Aim: To evaluate systemic 68Ga-DOTATATE uptake as a marker of somatostatin receptor-2 (SSTR2)-expressing macrophage inflammation in patients with heart failure with preserved ejection fraction (HFpEF), and to determine whether tracer uptake correlates with HFpEF severity using two clinical scoring systems.
Methods: We retrospectively analyzed 125 patients who underwent 68Ga-DOTATATE PET/CT for neuroendocrine tumor follow-up up with available echocardiography and clinical data. Inclusion criteria were the availability of complete datasets including TTE and PET/CT reports, and a preserved Left Ventricular Ejection Fraction (LVEF ≥ 50%). Patients with sarcoidosis were excluded. Patients were stratified by HFA-PEFF score into low (0–4) and high (5–7), and by H2FPEF score into low (0–1), intermediate (2–5), and high (6–9) HFpEF probability groups. Regions of interest were placed in myocardium, carotids, spleen, and bone marrow; SUVmean, SUVmax, and target-to-background ratio (TBR) metrics were recorded. Statistics was carried out using t-test and ANOVA.
Results: Eight patients were excluded, five due to incomplete TTE documentation alongside two with sarcoidosis and one with diffuse vertebral metastase. That results in a cohort of 117 patients (64 female, 53 male; mean age 68.4 ± 9.3). 28 patients had an elevated HFA-PEFF score, whereas 89 had a low HFpEF likelihood according to HFA-PEFF. Myocardial SUVmean was significantly higher in patients with elevated HFA-PEFF score (1.07 ± 0.35 vs. 0.92 ± 0.30; p = 0.041). Myocardial SUVmax showed a similar, non-significant trend (1.27 ± 0.41 vs 1.13 ± 0.35; p = 0.102). No significant differences were found between HFA-PEFF groups for myocardial TBR, spleen SUVmean, bone marrow SUVmean, or carotid TBR.
When stratified by H2FPEF probability (low/intermediate/high), only 4 patients met high HFpEF probability criteria. 94 patients met intermediate and 19 patients low HFpEF probability criteria. No significant difference was found for myocardial SUVmean, SUVmax or TBR between the three groups. Similar non-significant findings were obtained for spleen, bone marrow, and carotid TBR.
Conclusions: In this retrospective cohort, myocardial 68Ga-DOTATATE uptake was modestly but significantly higher in patients with an elevated HFA-PEFF score, supporting a potential association between myocardial SSTR2-positive inflammation and HFpEF severity as defined by the HFA-PEFF algorithm. In contrast, H2FPEF probability groups showed no significant differences in tracer uptake underscoring the heterogeneity of this syndrome. These findings highlight the potential of 68Ga-DOTATATE PET/CT as a noninvasive imaging marker of inflammation for patient stratification in HFpEF and support further studies.
