Usefulness of Tomographic Thallium-20 Imaging for Detection of Restenosis After Percutaneous Transluminal Coronary Angioplasty
1
Harvey S. Hecht, MD, Richard E. Shaw, PhD, Thomas R. Bruce, MD, Colman Ryan, MD, Simon H. Stertzer, MD, and Richard K. Myler, MD
The role of tomographic thallium-201 exercise and redistribution imaging in the detection of restenosis after percutaneous transluminai coronary angiopiasty (PTCA) was evaluated in 116 patients: 61 (53%) with l- and 55 (47%) with multivessel PTCA, with a total of 185 dilated vessels. Complete revascularization was performed in 89 (77%) and partial revascuiarization in 27 (23%) of the patients. Restenosis was angiographicaily demonstrated in 69 (60%) of the patients and 85 (46%) of the vessels 6.4 f 3.1 months after PTCA. Disease progression in previously normal vessels was noted in 11 patients. The results were: (1) for detection of restenosis in the group of patients, single-photon emission computed tomographic (SPECT) versus exercise electrocardiographic sensitivity was 93 vs 52% (p 85% of predicted maximal heart rate (%) Chest pain during exercise test (%) Total patients Patients with restenosis Patients with restenosis or partial revascularization or progression, or a combination of these
PTCA = percutaneous
7.5f3.1 140& 170f21
Coronary
Arteriography
One-vessel PTCA (%) Two-vessel PTCA (“‘) Three-vessel PTCA (%) Total vessels dilated Left anterior descending Right coronary Left circumflex Patients with restenosis (%) Vessels with restenosis (%) Total Left anterior descending Right coronary Left circumflex Diameter reduction (%) Immediately before PTCA Immediately after PTCA Time of restudy
58f9 93/23 (80/20) 49 (42) 9 (8) 106 (91) 97 (84)
Age (YU Gender m/f (%) Prior myocardial infarction (%) Diabetes mellitus (%) Antianginal drugs (%) Calcium antagonists Nitrates p blockers Chest pain before PTCA (%) Chest pain after PTCA (%) Mos after PTCA PTCA = percutaneous
TABLE
Population
translumlnal
coronary
61(53)
40 (34) 15 (13) 185
83 62 40 70 (60) 85 44 24 17
(46) (53) (39) (43)
78&14
22f6 78f13 angioplasty.
13
77 (66)
recorded before the PTCA. Prediction of the absence or presence of restenosis was then made before angiographic reevaluation, based on the presence or absence of ischemic redistribution in the territory of the individual vessels. Statistical analyses were performed using the Student t test and chi-square analysis.
30 (26) 39 (34) 36 (31)
RESULTS
minutes after isotope injection, 3 to 5 hours later, and, when indicated, 24 hours later, on a Siemens Orbiter large field-of-view tomographic camera interfaced with a Medical Data Systems A3 computer. We processed data using a previously described protocol.12 Tomograms were reoriented in the short-axis, vertical longaxis and horizontal long-axis planes, reconstructed at 1 pixel/slice, representing approximately 6.2-mm thickness and divided into multiple segments for analysis. Qualitative analysis of each segment of the exercise and redistribution views was performed on a 0 to 4 scale (0 = normal, 1 = equivocally reduced thallium uptake, 2 = mildly reduced uptake, 3 = moderately reduced uptake, and 4 = severely reduced uptake) by 2 independent observers. Scores of 22 were considered abnormal and differences of opinion were resolved by consensus. Quantitative analysisI was performed and was used as an adjunct for visual analysis but final decisions were based on the visual evaluation. Myocardial ischemia was categorized as either total or partial normalization of a segment from exercise to redistribution imaging with a minimal improvement of 1 point on the visual scale. oronary arteriography: All patients underwent selective coronary arteriography within the week after the SPECT exercise imaging. Selective left and right coronary arteriograms were obtained with either the Judkins or Sones approach. Restenosis was defined as return of a previously dilated vessel to a 1.50% diameter reduction, determined by magnified electronic caliper measurements. image ~orre~atio~~~ The SPEGT image regions were assigned to the distribution of individual vessels guided by the coronary anatomy obtained from the angiogram
The characteristics of the patient population and exercise performance are listed in Tables I and II. Almost all were receiving antianginal medications. Whereas 103 (89%) of the patients experienced chest pain before angioplasty, only 75 (65%) were symptomatic at the time of restudy and only 30 (26%) experienced chest pain during the exercise test. Coronary arteriography (Table 111): The patients were evenly divided between those undergoing l- and multivessel PTCA. Eighty-nine patients were totally revascularized (i.e., all vessels with >50% stenosis were dilated), with a total of 150 vessels undergoing PTCA. In 27 patients, only partial revascularization was accomplished, with a total of 35 vessels undergoing PTCA; 3 1 vessels, including 16 old total occlusions, were not dilated. At the time of restudy, 70 (60%) of the patients had 2 1 vessel with restenosis. Of the total 185 vessels, restenosis occurred in 85 (46%). There were no differences in the restenosis rates in the 3 coronary arteries. In those vessels in which restenosis occurred, the percent narrowing at the time of restudy was virtually identical to that immediately before PTCA. Development of significant disease in vessels that had
1
Harvey S. Hecht, MD, Richard E. Shaw, PhD, Thomas R. Bruce, MD, Colman Ryan, MD, Simon H. Stertzer, MD, and Richard K. Myler, MD
The role of tomographic thallium-201 exercise and redistribution imaging in the detection of restenosis after percutaneous transluminai coronary angiopiasty (PTCA) was evaluated in 116 patients: 61 (53%) with l- and 55 (47%) with multivessel PTCA, with a total of 185 dilated vessels. Complete revascularization was performed in 89 (77%) and partial revascuiarization in 27 (23%) of the patients. Restenosis was angiographicaily demonstrated in 69 (60%) of the patients and 85 (46%) of the vessels 6.4 f 3.1 months after PTCA. Disease progression in previously normal vessels was noted in 11 patients. The results were: (1) for detection of restenosis in the group of patients, single-photon emission computed tomographic (SPECT) versus exercise electrocardiographic sensitivity was 93 vs 52% (p 85% of predicted maximal heart rate (%) Chest pain during exercise test (%) Total patients Patients with restenosis Patients with restenosis or partial revascularization or progression, or a combination of these
PTCA = percutaneous
7.5f3.1 140& 170f21
Coronary
Arteriography
One-vessel PTCA (%) Two-vessel PTCA (“‘) Three-vessel PTCA (%) Total vessels dilated Left anterior descending Right coronary Left circumflex Patients with restenosis (%) Vessels with restenosis (%) Total Left anterior descending Right coronary Left circumflex Diameter reduction (%) Immediately before PTCA Immediately after PTCA Time of restudy
58f9 93/23 (80/20) 49 (42) 9 (8) 106 (91) 97 (84)
Age (YU Gender m/f (%) Prior myocardial infarction (%) Diabetes mellitus (%) Antianginal drugs (%) Calcium antagonists Nitrates p blockers Chest pain before PTCA (%) Chest pain after PTCA (%) Mos after PTCA PTCA = percutaneous
TABLE
Population
translumlnal
coronary
61(53)
40 (34) 15 (13) 185
83 62 40 70 (60) 85 44 24 17
(46) (53) (39) (43)
78&14
22f6 78f13 angioplasty.
13
77 (66)
recorded before the PTCA. Prediction of the absence or presence of restenosis was then made before angiographic reevaluation, based on the presence or absence of ischemic redistribution in the territory of the individual vessels. Statistical analyses were performed using the Student t test and chi-square analysis.
30 (26) 39 (34) 36 (31)
RESULTS
minutes after isotope injection, 3 to 5 hours later, and, when indicated, 24 hours later, on a Siemens Orbiter large field-of-view tomographic camera interfaced with a Medical Data Systems A3 computer. We processed data using a previously described protocol.12 Tomograms were reoriented in the short-axis, vertical longaxis and horizontal long-axis planes, reconstructed at 1 pixel/slice, representing approximately 6.2-mm thickness and divided into multiple segments for analysis. Qualitative analysis of each segment of the exercise and redistribution views was performed on a 0 to 4 scale (0 = normal, 1 = equivocally reduced thallium uptake, 2 = mildly reduced uptake, 3 = moderately reduced uptake, and 4 = severely reduced uptake) by 2 independent observers. Scores of 22 were considered abnormal and differences of opinion were resolved by consensus. Quantitative analysisI was performed and was used as an adjunct for visual analysis but final decisions were based on the visual evaluation. Myocardial ischemia was categorized as either total or partial normalization of a segment from exercise to redistribution imaging with a minimal improvement of 1 point on the visual scale. oronary arteriography: All patients underwent selective coronary arteriography within the week after the SPECT exercise imaging. Selective left and right coronary arteriograms were obtained with either the Judkins or Sones approach. Restenosis was defined as return of a previously dilated vessel to a 1.50% diameter reduction, determined by magnified electronic caliper measurements. image ~orre~atio~~~ The SPEGT image regions were assigned to the distribution of individual vessels guided by the coronary anatomy obtained from the angiogram
The characteristics of the patient population and exercise performance are listed in Tables I and II. Almost all were receiving antianginal medications. Whereas 103 (89%) of the patients experienced chest pain before angioplasty, only 75 (65%) were symptomatic at the time of restudy and only 30 (26%) experienced chest pain during the exercise test. Coronary arteriography (Table 111): The patients were evenly divided between those undergoing l- and multivessel PTCA. Eighty-nine patients were totally revascularized (i.e., all vessels with >50% stenosis were dilated), with a total of 150 vessels undergoing PTCA. In 27 patients, only partial revascularization was accomplished, with a total of 35 vessels undergoing PTCA; 3 1 vessels, including 16 old total occlusions, were not dilated. At the time of restudy, 70 (60%) of the patients had 2 1 vessel with restenosis. Of the total 185 vessels, restenosis occurred in 85 (46%). There were no differences in the restenosis rates in the 3 coronary arteries. In those vessels in which restenosis occurred, the percent narrowing at the time of restudy was virtually identical to that immediately before PTCA. Development of significant disease in vessels that had
