The longitudinal care cascade for hypertension: a clinic-based study of people with and without HIV in South Africa.

Background: Hypertension (HTN) constitutes a major and growing public health challenge in South Africa, a setting where HIV prevalence also remains high. Despite this dual burden, longitudinal evidence describing how individuals move through the HTN care cascade particularly comparing people living with HIV (PLHIV) and people not living with HIV (PNLHIV) remains limited. Understanding patterns of progression and regression across the cascade is essential to inform health system strategies for integrated chronic disease management. Methods and Findings: We conducted a longitudinal secondary analysis using data collected from the iHEART-SA trial, which was implemented across nine public primary healthcare clinics in Johannesburg between August 2022 and May 2024. with follow-up through May 2025. Adults (≥18 years) with a known HIV status and a completed medical file review were included. Progression and regression were assessed across the HTN care cascade.Of 23 855 participants, 78.5% were PLHIV (median age 42 years, IQR 36-49; 69% female). Overall, 34.4% had high blood pressure (BP), with prevalence higher among PNLHIV than PLHIV (53.5% vs 29.3%; p<0.001). Along the HTN care cascade, PLHIV were substantially more likely to remain undiagnosed compared with PNLHIV (aRR 3.40; 95% CI 3.12-3.71). Among those treated, PLHIV were less likely to achieve BP control (aRR 0.83; 95% CI 0.75-0.91). During follow-up, PLHIV experienced higher rates of cascade regression, including regression to untreated HTN (29% vs 19%; aRR 1.51; 95% CI 1.35-1.70) and from controlled to uncontrolled BP (aRR 1.12; 95% CI 1.05-1.18). Conclusions: Despite frequent health-system contact, PLHIV had lower HTN diagnosis and higher regression, including treatment discontinuation and loss of BP control, underscoring persistent gaps in longitudinal HTN management within HIV programmes and the need for integrated and targeted chronic care models that ensure treatment continuity and sustained control.