[Prevention of recurrences of cerebral ischemic vascular accidents by platelet antiaggregants. Results of a 3-year controlled therapeutic trial]. Dipyridamole: a controlled trial of its effect in acute myocardial infarction. Anti-platelet therapy in graft thrombosis: results of a prospective, randomized, double-blind study. Persantine-Aspirin Reinfarction Study. Part II. Secondary coronary prevention with persantine and aspirin. Treatment of claudication with dipyridamole and aspirin. Dipyridamole in the treatment of angina pectoris. A double-blind evaluation. Veterans Administration Cooperative Study on antiplatelet agents in diabetic patients after amputation for gangrene: II. Effects of aspirin and dipyridamole on atherosclerotic vascular disease rates. Persantine and aspirin in coronary heart disease. The Persantine-Aspirin Reinfarction Study Research Group. Aspirin plus dipyridamole versus aspirin alone after cerebral ischaemia of arterial origin (ESPRIT): randomised controlled trial. Drug-induced inhibition of platelet function delays progression of peripheral occlusive arterial disease. A prospective double-blind arteriographically controlled trial. Frequent reocclusion of patent infarct-related arteries between 4 weeks and 1 year: effects of antiplatelet therapy. [Ischemic cerebrovascular disease: treatment with various anti-platelet aggregation drugs. Clinical follow-up of 80 patients (22-34 months)]. Dipyridamole in chronic stable angina pectoris; a randomized, double blind, placebo-controlled, parallel group study. Treatment of angina pectoris with dipyridamole: a long-term double blind study. Effect of aspirin alone and aspirin plus dipyridamole in early diabetic retinopathy. A multicenter randomized controlled clinical trial. The DAMAD Study Group. Persantine Aspirin Trial in cerebral ischemia. Part II: Endpoint results. The American-Canadian Co-Operative Study group. Treatment of angina pectoris with dipyridamole: a double-blind study. "AICLA" controlled trial of aspirin and dipyridamole in the secondary prevention of athero-thrombotic cerebral ischemia. [Treatment of unstable angina with dipyridamole combined with low doses of aspirin. A multicenter pilot double-blind controlled study].
nan A controlled trial of oral dipyridamole in 103 patients with acute myocardial infarction showed no difference in the number of complications or deaths in either the control or the treated groups. It is concluded that dipyridamole has no benefit in acute myocardial infarction. Hemodialysis (HD) vascular access thrombosis remains a major cause of morbidity, accounting for 17.4% of all HD patient hospital admissions in 1986. We initiated this prospective, randomized, double-blind, placebo-controlled, parallel group study to examine if dipyridamole and/or aspirin decreased the rate of thrombosis of expanded polytetrafluoroethylene (ePTFE) grafts in HD patients. Two patient groups were studied: Type I--with a new ePTFE graft; and Type II--with thrombectomy and/or revision of a previously placed ePTFE graft. One hundred and seven patients were followed for 18 months or until the first thrombotic episode. Actuarial analysis of Type I patients showed cumulative thrombosis rates (mean +/- SEM) of 21 +/- 9% on dipyridamole alone, compared with 25 +/- 11% on dipyridamole and aspirin combination, 42 +/- 13% on placebo, and 80 +/- 12% on aspirin alone. The relative risk of thrombosis with dipyridamole was 0.35 (P = 0.02) and that for aspirin was 1.99 (P = 0.18). In Type II patients, the rate of thrombosis was high in all study drug and placebo groups (overall 78% thrombosis) and actuarial analysis was not carried out because of the small number of patients enrolled. We conclude that dipyridamole is beneficial in patients with new ePTFE grafts and that aspirin does not improve the risk of thrombosis in ePTFE grafts. Neither dipyridamole nor aspirin has any beneficial effect in patients with prior thrombosis of ePTFE grafts. In the Persantine-Aspirin Reinfarction Study, Part II (PARIS II), 3,128 persons who had recovered from myocardial infarction, suffered from 4 weeks to 4 months previously, were randomized into two groups: dipyridamole (Persantine) plus aspirin (n = 1,563) and placebo (n = 1,565). The average length of follow-up was 23.4 months. Prespecified primary end points were coronary incidence (definite nonfatal myocardial infarction plus death due to recent or acute cardiac event), coronary mortality (death due to recent or acute cardiac event) and total mortality, each at 1 year of patient follow-up and at the end of the study. Coronary incidence in the Persantine plus aspirin group was significantly lower than in the placebo group, both at 1 year (30% reduction) and at the end of the study (24% reduction). The statistically significant differences in coronary incidence, at 1 year and at the end of the study, in favor of the combination treatment remained after adjustment for multiple baseline variables and adjustment for multiple testing (three end points for two time periods). Although there were reductions for other end points, these differences were not statistically significant. Coronary mortality was 20% lower in the Persantine plus aspirin group compared with the placebo group at 1 year, and 6% lower overall. Total mortality in the treated group compared with the placebo group was 11% lower at 1 year and 3% lower overall. The reduced rates of coronary incidence largely reflected lower rates of definite nonfatal myocardial infarction in the Persantine plus aspirin group. Several subgroups were defined a priori and at the end of the study. The beneficial effect of Persantine plus aspirin compared with placebo for coronary incidence tended to be greater for the following groups of patients: those who had a non-Q wave infarct; those who were not taking digitalis; those who were receiving beta-receptor blocking drugs at baseline; those who were in New York Heart Association functional class I; those who had had only one myocardial infarction; or those who were enrolled in the study early, that is within 85 days of the qualifying myocardial infarction. nan nan We report the results of a randomized multicenter clinical trial on the effects of aspirin plus dipyridamole versus placebo on major vascular end points in 231 non-insulin-dependent diabetic men with either a recent amputation for gangrene or active gangrene. Primary end points were death from atherosclerotic vascular disease plus amputation of the opposite extremity for gangrene. There were 24 atherosclerotic deaths in the drug treatment group (21.8%) and 23 in the placebo group (19.0%). There were 22 patients in the drug treatment group (20.0%) and 29 patients in the placebo group (24.0%) with opposite-side amputations. Survival curve analyses revealed little difference between these groups for major vascular end points, total mortality, all amputations, or myocardial infarctions. The most noteworthy group difference was observed for cerebrovascular end points (strokes and transient ischemic attacks), with an incidence of 8.2% (9 patients) in the drug treatment group and 19.0% (23 patients) in the placebo group. We conclude from this study that antiplatelet agents have no effect on the primary vascular end points, vascular deaths and/or amputation of the opposite extremity, in this population. Similarly, no effects were seen on secondary vascular end points, except for a suggestion of protection versus strokes and transient ischemic attacks. However, this finding must be interpreted with caution, since it is a secondary end point and was found only after multiple analyses of the data. In the Persantine-Aspirin Reinfarction Study (PARIS) trial, 2026 persons who had recovered from myocardial infarction (MI) were randomized into three groups: Persantine plus aspirin (PR/A) (n = 810); aspirin alone (ASA) (n = 810); placebo (PLBO) (n = 406). The average length of follow-up study was 41 months. Results for the three specified primary end points were: total mortality 16% lower in PR/A and 18% lower in ASA compared with PLBO; coronary mortality 24% and 21% lower; incidence of nonfatal MI plus fatal coronary disease 25% and 24% lower. These differences were not satistically significant by the study criterion (Z greater than or equal to 2.6). By life-table analysis, the rates of coronary mortality and coronary incidence were about 50% lower in the PR/A group than in the PLBO group from 8-24 months, and for coronary incidence all Z values were greater than or equal to 2.6; ASA rates were about 30% lower than PLBO rates, and for coronary incidence, Z values were greater than or equal to 2.6 at two points. For these end points, from 8-20 months, PR/A rates were about 30% lower than ASA rates, but all Z values were less than 2.0 PR/A and ASA patients entering within 6 months of last MI showed the largest percentage reductions in mortality; only the difference between PR/A and PLBO groups for 3-year coronary mortality yielded a Z value of 2.6. Results of trials of aspirin and dipyridamole combined versus aspirin alone for the secondary prevention of vascular events after ischaemic stroke of presumed arterial origin are inconsistent. Our aim was to resolve this uncertainty.
                We did a randomised controlled trial in which we assigned patients to aspirin (30-325 mg daily) with (n=1363) or without (n=1376) dipyridamole (200 mg twice daily) within 6 months of a transient ischaemic attack or minor stroke of presumed arterial origin. Our primary outcome event was the composite of death from all vascular causes, non-fatal stroke, non-fatal myocardial infarction, or major bleeding complication, whichever happened first. Treatment was open, but auditing of outcome events was blinded. Primary analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN73824458) and with (NCT00161070).
                Mean follow-up was 3.5 years (SD 2.0). Median aspirin dose was 75 mg in both treatment groups (range 30-325); extended-release dipyridamole was used by 83% (n=1131) of patients on the combination regimen. Primary outcome events arose in 173 (13%) patients on aspirin and dipyridamole and in 216 (16%) on aspirin alone (hazard ratio 0.80, 95% CI 0.66-0.98; absolute risk reduction 1.0% per year, 95% CI 0.1-1.8). Addition of the ESPRIT data to the meta-analysis of previous trials resulted in an overall risk ratio for the composite of vascular death, stroke, or myocardial infarction of 0.82 (95% CI 0.74-0.91). Patients on aspirin and dipyridamole discontinued trial medication more often than those on aspirin alone (470 vs 184), mainly because of headache.
                The ESPRIT results, combined with the results of previous trials, provide sufficient evidence to prefer the combination regimen of aspirin plus dipyridamole over aspirin alone as antithrombotic therapy after cerebral ischaemia of arterial origin. 240 patients were admitted to a double-blind study to determine the effect of long-term treatment with platelet-function inhibiting agents on occlusive arterial disease in the lower extremities. Patients were randomised into 1 of 3 treatment groups: aspirin 330 mg; dipyridamole 75 mg and aspirin 330 mg; or matching placebo 3 times daily. The duration of treatment was 2 years. Arteriography was carried out at the beginning of the study and 2 years later or before if deterioration was observed. 199 patients completed the study according to the trial protocol. The serial arteriograms were assessed in pairs qualitatively, by means of simple comparative viewing, and semiquantitatively with Bollinger's score system. Progression of the disease was most pronounced in the placebo-treated group, less so in the aspirin-treated group, and least of all in the dipyridamole-and-aspirin group. Patients who smoke and those with hypertension may benefit most from treatment with the 2 preparations under investigation. This study assessed the effect of the combination of aspirin and dipyridamole on patency of the infarct-related artery between 4 weeks and 1 year after myocardial infarction.
                Patency of the infarct-related artery is an important determinant of prognosis after myocardial infarction. The incidence of late reocclusion and the effects of antiplatelet therapy are unknown.
                To investigate the importance of antiplatelet therapy for the prevention of late reocclusion, 215 patients who had a patent infarct-related artery 4 weeks after myocardial infarction were randomized in a double-blind manner to receive either a combination of 25 mg of aspirin and 200 mg of dipyridamole twice daily or placebo. One hundred fifty-four patients underwent further coronary arteriography 1 year later.
                At 1 year, 38 (25%) of 154 patients had reocclusion of the infarct-related artery; 18 (23%) of 79 patients receiving aspirin and dipyridamole had late reocclusion versus 20 (27%) of 75 who received placebo (p = NS). The rate of reocclusion was related to the severity of the residual coronary artery stenosis at 4 weeks (< 50% stenosis 9.2%; 50% to 69% stenosis 11.6%; 70% to 89% stenosis 30.4%; > or = 90% stenosis 70%, p < 0.01). The majority of reocclusions were silent, and only 17 (45%) of 38 were clinically associated with further infarction. There were no differences for a hierarchic end point of cardiac death, myocardial infarction or revascularization (14.8% aspirin and dipyridamole vs. 17.8% placebo).
                Late reocclusion of the patent infarct-related artery is a frequent event, occurring in 25% of patients. Antiplatelet therapy with the combination of aspirin and dipyridamole does not alter the overall rate of late reocclusion. Other strategies are required to reduce late reocclusion. Personal experience in the treatment of Ischaemic Cerebrovascular Disease with platelet suppressant drugs is reported. 80 patients were treated with 5 different protocols: 1) group "A": dipyridamol (14 patients); 2) group "B": acetylsalicylic acid (ASA) (14 patients); 3) group "C": dipyridamol and ASA (22 patients); 4) group "D": ditazol (15 patients); 5) group "E": isoxsuprine resinate (15 patients) and followed-up for 22-34 months. The evolution of the disease is discussed and recurrences evaluated on the basis of initial clinical features and particular treatment given. Oral dipyridamole induces accumulation of endogenous adenosine, which in a hypoxic milieu exerts experimentally an angiogenic effect on coronary collateral circulation. A meta-analysis of 13 randomized placebo-controlled trials published between 1960 and 1992 showed evidence of benefit for dipyridamole in the treatment of angina pectoris, especially with longer duration of treatment. Aim To assess the efficacy and safety of dipyridamole in the treatment of patients with chronic stable angina in a large scale, international, randomized, placebo-controlled, parallel group study.
                Four hundred patients with chronic stable angina pectoris and a positive treadmill exercise test were randomized to receive either modified release dipyridamole (200 mg b.i.d. p.o., n=198) or corresponding placebo (n=202), for 24 weeks as an add-on to conventional antianginal therapy and for 4 additional weeks as monotherapy--the latter after withdrawal of standard treatment with calcium antagonists and/or beta-blockers and/or long-acting (prophylactic) nitrates.
                Of the 198 patients randomized to dipyridamole, 134 completed the add-on and only 12 the monotherapy phase. Of the 202 patients randomized to placebo, 162 reached the add-on and only 12 the monotherapy phase. Serious adverse events occurred in 15 patients with dipyridamole and in 12 with placebo (7.6% vs 6.0, P=0.52). Increase over the baseline treadmill exercise test was similar in the treatment groups at each stage of the trial for all the main efficacy parameters: total treadmill exercise test duration; time to first anginal pain (except for a -13 s difference in favour of placebo at week 24;P=0.040); time to ST segment depression >0.1 mVolt (except for a +21 s difference in favour of dipyridamole at week 8;P=0.024; this latter difference was totally attributable to patients with lower exercise tolerance--Bruce stage II at study entry).
                In patients with chronic stable angina treated with regular antianginal background medication, the use of oral dipyridamole is safe and well tolerated. Antianginal and antiischaemic efficacy, as assessed by exercise testing, is comparable to placebo, except for a beneficial effect on time to ischaemia after 2 months, totally attributable to patients with lower exercise tolerance at study entry.
                Copyright 2001 The European Society of Cardiology. nan In a double-blind randomized controlled clinical trial conducted in two French and two United Kingdom centers, the effect of antiplatelet agents, i.e., aspirin alone (330 mg 3 times daily) or in combination with dipyridamole (75 mg 3 times daily), was tested versus placebo in 475 patients with early diabetic retinopathy. The assessment of retinopathy was based on change in the number of microaneurysms (MAs) present in the macular field, as seen on fluorescein angiograms, over 3 yr. Forty-one patients did not complete the study. At least three readable initial and yearly angiograms were available on 420 patients (266 treated with insulin and 154 not treated); the results reported are based on these patients. The mean yearly increase in definite MAs was similar in insulin-treated and non-insulin-treated diabetic patients. There was no significant difference between the aspirin-alone group (0.69 +/- 5.1 mean +/- SD, n = 145) and the aspirin-plus-dipyridamole group (0.34 +/- 3.0, n = 142). In the placebo group the mean yearly increase (1.44 +/- 4.5, n = 133) was significantly higher than in the treated group (P = .02, 1-tailed t test). There was a clear relationship between the deterioration in ophthalmological signs and the increase in mean yearly MAs (clinically stable, 0.38 +/- 3.96, n = 293; deteriorating, 1.79 +/- 4.89, n = 127; P = .002, 2-tailed t test). We conclude that aspirin alone and in conjunction with dipyridamole significantly slows the progression of MA evolution in early diabetic retinopathy. The Persantine Aspirin Trial focused on the question of whether the administration of the combination of aspirin and dipyridamole (Persantine) would result in a lower incidence of cerebral or retinal infarction or death than the administration of aspirin alone for persons with a history of recent carotid territory transient ischemic attacks (TIAs). Fifteen centers in the United States and Canada participated and 890 individuals were admitted and randomly allocated to either aspirin (325 mg) plus placebo or aspirin (325 mg) plus Persantine (75 mg) four times daily. Ninety eight percent of the subjects were followed for at least one year; many were followed for four to five years. The results of life table analysis indicate that the overall endpoint rates for the "aspirin only" and "aspirin plus Persantine" groups are identical. Thus, for TIA patients taking aspirin, the addition of Persantine contributes nothing. There was a clustering of stroke endpoints during the first month after randomization. Deaths from all causes were essentially equally divided between the two treatment groups. nan 604 Patients with atherothrombotic cerebral ischemic events (transient, 16%: or completed, 84%) referrable either to the carotid or to the vertebral-basilar circulation were entered into a double blind randomized clinical trial (AICLA) to determine whether aspirin (A) (1 g/day) or aspirin (1 g/day) + Dipyridamole (225 mg/day) (AD) would produce a significant reduction in the subsequent (3 years) occurrence of fatal and nonfatal cerebral infarction. Randomization produced remarkably comparable treatment groups and this good comparability was maintained throughout the study. Adherence to the protocol and drug compliance were excellent. Side effects, particularly symptoms of peptic ulcer and hemorrhagic events were significantly (p less than 0.03) more frequent in the two treatment groups containing aspirin. With the exception of patients who withdrew from the study, each patient was followed for 3 years. At the end of the study, the number of fatal and nonfatal cerebral infarctions was 31 in the placebo (P) group, 17 in the A group and 18 in the AD group. Taking into account the duration of follow-up for each patient, these figures correspond to cumulative rates of 18% in the P group and 10.5% in each of the 2 active treatment groups. Analysis with the Mantel Method showed: 1)--A difference at the 6% level between the 3 groups and between P and AD; 2)--A difference at the 5% level between P and A; 3)--No difference between (A and AD; 4)--A difference at the 2% level between the P group and the two treated groups taken together (A + AD). Among other diseases occurring during the trial, the only significant difference concerned myocardial infarction, which was less frequent in the 2 treated groups (P less than 0.05). Subgroup analysis failed to show a significant sex difference in the efficacy of aspirin. It is concluded that, in patients comparable to those defined in the protocol, Aspirin (1 g) has a significantly beneficial effect in the secondary prevention of atherothrombotic cerebral infarction. In order to assess the usefulness of a combination of low-dose aspirin (25 mg b.i.d.) with dipyridamole (200 mg b.i.d.) in the prevention of major coronary events in patients with acute unstable angina, we performed a prospective, double-blind, placebo-controlled study involving 88 consecutive patients admitted to three Hospital Departments of Cardiology. The patients entered the study as soon as possible after hospital admission, and were treated and followed up to one year. There was no appreciable difference in side effects and adverse reactions between the treatment and control group. The incidence of cardiac death and/or nonfatal myocardial infarction during the whole period of observation was 14% (6/44) in the treatment group and 25% (11/44) in the placebo group by "intention-to-treat" analysis; 16% (4/25) and 32% (10/31), respectively, by "drug-efficacy" analysis (p = 0.21 by Fisher's exact test, non significant difference). However, when considering the only events occurred in the first month (2/44 in the treatment group and 9/44 in the placebo group, amounting to 4.5 and 20 percent, respectively), the combination of dipyridamole with low-dose aspirin reached a statistically significant protective effect (p = 0.04). The results of this pilot study provide strong evidence for a beneficial effect of the regimen tested in patients with acute unstable angina, at least in the first weeks of treatment, while at the same time suggesting a safe alternative for patients with contraindications to higher doses of aspirin.
For patients who presented with arterial vascular disease, there was no evidence that dipyridamole, in the presence or absence of another antiplatelet drug reduced the risk of vascular death, though it reduces the risk of further vascular events. This benefit was found only in patients presenting after cerebral ischaemia. There was no evidence that dipyridamole alone was more efficacious than aspirin.