Cardiovascular morbidity, heart rates and use of antimuscarinics in patients with overactive bladder

Abstract

Objective: To determine if cardiovascular (CV) comorbidity and treatment-associated antimuscarinic effects differ between patients with and without overactive bladder (OAB), and between treated and untreated patients with OAB, as OAB, CV disorders and exposure to medications with antimuscarinic effects are common in older patients.

Patients and methods: Adults from the HealthCore Integrated Research Database with a diagnosis of OAB (International Classification of Diseases-9 codes; from 1 January 2000 to 31 December 2006) or a pharmacy claim for an antimuscarinic OAB medication, formed the OAB cohort, further stratified as treated and untreated. A random sample of patients with neither a diagnosis for OAB nor any urinary bladder dysfunction, nor a pharmacy claim for antimuscarinics, formed the non-OAB cohort. CV comorbidities and use of medications with antimuscarinic effects were assessed for the 12 months before OAB diagnosis/treatment. Information on heart rate (HR) on the day of the first OAB drug prescription was obtained from the GE Healthcare dataset. HR was assessed for patients aged > or =18 years with a diagnosis of OAB who were prescribed antimuscarinics (oxybutynin or tolterodine) at any dose or oral formulation between January 1995 and November 2006.

Results: The 6607 patients with OAB, with a substantial proportion with elevated HR at baseline, were more likely to have CV comorbidities (39% vs 21%; P < 0.001) and previous exposure to medications with antimuscarinic effects (33% vs 17%; P < 0.001) than the non-OAB patients. Rate of CV comorbidities (40% vs 38%; P = 0.326) did not differ between treated and untreated patients with OAB. However, there was a difference in previous exposure to medications with antimuscarinic effects (37% vs 29%; P < 0.001); 39.1% of patients with OAB had a HR of >80 beats/min before starting antimuscarinic treatment.

Conclusion: In this study, the prevalence of CV comorbidities was significantly higher in patients with than without OAB; previous exposure to medications with antimuscarinic effects was also higher in patients with OAB. There was no difference in pre-existing CV comorbidities between the treated and untreated patients with OAB, but the high use of medications with antimuscarinic effects among these patients suggests that the presence of CV comorbidity might not be considered before using antimuscarinic agents for OAB.