Lower respiratory tract infection hospitalisation is linked to heightened risk of future cardiometabolic disease and adverse cardiac remodelling

Background Lower respiratory tract infections (LRTIs) may promote persistent inflammation and adverse cardiovascular remodelling, contributing to long-term risk [1]. Although acute cardiovascular complications are recognised [2], their long-term impact remains unclear. Purpose To evaluate whether prior hospitalised LRTIs are associated with cardiometabolic disease and adverse cardiac remodelling in the UK Biobank imaging cohort. Methods We analysed 43,184 UKB participants undergoing first cardiovascular magnetic resonance (CMR) imaging between 2014 and 2020. Prior LRTIs were identified from linked inpatient ICD-9/10 primary diagnosis records (2005 to imaging). Distinct episodes were defined >= 14 days apart. Exposure was modelled as binary and per additional episode (range 0–3). Outcomes included CMR-derived cardiac structure and function measures and prevalent and incident cardiometabolic disease (CMD: MI, IHD, HF, AF). Associations with continuous CMR phenotypes and disease outcomes were assessed using multivariable linear and logistic regression adjusted for demographic, socioeconomic, lifestyle and clinical factors with FDR correction. Results Of 43,184 participants (mean age 55.2±7.6 years; 48% male), 585 (1.4%) had prior LRTI; 561 (95.9%) had 1 episode. Compared with no LRTI, prior infection was associated with higher odds of prevalent composite CMD (OR 2.53, 95% CI 1.99–3.22) and individual outcomes including MI (1.88, 1.24–2.84), IHD (1.75, 1.30–2.36), HF (4.07, 2.39–6.93) and AF (3.51, 2.56–4.80), all FDR-significant. Increasing infection burden was associated with progressively higher odds of prevalent CMD (per episode OR 2.34, 1.87–2.92), consistent with a graded association. During a median follow-up of 4.5 years (IQR 3.7–5.9), prior LRTI was associated with higher odds of incident composite CMD (OR 1.42, 1.09–1.86), with similar per +1 episode associations (OR 1.45, 1.13–1.86); disease-specific incident outcomes were directionally positive but attenuated after FDR correction. Prior LRTI was also associated with adverse cardiac remodelling on CMR, including lower LVGLS (β −0.015), LVGCS (−0.014), LA emptying fraction (−0.023), RVGLS (−0.014), RVEDVi (−0.010), RAVi (−0.011), and higher pericardial fat (0.014), all FDR-significant. Increasing infection burden was associated with further reductions in strain and chamber function, higher native T1, LA maximum volume and pericardial fat. Conclusion Prior hospitalised LRTI was associated with higher odds of prevalent and incident cardiometabolic disease and adverse cardiac remodelling on CMR, with evidence of a graded relationship with infection burden. These findings suggest prior LRTI may identify individuals at heightened long-term cardiovascular risk and contribute to measurable structural and functional cardiac alterations.