. Objectives.  Low‐dose aspirin given for secondary prevention of cardiovascular disease is frequently withdrawn prior to surgical or diagnostic procedures to reduce bleeding complications. This may expose patients to increased cardiovascular morbidity and mortality. Aim of the study was to review and quantify cardiovascular risks because of periprocedural aspirin withdrawal and bleeding risks with the continuation of aspirin. Methods.  We screened MEDLINE (January 1970–October 2004) with additional manual cross‐referencing for clinical studies, surveys on the opinions of doctors and guidelines. Results.  Studies reporting the relative risk of acute cardiovascular events after aspirin withdrawal when compared with its continuation were not found. However, retrospective investigations revealed that aspirin withdrawal precedes up to 10.2% of acute cardiovascular syndromes. The time interval between discontinuation and acute cerebral events was 14.3 ± 11.3 days, 8.5 ± 3.6 days for acute coronary syndromes, and 25.8 ± 18.1 days for acute peripheral arterial syndromes (P < 0.02 versus acute coronary syndromes). On aspirin‐related bleeding risks, we obtained 41 (12 observational retrospective, 19 observational prospective, 10 randomized) studies, reporting on 49 590 patients (14 981 on aspirin). Baseline frequency of bleeding complications varied between 0 (skin lesion excision, cataract surgery) and 75% (transrectal prostate biopsy). Whilst aspirin increased the rate of bleeding complications by factor 1.5 (median, interquartile range: 1.0–2.5), it did not lead to a higher level of the severity of bleeding complications (exception: intracranial surgery, and possibly transurethral prostatectomy). Surveys amongst doctors on the management of this problem demonstrate wide variations. Available guidelines are scarce and in part contradictory. Conclusions.  Only if low‐dose aspirin may cause bleeding risks with increased mortality or sequels comparable with the observed cardiovascular risks after aspirin withdrawal, it should be discontinued prior to an intended operation or procedure. Controlled clinical studies are urgently needed.

These results show that glimepiride maintains myocardial preconditioning, while glibenclamide might be able to prevent it.

One hundred patients undergoing routine diagnostic or interventional catheterization were randomly assigned to receive either percutaneously applied collagen (group A; n = 50) or conventional pressure dressing (group B; n = 50) for sealing of the femoral artery. Clinical variables were comparable in both groups. The heparin dose was 100 IU/kg in 30 patients and 200 IU/kg in 20 patients of either group. The average compression time was 4.3 min in group A and 42.3 min in group B (p < .001). Bleeding was not observed in group A but was observed in 6/50 patients in group B. The time to ambulation was 6.4 hr (range, 4-12 hr) in group A and 21.6 hr (range, 10-48 hr) in group B (p < .001). Hematomas with a diameter of > 6 cm developed in 4/50 patients in group A and in 11/50 patients in group B (p < .05). Blood-transfusions or surgical interventions were not required and there was no loss of ankle pulses in either group. In conclusion, percutaneously applied collagen reduced compression time and duration of bedrest after diagnostic catheterization and PTCA. Despite earlier ambulation, the incidence of bleeding was lower with collagen than with conventional pressure dressing.

No abstract

Krebs-Henseleit buffer (KH) and a perfluorochemical (FC-43) were compared as perfusates in an isolated working rabbit heart preparation. Both perfusates were oxygenated in an identical manner using an infant bubble oxygenator. After 60 min of perfusion, no difference could be detected in the ratio of wet to dry heart weight between KH- and FC-43-perfused hearts (KH, 6.25 +/- 0.3; FC-43, 5.99 +/- 0.20). Left ventricular systolic pressure, maximal rate of left ventricular pressure rise, mean aortic systolic pressure, cardiac output, aortic flow, left ventricular power, and myocardial O2 consumption (MVO2) were significantly higher in FC-43-perfused hearts throughout the time of perfusion. However, there were no differences in resistance to cardiac output and heart rate. In KH- and FC-43-perfused hearts, MVO2 and left ventricular power were closely correlated (KH, r = 0.793; FC-43, r = 0.831). Significantly higher coronary flow of KH-perfused hearts could be attributed to the lower viscosity of KH (1.05 Pa . s) compared with FC-43 (1.91 Pa . s). Increased O2 extraction during KH perfusion could not compensate for low O2-carrying capacity of KH buffer (345 compared with 705 nmol O2 X ml-1 in FC-43 emulsion). A postischemic increase of coronary flow was observed only in FC-43-perfused hearts (28%). These results demonstrate a different response of perfused heart preparations to FC-43 and KH buffer.