Omicron SARS-CoV-2 outcomes in vaccinated individuals with heart failure and ischaemic heart disease

Abstract

Introduction: Outcomes after SARS-CoV 2 Omicron infection in patients with heart failure (HF) and ischaemic heart disease (IHD) remain poorly defined. Method: In a highly vaccinated cohort of adult Singapore citizens and permanent residents, we used Cox proportional hazards models (adjusted for sociodemographic variables and comorbidities) to compare the risks of Omicron infection, COVID 19–related hospitalisation, and severe COVID 19 between individuals with HF or IHD and matched controls without these conditions. Results: From national databases, we identified 15,426 HF patients matched 1:~3 to 41,221 controls, and 110,442 IHD patients matched 1:~2 to 223,843 controls. Over 80% of HF and IHD patients had received at least 3 vaccine doses. During the Omicron-predominant period, both HF and IHD cohorts demonstrated higher adjusted risks of COVID 19 hospitalisation compared with matched controls (HF: aHR 1.77, 95% confidence interval [CI] 1.65–1.90; IHD: aHR 1.21, 95% CI 1.17–1.26). Among those with at least 1 HF- or IHD-related admission in the prior year, hospitalisation risk was further elevated (HF: aHR 1.27, 95% CI 1.13–1.42; IHD: aHR 1.11, 95% CI 1.01–1.23). Receipt of ≥3 vaccine doses was associated with substantially lower risk of severe COVID 19 versus only 2 doses (HF: aHR 0.35, 95% CI 0.28–0.43; IHD: aHR 0.27, 95% CI 0.23–0.32). A fourth dose conferred additional reductions in infection and adverse outcomes, though CIs for infection overlapped with those for 3 doses. Conclusion: During Omicron predominance, HF and IHD patients experienced greater risk of COVID-19 hospitalisation and severe COVID 19 versus matched controls. Booster vaccinations attenuated these risks. Individuals with recent HF/IHD admissions should be prioritised for receipt of booster vaccine doses.