Radionuclide angiography for risk stratification of patients with coronary artery disease

[Decision making in cardiology: methodology]

This article reviews the methods employed in usual clinical thinking for making decisions, the problems and limitations inherent in them and claims that a more frequent utilization of the so called "Evidence Based Medicine" methods is a more valid and efficient alternative for medical decision making. We also describe the theoretical basis and strategies used in the medical decision process; the specific concepts and basic components for building decision trees are also shown. Finally, a real case is presented and approached step by step: the statement of the decision problem, its possible alternatives, the allocation of probabilities to each outcome based on the best available evidence, and the calculations of the expected values (projected usefulness, cost-effectiveness) and sensitivity analysis by means of specific software for making decisions.

Assessment of left ventricular function: comparison between radionuclide angiography and semiquantitative two-dimensional echocardiographic analysis

Measurement of global left ventricular function is important in the follow-up of cardiac patients and is a good prognostic indicator in acute cardiac situations. We compared quantitative measurements of global left ventricular function made with radionuclide angiography (RNA) and contrast cardiac ventriculography (CVG) to visual semiquantitative estimates from two-dimensional echocardiographic images (2D-echo). Three hundred and thirty-nine consecutive patients who underwent RNA were assessed with 2D-echo within 3 months. In addition, 92 of these patients also underwent CVG (correlation of ejection fraction between CVG and RNA: r=0.82; P<0.0001). The RNA mean ejection fractions in the four 2D-echo groups (0=normal, 1=slightly, 2=moderate, or 3=severe reduced left ventricular function) differed markedly (P<0.0001); however, there was overlapping among the groups (2D-echo score/RNA ejection fraction: 0=57.3%+/-12.8%; 1=46.0%+/-12.9%; 2=29.6%+/- 12.2%; and 3=24.6%+/-11. 5%) and the difference between 2D-echo scores 2 and 3 was not significant. 2D-echo showed a good concordance in RNA classes (0=>/=505; 1=35%-49%; 2=21%-34%; and 3=</=20% ejection fraction) 0 (133/166; 80%) and 3 (18/30; 60%) but low concordance in classes 1 (27/82; 33%) and 2 (21/61; 34%). For accurate assessment of global left ventricular ejection fraction, visual semiquantitative judgement of a 2D echocardiographic image is limited in comparison to CVG or RNA, especially in patients with a slight or moderate reduction in left ventricular ejection fraction.