Background: Data on long-term cardiovascular outcomes in systemic lupus erythematosus (SLE) are sparse. Objectives: This study sought to examine the long-term risk and prognosis associated with cardiovascular outcomes, including heart failure (HF), in patients with SLE. Methods: Using Danish administrative registries, risks of outcomes were compared between SLE patients (diagnosed 1996 to 2018, no history of cardiovascular disease) and age-, sex-, and comorbidity-matched control subjects from the background population (matched 1:4). Furthermore, mortality following HF diagnosis was compared between SLE patients developing HF and age- and sex-matched non-SLE control subjects with HF (matched 1:4). Results: A total of 3,411 SLE patients (median age: 44.6 years [25th to 75th percentile: 31.9 to 57.0 years]; 14.1% men) were matched with 13,644 control subjects. The median follow-up was 8.5 years (25th to 75th percentile: 4.0 to 14.4 years). Absolute 10-year risks of outcomes were: HF, 3.71% (95% confidence interval [CI]: 3.02% to 4.51%) for SLE patients, 1.94% (95% CI: 1.68% to 2.24%) for control subjects; atrial fibrillation, 4.35% (95% CI: 3.61% to 5.18%) for SLE patients, 2.82% (95% CI: 2.50% to 3.16%) for control subjects; ischemic stroke, 3.75% (95% CI: 3.06% to 4.54%) for SLE patients, 1.92% (95% CI: 1.66% to 2.20%) for control subjects; myocardial infarction, 2.17% (95% CI: 1.66% to 2.80%) for SLE patients, 1.49% (95% CI: 1.26% to 1.75%) for control subjects; venous thromboembolism, 6.03% (95% CI: 5.17% to 6.98%) for SLE patients, 1.68% (95% CI: 1.44% to 1.95%) for control subjects; and the composite of implantable cardioverter-defibrillator implantation/ventricular arrhythmias/cardiac arrest, 0.89% (95% CI: 0.58% to 1.31%) for SLE patients, 0.30% (95% CI: 0.20% to 0.43%) for control subjects. SLE with subsequent HF was associated with higher mortality compared with HF without SLE (adjusted hazard ratio: 1.50; 95% CI: 1.08 to 2.08). Conclusions: SLE patients had a higher associated risk of HF and other cardiovascular outcomes compared with matched control subjects. Among patients developing HF, a history of SLE was associated with higher mortality.