Post COVID‐19 syndrome with impairment of flow‐mediated epicardial vasodilation and flow reserve

Abstract

Aims The aim of this study is to evaluate whether post‐acute sequelae of COVID‐19 cardiovascular syndrome (PASC‐CVS) is associated with alterations in coronary circulatory function. Materials and Methods In individuals with PASC‐CVS but without known cardiovascular risk factors ( n = 23) and in healthy controls (CON, n = 23), myocardial blood flow (MBF) was assessed with 13 N‐ammonia and PET/CT in mL/g/min during regadenoson‐stimulated hyperemia, at rest, and the global myocardial flow reserve (MFR) was calculated. MBF was also measured in the mid and mid‐distal myocardium of the left ventricle (LV). The Δ longitudinal MBF gradient (hyperemia minus rest) as a reflection of an impairment of flow‐mediated epicardial vasodilation, was calculated. Results Resting MBF was significantly higher in PASC‐CVS than in CON (1.29 ± 0.27 vs. 1.08 ± 0.20 ml/g/min, p ≤ .024), while hyperemic MBFs did not differ significantly among groups (2.46 ± 0.53 and 2.40 ± 0.34 ml/g/min, p = .621). The MFR was significantly less in PASC‐CVS than in CON (1.97 ± 0.54 vs. 2.27 ± 0.43, p ≤ .031). In addition, there was a Δ longitudinal MBF gradient in PASC‐CVS, not observed in CON (−0.17 ± 0.18 vs. 0.04 ± 0.11 ml/g/min, p < .0001). Conclusions Post‐acute sequelae of COVID‐19 cardiovascular syndrome may be associated with an impairment of flow‐mediated epicardial vasodilation, while reductions in coronary vasodilator capacity appear predominantly related to increases in resting flow in women deserving further investigations.

PET-determined prevalence of coronary microvascular dysfunction and different types in a cardio-metabolic risk population

“…As the invasive assessment of CMD is performed in a highly selected study population referred for coronary angiography, the prevalence of CMD in patients with non-obstructive CAD in a more general clinical population remains uncertain. In this respect, PET-determined myocardial perfusion and myocardial blood flow (MBF) in absolute terms in milliliters per minute per gram (mL/min/g) during pharmacologically-induced hyperemia and at rest with derived myocardial flow reserve (MFR) affords a non-invasive means for the detection and characterization of CMD [6] , [7] , [8] . Such PET-determined CMD carries important diagnostic and prognostic information amenable to specific medical treatment that improve symptoms and potentially patient outcome [9] .…”

An obscure myocardial blood flow may illuminate post‐acute sequelae of COVID‐19 cardiovascular syndrome

“…Yet, thus far, it had not been implemented to investigate PASC‐CVS. In the present study, Verma et al 14 take advantage of this sensitive non‐invasive imaging approach to evaluate the potential association between PASC‐CVS and alterations in the coronary circulatory function. To this end, Schindler 's group assessed myocardial perfusion with 13 N‐ammonia and PET/CT in 23 patients with diagnosed PASC‐CVS.…”