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Biomedical subjects

V Fuster

Publications and source records attributed to V Fuster.

At least 469 records · Page 26Linked to original sources
PubMed1979

Reduction of intimal thickening in canine coronary bypass vein grafts with dipyridamole and aspirin.

The potential benefit of platelet inhibitor drugs on coronary arterial bypass vein grafts was assessed in dogs with magnification-corrected angiographic luminal measurements and quantitative histologic evaluation of the vein grafts. There were 11 control animals and 11 animals treated with dipyridamole, 55 mg/day, plus aspirin, 325 mg/day. Eighteen animals with patent grafts were studied when electively killed 2, 4 or 6 months after grafting. At 14 days, there was greater angiographic narrowing in the most distal 1 cm of vein grafts in control than in treated dogs (P less than 0.01). This same angiographic narrowing persisted in control dogs until they were killed (P less than 0.03). Computer-assisted measurements of the entire area of intimal thickening were done on vein graft cross sections taken 1 cm from the distal anastomosis. The circumference of the vein grafts at the intimal-media junction was measured from the same section and the potential maximal luminal area calculated. The calculated luminal narrowing due to intimal thickening was greater in control than in treated dogs (P less than 0.03). These data correlate well with the demonstrated angiographic narrowing. The findings indicate that the degree of early intimal thickening that persists 2 to 6 months postoperatively in canine coronary bypass vein grafts may be reduced by the platelet inhibitor combination of dipyridamole plus aspirin.

Animals↗
PubMed1979

Noninvasive radioisotopic technique for detection of platelet deposition in coronary artery bypass grafts in dogs and its reduction with platelet inhibitors.

At 8 and 32 hours after saphenous vein bypass graft surgery in six dogs, in vivo images of the graft were obtained with a gamma camera after intravenous injection, 2 hours postoperatively of autologous platelets labeled with indium-111. Platelet deposition in the grafts could be imaged in vivo from the scintiphotos. In vitro images of the excised heart showed saphenous vein graft uptake confirming the in vivo image. In vitro determination of radioactivity in the graft averaged 17 +/- 14 times greater than in blood and 33 +/- 26 times greater than in the lung. Under identical conditions, in eight dogs treated with dipyridamole (55 mg/day) plus aspirin (325 mg/day), the grafts appeared to have considerably less platelet deposition as estimated by imaging. In vitro determination of radioactivity in the graft averaged 5 +/- 2 times greater than in blood and 8 +/- 4 times greater than in the lung (p less than 0.01). This noninvasive technique may be a promising tool for a better understanding of the role played by platelets in the process of occlusion of saphenous vein bypass grafts in man and its prevention with platelet inhibotors.

Animals↗
PubMed1979

Ebstein's anomaly: the clinical features and natural history of Ebstein's anomaly of the tricuspid valve.

The clinical features and natural history of Ebstein's anomaly are analyzed on the basis of experience with 67 consecutive patients who have had a mean follow-up of 12 years. Of the total group, 26 (39%) of the patients remained in functional Class I or II and 41 (61%) progressed at some time into Class III or IV. Death occurred in 14 (21%) of the patients, and these were characterized by one or more of the following features: (1) they were in functional Class III or IV, (2) they had moderate to severe cardiomegaly with a cardiothoracic ratio greater than 0.65, (3) they had cyanosis or an arterial oxygen saturation of less than 90%, and (4) they were infants when the diagnosis was made (10 patients, of whom 5 died). In patients in Class III or IV, a comparison was made between patients treated medically (10) and those treated surgically--either with tricuspid valve replacement (15) or with a modified tricuspid annuloplasty (16). It appears that modified tricuspid annuloplasty is the procedure of choice, because despite an operative mortality of 25% (4 patients), 12 of the 16 patients so treated improved clinically or had a reduction in heart size.

Adolescent↗
PubMed1979

Dipyridamole levels in plasma of man and other species.

Measurements were made of the concentration of dipyridamole in the plasma of man, dogs, pigs, and pigeons at different times after oral administration of the drug. In dogs and in man, there was considerable variation in the plasma levels of the drug in different subjects. Pigs and pigeons always had much lower levels of the drug in plasma than did men and dogs given comparable doses. After intravenous injection of dipyridamole to pigs, a large proportion of the drug appeared to leave the plasma almost immediately; subsequently, the half-life of the drug remaining in the plasma was quite similar to that previously reported in man. The administration of aspirin with dipyridamole sometimes resulted in higher blood levels of the drug in dogs, man, and pigs, but the effects were small. The wide variations in plasma drug levels observed indicate that in future human or experimental trials designed to evaluate the antithrombotic effect of dipyridamole, plasma levels of the drug should be routinely monitored.

Administration, Oral↗
PubMed1978

The von Willebrand pig as a model for atherosclerosis research.

In order to evaluate a possible role played by platelets in the development of atherosclerosis, the aortas of 11 control pigs and 11 homozygous von Willebrand (vWd) pigs were examined for spontaneous atherosclerosis. Of the 11 normal pigs, 6 showed multiple atherosclerotic plaques with an intimal thickening of 63 to 130 micrometer. In contrast, none of the von Willebrand pigs had multiple plaques and only one showed a single lesion of more than 2 mm in diameter. In a prospective study 5 control pigs and 5 vWd pigs were given a high (2%) cholesterol diet from the age of 3 to 9 months. All of the controls developed atherosclerotic plaques. In 4 of the pigs the plaques exceeded 13% of the aortic surface with an intimal thickening of 50 to 390 micrometer. In contrast, only one of the vWd pigs developed atherosclerotic plaques which only involved 7% of the aortic surface. Most of the vWd pigs, however, developed non-atherosclerotic flat fatty lesions. These findings may be related to the impaired platelet arterial wall interaction in vWd. The vWd pigs seem to be an ideal model for atherosclerosis research.

Animals↗
PubMed1978

Imaging platelet deposition with 111In-labeled platelets in coronary artery bypass grafts in dogs.

At 8 and 32 hours after saphenous vein aortocoronary artery bypass graft surgery in four dogs, images of the grafts were obtained with a gamma camera after intravenous injection, 2 hours postoperatively, of autologous platelets labeled with indium-111. The location of platelet deposition could be accurately estimated from the scintiphotos. In vitro radioactivity counting of the segments of the isolated grafts showed 4 to 15 times greater activity in the grafts than in blood and 25 to 100 times greater activity than in normal myocardium. This was sufficient for delineating accurately the area of platelet deposition. This noninvasive technique may be a promising tool for a better understanding of the role played by platelets in the process of occlusion of saphenous vein bypass grafts in man.

Animals↗
PubMed1978

Effect of aspirin on prevention of coronary and cerebrovascular disease in patients with rheumatoid arthritis. A long-term follow-up study.

Between 1950 and 1975, 473 Rochester patients had the diagnosis of rheumatoid arthritis and received aspirin treatment. These patients were followed for an average of 10 years to determine whether they experienced myocardial infarction, classic angina pectoris, sudden unexpected death, or cerebral infarction less often than expected on the basis of age- and sex-specific incidence rates of each event known for the Rochester population. In none of these disease entities, separately, or combined, was the expected number significantly different from the observed. However, when we examined these events separately by sex, observed numbers in males were 30 to 50% less than expected in all four studied end-events. Because the male population was small, none of these differences reached statistical significance. The possible effect of aspirin in the primary prevention of vascular disease in males is discussed in light of the recent similar reported results in secondary prevention.

Adult↗
PubMed1977

Quantitation of left ventricular myocardial fiber hypertrophy and interstitial tissue in human hearts with chronically increased volume and pressure overload.

Using new techniques, we quantitated left ventricular myocardial fiber hypertrophy and interstitial tissue in four groups of autopsied hearts free of coronary disease: 1) 22 normal hearts, 2) 20 hearts from patients with mitral incompetence (NYHA Class II-III) who died early after mitral valve replacement from causes other than cardiac failure, 3) 22 hearts from patients with mitral incompetence (NYHA Class III-IV) who died early after mitral valve replacement from cardiac failure with low cardiac output syndrome, and 4) 22 hearts from patients with hypertensive heart disease (NYHA Class II-III). Myocardial fiber hypertrophy was quantitated by measuring cross-sectional myocardial fiber diameter; the proportion of interstitial tissue was quantitated by using a computerized, high-resolution video image-digitizing system. Myocardial fiber average diameter in groups 2, 3 and 4 was significantly higher than group 1. The proportion of interstitial tissue was significantly increased in group 3. In chronic mitral incompetence an increase in left ventricular interstitial tissue may play a role in the development of severe cardiac failure.

Cardiomegaly↗
PubMed1977

Spontaneous endothelial cell injury in the intimal cushions of atherosclerotic pigeons.

Since endothelial damage precedes sterol accumulation, platelet factor 4-like activity elevations and alterations in thrombocyte adhesiveness, it clearly is one of the earliest events in the pathogenesis of spontaneous pigeon atherosclerosis. Although the relationships among endothelial damage and the other events have not been elucidated, it is conceivable that products released from thrombocytes subsequent to adhesion on damaged endothelium may trigger other localized changes in the intimal cushion area and lead to the progression of atherosclerosis.

Animals↗
PubMed1976

Hematological and vascular concepts in relation to stroke.

This review has highlighted some of the factors which influence the formation and fate of thrombi. Rheology and flow, the coagulation mechanism, the fibrinolytic enzyme system, and the properties of platelets to adhere and aggregate all play a significant role. Of paramount importance to neurosurgeons is the role of the vascular wall in thrombogenesis. The ulcerated atherosclerotic plaque demonstrates this point. Factors contributing to thromboembolism in this setting include stenosis and reduced flow, turbulence, and the elements in the lesion with which blood interacts. These are principally collagen, ADP, fatty acids, and the thromboplastic activity of vascular subendothelial tissue. Current concepts of the etiologies of atherosclerosis were discussed. Along with other predisposing factors, platelets may play a significant role in the initiation of the process. The current status of clinical trials with inhibitors of platelet function in the treatment of cerebrovascular disorders was reviewed. In vascular reconstructive surgery, the principles which underlie good technique are those which best insure against thrombosis. The briefest possible period of stasis during surgery should be maintained. The reconstruction should result in a smooth blood flow pattern with rapid runoff and minimal stenosis or gaps between apposed endothelial surfaces.

Aspirin↗