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Results of adenosine single photon emission computed tomography thallium-201 imaging in hemodynamic nonresponders
S V Aksut1, S Pancholy, D Cassel
1Philadelphia Heart Institute, Presbyterian Medical Center, PA 19104, USA.
Insights
Adenosine myocardial perfusion imaging using SPECT thallium-201 is effective for detecting coronary artery disease (CAD). Lack of blood pressure drop during adenosine infusion does not impact the diagnostic accuracy of this important cardiovascular imaging technique.
Area of Science:
- Cardiology
- Nuclear Medicine
- Diagnostic Imaging
Background:
- Adenosine infusion commonly causes a decrease in systolic blood pressure due to systemic vasodilation.
- Some patients do not exhibit this hemodynamic response (nonresponders) during adenosine stress testing.
- The impact of this non-response on the diagnostic accuracy of myocardial perfusion imaging is not well understood.
Purpose of the Study:
- To evaluate the sensitivity of adenosine SPECT thallium-201 imaging in detecting coronary artery disease (CAD) in patients who do not show a blood pressure decrease during adenosine infusion (nonresponders).
Main Methods:
- Retrospective analysis of adenosine SPECT thallium-201 imaging results.
- Comparison of diagnostic sensitivity between nonresponders (n=102) and responders (n=341) to adenosine.
- Patient characteristics and coronary artery disease extent by angiography were analyzed.
Main Results:
- No significant differences were observed in age, gender, comorbidities, or extent of CAD between nonresponders and responders.
- The sensitivity of SPECT thallium-201 for detecting one-vessel disease, multivessel disease, and overall CAD was similar in both groups (p=NS).
- Sensitivity for all CAD was 87% in nonresponders and 91% in responders.
Conclusions:
- Lack of a systemic hemodynamic response (blood pressure decrease) during adenosine infusion does not compromise the sensitivity of SPECT thallium-201 imaging for detecting coronary artery disease.
- Adenosine SPECT thallium-201 remains a reliable tool for CAD assessment, irrespective of the patient's blood pressure response to adenosine stress.
Abstract:
Systolic blood pressure typically decreases during adenosine infusion because of stimulation of A2b receptors, resulting in systemic vasodilation. This study examined the results of adenosine single photon emission computed tomography (SPECT) thallium-201 imaging in patients who did not show such a decrease in blood pressure during peak adenosine effect (nonresponders). The 102 nonresponders and 341 responders had no significant differences in age, gender, history of diabetes mellitus, hypertension, or previous myocardial infarction. The extent of coronary artery disease (CAD) by angiography was also similar. The sensitivity of SPECT thallium-201 imaging in patients with one-vessel disease was 82% in nonresponders and 84% in responders (p value not significant [NS]); in patients with multivessel disease, it was 90% in nonresponders and 94% in responders (p = NS) and for all CAD, it was 87% in non-responders and 91% in responders (p = NS). Thus lack of hemodynamic systemic response during adenosine infusion does not affect sensitivity for detecting CAD.