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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Analysis of Variance, Dipyridamole, Exercise Test, Female, Follow-Up Studies, Heart Rate, Humans, Kaplan-Meier Estimate, Linear Models, Male, Middle Aged, Myocardial Infarction, Predictive Value of Tests, Prognosis, Proportional Hazards Models, Recurrence, Research Design, Retrospective Studies, Risk Assessment, Thallium Radioisotopes, Time Factors, Tomography, Emission-Computed, Single-Photon, Vasodilator Agents, Ventricular Function, Left.
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Does depressed heart rate response to vasodilator stress for myocardial SPECT predict mortality in patients after myocardial infarction? Context: As heart rate (HR) response during vasodilator stress myocardial perfusion studies can be a marker of HR variability, we investigated its prognostic value in patients after myocardial infarction (MI). Subjects were 147 survivors of MI who underwent vasodilator stress thallium-201 scintigraphy. HR response was measured as peak to basal (P/B) ratios during vasodilator infusion. End points for survival analysis were all-cause deaths, non-fatal recurrent MI, and soft events. HR response was significantly depressed in the post-MI patients compared to controls (p<0.0005). HR response correlated to LVEF (r=0.37, p<0.0001) and summed stress scores (r=-0.18, p<0.05), but not with antianginal medication. During 58+/-30 mo of follow-up, there were 15 deaths, 7 recurrent MI, and 11 soft events. Low HR response, old age, low LVEF, and high difference score were significant univariate risk factors for death. Multivariate analysis identified low HR response (p=0.03), high stress score (p=0.02), and low LVEF (p=0.05) as independent predictors of mortality. The predictive value of HR response was incremental to that offered by other variables (p=0.02).
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HR response, readily attained during vasodilator stress myocardial perfusion studies, may provide useful additional prognostic information in post-MI patients. Final Decision: yes