Analysis of coronary flow velocity reserve, TIMI flow and global longitudinal strain in women with cardiac syndrome X

Populacija osoba sa bolom u grudima i normalnim nalazom koronarografije je heterogena. Kardijalni sindrom X (eng. Cardiac Syndrome X - CSX) je najčešće zastupljen kod žena perimenopauzalne životne dobi, a definisan je pojavom bola u grudima, depresijom ST segmenta na testu opterećenja i angiografski isključenom epikardnom koronarnom bolesti. Mikrovaskularna disfunkcija (MVD) i posledična ishemija povezana je sa lošijom kliničkom prognozom i najverovatnije je objašnjenje elektrokardiografske pozitivnosti stres eho testova i simptoma bola u grudima kod žena sa CSX. Longitudinalna funkcija leve komore (LK) je posebno vulnerabilna na pojavu mikrovaskularne ishemije te se ona smatra ranim markerom subkliničke sistolne disfunkcije LK. Iako su u dosadašnjoj literaturi CSX i angiografski fenomen usporenog protoka kontrasta (eng. Slow Coronary Flow - SCF), koji se karakteriše usporenom opacifikacijom koronarnih arterija kontrastnim sredstvom u odsustvu epikardne bolesti, posmatrani kao zasebni klinički entiteti, bitno je napomenuti činjenicu da oni imaju zajednički patofiziološki supstrat – primarnu abnormalnost koronarne mikrocirkulacije - MVD. U tom smislu u aktuelnoj literaturi do sada nema podataka o proceni očuvanosti mikrovaskularne funkcije i sistolne longitudinalne funkcije LK u CSX populaciji stratifikovanoj prema prisustvu SCF. Cilj: Osnovni cilj naše studije je bio da se kod bolesnica sa CSX stratifikovanih po podgrupama u zavisnosti od prisustva SCF, analizira mikrovaskularna funkcija kvantifikacijom koronarne rezerve protoka (eng. Coronary Flow Velocity Reserve - CFVR) i kontraktilna funkcija LK metodom globalnog indeksa naprezanja (eng. Global Longitudinal Strain - GLS). Metode: Ispitivana populacija je uključivala 70 žena sa CSX (61±7 godina starosti) i 34 po godinama adaptiranih žena iz kontrolne grupe. Ovo istraživanje je sprovedeno u periodu od januara 2014. godine do juna 2019. godine na Klinici za kardiologiju Kliničkog centra Srbije. CSX grupa je stratifikovana u dve podgrupe u zavisnosti od prisustva SCF utvrđenog koronarnom angiografijom: CSX- eng. Thrombolysis In Myocardial Infarction -TIMI 3- podgrupa sa normalnim protokom (n = 38) i CSX-TIMI 2- podgrupa sa SCF (n = 32). Ispitanicama iz CSX i kontrolne grupe učinjen je klinički i ehokardiografski pregled, stres eho test, merenja CFVR-a za levu prednje descendentnu (eng. left anterior descending - LAD) i posterodescendentnu (eng. posterior descending - PD) koronarnu arteriju, kao i kvantifikacija GLS LK u miru i nakon opterećenja...Patients with chest pain and normal coronary arteries represent a rather nonhomogeneous population. Cardiac syndrome X (CSX) is defined by angina-like chest pain, ST segment depression during exercise and normal coronary arteries found mostly in post-menopausal women. Microvascular dysfunction (MVD) and consecutive ischemia carry an adverse prognosis, and most probably account for angina symptoms and electrocardiographically positive stress tests in women with CSX. Left ventricular (LV) longitudinal function is particularly susceptible to the effects of microvascular ischemia and as such is considered an early marker of subclinical systolic dysfunction. Although angiographic phenomenon of slow coronary flow (SCF) characterized by delayed opacification of coronary arteries in the absence of an obstructive coronary disease and CSX are still considered separate clinical entities in the contemporary literature, it is important to note that they share the same underlying mechanism of primary abnormality of microvascular function – MVD. In that sense, evaluation of microvascular and LV systolic longitudinal function in CSX patients with regard to the presence of SCF have not been investigated yet. Objective: The main objective of our study was to assess microvascular function by coronary flow velocity reserve (CFVR) and LV contractile function by global longitudinal strain (GLS) in CSX patients with respect to presence of SCF. Methods: Study population consisted of 70 women with CSX (mean age 61±7 years) and 34 age- and gander matched controls. All the women were recruited at the Cardiology Clinic, Clinical center of Serbia, Belgrade, during the period from January 2014 to June 2019. CSX group was stratified into two subgroups depending on SCF presence: CSX- Thrombolysis In Myocardial Infarction -TIMI 3 normal flow subgroup (n=38) and CSX-TIMI 2- SCF subgroup (n=32) as defined by coronary angiography. Both women from the CSX and the control group had clinical and echocardiographic examination, stress echo test, CFVR measurements for left anterior descending (LAD) and posterior descending (PD) artery as well as LV GLS at rest and during exercise performed. Left heart catheterization was performed for the whole CSX group, while none of the controls have undergone coronary angiography because of ethical reasons. Clinical status of the women from the CSX group was evaluated on the basis of Seattle Angina Questionnaire (SAQ)..