Modulatory impact of cardiac rehabilitation on hyperhomocysteinemia in patients with coronary artery disease and "normal" lipid levels.

In coronary patients with "relatively normal" lipid values and hyperhomocystinemia (levels > or =15 micromol/L), significant 12% reductions in homocysteine levels occurred after cardiac rehabilitation and exercise training. This benefit from cardiac rehabilitation and exercise training may lead to 20% to 30% reductions in overall coronary artery disease risk.

Comparative analysis of cardiac troponin I and creatine kinase-MB as markers of acute myocardial infarction.

BACKGROUND: The World Health Organization (WHO) criteria for the diagnosis of acute myocardial infarction (AMI) includes presentation of chest pain over 20 min, evolutionary changes on the electrocardiogram (ECG), and abnormal levels of cardiac enzymes. HYPOTHESIS: A multicenter study was conducted to evaluate the efficacy of cardiac troponin I (cTnI) in detecting and ruling out AMI. METHODS: The normal range for cTnI in 149 apparently healthy subjects without known history of cardiac or other diseases was 0 to 0.5 ng/ml. Cutoffs of 2.5 ng/ml for c TnI and 5.0 ng/ml for creatine kinase-MB (CK-MB) were used. RESULTS: The diagnostic sensitivity of blood collected from 291 consecutive patients with suspicion of AMI was 95.0 and 96.4%, respectively, for samples obtained at 4-48 h after AMI onset. CK-MB was more sensitive during the early 4-8 h interval (84 vs. 74%); both had 100% sensitivity from 12-36 h. CTnI remained at 100% for 72 h, while CK-MB declined to 57%. The clinical specificity was 97.4 vs. 85.8%, respectively, on non-AMI patients with cardiac and noncardiac diseases, and those with renal disease. CONCLUSION: cTnI is an excellent marker for detecting and ruling out AMI, because it has better specificity and a wider diagnostic window than the accepted standard, CK-MB.

The effects of supraceliac aortic clamping on the anticoagulant effects of heparin.

BACKGROUND: Coagulopathy is frequently encountered during supraceliac aortic clamping. Patients are routinely heparinized during these operations. This experiment was undertaken to evaluate the effect of supraceliac aortic cross-clamping (XC) on heparin pharmacodynamics. MATERIAL AND METHODS: Fourteen mongrel dogs were randomly divided into three groups: Group 1 (X; n = 6), 90 minutes aortic XC; Group 2 (SH; n = 4), sham operation and heparin, 100 mg/kg intravenously; and Group 3 (XH; n = 4), heparin, 100 mg/kg intravenously 3 minutes before XC. Prothrombin time (PT) and partial prothrombin time (PTT) were measured serially. Heparin concentrations were estimated via automated titration with protamine sulfate. RESULTS: After XC, PTT is increased during reperfusion. Heparin administration (XH) before aortic XC increases PTT above those with X or SH. Anticoagulation was potentiated and prolonged by XC. There was no difference in heparin concentration or PT. CONCLUSION: Supraceliac aortic clamping significantly affects heparin pharmacodynamics and may contribute to coagulopathy.

Improvement in 'stat' laboratory turnaround time. A model continuous quality improvement project.

BACKGROUND: Continuous quality improvement is being advocated as the process that, if adopted, would improve the efficiency, productiveness, and quality of medical institutions, thereby helping to solve the health care crisis our country is facing. To determine if these techniques could be effective in a tertiary-care multispecialty group practice, a model project was undertaken. The model project chosen was to determine if we could improve the turnaround time for "stat" laboratory examinations performed in our large outpatient facility. METHODS: A 10-member team consisting of everyone involved in the process of laboratory testing was empowered to evaluate the present process and make appropriate changes. With traditional techniques of quality improvement, the process was assessed, data were collected and statistically analyzed, changes were introduced, and data were recollected and analyzed. RESULTS: After intervention, the preanalytic delays were reduced by 76% and the postanalytic delays by 88%. Waiting time for patients was reduced by an average of 62%. By instituting the changes suggested, the institution saved $225,000 on a one-time basis and $40,000 to $50,000 on a recurring basis. CONCLUSION: Adoption of quality improvement techniques appears to be a desirable management paradigm that should be explored by all medical institutions interested in maximizing the quality of care offered while at the same time minimizing its cost.

Niacin-induced clotting factor synthesis deficiency with coagulopathy.

Although coagulopathy is a well-known complication of severe niacin-induced hepatotoxic reaction, it is not found in patients with minimal aminotransferase level elevations. Three patients with significant clotting factor synthesis deficiency and coagulopathy (prothrombin times, greater than 1.5 times control) from sustained-release niacin had only mild aminotransferase level elevations (1.5 to 2.0 times normal). In each case, protein deficiency, coagulopathy, and aminotransferase level elevation resolved promptly after withdrawal of niacin therapy. In one case, this syndrome recurred after rechallenge with sustained-release niacin, whereas the coagulopathy did not recur in a second patient rechallenged with crystalline niacin. Deficiency in protein synthesis, including coagulation factors, and coagulopathy are unrecognized complications of sustained-release niacin therapy. These cases indicate the need to measure prothrombin times routinely in patients who develop even mild aminotransferase level elevation while receiving sustained-release niacin therapy. These data are important in light of the increasing use of sustained-release niacin in the treatment of patients with lipid disorders.

Progressive myelofibrosis in agnogenic myeloid metaplasia.

Progression of myelofibrosis in agnogenic myeloid metaplasia (AMM) has only rarely been documented because of the paucity of patients with sequential bone marrow examinations. At our institution, 27 patients with AMM underwent marrow examinations, separated by at least six months. Of the 20 patients who did not have maximal myelofibrosis shown by the original biopsy, 18 displayed temporal progression of the process; 11 of them had an increase of two or more grades using the Bauermeister scale. The grade remained constant in the remaining two patients. Several cases of a decreased degree of fibrosis or variation of grade in concomitant specimens showed that fibrosis may not proceed at an identical rate throughout the marrow and that the degree may vary with location.