Abstract
BACKGROUND: Coronary microvascular dysfunction (CMD) is usually evaluated measuring coronary flow velocity reserve (CFVR). A more comprehensive analysis of CFVR including additional consideration of the associated logical companion-CFVR, where hyperemic diastolic coronary flow velocity may act as surrogate, was applied in this study to elucidate the mechanism of CMD in psoriasis. METHODS AND RESULTS: Coronary flow velocity reserve was analysed using transthoracic echocardiographs of 127 psoriasis patients (age 36 ± 8 years; 104 males) and of 52 sex- and age-matched healthy controls. CFVR determination was repeated in the patient subgroup (n = 78) receiving anti-inflammatory therapy. Baseline and hyperemic microvascular resistance (MR) were calculated. CMD was defined as CFVR ≤ 2.5. Four endotypes of CMD were identified referring to concordant or discordant impairments of hyperemic flow or CFVR. We evaluated the companion-CFVR, as derived from the quadratic mean of hyperemic and diastolic flow velocity at rest. Coronary flow parameters, including CFVR (p = 0.01), were different among the two endotypes having CFVR > 2.5. Specifically, all 11 (14%) patients with CFVR deterioration despite therapy, belonged to endotype 1, and had higher baseline and hyperemic MR (p < 0.0001, both). Interestingly, while CFVR was comparable in patients with worsened versus those with improved CFVR, the companion-CFVR could discriminate by being lower in patients with worsened CFVR (p = 0.01). CONCLUSIONS: The reduced CFVR in psoriasis is driven by decreased companion-CFVR, combined with increased hyperemic MR. Adoption of the mandatory companion-CFVR enables a personalized characterization superior to that achieved by exclusive consideration of CFVR.