OBJECTIVES To determine the proportion of OAB patients potentially at risk for adverse events by assessing CV co-morbidity as measured during the six months prior to OAB diagnosis/treatment by biologic measures, CV diagnoses, and CV concomitant drug use among treated and untreated OAB patients. METHODS The GE Centricity EMR database was utilized to identify patients with a diagnosis of OAB using ICD-9 codes or a prescription between January 1, 1996 to March 30, 2007 for an OAB antimuscarinic agent. The treated OAB patients with 13 months of continuous eligibility pre- and post-index date formed the OAB cohort. Based on the presence of ≥ 1 pharmacy claim for an OAB antimuscarinic agent, the OAB cohort was stratified as treated or untreated. A random sample of age and gender matched patients formed a comprehensive non-OAB control cohort; they had no diagnosis of OAB, urinary bladder dysfunction, or pharmacy claim for an OAB antimuscarinic agent. RESULTS OAB patients (N: 41,440; 83.6% women; median age 65 years), when compared to non-OAB patients (N: 77,272; 83.2% women; median age 64 years), were more likely to have CV comorbidities (57.6% vs. 44.6%; p<0.001), a high heart rate (≥ 80 beats / minute) (31.4% vs. 19.9%; p<0.001), higher Framingham risk (9.9% vs. 9.6%; p<0.005) as well as use of CV medications (57.1% vs. 38.8%; p<0.001). In treated vs. untreated OAB patients, CV comorbidities (58.8% vs. 53.7%; p<0.001), proportion with a high heart rate (32.3% vs. 27.6%; p<0.001) and Framingham risk (10.2% vs. 8.6%; p<0.001) and use of CV medications (60.7% vs. 42.4%; p<0.001) also differed. CONCLUSIONS CV comorbidities were more prevalent in OAB patients than in patients without OAB. Among the OAB patients, CV co-morbidity and prior exposure to CV medications was more prevalent in those who received antimuscarinic treatment than in patient who did not receive treatment.