Long-term prognostic value of exercise technetium-99m tetrofosmin myocardial perfusion single-photon emission computed tomography

Abstract

BackgroundExercise 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) is a useful tool for short- and medium-term risk stratifications. Currently, the long-term prognostic application of this technique has not been evaluated.Methods and ResultsExercise 99mTc-tetrofosmin was performed in 655 consecutive patients. Ten patients who underwent revascularization <60 days after nuclear testing were excluded from the analysis. The present data are based on 638 patients with complete follow-up. An abnormal SPECT study was defined as the presence of fixed and/or reversible perfusion defects. End points were cardiac death, nonfatal infarction, and late coronary revascularization. A total of 344 (54%) patients had an abnormal SPECT study. Perfusion defects included fixed defects alone in 186 patients (29%) and reversible defects in 158 (25%) patients. During a mean follow-up of 11.0 ± 3.3 years, 174 (27%) patients died (all-cause mortality). Nonfatal myocardial infarction occurred in 76 (12%) patients, and late coronary revascularization was performed in 194 (30%) patients. Univariable and multivariable Cox proportional hazard regression analyses showed that exercise 99mTc-tetrofosmin SPECT provided prognostic information incremental to clinical data and exercise test data. Patients with a normal SPECT had a relatively favorable long-term prognosis, in contrast to patients with an abnormal study who had a significantly increased risk of cardiac events. The SPECT parameters abnormal scan, reversible defect, and summed rest score were strong predictors of long-term outcome.ConclusionExercise 99mTc-tetrofosmin myocardial perfusion SPECT has an incremental long-term prognostic value over clinical and stress test parameters for the prediction of major adverse cardiac events.

Impact of Appropriate Use on the Prognostic Value of Single-Photon Emission Computed Tomography Myocardial Perfusion Imaging

“…Normal MPI was defined on the basis of perfusion as SSS of 0-3. 22 Perfusion abnormalities were further categorized on the basis of SSS into mild (4)(5)(6)(7)(8), moderate (9-13), or severe (>13). 22 Reversible perfusion abnormalities, signifying stress-induced myocardial ischemia, were defined as SDS ≥2 and further categorized on the basis of SDS as mild (2-4), moderate (5-7), or severe (>7).…”

“…[1][2][3][4][5][6] Numerous studies have demonstrated that abnormal MPI predicts a multifold increase in the risk of major adverse cardiac events (MACE). [1][2][3][4][5][6] Furthermore, the prognostic utility of MPI is incremental to clinical, treadmill stress test, and coronary angiography data. [7][8][9] The robust prognostic data, favorable diagnostic performance, and wide availability of SPECT-MPI have led to a great expansion in use with consequent excessive expenditure.…”

Prognosis in patients with suspected or known ischemic heart disease and normal myocardial perfusion: Long-term outcome and temporal risk variations

“…25,38 In the European context, reported followup periods were 10, 11, and 15 years, respectively, in only 47, 294, and 233 patients with normal MPS, 14,15,35 However, in small, low-risk populations a consequently low overall event rate precludes differentiation of risk. 39 The strengths of the present study are the large population, the completeness of follow-up, and a follow-up period sufficiently long to allow for the prognostic importance of underlying risk factors to become unmasked with the opportunity of bringing new aspects to changes in risk over time.…”

“…12,13 Recently, reports on long-term outcome after (normal) MPS have also been emerging. 14,15 Despite this wealth of information, gaps in our knowledge base do still remain. 11,16 These knowledge gaps concern long-term outcome, in some cases revealing shifts in risk over time, thus refining our knowledge on prognosis.…”

The prognostic value of cardiac SPECT performed at the primary care physician’s office

“…[2][3][4][5] Numerous studies have demonstrated that patients with normal MPI have an annual risk of major adverse cardiovascular events (MACE) of less than 1%, while an abnormal MPI scan predicts a multifold increase in risk. [2][3][4][5][6] Multiple studies demonstrated that the prognostic utility of MPI is incremental to clinical data, exercise treadmill test, and coronary angiography. [7][8][9] In addition, MACE risk can be further defined by severity, size, and reversibility of perfusion abnormalities.…”