{"doi":"10.1016/j.ijcha.2025.101606","title":"Functional or structural impairment of flow-mediated epicardial vasodilation may precede coronary microvascular dysfunction","abstract":"Background: The aim was to investigate whether functional and/or structural impairment of flow-mediated epicardial vasodilation (IEV) may precede coronary microvascular dysfunction (CMD) in a cardiometabolic risk population. Methods: N-ammonia positron emission tomography/computed tomography evaluated global and longitudinal myocardial blood flow (MBF) during pharmacologically induced hyperemia and at rest. Normal coronary microvascular function (nCMF) was defined by a myocardial flow reserve (MFR = MBFstress/MBFrest) of ≥ 2.0, while an abnormal MFR of < 2.0 (predominantly due to decreases in hyperemic MBF) denoted classical CMD. Normal flow-mediated epicardial vasodilation (NEV) was defined as longitudinal hyperemic MBF gradient < -0.10 mL/g/min, whereas a value ≥ -0.10 mL/g/min signifiedIEV. Patients were grouped as follows: group 1 (G1): nCMF and NEV (n = 93); group 2 (G2): nCMF and IEV (n = 62), and group 3 (G3): CMD and IEV (n = 78). From non-gated CT, a semiquantitative four-point scoring system was used to indicate coronary artery calcifications score (CCS). Results: The prevalence of diffuse coronary artery calcification was highest in G1 with 51 %, followed by G3 with 46 % and G2 with 34 %. The extent of CCS was mild-to-moderate and did not differ significantly among groups (p = 0.222). Overall, IEV was present in 60 %, while there was a comparable prevalence of IEV between G2 and G3 (27 % and 33 %, p = 0.27). The hyperemic MBF gradient was highest in G2, intermediate in G3, and lowest in G1 (-0.22 ± 0.11 and -0.18 ± 0.10 vs. 0.03 ± 0.08 mL/g/min; p < 0.001, respectively). Conclusions: In this cardio-metabolic risk population, in about one third of these symptomatic patients functional and/or structural impairment of flow-mediated epicardial vasodilation may precede coronary microvascular dysfunction.","journal":"IJC Heart & Vasculature","year":2025,"id":530176,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":5,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9427,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1410301,"name":"Salwa Mikhail","orcid":null,"position":1,"is_corresponding":false},{"id":1152854,"name":"Ashwin Singh Parihar","orcid":"0000-0002-7983-4117","position":2,"is_corresponding":false},{"id":824187,"name":"Sudhir Jain","orcid":"0000-0002-6087-8507","position":3,"is_corresponding":false},{"id":36540,"name":"Thomas H. Schindler","orcid":"0000-0002-2141-7716","position":4,"is_corresponding":false},{"id":973478,"name":"Ines Valenta","orcid":null,"position":0,"is_corresponding":true}],"reference_count":31,"raw_metadata":null,"created_at":"2026-07-19T02:51:05.836974Z","pmid":"39963577","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}