Normal values of myocardial blood flow measured with dynamic myocardial CT perfusion.

AIMS: Dynamic myocardial CT perfusion (DM-CTP) can, in combination with coronary CT angiography (CCTA), provide anatomical and functional evaluation of coronary artery disease (CAD). However, normal values of myocardial blood flow (MBF) are needed to identify impaired myocardial blood supply in patients with suspected CAD.We aimed to establish normal values for MBF measured using DM-CTP, to assess the effects of age and sex, and to assess regional distribution of MBF. METHODS AND RESULTS: A total of 82 healthy individuals (46 women) aged 45-78 years with normal coronary arteries by CCTA underwent either rest and adenosine stress DM-CTP (n = 30) or adenosine induced stress DM-CTP only (n = 52). Global and segmental MBF were assessed. Global MBF at rest and during stress were 0.93 ± 0.42 mL/min/g and 3.58 ± 1.14 mL/min/g respectively. MBF was not different between the sexes (P = 0.88 at rest and P = 0.61 during stress) and no correlation was observed between MBF and age (P = 0.08 at rest and P = 0.82 during stress). Among the 16 myocardial segments, significant inter-segmental differences were found (P < 0.01), which was not related to age, sex or coronary dominance. CONCLUSION: Myocardial blood flow assessed by DM-CTP in healthy individuals with normal coronary arteries displays significant intersegmental heterogeneity which does not seem to be affected by age, sex or coronary dominance. Normal values of myocardial blood flow may be helpful in the clinical evaluation of suspected myocardial ischemia using DM-CTP.

Early Coronary Atherosclerosis in Women With Previous Preeclampsia.

BACKGROUND: Women with previous preeclampsia have an increased risk of coronary artery disease later in life. OBJECTIVES: This study aimed to determine the prevalence of coronary atherosclerosis in younger women with previous preeclampsia in comparison with women from the general population. METHODS: Women aged 40-55 years with previous preeclampsia were matched 1:1 on age and parity with women from the general population. Participants completed an extensive questionnaire, a clinical examination, and a coronary computed tomography angiography (CTA). The main study outcome was the prevalence of any coronary atherosclerosis on coronary CTA or a calcium score >0 in case of a nondiagnostic coronary CTA. RESULTS: A total of 1,417 women, with a mean age of 47 years, were included (708 women with previous preeclampsia and 709 control subjects from the general population). Women with previous preeclampsia were more likely to have hypertension (284 [40.1%] vs 162 [22.8%]; P < 0.001), dyslipidemia (338 [47.7%] vs 296 [41.7%]; P = 0.023), diabetes mellitus (24 [3.4%] vs 8 [1.1%]; P = 0.004), and high body mass index (27.3 ± 5.7 kg/m2 vs 25.0 ± 4.2 kg/m2; P < 0.001). Cardiac computed tomography was performed in all women. The prevalence of any coronary atherosclerosis was higher in the preeclampsia group (193 [27.4%] vs 141 [20.0%]; P = 0.001) with an OR: 1.41 (95% CI: 1.08-1.85; P = 0.012) after adjustment for age, dyslipidemia, diabetes mellitus, smoking, body mass index, menopause, and parity. CONCLUSIONS: Younger women with previous preeclampsia had a slightly higher prevalence of coronary atherosclerosis compared with age- and parity-matched women from the general population. Preeclampsia remained an independent risk factor after adjustment for traditional cardiovascular risk factors. (The CoPenHagen PREeClampsia and cardIOvascUlar diSease study [CPH-PRECIOUS]; NCT03949829).

Optimization of image sampling rate to lower the radiation dose of dynamic myocardial CT perfusion.

BACKGROUND: Dynamic myocardial CT perfusion (CTP) has emerged as a potential strategy to combine anatomical and functional evaluation in a single modality. However, this method results in a high radiation dose. METHODS: Dynamic CTP was performed in 56 patients with suspected or known ischemic heart disease of whom 48 had complete CT-data. Datasets with reduced sampling rate of 2- and 3 RR-intervals (2RR and 3RR) were constructed post hoc. Myocardial blood flow (MBF) estimates from the 2RR and 3RR datasets were compared with estimates based on the full dataset (1RR) using the two one-sided test of equivalence for paired samples. RESULTS: Significant equivalence was found for rest MBFLV (p â€‹< â€‹0.001), stress MBFLV (p â€‹< â€‹0.001) and for the CFRLV (p â€‹= â€‹0.005) when comparing 2RR blood flow estimates with the results based on the 1RR dataset. The 2RR reconstruction protocol led to an estimated reduction in radiation dose of 35.4 â€‹± â€‹3.8%. CONCLUSION: MBF can be quantitated with dynamic CTP using a sampling strategy of one volume for every second heartbeat. This strategy could lead to a significant reduction in radiation dose.