Lack of concordance between a rapid bedside and conventional laboratory method of cardiac troponin testing: impact on risk stratification of patients suspected of acute coronary syndrome.

OBJECTIVES: This study was designed to test the usefulness of a bedside assay as compared to a laboratory method of troponin testing to predict adverse cardiac outcome of chest pain patients. METHODS: We studied 358 ER visits of patients suspected of a non ST-elevation acute coronary syndrome. cTnI (Immulite, DPC) on a lab analyser and cTnT (Cardiac Reader, Roche) at bedside were measured at baseline. The between-assay level of concordance, reporting turnaround times and clinical outcomes during 180 days of follow-up were assessed. Death and myocardial infarction were then evaluated according to troponin result, either concordant negative, discordant or concordant positive. RESULTS: Discordance occurred in 11.4% (41/358) of cases. The proportion of patients with a positive cTnI and negative cTnT result (8.9%) versus the reverse (2.5%) differed significantly (p<0.001). The median time gained using the rapid test was 72 min. The rate of death and/or MI was 25% (10/40) among patients with discordant results as compared to 7.5% (17/228) with a concordant negative result (p<0.001). All patients from the discordant group with an event had a positive cTnI result, while cTnT was negative. CONCLUSION: Patients with a discordant reading were at high risk of adverse cardiac outcome, which was only identified by the laboratory cTnI assay. Markedly, the use of the rapid assay saved time at the expense of clinical sensitivity.

Finapres arterial pulse wave analysis with Modelflow is not a reliable non-invasive method for assessment of cardiac output.

Non-invasive continuous monitoring of cardiac output could be very useful in clinical care and in research settings, particularly in elderly subjects. We studied whether Finapres arterial pulse wave analysis with Modelflow is a reliable non-invasive method for the assessment of cardiac output in healthy elderly subjects. We compared Modelflow cardiac output (MFCO) with thermodilution cardiac output (TDCO) in 28 healthy subjects, aged 70+/-4 years (mean+/-S.D.). TDCO was measured during right-sided heart catheterization, while MFCO was calculated with Modelflow(R) software from non-invasive arterial Finapres blood pressure, which was measured simultaneously. The two methods were compared using a paired t-test, by Pearson correlation, and by Bland-Altman analysis. TDCO was 6.4+/-1.1 litres/min (mean+/-S.D.) and MFCO was 4.7+/-1.3 litres/min (P<0.001). There was no significant correlation between MFCO and TDCO (r=0.28, P=0.13). Mean difference (bias) was -1.7 litres/min (S.E.M. 0.27 litres/min), with an S.D. (precision) of 1.5 litres/min. The 95% limits of agreement were -4.6 to +1.1 litres/min. In conclusion, non-invasive MFCO values differed significantly from and showed no significant correlation with invasively determined TDCO values in the normal range. Although simple, non-invasive and patient-friendly, the Modelflow method is inaccurate for assessment of cardiac output without invasive calibration.

Aspirin plus coumarin versus aspirin alone in the prevention of reocclusion after fibrinolysis for acute myocardial infarction: results of the Antithrombotics in the Prevention of Reocclusion In Coronary Thrombolysis (APRICOT)-2 Trial.

BACKGROUND: Despite the use of aspirin, reocclusion of the infarct-related artery occurs in approximately 30% of patients within the first year after successful fibrinolysis, with impaired clinical outcome. This study sought to assess the impact of a prolonged anticoagulation regimen as adjunctive to aspirin in the prevention of reocclusion and recurrent ischemic events after fibrinolysis for ST-elevation myocardial infarction. METHODS AND RESULTS: At coronary angiography <48 hours after fibrinolytic therapy, 308 patients receiving aspirin and intravenous heparin had a patent infarct-related artery (Thrombolysis In Myocardial Infarction [TIMI] grade 3 flow). They were randomly assigned to standard heparinization and continuation of aspirin alone or to a 3-month combination of aspirin with moderate-intensity coumarin, including continued heparinization until a target international normalized ratio (INR) of 2.0 to 3.0. Angiographic and clinical follow-up were assessed at 3 months. Median INR was 2.6 (25 to 75th percentiles 2.1 to 3.1). Reocclusion (< or =TIMI grade 2 flow) was observed in 15% of patients receiving aspirin and coumarin compared with 28% in those receiving aspirin alone (relative risk [RR], 0.55; 95% CI 0.33 to 0.90; P<0.02). TIMI grade 0 to 1 flow rates were 9% and 20%, respectively (RR, 0.46; 95% CI, 0.24 to 0.89; P<0.02). Survival rates free from reinfarction and revascularization were 86% and 66%, respectively (P<0.01). Bleeding (TIMI major and minor) was infrequent: 5% versus 3% (P=NS). CONCLUSIONS: As adjunctive to aspirin, a 3-month-regimen of moderate-intensity coumarin, including heparinization until the target INR is reached, markedly reduces reocclusion and recurrent events after successful fibrinolysis. This conceptual study provides a mechanistic rationale to further investigate the role of prolonged anticoagulation after fibrinolytic therapy.