Analysis of Perfusion Studies following Coronary Angioplasty: Time Interval between Angioplasty and Perfusion. Restenosis and Ischemia

pp. 196-202

Abstract

Background

International guidelines coincide in recommending that the best time to perform perfusion studies in patients undergoing coronary angioplasty is about six months following the procedure. However, cardiologists order these studies earlier, for several reasons.

Objectives

To determine reversible perfusion defects (RPDs), time interval between percutaneous transluminal coronary angioplasty (PTCA) and perfusion test, false positive results, ischemic burden in patients without coronary lesions and with coronary lesions in other vessels that were not treated with PTCA, and reasons for ordering a SPECT.

Material and Methods

Sixty four consecutive patients undergoing a first SPECT during the first year following a PTCA were included in two groups. Group 1: 44/64 patients (68.8%) without lesions in other coronary arteries that had not been treated with PTCA and group 2: 20/64 patients (31.2%) with lesions in other coronary arteries that had not been treated with PTCA. Mean age was 57.3±10 years. Perfusion defects were assessed based on a semiquantitative visual analysis using a validated model of 17 segments.

Results

A total of 12 patients (18.7%) out of 64 presented RPDs: 9/44 (20.4%) in group 1 and 3/20 (15%) in group 2. There were 3/12 (25%) false positive results during the first month following two balloon angioplasties and one stent implant. Two of these results were confirmed by SPECT performed later and one by coronary angiography; all patients belonged to group 1. Time interval between PTCA and SPECT was as follows: first trimester in 33 patients, second trimester in 22 patients and third trimester or later in 9 patients. There were no significant differences between both groups in the triple score. SSS: 5.3±3.07 in group 1 and 7±4.5 in group 2; p >0.99. SRS: 1.66±1.73 in group 1 and 0.6±1.15 in group 2; p >0.99. SDS: 4.3±1.7 in group 1 and 6.3±3.5 in group 2; p >0.99. Reasons for test ordering were: control study in 49/64 (76.5%) and presence of symptoms in 15/64 (23.4%). A positive correlation between angina and RPDs was seen in 1/9 patients (11.1%).

Conclusions

SPECT was performed in 51.5% of patients within 3 months following angioplasty. No differences in ischemic burden among patients without coronary lesions or with lesions in other vessels were reported. False positive results were observed in 25% of patients with RPDs who were evaluated during the first month following angioplasty. SPECT was ordered as a control study in 76.5% of cases and there was low correlation between the presence of symptoms and studies positive for ischemia.