CARDIOVASCULAR HAEMODYNAMICS IN TWO GROUPS OF HYPERTENSION: RESISTANT HYPERTENSION AND MALIGNANT HYPERTENSION

Objective: Patients with malignant and resistant hypertension have poor prognosis and high rate of complications. Understanding the pathophysiological mechanisms underlying the severe forms of hypertension and their relationship to cardiac haemodynamics and vascular function is crucial to the management of blood pressure (BP). Design and method: In a cross-sectional comparison, of age and sex matched groups, we assessed left ventricle (LV) strain function using speckle tracking echocardiography (STE), (Figure 1), endothelial function using flow mediated dilation (FMD) and arterial stiffness using pulse wave velocity (PWV) in patients with confirmed RH (n = 23), treated malignant hypertension (MHT) (n = 54) and normotensive control (NC) (n = 23). Results: Characteristics pf study population are provided in table 1. Both hypertension groups showed markedly reduced global longitudinal strain (GLS) vs. NC (MHT -15.6% {-17 – -15}, RH -17.7% {-20 – -16} vs. NC -25% {-28 – -22]}, all p < 0.001) with GLS being lower in MHT vs. RH (p < 0.05). Both hypertensive groups also showed preserved but lower global circumferential strain (GCS) vs. NC (MHT -30.7% ± 4.7, RH -30.0% ± 4.3 vs. NC -34.3% ± 4.5, p = 0.004 and p = 0.03, respectively). FMD was markedly attenuated in both hypertensive groups (RH: 5.5 % ±2.6 and MHT: 5.9 % ± 2.6 vs. NC: 9.9 % ± 2.5%, p < 0.001). Carotid-femoral pulse wave velocity (cfPWV) was increased in both hypertensives compared to NC (p < 0.05). Subendocardial viability ratio (SEVR) and total peripheral resistance (TPR) were decreased in MHT compared to NC (p = 0.01 and p = 0.002, respectively). After adjustment for potential confounders (presence of hypertension, duration of hypertension, age, BMI, and eGFR), presence of MHT (p < 0.001), presence of RH (p < 0.001) and age (p = 0.01) showed significant negative association with GLS, whereas eGFR showed significant positive association with GLS (p = 0.03), (Table 2). Conclusions: This is the first cardio-vascular assessment of two extreme phenotypes of hypertension. Patients with MHT and RH had persistent impaired cardiac remodelling independent of preserved EF, impaired endothelial function and elevated arterial stiffness. Early cardiac remodelling marker, GLS was more impaired in MHT patients.