Abstract:
This single-center cohort study sought to evaluate the association between Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Angina with Non-Obstructive Coronary Arteries (ANOCA), by determining the observed frequency of ME/CFS among patients with ANOCA diagnosed by coronary function testing (CFT). Additionally, we performed an exploratory analysis of the diagnostic utility of invasive cardiopulmonary exercise testing (iCPET) in ME/CFS patients with CFT-confirmed ANOCA, with the aim of identifying the predominant physiological mechanism responsible for exertional limitation in this population.
Systematic medical record review of 261 patients with CFT-confirmed ANOCA was performed using standardized diagnostic criteria to identify concurrent ME/CFS diagnosis. ME/CFS was identified in 47 patients, representing an observed frequency of 18%. The only statistically significant difference between ANOCA patients with and without ME/CFS was a higher frequency of connective tissue disease in the ME/CFS group (p = 0.0221). In a separate cohort of 27 patients with ME/CFS who underwent iCPET, 24 patients (89%) had CFT-confirmed ANOCA.
The diagnosis of ANOCA by CFT prompted a change in medical management in 81% of patients in this cohort. iCPET revealed a primary peripheral limitation to exercise, characterized by impaired peak systemic oxygen extraction despite normal peak oxygen delivery. This study demonstrates a clinically significant association between ME/CFS and ANOCA.
These findings underscore the clinical value of CFT in patients with ME/CFS and exertional chest pain and highlight iCPET as a complementary tool for hemodynamic phenotyping in this population. Prospective studies incorporating simultaneous CFT and iCPET with molecular phenotyping are warranted.
Source: Mackay Z, Shah S, Villalobos JG, Latif N, Arun A, Joseph P, Heerdt P, Singh I. Hemodynamic Phenotyping in ME/CFS and ANOCA: Complementary Insights from Coronary Function Testing and Invasive Cardiopulmonary Exercise Testing. Am J Physiol Heart Circ Physiol. 2026 Sep 21. doi: 10.1152/ajpheart.90080.2026. Epub ahead of print. PMID: 42767811. https://journals.physiology.org/doi/abs/10.1152/ajpheart.90080.2026 (Full text available as PDF file)