Blunted heart rate response as a predictor of cardiac death in patients undergoing vasodilator stress technetium-99m sestamibi gated SPECT myocardial perfusion imaging
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The prognostic value of a blunted heart rate response (BHR) during ECG-gated vasodilator stress SPECT MPI in relation to ventricular function on long-term cardiovascular events is not well established. We performed this study to evaluate the incremental prognostic value of BHR during pharmacological stress SPECT MPI.
Consecutive patients who underwent dipyridamole stress Tc-99m sestamibi ECG-gated SPECT MPI (without exercise) were identified. The ratio of peak stress heart rate to baseline was noted. If the ratio was <1.20, it was considered blunted (BHR). The images were interpreted using the standard ASNC 17 segment model. Patients were followed up for a mean time period of 2.3 ± 1.5 years.
Sixty-four percent (2,890/4,484) of patients demonstrated BHR during dipyridamole stress testing. Cardiac death, the primary end point, occurred in 6.8% of patients. Patients with BHR had a significantly lower cardiac death-free survival as compared to NO BHR group in total population (83% vs 94%; P < .001) as well as in subgroup with normal ejection fraction (89% vs 96%; P < .001). BHR was an independent predictor of cardiac death after adjusting for multiple clinical, perfusion, and function-related gated SPECT variables.
Blunted heart rate response during vasodilator stress SPECT MPI is an important prognostic marker for cardiac death.
KeywordsDipyridamole pharmacologic stress vasodilator stress myocardial perfusion imaging SPECT technetium-99m
- 9.Cerqueria MD, Weissman NJ, Dilsizian V, Jacobs AK, Kaul S, Laskey WK. Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart: A statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association. Circulation 2002;105:539-42.CrossRefGoogle Scholar
- 11.Sharir T, Germano G, Kang X, Lewin HC, Miranda R, Cohen I, et al. Prediction of myocardial infarction versus cardiac death by gated myocardial perfusion SPECT: Risk stratification by the amount of stress-induced ischemia and the poststress ejection fraction. J Nucl Med 2001;42:831-7.PubMedGoogle Scholar
- 15.Stein PK, Barzilay JI, Chaves PH, Mistretta SQ, Domitrovich PP, Gottdiener JS, et al. Novel measures of heart rate variability predict cardiovascular mortality in older adults independent of traditional cardiovascular risk factors: The Cardiovascular Health Study (CHS). J Cardiovasc Electrophysiol 2008;19:1169-74.CrossRefPubMedGoogle Scholar