Comparison of the amount of ischemic myocardium in patients experiencing angina during treadmill testing versus those who had no angina during stress test

ABSTRACT

Previous studies that used thallium 201 scintigraphy to compare the amount of ischaemic myocardium in patients who had no anginal pain versus those who experienced angina during treadmill testing used either planar or SPECT imaging, the disparity in results was explained by the fact that different modalities of imaging were used seventy consecutive patients with at least one unequivocal reversible defect were included in our study, we used combined planar and SPECT imaging. Of the 70 patients 67 were males. 68% were known to have coronary artery disease, 54% had previous MI, and 62% had typical chest pain at rest. Twenty-five patient had no chest pain [Group 1], while 45 patients had chest pain during treadmill testing [group 2]. Both groups were identical regarding most clinical finding, except for the incidence of typical chest pain at rest, which was 30% in group 1 and 78% in group 2 P<0.01. Peak heart rate was 154 +/- 17 in group 1 versus 137+17 group 2 P < 0.0001, double product 45 + 5 [10_] versus 21 +/- 4 [10_] P <0.01, duration of exercise 8 +/- 3 min in group 1 versus 5.4 +/- 2.4 min in group 2 P< 0.0001. Stress test was positive in 3/25 patient's in-group 1 versus 18/45 patients in-group 2 P <0.02. The number of reversible defect on planar images was 3.5 +/- 2.3 group 1 versus 4.9 +/- 2.3 group 2 P<0.007 and 4 +/- 2.1 group 1 versus 5.4 +/- 2.3 P<0.009 in group 2 on SPECT images. The grade of worst reversible defect on planar images was 1.08 +/- 0.71 in-group 1 versus 0.77 +/- 0.67 in-group 2. P <0.04 and was 1.2 +/- 0.67 group 1 versus 0.74 +/- 0.62 P < 0.002 group 2 on SPECT images. The ischaemic index on planar images was 1.1 +/- 0.9 group 1 versus 1.61 +/- 1 group 2 P < 0.02 and 0.8 +/- 0.6 group 1 versus 1.3 +/- 0.8 group 2 P <0.008 on SPECT images. Thus both exercise ECG and T1-201 scintigraphy findings show lesser ischaemia in patients with no chest pain versus those with chest pain on treadmill testing. The results of this study were similar for both planar and SPECT imaging