Abstract Background The onset of acute cardiovascular complications following a stroke, also known as "Stroke-Heart Syndrome", can occur in up to 20% of patients following a stroke. The syndrome remains under-investigated and limited data exists related to the occurrence and impact of the Stroke-Heart Syndrome in an Asian population. Objectives We aimed to investigate the potential impact of the Stroke-Heart Syndrome and its associations in a retrospective population based-cohort study. Methods The analysis included patients with new-onset ischaemic stroke (IS) June 2006 and May 2022 with 5 years’ follow-up. Patients who developed acute cardiovascular complications within 28 days of their index stroke were compared to patients who did not. The association between acute cardiovascular complications and longer term outcomes were evaluated using multivariate Fine-Grey analyses to adjust for competing risk of mortality, and a Cox regression model for all-cause mortality. Inverse probability of treatment weighting was applied prior to analysis. Furthermore, a hierarchical cluster analysis was performed in the cohort of stroke patients with "Stroke-Heart Syndrome", to further evaluate associations between the identified clusters and (i) longer term outcomes, as well as (ii) the development of acute cardiovascular complications. Results A total of 141,118 patients (median age 72.4 (IQR 62.6 to80.8) years; 45.4% female) were included in the analysis, 6,457 of who developed acute cardiovascular complications, and 134,661 of whom did not. At 5 years follow-up, acute cardiovascular complications were associated with a higher risk of developing recurrent ischaemic stroke (Sub-distribution Hazard Ratio [SHR]: 1.20, 95% Confidence Interval [CI]: 0. 1.12-1.28, p= <0.001), haemorrhagic stroke (SHR: 1.15, 95%CI: 1.03-1.28, p=0.014), myocardial infarction (SHR: 1.53, 95%CI: 1.39-1.69, p=<0.001), and cardiovascular death (SHR: 1.57, 95%CI: 1.45-1.71, p=<0.001) as well as all-cause mortality (HR: 1.07, 95%CI: 1.07-1.07, p=<0.001). A total of 4 clusters were identified in the cluster analysis. Compared to Cluster 3, the other Clusters were associated with increased 5-year risk of myocardial infarction, cardiovascular death and all-cause mortality (p=<0.001). In this cohort, compared to Cluster 2, the other clusters had an increased risk of developing acute cardiovascular complications, in particular acute ischaemic heart disease and acute heart failure (p=<0.001). Cluster 3 tended to be younger with fewer comorbidities and prescribed medications. Over 90% of the patients in Cluster 2 were aged over 75 (with 43% aged 85 years or over). Conclusion Stroke-Heart Syndrome was associated with long-term adverse cardiovascular events in this Asian cohort of ischaemic stroke patients.