Background Being unmarried is associated with decreased survival in the general population. Whether married, divorced, separated, widowed, or never‐married status affects outcomes in patients with cardiovascular disease has not been well characterized.

Methods and Results A prospective cohort (inception period 2003–2015) of 6051 patients (mean age 63 years, 64% male, 23% black) undergoing cardiac catheterization for suspected or confirmed coronary artery disease was followed for a median of 3.7 years (interquartile range: 1.7–6.7 years). Marital status was stratified as married (n=4088) versus unmarried (n=1963), which included those who were never married (n=451), divorced or separated (n=842), or widowed (n=670). The relationship between marital status and primary outcome of cardiovascular death and myocardial infarction was examined using Cox regression models adjusted for clinical characteristics. There were 1085 (18%) deaths from all causes, 688 (11%) cardiovascular‐related deaths, and 272 (4.5%) incident myocardial infarction events. Compared with married participants, being unmarried was associated with higher risk of all‐cause mortality (hazard ratio [HR]: 1.24; 95% confidence interval [CI], 1.06–1.47), cardiovascular death (HR: 1.45; 95% CI, 1.18–1.78), and cardiovascular death or myocardial infarction (HR: 1.52; 95% CI, 1.27–1.83). Compared with married participants, the increase in cardiovascular death or myocardial infarction was similar for the participants who were divorced or separated (HR: 1.41; 95% CI, 1.10–1.81), widowed (HR: 1.71; 95% CI, 1.32–2.20), or never married (HR: 1.40; 95% CI, 0.97–2.03). The findings persisted after adjustment for medications and other socioeconomic factors.

Conclusions Marital status is independently associated with cardiovascular outcomes in patients with or at high risk of cardiovascular disease, with higher mortality in the unmarried population. The mechanisms responsible for this increased risk require further study.