Biomedical subjects

J D Friedman

Publications and source records attributed to J D Friedman.

52 records · Page 3Linked to original sources

PubMed1994

Myocardial perfusion imaging with technetium-99m-sestamibi: comparative analysis of available imaging protocols.

Several protocols for rest and stress myocardial perfusion imaging with 99mTc-sestamibi have been developed, each with distinct advantages and disadvantages. The various approaches have similar sensitivities and specificities for detection of coronary artery disease (CAD), but differ mainly in their ability to identify defect reversibility. The dual-isotope approach, with a rest 201Tl study and a stress 99mTc-sestamibi study, permits optimal evaluation of both stress perfusion and defect reversibility. Gated SPECT may be added to any of the protocols and aids in identifying artifacts, defining regional wall thickening and assessing ventricular function. First-pass 99mTc-sestamibi radionuclide angiography can add exercise ventricular function data to the study. Clinical trials have shown that the various protocols for 99mTc-sestamibi provide diagnostic and prognostic information comparable to that derived from traditional 201Tl imaging, with the added advantage of higher quality images and increased certainty in interpretation.

Coronary Circulation↗

PubMed1993

Separate acquisition rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion single-photon emission computed tomography: a clinical validation study.

OBJECTIVES: This study assessed the validity of a novel approach to myocardial perfusion scintigraphy that provides the opportunity to avoid the drawbacks of standard same-day rest/stress technetium-99m sestamibi myocardial perfusion studies by using separate-acquisition dual-isotope rest thallium-201 and exercise technetium-99m sestamibi single-photon emission computed tomography (SPECT). BACKGROUND: Standard same-day rest/stress technetium-99m sestamibi myocardial perfusion studies are cumbersome, associated with a potential decrease in perceived stress defect severity compared with thallium-201 due to the presence of rest technetium-99m sestamibi and may be unable to differentiate hibernating from infarcted myocardium. METHODS: The dual-isotope procedure was performed in 63 patients without previous myocardial infarction undergoing coronary angiography to evaluate sensitivity and specificity for coronary artery disease and in 107 patients with a low (< 5%) likelihood of coronary artery disease to evaluate normalcy rate. To validate defect reversibility, the dual-isotope SPECT study was compared with stress/rest technetium-99m sestamibi SPECT studies in a separate group of 31 patients with previous documented myocardial infarction who underwent a rest technetium-99m sestamibi study in addition to the dual-isotope SPECT study. RESULTS: In angiographic correlations, dual-isotope SPECT demonstrated high sensitivity for detecting patients with > or = 50% stenosis (91%, 55 patients) and > or = 70% stenosis (96%, 52 patients). In a small group of patients, high specificity was also observed (75% for < 50% stenosis [8 patients] and 82% for < 70% stenosis [11 patients]). A very high normalcy rate of 95% was also found. In the patient group assessed for defect reversibility, in zones with no previous myocardial infarction, segmental agreement for defect type between rest thallium-201 and rest technetium-99m sestamibi studies was 97% (kappa = 0.79, p < 0.001). In myocardial infarct zones, segmental agreement for defect type was 98% (kappa = 0.93, p < 0.001). Image quality was generally good to excellent. CONCLUSIONS: Our findings demonstrate that separate-acquisition dual-isotope myocardial perfusion SPECT is accurate for coronary artery disease detection, correlates well with rest-stress sestamibi studies for assessment of defect reversibility and results in good to excellent image quality. This approach provides an excellent method for the combined assessment of stress myocardial perfusion and myocardial viability.

Aged↗

PubMed1993

Soft tissue reconstruction. Monitoring.

Despite recent advances in technology, no safe and completely reliable monitoring device is available for clinical use. As a result, direct clinical evaluation remains the mainstay of post-operative monitoring efforts. Although we have found this technique to be reliable, we tend to supplement it with Doppler ultrasonography, particularly in those patients in whom the flap remains buried beneath the skin. In patients with replants, we use pulse oximetry as an adjunct to clinical findings. This has proved to be reliable in our experience. However, should any question arise concerning altered tissue perfusion, we remain liberal in our indications for reexploration. The old adage of "better safe than sorry" certainly applies, for it is much easier to reexplore a flap than to lose a potentially salvageable reconstruction. The future remains promising for techniques such as laser Doppler study and various methods of measuring transcutaneous oxygen. However, further experimental and clinical trials are necessary to determine the efficacy of these methods.

Blood Gas Monitoring, Transcutaneous↗

PubMed1992

Quantitative stress-redistribution thallium-201 SPECT using prone imaging: methodologic development and validation.

Prone 201Tl myocardial perfusion SPECT has been shown to improve left ventricular inferior wall counts compared to supine imaging, thus minimizing diaphragmatic attenuation. Prone SPECT quantitative normal limits were developed and prospectively applied to 36 patients who had coronary angiography. The prone imaging table used had a cut-out under cardiac area which increased the average myocardial counts by 10.7% compared to prone SPECT through the standard table. Overall specificity and sensitivity were 80% and 93%, respectively. For the right, left circumflex and left anterior descending coronary arteries, the specificities were 94%, 71%, and 94%; and sensitivities were 88%, 89% and 78%, respectively. The normalcy rate in 55 normal patients was 89%. Incidence and the severity of patients motion in 200 prone SPECT studies were compared to 200 supine SPECT studies. Mild and severe motion occurred in 12% and 4% of the supine studies and in only 3.5% and none of the prone studies, respectively. When compared to supine SPECT, prone SPECT had higher (p less than 0.01) regional counts/pixel in the inferior wall and septum, but required an average increase of 2.9 +/- 1.0 cm in camera to chest wall distance and resulted in a reduction of total myocardial counts. Prone SPECT provides an alternative approach for patients who cannot tolerate supine imaging. It should be considered when inferior wall defects on supine imaging pose a diagnostic dilemma and when motion on supine imaging necessitates repeat acquisition.

Aged↗

PubMed1991

Frequency of late reversibility in stress-redistribution thallium-201 SPECT using an early reinjection protocol.

To assess the efficacy of an early thallium-201 reinjection protocol for reducing the need for late redistribution imaging, the frequency of thallium-201 late reversibility was prospectively assessed in 62 patients who had stress-redistribution thallium-201 studies by single-photon emission computerized tomography (SPECT), and who received 1 mCi of thallium-201 reinjection immediately following stress tomographic acquisition. These patients also demonstrated greater than or equal to 2 segments with nonreversible defects at 4-hour imaging and underwent late (18-to 72-hour) redistribution imaging. When the criterion of late reversibility was defined as greater than or equal to 1 segment with a 4-hour nonreversible defect demonstrating late reversibility, late reversibility was present in 36 (58%) of the 62 patients and in 88 (24%) of 368 SPECT segments. When the criterion of greater than or equal to 2 segments was used, late reversibility was found in 21 (34%) of the 62 patients and in 73 (20%) of the 368 segments. Of the 21 patients who had greater than or equal to 2 late reversible segments, 12 (57%) exhibited late reversibility in greater than or equal to 3 segments. The frequency of detected reversible defects increased from 32% by 4-hour imaging to 48% by combined 4-hour and late imaging (p less than 0.0001). The patients who demonstrated late reversibility could not be distinguished from those who had only late nonreversible defects by analysis of the clinical, exercise, and electrocardiographic (ECG) variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1991

A new approach to the assessment of tomographic thallium-201 scintigraphy in patients with left bundle branch block.

To determine whether a new approach to interpretation could improve the accuracy of thallium-201 single photon emission computed tomography (SPECT) for detection of left anterior descending coronary artery disease in patients with left bundle branch block, 69 patients were evaluated. Forty-four had angiographically proved coronary artery disease; the remaining 25 were considered to have a "low" (mean 13.5 +/- 6.4%, range 3.4% to 24.9%) likelihood of disease before thallium-201 scintigraphy. The conventional scintigraphic criterion for detection of left anterior descending artery disease (septal, anterior or apical defects) was compared with a new criterion that required the apex to be abnormal to indicate left anterior descending disease. The normalcy rates in the low likelihood patient group were significantly improved by using the new approach, from 16% to 80% (p less than 0.0001) by visual analysis and from 24% to 64% (p = 0.003) by quantitative SPECT polar map analysis. The sensitivity for left anterior descending disease was similar for the conventional and the new method by visual (100% vs. 94%) and quantitative (100% vs. 83%) analyses. In contrast, the specificity was significantly improved by using the new approach, from 14% to 79% (p = 0.0006) by visual analysis and 14% to 64% (p = 0.007) by quantitative analysis. In conclusion, septal and anterior thallium-201 SPECT defects are common in patients with left bundle branch block without coronary artery disease, resulting in low specificity for left anterior descending artery disease. The normalcy rates and accuracy for detection of left anterior descending coronary artery disease were significantly better when an apical defect was used as the criterion for disease.

Aged↗

PubMed1990

Development and prospective application of quantitative 2-day stress-rest Tc-99m methoxy isobutyl isonitrile SPECT for the diagnosis of coronary artery disease.

The clinical diagnostic accuracy of 2-day stress/rest quantitative Technetium-99m (Tc-99m) methoxy-isobutyl-isonitrile (Tc-sestamibi) single photon emission computerized tomography (SPECT) was assessed in a validation population of 61 patients from two different sites using two different camera/computer systems. The study population was made up of 53 catheterized patients, 29 from Cedars-Sinai Medical Center (CSMC) and 24 from the University of Texas Southwestern Medical Center (UTSMC), and eight UTSMC patients with a less than 5% pre-test likelihood of coronary artery disease. Interpretation employed gender-specific normal limits developed in an additional 15 men and 8 women at CSMC with less than a 5% likelihood of significant coronary artery disease. The results from CSMC compared with those from UTSMC were not different from each other. The overall sensitivity for detection of patients with coronary artery disease (greater than or equal to 50% stenosis) was 94% (CSMC: 92%, UTSMC: 95%). Overall specificity in the five patients with normal coronary arteriograms was 80% (CSMC: 67%, UTSMC: 100%). The normalcy rate in patients with a low likelihood of coronary artery disease was 88%. Vessel sensitivity was 85% (CSMC: 84%, UTSMC: 85%), while vessel specificity was 71% (CSMC: 72%, UTSMC: 69%). There was also no significant difference in the sensitivities and specificities between male and female populations. In addition, the agreement with coronary angiography for assessment of disease extent (normal coronary arteriogram, single or multivessel disease) was 75% (kappa = 0.6 +/- 0.1). This study demonstrated that Tc-sestamibi SPECT by quantitative analysis is accurate for the detection and localization of coronary artery disease. Furthermore, the CSMC quantitative method was shown to provide similar diagnostic accuracy when applied to data acquired at a different site using a different camera/computer system.

Adult↗

PubMed1990

The frequency of late reversibility in SPECT thallium-201 stress-redistribution studies.

The frequency of thallium-201 late reversibility was prospectively assessed in 118 patients who had stress-redistribution thallium-201 studies by single photon emission computed tomography (SPECT). These patients demonstrated two or more segments with nonreversible defects at 4 h imaging and underwent late (18 to 72 h) redistribution imaging. When the criterion of late reversibility was defined as greater than or equal to 1 segment with 4 h nonreversible defects demonstrating late reversibility, it was present in 62 (53%) of the 118 patients and 164 (22%) of 762 segments. When the criterion of greater than or equal to 2 segments was used, late reversibility was found in 41 (35%) of 118 patients and 143 (19%) of 762 segments. The frequency of detected reversible defects increased from 27% at 4 h imaging to 43% at combined 4 h and late imaging (p less than 0.0001) and was significantly increased in all myocardial regions. In comparing the efficacy of initial and late imaging alone versus performing initial, 4 h and late imaging for the identification of reversible defects, 421 (94%) of 449 segments classified as reversible by the latter protocol were also correctly identified by the early and late imaging only approach, with the remaining 6% (28 segments) comprising those segments demonstrating the reversible pattern at 4 h and the nonreversible pattern at late imaging. No major differences were noted with respect to clinical, stress electrocardiographic and scintigraphic variables between the 118 patients undergoing late imaging and 98 additional randomly selected patients with two or more nonreversible defects at 4 h, who did not have late imaging.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1989

Comparison of myocardial washout rate of thallium-201 between rest, dipyridamole with and without aminophylline, and exercise states in normal subjects.

The myocardial washout rate of thallium-201 was studied in 85 subjects with a less than 5% likelihood of coronary artery disease undergoing rest (group I, n = 12), dipyridamole (group II, n = 24) and exercise (group III, n = 49) stress thallium-201 scintigraphy. Subjects receiving dipyridamole were subdivided into group IIA (n = 11), who received an aminophylline injection 10 minutes after dipyridamole infusion, and group IIB (n = 13), who did not. The mean and highest washout rate values in each of 3 segments in the anterior, 45 degrees and 85 degrees left anterior oblique views were calculated. In group II the mean washout rate of thallium-201 was similar in all segments of each view and the overall mean washout rate did not differ between the 3 views studied. There was a good correlation between the mean and highest washout rate values in individual subjects (r = 0.98, p less than 0.001). The mean +/- standard deviation myocardial 4-hour washout rate of thallium-201 (anterior view) was 10 +/- 6% in group I compared with 40 +/- 14% in group IIA (p less than 0.05 vs group I), 31 +/- 13% in group IIB (p less than 0.05 vs group I) and 54 +/- 11% in group III (p less than 0.05 each vs group IIA and group IIB, respectively). There was a wide variation in mean washout rate values in group II (range 12 to 58%), and this variation was not altered by aminophylline administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Experience with colonic volvulus.

Fifty-eight cases of colonic volvulus were reviewed including 30 cases of sigmoid volvulus, 27 cases of cecal volvulus, and 1 of transverse colon volvulus. Decompression procedures were attempted in 31 instances of sigmoid volvulus in 27 patients and were successful 25 times (81 percent). Seven patients with sigmoid volvulus did not undergo surgery and of those, two died of unrelated causes, one was lost to follow-up, one was well, and three had recurrent volvulus. Twenty-four operations were performed on 23 patients and there were three deaths (13 percent mortality). There was one recurrence in two patients who underwent simple detorsion. Chronic large-bowel motility disturbances were a persistent problem in 9 of 20 (45 percent) surgical survivors. Among 27 instances of cecal volvulus, one was reduced by contrast enema and ten endoscopic attempts at decompression were unsuccessful. Twenty-six operations were done and there were four operative deaths (15 percent mortality). There were no recurrences. Large-bowel motility disorders were noted in follow-up in 3 of 22 patients (14 percent). Overall there were 10 deaths in 58 patients for a 17 percent mortality rate. These data support the importance of endoscopic decompression for sigmoid volvulus but not for cecal volvulus. Definitive treatment of both forms of volvulus should include assessment of colonic motility.

Adult↗

PubMed1986

Quantitative analysis of stress thallium-201 myocardial scintigrams: a multicenter trial.

Previously we validated a method for quantification of 201TI myocardial stress distribution and washout in which the patient's stress and washout circumferential profiles are compared with observed normal limits. The present study reports the results of a multicenter trial in which this method, utilizing normal limits from our institution, was employed to evaluate the presence, location, and extent of coronary artery disease (CAD). The normal limits utilized were generated from 49 patients having a low likelihood of CAD. The study population included 157 patients from four centers in the United States and Canada as well as a comparative prospective population from Cedars-Sinai Medical Center (CSMC) of 51 patients with CAD, 30 patients with normal coronary arteriograms, and 30 additional low-likelihood normals. The results in the combined centers regarding overall detection of CAD revealed a sensitivity of 84% and a frequency of test normality in the patients with low likelihood of CAD of 88%, compared to a sensitivity of 82% and true normalcy rate of 83% obtained in the prospective CSMC population. The sensitivity for detecting disease increased according to the extent of angiographic CAD in both the multicenter sites and the prospective CSMC group. Regarding localization of disease, similar sensitivities and specificities for detecting disease in individual coronary arteries were found in the multicenter sites and the prospective CSMC population. The results indicate that our method for quantifying 201TI stress-redistribution scintigrams utilizing standard normal limits can be applied at other institutions using a variety of scintillation cameras with similar accuracy to that currently obtained at our institution.

Adult↗

PubMedDate not supplied

Rest and treadmill exercise first-pass radionuclide ventriculography: validation of left ventricular ejection fraction measurements.

BACKGROUND: To assess the accuracy of rest and treadmill exercise first-pass radionuclide ventriculographic measurements of left ventricular ejection fraction (LVEF), 40 patients underwent treadmill exercise first-pass and bicycle exercise equilibrium radionuclide ventriculography. To determine the frequency of technically adequate treadmill exercise first-pass studies, an additional 128 consecutive patients undergoing treadmill exercise first-pass procedures during stress 99mTc-labeled sestamibi myocardial perfusion studies were assessed. METHODS AND RESULTS: The treadmill exercise first-pass procedure used a multicrystal camera and an 241Am point source to allow for correction of patient motion. Excellent correlations were observed between resting first-pass and resting equilibrium LVEF (r = 0.91; standard error of the estimate = 5.6). A high correlation was also observed between treadmill exercise first-pass and bicycle equilibrium exercise LVEF measurements (r = 0.85, standard error of the estimate = 7.6). Treadmill first-pass LVEF systematically underestimated the bicycle equilibrium LVEF. Intraobserver agreement for rest and exercise first-pass LVEF was high (r values of 0.98 and 0.94, respectively). Of the 168 consecutive treadmill exercise first-pass studies evaluated for technical adequacy, 21 (12.5%) were deemed technically inadequate, with most of the sources of error being avoidable. The frequency of technically adequate studies was as high (87%) in high levels of exercise (Bruce stages 3 and 4) as in lower levels (88%). The findings of this study validate the first-pass treadmill exercise LVEF measurement. CONCLUSION: This procedure now provides the option for combining the information of peak treadmill exercise LVEF with measurements of exercise myocardial perfusion from the same injection of radioactivity.

Adult↗

PubMedDate not supplied

Comparative localization of myocardial ischemia by exercise electrocardiography and myocardial perfusion SPECT.

BACKGROUND: Prior angiographic study has shown that the patterns of ST-segment depression during exercise do not provide localizing information of the responsible coronary lesion. However, little is known regarding the ability of exercise-induced ST-segment displacement to localize myocardial perfusion defects. METHODS AND RESULTS: We studied 552 consecutive patients without prior myocardial infarction who had reversible perfusion defect in one vascular territory on rest 201Tl/exercise 99mTc-labeled sestamibi dual-isotope myocardial perfusion single photon emission computed tomography (SPECT) and ischemic ST depression or elevation during exercise. Of these, 192 patients had angiographically documented coronary artery disease (CAD). Two hundred thirty-two patients had maximal ST depression in anterior leads, 247 patients had maximal ST depression in inferior leads, and 45 patients had similar maximal ST depression in both anterior and inferior leads. Twenty-eight (5%) patients had ST elevation with absent Q waves. In patients with maximal ST depression in anterior leads, perfusion defects were found in the territory of the left anterior descending coronary artery (LAD) in 30%, in the territory of the right coronary artery (RCA) in 52%, and in the territory of the left circumflex coronary artery (LCX) in 18%. In patients with maximal ST depression in inferior leads, perfusion defects were found in RCA territory in 44%, in the LAD territory in 42%, and in the LCX territory in 14%. Compared with exercise ST depression, the less common finding of ST elevation did provide accurate localization of perfusion defects. When ST elevation was greatest in the anterior leads, 96% of patients had LAD territory defects. When ST elevation was most prominent in the inferior leads, 100% patients had RCA territory defects. Data of coronary angiograms demonstrated that myocardial perfusion SPECT correctly identified the most stenotic coronary disease for LAD (94%), LCX (72%), and RCA (75%). CONCLUSIONS: The findings of this study indicate that the site of maximal ST-segment depression does not identify the localization of myocardial perfusion defects. However, the less common finding of exercise-induced ST-segment elevation does predict localization of myocardial ischemia.

Adult↗

PubMedDate not supplied

Diagnostic efficacy of stress technetium 99m-labeled sestamibi myocardial perfusion single-photon emission computed tomography in detection of coronary artery disease among patients over age 80.

BACKGROUND: Because symptoms of myocardial ischemia in elderly patients are often atypical, accurate noninvasive assessment of the presence, extent, and severity of coronary artery disease (CAD) would be especially useful to avoid unnecessary catheterization or invasive intervention. This study assessed the safety and diagnostic efficacy of 99mTc-labeled sestamibi (99mTc-sestamibi) exercise and pharmacologic myocardial perfusion single-photon emission computed tomography (SPECT) with adenosine or dipyridamole in patients age 80 years or older. METHODS AND RESULTS: Stress 99mTc-sestamibi SPECT was performed in 75 consecutive patients who were 80 years old or older (range: 80 to 91 years) with suspected CAD and who underwent coronary angiography within 6 months of the nuclear study. Of these patients, 51 underwent a pharmacologic (adenosine = 42; dipyridamole = 9) stress study and 24 underwent an exercise treadmill study. A normalcy rate was derived from an additional 36 patients (ages 83 +/- 3 years) who had undergone stress 99mTc-sestamibi SPECT and who had a relatively low likelihood (< 20%) of CAD. No serious adverse events occurred during or after the exercise or the pharmacologic stress test. The overall sensitivity and specificity for detecting CAD with > or = 70% stenosis was 95% (52/55) and 75% (15/20), whereas the corresponding results were 87% (55/63) and 83% (10/12) for detecting patients with > or = 50% stenosis. The sensitivity and specificity for pharmacologic stress 99mTc-sestamibi SPECT were 95% (35/37) and 71% (10/14) for detecting > or = 70% stenosis, and 86% (37/43) and 75% (6/8) for detecting CAD with > or = 50% stenosis. The sensitivity and specificity of treadmill testing were 94% (17/18) and 83% (5/6) in detecting CAD with stenosis > or = 70% and 90% (18/20) and 100% (4/4) in detecting CAD with stenosis > or = 50%. The normalcy rate among the low likelihood patients was 83% (30/36). The accuracy of stress sestamibi testing was similar for patients with or without angina. CONCLUSIONS: Our findings suggest that exercise or pharmacologic myocardial perfusion SPECT with 99mTc-sestamibi is safe and diagnostically accurate for CAD detection in very elderly patients, irrespective of symptoms. Pharmacologic myocardial perfusion SPECT with adenosine or dipyridamole appears to be a valuable alternative to treadmill stress in very elderly patients incapable of performing adequate exercise.

Aged↗

PubMedDate not supplied

Repeatability of treadmill exercise ejection fraction and wall motion using technetium 99m-labeled sestamibi first-pass radionuclide ventriculography.

BACKGROUND: Peak treadmill exercise radionuclide ventriculography (RVG) with technetium 99m has recently been validated for determination of left ventricular ejection fraction (LVEF). However, the repeatability of this technique for determination of both LVEF and regional wall motion has not been reported. METHODS AND RESULTS: Each of 27 clinically stable patients underwent two treadmill exercise RVG studies within 40 +/- 51 days. The level of exercise achieved in the two tests was similar (double product: 26,357 +/- 3877 vs 26,621 +/- 4287), and there was no change in clinical or treatment status between the studies. Acquisition and processing were accomplished with a mobile multicrystal camera and a new version of a commercial software (Scinticor SIM 400 V. 4.1 BETA, Milwaukee, Wis.) that uses two left ventricular regions of interest. The two tests were compared to assess agreement (repeatability) on both an automatically calculated LVEF and wall motion in five left ventricular segments (basal anterior, distal anterior, apical, distal inferior, and basal inferior), with a 3-point semiquantitative visual score. Intraobserver and interobserver agreements (reproducibility) also were assessed on quantitative exercise LVEF derived from the same RVG test from a separate group of 20 patients with a broad range of exercise LVEF. The first and second treadmill exercise LVEFs were highly correlated (r = 0.92, SEE = 3.96, y = 0.97x + 0.58; and r = 0.99, SEE = 1.32, y = 0.99x + 0.25, respectively). Results of segmental visual score agreement between the first and the second treadmill first-pass studies were as follows: overall, 86% (116/135, kappa = 0.74); basal anterior, 85% (23/27, kappa = 0.72); distal anterior, 85% (23/27, kappa = 0.84); apical, 93% (25/27, kappa = 0.85); distal inferior, 93% (25/27, kappa = 0.80); and basal inferior, 67% (18/27, kappa = 0.64). CONCLUSION: Treadmill exercise first-pass RVG is a highly repeatable and reproducible test for quantitative LVEF and visual regional wall motion analysis. Our results imply the procedure may be useful for serial follow-up of patients with coronary artery disease and for the evaluation of the efficacy of medical or interventional treatment.

Adult↗

PubMedDate not supplied

Serial changes on quantitative myocardial perfusion SPECT in patients undergoing revascularization or conservative therapy.

BACKGROUND: Little is known about changes of myocardial perfusion in patients undergoing coronary revascularization or medical therapy. The purpose of this observational study was to assess the long-term effects of revascularization or conservative therapy on serial quantitative myocardial perfusion single photon emission computed tomography (SPECT). METHODS AND RESULTS: The study population consisted of 421 patients who underwent serial rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion SPECT with at least a 1-year interval between the 2 studies and who had abnormal quantitative scan results on the first stress SPECT. The mean interval between scans was 32.7 +/- 15.9 months. Patients were divided into 3 groups according to stress defect extent: group 1 had small stress defects (4%-10%, n = 145), group 2 had intermediate stress defects (>10%-20%, n = 144), and group 3 had extensive stress defects (>20%, n = 132) at baseline. Forty patients in group 1, 44 in group 2, and 54 in group 3 underwent coronary revascularization between 2 SPECT studies; the others had conservative therapy. In group 3 patients with revascularization, stress defect extent and reversible defect extent were remarkably reduced (14.5% +/- 13.6% and 13.1% +/- 12.5%, respectively; both P <.0001), with greater improvement in those patients reporting increased use of cardiac medications; resting defect extent was slightly reduced (1.9% +/- 6.4%, P <.05). In group 3 patients with conservative therapy, a small reduction in stress defect extent was noted (2.3% +/- 8.3%, P <.05). In group 2, there were modest, similar reductions in reversible defect extent in both the patients with revascularization (2.7% +/- 7.7%, P <.05) and those with conservative therapy (1.8% +/- 7.3%, P <.05), as well as a small but significant reduction in stress defect extent in those with conservative therapy (2.1% +/- 8.2%, P <.05). In group 1 patients, no significant changes in stress, rest, or reversible defect extent were found with either therapy. CONCLUSIONS: The findings of this study show that improvement in quantitative myocardial perfusion abnormalities over time occurs in some patients with either revascularization or conservative therapy and suggest that, in patients with extensive defects, greater improvement may be seen in those who undergo revascularization.

Adenosine↗