Sequential thallium-201 myocardial perfusion studies after successful percutaneous transluminal coronary artery angioplasty: delayed resolution of exercise-induced scintigraphic abnormalities.

Abstract

To characterize the sequential changes of myocardial perfusion scintigraphy in patients with coronary artery disease (CAD) after complete revascularization, 43 patients undervwent exercise thallium-201 (201T1) myocardial perfusion scintigraphy before and at 9 5 days, 3.3 ± 0.6, and 6.8 -+ 1.2 months after percutaneous transluminal coronary angioplasty (PTCA). Only patients with single-vessel CAD, without previous myocardial infarction, and without evidence of restenosis at 6 to 9 months after PTCA were included. Perfusion scans were analyzed blindly with the use of a new quantitative method to define regional myocardial perfusion in the topographic distribution of each coronary artery, which was shown to be reproducible (r = .94 or higher and SEE of 7% or less, between repeated measures by one and two operators). At 4 to 18 days after PTCA, the mean treadmill walking time increased by 123 + 42 sec, mean exercise-induced ST segment depression decreased by 0.6 + 0.3 mm, group maximal heart rate increased by 20 + 9 beats/min, and group systolic blood pressure at peak exercise increased by 24 + 10 mm Hg, compared with pre-PTCA values (p < .001). However, no group differences were noted in these variables between the three post-PTCA stages. Myocardial perfusion in the distribution of the affected (dilated) coronary artery, on the other hand, improved progressively. In the 45 degree left anterior oblique view for instance, myocardial perfusion increased at 9 days after PTCA (from 68 + 24% before PTCA to 91 + 9%, p < .001) and at 3.3 months after PTCA (101 + 8%, p < .05 vs 9 days after PTCA), but no further significant changes were seen at 6.8 months after PTCA (102 ± 8 %). Similar changes were noted in the other two views. No relationship between minor complications during PTCA and delayed improvement on the 20tTl was observed.Myocardial ischemia was diagnosed in 12 of the 43 scans recorded a few days after PTCA, but in none recorded at later stages. We conclude that 201T1 scans after PTCA often show delayed improvement and therefore, an abnormal myocardial perfusion scan soon after PTCA does not necessarily reflect residual coronary stenosis or recurrence. Circulation 77, No. 1, 86-95, 1988. PERCUTANEOUS transluminal coronary artery angioplasty (PTCA) has been shown to improve exercise tolerance and to prevent stress-induced myocardial ischemia in selected patients with coronary artery disFrom the Divisions

Myocardial Perfusion Abnormalities Early (12–24 h) after Coronary Stenting or Balloon Angioplasty: Implications Regarding Pathophysiology and Late Clinical Outcome

“…The presence of early reversible perfusion defects predicted late coronary restenosis [4, 5, 6]. In some patients, reversible perfusion defects resolved in the months following the procedure [15]. …”

Myocardial ischemia is a key factor in the management of stable coronary artery disease

“…In the era of coronary angioplasty, many studies reported that numerous "false positive" reversible perfusion defects occurred early after angioplasty, possibly as a result of inadequate early vessel remodeling or sustained abnormalities of coronary vasomotor tone. However, a significant percentage of patients showed persistent abnormalities in the later period [59][60][61][62][63][64][65][66] . In one study, 76% of patients without prior myocardial infarction showed improvement in perfusion abnormalities after angioplasty, but only 34% had completely reversible ischemia [60] .…”

Contrast Echocardiography in Coronary Artery Disease

“…Non- invasive diagnosis of restenosis can be challenging. Previous SPECT studies have demonstrated that normalization of regional myocardial perfusion usually occurs after successful revascularization (Manyari et al, 1988;Zhang et al, 2004). In a follow-up study using quantitative contrast stress echocardiography in 33 patients with stable angina pectoris treated with percutaneous coronary intervention and stent implantation, there was no improvement in stress-induced myocardial perfusion during follow-up in patients who had developed a significant angiographic restenosis, while the stress-induced perfusion was improved in patients with successful revascularisation at 9 months .…”