Original ArticleIncremental prognostic value of coronary flow reserve assessed with single-photon emission computed tomography
Introduction
Myocardial perfusion imaging with single-photon emission computed tomography (SPECT) is an established diagnostic and prognostic method for evaluation of patients with suspected or known coronary artery disease (CAD).1 This technique has proven to be useful in prognostic stratification and provides information for the clinical decision-making process.2 Normal stress SPECT imaging is associated with a very low event rate (≤1%/year), leading to a negative predictive value of more than 99%.3 In contrast, abnormal SPECT increases the annualized event rate by a factor of 7, and the risk of events is related to the severity of perfusion abnormalities.4 However, the limitations of relative perfusion imaging by SPECT suggest that patient care might be enhanced by the use of quantitative measures of perfusion reserve.5,6 Although positron emission tomography (PET) imaging is the gold standard to measure CFR in non-invasive way, attempts have been recently made to obtain quantitative CFR by dynamic SPECT imaging.7, 8, 9, 10 This approach is potentially open to implementation in most nuclear cardiology laboratories and it could be adapted for general application.11 A good correlation between CFR values estimated by SPECT and those measured by intravascular Doppler ultrasound has been reported.8,10 This technique has been also validated by comparison with PET, despite some underestimation at higher flow rate.9 These findings support the concept that SPECT may compete with other modalities for CFR estimation.1,11 However, no data are currently available on the predictive value of SPECT estimated CFR. Therefore, the aim of this study was to assess the long-term prognostic value of CFR estimated by SPECT imaging in patients with suspected myocardial ischemia.
Section snippets
Patients
The study population included 106 consecutive patients who underwent stress SPECT imaging because of suspected myocardial ischemia; 29 of these patients had known CAD. In all patients, beta-blockers and calcium antagonists were withheld for 48 h and long-acting nitrates for 12 h before testing. Cardiovascular risk factors such as hypertension, diabetes mellitus, dyslipidemia, smoking, or positive family history for CAD were assessed at the time of SPECT imaging by reviewing patient charts. The
Results
SPECT imaging was performed in 106 patients. Follow-up data were complete in 103 (97% of the total) patients. Of these, four patients were excluded due to early revascularization (<60 days), leaving 99 patients (80 men, mean age 59 ± 11 years) available for the analysis.
Discussion
To the best of our knowledge, this is the first study assessing the long-term prognostic value of CFR estimated by SPECT imaging in patients with suspected myocardial ischemia. The main result of the study is that CFR is a strong independent predictor of major adverse cardiovascular events and provides incremental prognostic information over those obtained from clinical and myocardial perfusion data.
The quantitative assessment of CFR may be useful for the functional evaluation of CAD, allowing
Conclusions
Myocardial perfusion findings and CFR at SPECT imaging are both independent predictors of cardiac events. In this pilot study, estimated CFR using myocardial retention index appears to provide prognostic information along with myocardial perfusion data. The findings of this study support further evaluation in larger investigations to establish the prognostic value of CFR estimated by SPECT imaging.
Acknowledgment
The authors have indicated they have no financial conflicts of interest.
References (26)
- et al.
ACCF/ASNC appropriateness criteria for single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI): A report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group and the American Society of Nuclear Cardiology endorsed by the American Heart Association
J Am Coll Cardiol
(2005) - et al.
Stress myocardial perfusion single-photon emission computed tomography is clinically effective and cost effective in risk stratification of patients with a high likelihood of coronary artery disease (CAD) but no known CAD
J Am Coll Cardiol
(2004) Challenges for measurement of myocardial perfusion and perfusion reserve by SPECT imaging
J Nucl Cardiol
(2007)The clinical assessment of coronary flow reserve in patients with coronary artery disease
J Nucl Cardiol
(2004)- et al.
Estimation of coronary flow reserve with the use of dynamic planar and SPECT images of Tc-99m tetrofosmin
J Nucl Cardiol
(2001) - et al.
Estimation of coronary flow reserve by Tc-99m sestamibi imaging in patients with coronary artery disease: Comparison with the results of intracoronary Doppler technique
J Nucl Cardiol
(2004) - et al.
Assessment of coronary flow reserve using single photon emission computed tomography with technetium 99m-labeled tracers
J Nucl Cardiol
(2008) - et al.
Estimation of coronary flow reserve by sestamibi imaging in type 2 diabetic patients with normal coronary arteries
J Nucl Cardiol
(2007) - et al.
American Society of Nuclear Cardiology. Myocardial perfusion and function: Single photon emission computed tomography
J Nucl Cardiol
(2007) - et al.
Stress cardiac single-photon emission computed tomographic imaging late after coronary artery bypass surgery for risk stratification and estimation of time to cardiac events
J Thorac Cardiovasc Surg
(2008)
Universal definition of myocardial infarction
J Am Coll Cardiol
Noninvasive quantitation of myocardial blood flow in human subjects with oxygen-15-labeled water and positron emission tomography
J Am Coll Cardiol
Long-term prognostic value of 13N-ammonia myocardial perfusion positron emission tomography added value of coronary flow reserve
J Am Coll Cardiol
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See related editorial, doi:10.1007/s12350-011-9408-6.