy and clinical, and angiographic and hemodynamic variables in patients with CAD. METHODS: Forty-nine subjects were divided into three study groups. Patients in Groups A (n = 11) and B (n = 20) had a low (<5%) likelihood of CAD. Group A underwent maximal exercise thallium stress testing. Group B underwent thallium dipyridamole scintigraphy. Group C (n = 18) consisted of patients with coronary artery disease who had dipyridamole thallium scintigraphy and cardiac catheterization within 2 wk. Thallium lung-to-myocardial ratio (L/M), left ventricular dilation and perfusion defect site were compared to hemodynamic, clinical and angiographic variables. RESULTS: The Group A L/M ratio of 0.23 +/- 0.05 (mean +/- 1 s.d.) was significantly lower (p < 0.001) compared to the Group B L/M ratio of 0.31 +/- 0.05. In Group C, the UM ratio showed correlation with indices of left ventricular dysfunction including lower resting ejection fraction (p = 0.02, r = 0.83), higher pulmonary capillary wedge pressure (p = 0.01, r = 0.58) and lower cardiac index (p = 0.03, r = 0.54). Left ventricular dilation was associated with hemodynamic changes of ventricular failure including lower resting ejection fraction (p = 0.008, r = 0.88) and higher pulmonary capillary wedge pressure (p = 0.02, r =0.54). Immediate and delayed perfusion defect size showed good correlation with lower resting left ventricular ejection fraction (p = 0.02, r = 0.83, and p = 0.004, r = 0.91, respectively). CONCLUSION: Lung uptake, left ventricular dilation and perfusion defect size show good correlation to hemodynamic indices of resting left ventricular dysfunction. A combination of these factors may be a better predictor of future cardiac events and prognosis.

Cardiac Catheterization↗
PubMed1996

[Value of dipyridamole-atropine stress echocardiography for detection of patients with restenosis after PTCA].

UNLABELLED: Stress-Echocardiography has been proven to be a valuable method in the diagnosis of patients with suspected coronary artery disease. It has been demonstrated that the addition of atropine can increase the sensitivity of pharmacological stress-echocardiography-tests. The aim of our study was to evaluate the diagnostic potential of dipyridamole-atropine-echocardiography for the detection of restenosis after coronary angioplasty. We investigated 50 patients 3-6 months after primary successful coronary angioplasty. Restenosis was defined as recurrence of stenosis of > or = 70% at the site of dilatation determined by quantitative coronary angiography. All patients were investigated on antianginal medication and underwent control-coronary angiography within 1-3 days after the echocardiographic study. In 17/23 patients with restenosis, the dipyridamole-atropine-stress-test was pathologic (sensitivity 74%), in 25/27 patients without significant restenosis the echocardiography stress-test was normal (specificity 93%). In 6 patients with restenosis and an unsuspicious stress-test, the percent diameter of restenosis did not exceed > or = 90% lumen narrowing, restenosis of the LAD was correctly identified in all patients (n = 11). The diagnostic accuracy of the dipyridamole-atropine-stress-test for the detection of patients with restenosis after PTCA in our study was 84%, the positive predictive value of a pathologic echocardiography stress-test for the detection of significant restenosis was 89%, the negative predictive value was 81%. CONCLUSIONS: Dipyridamole-atropine-echocardiography has diagnostic potential for non-invasive assessment of patients after coronary angioplasty. In patients with a normal echocardiographic stress-test, the probability of significant restenosis is considerably low, even if restenosis cannot be definitely excluded.

Aged↗
PubMed1997

Detection of coronary collaterals using dipyridamole PET myocardial perfusion imaging with rubidium-82.

UNLABELLED: This study evaluated the ability of dipyridamole PET myocardial perfusion imaging to detect coronary collaterals. A previous study showed an association between dipyridamole-induced coronary steal on PET imaging and the presence of coronary collaterals on angiography. METHODS: Dipyridamole PET myocardial perfusion imaging using 82Rb was performed in 45 patients who had recent coronary angiography. The stress/rest count ratio (rubidium activity with stress divided by activity at rest)-was used to express the change in regional tracer uptake with dipyridamole and was calculated manually and automatically. The accuracy of the stress/rest count ratio for detecting coronary collaterals was determined. RESULTS: A manual stress/rest count ratio < or = 0.80 identified coronary collaterals with 81% sensitivity, 92% specificity and 90% accuracy (p < 0.0001). An automated ratio < or = 0.80 had 90% sensitivity, 88% specificity and 90% accuracy (p < 0.0001). Vascular beds incorrectly identified by PET as having collaterals had an increased frequency of severe stenoses and abnormal wall motion. CONCLUSION: PET perfusion imaging using the stress/rest count ratio can serve as a unique imaging method to identify coronary collaterals noninvasively.

Collateral Circulation↗
PubMed2000

Platelet function in pregnant women receiving aspirin and dipyridamole.

PURPOSE: This study was undertaken to evaluate the hemostasis and coagulation profile of pregnant women receiving antiplatelet therapy with low-dose aspirin and dipyridamole for prevention of preeclampsia, intrauterine growth retardation, or pregnancy losses. METHODS: Twenty-three pregnant women who received antiplatelet therapy with combined aspirin (40 mg.day(-1)) and dipyridamole (150 mg.day(-1)) were enrolled in the study. Platelet aggregation and coagulation tests were performed before the start of aspirin and dipyridamole, during medication, and at 3 days and 6 days after cessation of medication. RESULTS: Collagen-induced platelet aggregation was decreased during medication (25 +/- 26%, P < 0.001) and at 3 days after cessation of medication (46 +/- 35%, P < 0.001) compared with that before the start of medication (89 +/- 7%). ADP-induced platelet aggregation was decreased during medication compared with that before medication (66 +/- 18% vs 92 +/- 7%, P < 0.001). The platelet count, prothrombin time, activated partial thromboplastin time, bleeding time, and levels of fibrinogen and antithrombin III did not change over time. The blood loss of these patients during vaginal delivery and cesarean section did not differ from that of normal women during vaginal delivery and repeat cesarean section, respectively. CONCLUSION: At the doses used in this study, aspirin and dipyridamole inhibited platelet aggregation for up to 3 days after cessation of medication. This abnormality of aggregation was not detected by the bleeding time and was not associated with clinically abnormal bleeding.

Journal Article↗
PubMedDate not supplied

Predicting cardiac events with Tl201 dipyridamole myocardial scintigraphy in renal transplant recipients.

BACKGROUND: Renal transplant recipients should be screened for coronary artery disease. The purpose of this study was to evaluate the usefulness of thallium-201 dipyridamole myocardial perfusion single-photon emission computed tomography (SPECT) to predict major cardiac events in these patients. METHODS AND RESULTS: Eighty-two consecutive patients (61 males) in hemodialysis (HD) treatment, awaiting renal transplantation, underwent dipyridamole Tl-201 SPECT for pretransplant risk stratification. SPECT semiquantitative analysis showed a normal perfusion pattern in 52 patients (group A) and fixed defects in 9 (group B). Reversible perfusion defects were found in 21 (group C). Cardiac death, myocadial infarction, and unstable angina were sought as cardiac events. During a follow-up lasting 28.3 +/- 21.6 months, three patients of group A died for a non-cardiac cause. In group C, six patients (28.6%) had a cadiac event: one had a non-q wave myocardial infarction after renal transplantation; five were admitted with unstable angina. No cardiac events were observed in groups A and B (p = 0.0001). SPECT semiquantitative analysis showed that a summed difference score > or = 3 significantly increased the risk of cardiac events (odds ratio 4.5, C.I. 2.5-8.1). CONCLUSION: Cardiac events were only observed in HD patients with Tl-201 SPECT dipyridamole reversible defects (group C). A normal pattern or a fixed defect in Tl-201 dipyridamole SPECT in HD patients identified a good long-term prognosis.

Aged↗
PubMed2006

Myocardial perfusion SPECT with dipyridamole stress test in cardiac syndrome X.

UNLABELLED: Cardiac syndrome X defines patients with typical anginal chest pain, a positive exercise ECG stress test and angiographically normal coronary arteries. AIM of this study was to evaluate the role of myocardial perfusion SPECT with dipyridamole stress in the diagnosis of cardiac syndrome X. PATIENTS, METHODS: 68 patients with syndrome X aged 32 to 60 years were subjected to myocardial imaging using (99m)Tc-MIBI according to the two-days protocol: at rest and after dipyridamole infusion. Semiquantitative evaluation of the images was based on the assessment of (99m)Tc-MIBI uptake in 17 myocardial segments using a 5-points scale (0 point -- normal uptake, 4 points -- no uptake). Scores obtained in each segment were summed up, constituting the summed rest score (SRS) and summed stress score (SSS). RESULTS: Mean SRS was 7.9 +/- 4.8 and mean SSS was 7.2 +/- 4.4 (non-significant difference). Individual comparison of SRS and SSS values revealed three patterns of scintigraphic images: 1) in 25 patients (36.8%), a paradoxical improvement of perfusion at stress images was found, 2) in 23 patients (33.8%), the myocardial perfusion deteriorated after dipyridamole, 3) in 20 patients (29.4%), no significant change of the myocardial perfusion between rest and stress images occurred. CONCLUSIONS: In cardiac syndrome X, myocardial SPECT with dipyridamole stress shows different patterns of myocardial perfusion that reflects heterogeneity of this pathology.

Electrocardiography↗