Abstract 20: Orthostatic Hypotension in Patients with Heart Failure taking Carvedilol or Metoprolol

Background: Metoprolol succinate and carvedilol are widely prescribed beta-blockers for the treatment of heart failure (HF). Both can reduce mortality, but unlike the β-1 selective metoprolol, carvedilol has α-1 blocking effects. Since orthostatic hypotension (OH) is a common comorbidity in HF patients, we conducted a case-control study to assess if the vasodilatory effect of carvedilol, compared to metoprolol, is associated with a higher risk for newly diagnosed OH.

Methods: A deidentified retrospective database of all HF patients seen at the Vanderbilt University Medical Center who were taking metoprolol or carvedilol (n=272,019) was used. Cases of newly diagnosed OH were defined as those who had a new diagnosis of OH after the first mention of either drug (n=3,006) and controls as those who did not have a diagnosis of OH (n=269,013). Demographic information, presence of other comorbidities, and concomitant use of other drugs known to cause hypotension were obtained. One-way analysis of variance (ANOVA) and Pearson’s chi-square tests were used to compare continuous and categorical variables between both groups, respectively.

Results: OH was diagnosed in 1% of all patients and metoprolol was more commonly prescribed than carvedilol (81% vs. 19%). Compared to controls, OH patients were older (58 vs. 66 yr) and had a higher rate of hypertension (22% vs. 96%), Parkinson disease (1% vs. 3%) and concomitant use of diuretics, calcium channel blockers, other α-1 blockers and other drugs associated with OH (Table). The prevalence of OH cases was higher in the carvedilol group compared to the metoprolol group (1.96% vs. 0.91%), but only age differed between the OH cases in both groups (metoprolol: 64 vs. carvedilol: 71 yr). We found that patients were more likely to be diagnosed with OH after taking carvedilol vs. metoprolol (unadjusted odds ratio 2.2078, 95% CI 2.0448 – 2.3838, p < 0.001).

Conclusions: The prevalence of OH among patients with heart failure was higher in patients taking carvedilol compared to metoprolol. Given that both drugs have similar beneficial effects on mortality, metoprolol appears to be preferable in the treatment of heart failure in patients at risk of developing OH. Studies to further assess the relationship between heart failure classification and orthostatic hypotension are needed.