Association Between Myocardial Ischemia, Microvascular Function and Patient-Reported Angina
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Prior studies have not found an association between myocardial ischemia and measures of health status. Whether positron emission tomography (PET)-derived coronary flow reserve (CFR) would be better correlated with burden of angina is currently unknown. Understanding the relationship between myocardial ischemia, flow reserve and health status may illuminate how these variables can be used to inform post-test decisions. Patients with known CAD referred for a clinically-indicated vasodilator PET myocardial perfusion imaging (MPI) between June 2009 and August 2013 who completed the Seattle Angina Questionnaire (SAQ) at the time of MPI and had available CFR data were identified. Angina frequency was determined using SAQ Angina Frequency scores according to previously published thresholds (none, monthly or weekly/daily; SAQ scores of 100, 61 99 and ≤ 60, respectively). The association between CFR and angina frequency was determined after adjusting for age, gender, and the presence of ischemia using ordinal logistic regression. A total of 171 patients met inclusion criteria (mean age 66.3 ± 10.2 years; 61% men). Angina occurred on daily to weekly basis in 44 (25.7%) patients and monthly in 77 (45%) patients. Unadjusted mean CFR did not vary significantly across the spectrum of anginal burden (P=0.28). In the adjusted model, there was a significant interaction between ischemia and CFR (P value = 0.015), such that higher CFR was associated with lower angina frequency only in patients with ischemia (OR per 1-unit increase in CFR 0.45 (95% CI [0.26 0.83], p=0.007), but not in those without ischemia (OR 1.10 (95% CI [0.63-2.00], p=0.85). PET-derived CFR modulates the association between the presence of ischemia and the frequency of patient-reported angina, and complements ischemia in identifying patients with greater frequency of angina.
Table of Contents
Introduction -- Methods -- Results -- Discussion -- Conclusion -- Appendix
M.S. (Master of Science)