Southern African Hypertension Society: Controlling Hypertension in Southern Africa

AFRICA Cardiovascular Journal of Africa • SAHS Biennial Congress 2024 6 Submission ID: 1617 Introduction Resistant hypertension (RH) is defined as blood pressure that remains above goal despite concurrent use of three or more antihypertensive agents of different classes. Patients with RH are at a greater risk of cardiovascular (CV) complications compared with patients who have controlled hypertension. The high CV risk is attributable, in part, to long-standing, poorly controlled hypertension. There is a paucity of data on RH and its association to cardiovascular disease (CVD) in Africans. This study defines the phenotype of RH using cardiovascular magnetic resonance imaging. Our findings may contribute to improved understanding of the pathophysiology of this disease in Africans. Methods The cardiovascular phenotype of patients with resistant uncontrolled hypertension (RUH) were compared to patients with resistant controlled hypertension (RCH) and matched controls, using cardiovascular magnetic resonance (CMR) and other imaging modalities. 61 participants (30 RUH, 20 RCH and 11 matched controls) underwent blood pressure measurements, CMR, echocardiography, electrocardiography, applanation tonometry and serum biomarker analysis. Results Patients with RUH were obese (73% vs 55%, p=0.01), with a history of retinopathy (47% vs 20%, p=0.001), albuminuria (33% vs 10%, p=0.002), myocardial infarction (10% vs 0%, p=0.009) and stroke (13.3% vs 0%, p=0.006). They had a longer duration of hypertension (10.5±10.7 vs. 3.6±3.4, p=0.02) with treatment that included an ACE-inhibitor (90% vs. 58%, p=0.01). They had higher mean arterial BP (115±17 vs 101±15 mmHg, p= 0.004), lower small artery elasticity (4.1±2.1 vs. 6.9±3.6ml/mmHgx100, p<0.001) and higher systemic vascular resistance (1754±418 vs. 1363±371 dyneXsecXcm-5, p=0.002) compared to patients with RCH. Patients with RUH and RCH compared to healthy controls on echocardiogrpahy had increased interventricular septum thickness (1.3±0.20 vs 1.2±0.17 vs 0.93±0.17), left ventricular (LV) posterior wall thickness (1.19±0.20 vs 1.08±0.16 vs 0.8±0.14, p<0.001) and increased deceleration time (200±43.7 vs 192±15.8 vs 167±7.9, p=0.02). On ECG, patients with RUH and RCH had a longer QRS duration (96.11±11.9 vs 95±15.9 vs 84±9.4, p=0.03) and on CMR, they had a higher LV stroke volume (vs 105±26 vs 100±21 vs 84±20, p=0.047), Native T1 molli (1243±44 vs 1236±57 vs 1184±23, p=0.002) and peak systolic circumferential strain rate (-1.3±0.3 vs -1.2±0.2 vs -1.1±0.3, p=0.048 ). Conclusion Vascular remodelling in RUH predates cardiovascular morbidity and can be used as an early indicator of remodelling using multimodal imaging. Name: Presenting Author Information Article Category Abstract Title University of Cape Town, Department of Medicine ltkphe001@myuct.ac.za English Abstract Students - Currently enrolled postgraduate students Vascular dysfunction and preclinical cardiovascular remodelling in resistant uncontrolled hypertension characterised by cardiovascular magnetic resonance and multi-modal imaging: a cross-sectional study Author Affiliation: Email: Pheletso Letuka Science Theme Clinical Authors Name & Surname Title Expertise Affiliation Email Country Pheletso LetukaFalatsi Mrs Cardiovascular Physiology Department of Medicine, University of Cape Town ltkphe001@myuct.ac.za South Africa Petronella Samuels Mrs Radiography Cape Universities Body Imaging Centre, University of Cape Town petronella.samuels@uct.ac.za South Africa Stephen Jermy Mr Biomedical engineering Cape Universities Body Imaging Centre, University of Cape Town stephen.jermy@uct.ac.za South Africa Hadil Saad Dr Medicine Department of Medicine, University of Cape Town hadil.saad@charite.de Germany Brian Rayner Prof Nephrology Department of Medicine, University of Cape Town brian.rayner@uct.ac.za South Africa Ntobeko Ntusi Cardiology Department of Medicine, University of Cape Town ntobeko.ntusi@uct.ac.za South Africa ORAL PRESENTATION

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