Comparison of ejection fraction and pulmonary blood volume ratio as markers of left ventricular function change after coronary angioplasty

Exercise-induced increases in pulmonary blood volume ratio have been shown to be a sensitive marker of coronary artery disease, and correlate well with exercise-induced increases in left ventricular filling pressure. To compare the impact of single vessel coronary disease on left ventricular systolic function (ejection fraction) versus diastolic filling pressure (pulmonary blood volume) before and after intervention, serial supine exercise gated blood pool scans were performed before and after coronary angioplasty in 32 patients with isolated left anterior descending coronary artery disease. By applying previously established criteria of abnormal ejection fraction (rest <50% or failure to rise by 5% with exercise) and pulmonary blood volume ratio (>1.06), 66% of the patients were found to have abnormal responses before angioplasty by ejection fraction compared with 81% abnormal responses by pulmonary blood volume ratio (p = 0.15). After angioplasty, the proportion of patients with abnormal ejection fraction (59%) was essentially unchanged, whereas only 38% continued to have an abnormal pulmonary blood volume ratio (p < 0.01 compared with before angioplasty). The mean pulmonary blood volume ratio also decreased significantly from 1.15 ± 0.10 before angioplasty to 1.02 ± 0.15 after angioplasty (p < 0.001). It is concluded that in single vessel coronary artery disease: 1) pulmonary blood volume ratio is abnormal at least as frequently as is ejection fraction; 2) in contrast to ejection fraction, pulmonary blood volume ratio improves significantly after successful angioplasty; and 3) pulmonary blood volume ratio may be a more sensitive indicator of changes in ventricular function after an intervention in single vessel coronary disease.