Quantitative myocardial perfusion should be interpreted in the light of sex and comorbidities in patients with suspected chronic coronary syndrome - a cardiac positron emission tomography study

Abstract

Abstract Background and aim Diagnosis and treatment of patients with suspected chronic coronary syndrome (CCS) currently relies on the degree of coronary artery stenosis and its significance for myocardial perfusion (1). However, myocardial perfusion can be affected by factors other than coronary stenosis (2-6). The aim of this study was to investigate to what extent sex, age, diabetes, hypertension and smoking affect quantitative myocardial perfusion, beyond the degree of coronary artery stenosis, in patients with suspected CCS. Methods Eighty-six patients (median age 69, range 46-86 years, 24 females) planned for elective coronary angiography due to suspected CCS were included. All patients underwent cardiac positron emission tomography (PET) using 13N-NH3 to quantify myocardial perfusion at rest and at adenosine stress. The stenosis degree of the culprit lesion for each main coronary artery was related to the myocardial segment with lowest myocardial perfusion (perfusionmin) at stress and lowest myocardial perfusion reserve (MPRmin) for its corresponding myocardial territory. Results Degree of coronary artery stenosis, male sex, increasing age, diabetes and smoking were independently associated with myocardial perfusionmin at stress (Table 1). Degree of coronary artery stenosis, age, diabetes and hypertension were independently associated with MPRmin (Table 1). Male sex was independently associated with a significantly lower myocardial perfusionmin at stress at 0-50% coronary artery stenosis but not for higher degree of stenosis (>50%) or MPRmin (Figure 1). Conclusion Sex, increasing age, diabetes, hypertension and smoking affect myocardial perfusion independently of coronary artery stenosis in patients with suspected CCS. Thus, these factors need to be considered when assessing the significance of reduced quantitative myocardial perfusion of patients with suspected CCS. Fig. 1 Myocardial perfusionmin at stress (A) and lowest myocardial perfusion reserve (B) in males and females with 0-50% and 51-100% stenoses. Solid lines indicate mean perfusion in each group. Dashed lines indicate the lower boundary of the current reference interval for myocardial perfusion at 2.0 ml/min/g. Univariable linear mixed model analyses were performed to compare the groups and obtain the p-values.