Noninvasive Assessment of Myocardial Perfusion in Different Blood Pressure Phenotypes and Its Association With Arterial Stiffness Indices.

Abstract

We investigated for the first time whether patients with recent-onset, uncomplicated hypertension and different hypertension phenotypes exhibit altered values of subendocardial viability ratio (SEVR), a surrogate measure of myocardial perfusion that correlates with the ratio of subendocardial to subepicardial blood flow. We additionally explored whether SEVR correlates with arterial stiffness in a population free from the long-term effects of essential hypertension. Nontreated individuals free from any known health problems were classified as true hypertensives (THs), white-coat hypertensives (WCHs), masked hypertensives (MHs), and normotensives. SEVR was noninvasively calculated with applanation tonometry in the radial artery. Carotid-femoral pulse wave velocity, central and peripheral pulse pressure (PP), augmentation index, and central systolic/diastolic blood pressure (BP) were assessed with applanation tonometry. Total arterial compliance index was calculated with impedance cardiography. In a total of 150 participants, normotensive individuals exhibited the highest values of SEVR (162.9 ± 25.3%), whereas SEVR appeared to be similar in MHs (150.2 ± 22.1%), WCHs (148.1 ± 20.4%), and THs (149.9 ± 24.8%) (P = 0.017). In the univariate analysis, SEVR significantly correlated with central systolic BP, peripheral PP, and total arterial compliance index. The association between SEVR and both central (P = 0.017) and peripheral PP (P = 0.003) remained significant after adjustment for heart rate and other parameters. SEVR, an alternative tool to the invasive assessment of microvascular coronary perfusion, presents different values across patients with divergent BP phenotypes and correlated with arterial stiffness, even in the absence of overt cardiovascular disease. Future studies need to address the potential utility of this easily implementable marker as a screening test for myocardial ischemia.