Victor A. Ferraris

Aspirin and postoperative bleeding after coronary artery bypass grafting.

ObjectiveTo evaluate the relationship between aspirin ingestion and postoperative bleeding complications, and to test the hypothesis that there is a subset of patients who are aspirin hyperresponders with a proclivity toward platelet dysfunction. Summary Background DataDespite numerous retrospective and prospective analyses, it is still controversial as to whether aspirin ingestion before coronary artery bypass grafting (CABG) is associated with significant postoperative bleeding. MethodsBetween January 1995 and December 1999, the records of 2,606 consecutive patients undergoing CABG were reviewed to identify patients with a history of aspirin ingestion up until the time of surgery. Aspirin ingestion was correlated with postoperative blood transfusion using multivariate analysis. In a subset of preoperative aspirin users (n = 40), bleeding times were measured before and after aspirin use. Flow cytometry was performed in another cohort of patients with known heart disease (n = 30) to determine the effect of aspirin on platelet surface receptors. ResultsDuring the 5-year study period, 63% of the CABG patients were identified as aspirin users. Among these, 23.1% required blood transfusions compared with 19% for the nonusers. Non-red blood cell transfusions were more common in aspirin users, as was reexploration for bleeding. Stratification of these results according to the frequency of aspirin use showed that aspirin is an independent multivariate predictor of postoperative blood transfusion only in high-risk patients. In the prospective studies, aspirin treatment resulted in a significant increase in the template bleeding time, an increase in platelet PAR-1 thrombin receptor activity, and a decrease in the binding of platelets to monocytes. ConclusionsThe findings support the hypothesis that aspirin is associated with a greater likelihood of postoperative bleeding. A platelet function testing algorithm that combines preoperative risk factor assessment, template bleeding times, and flow cytometry may allow the identification of aspirin hyperresponders who are at increased risk for bleeding.

Relaxant Effect of Human Brain Natriuretic Peptide on Human Artery and Vein Tissue

Brain natriuretic peptide (BNP) is a cardiac-derived peptide hormone with cardiovascular and renal actions that is structurally and functionally related to atrial natriuretic peptide (ANP). Previous studies using rat vascular tissue have demonstrated a direct vasorelaxant effect of BNP. However, species-specific potency issues have precluded an accurate measurement of the effect of human BNP. This report demonstrates the vasorelaxant effects of human BNP on human vascular tissue prepared from internal mammary artery and saphenous vein samples. The vasorelaxant effect of human BNP is compared to the other members of the natriuretic peptide family, human ANP and C-type natriuretic peptide (CNP). With regard to potency and magnitude of effect, human BNP and human ANP were similar in relaxing arterial tissue preconstricted with endothelin-1 (BNP ED50 = 1.9 nmol/L and ANP ED50 = 1.8 nmol/L) or phenylephrine (BNP ED50 = 10 nmol/L and ANP ED50 = 19 nmol/L), while CNP was significantly less effective. All three natriuretic peptides exhibited weak venodilating action. These data demonstrate that human BNP is a potent inhibitor of the vasoconstrictive actions of endothelin-1 and the alpha-adrenergic agonist phenylephrine on isolated human artery tissue preparations.

Operative Outcome And Hospital Cost

INTRODUCTION Because of concern about increasing health care costs, we undertook a study to find patient risk factors associated with increased hospital costs and to evaluate the relationship between increased cost and in-hospital mortality and serious morbidity. METHODS More than 100 patient variables were screened in 1221 patients undergoing cardiac procedures. Simultaneously, patient hospital costs were computed from the cost-to-charge ratio. Univariate and multivariate statistics were used to explore the relationship between hospital cost and patient outcomes, including operative death, in-hospital morbidity, and length of stay. RESULTS The greatest costs were for 31 patients who did not survive operation (

The Platelet Thrombin Receptor and Postoperative Bleeding

74,466, 95% confidence interval

Risk factors for postoperative morbidity

27,102 to

Outcome in critical care patients: A multivariate study

198,025), greater than the costs for 120 patients who had serious, nonfatal morbidity (

Pericardial substitutes: a survey.

60,335, 95% confidence interval

Traumatic thoracobiliary fistula

28,381 to

Assessing the medical literature: Let the buyer beware

130,897, p = 0.02) and those for 1070 patients who survived operation without complication (

Home heparin therapy used in a pregnant patient with a mechanical heart valve prosthesis

31,459, 95% confidence interval