Frequency and Economic Impact of Comorbid Cardiac Conditions with Multiple Sclerosis

BACKGROUND: Fingolimod, an oral immunomodulatory therapy approved to treat multiple sclerosis (MS) is contraindicated in patients with certain cardiac conditions, yet the frequency of these conditions in patients with MS is not known. This study assessed the frequency and economic impact of cardiac conditions among hospitalizations of patients with MS. OBJECTIVES: To determine the frequency and economic impact of selected comorbid cardiac conditions among hospitalizations of patients with a diagnosis of MS. METHODS: This was a retrospective, discharge-level cohort study of hospital discharge data from 2006-2010. The frequencies of cardiac conditions of interest (based on contraindications to fingolimod in the prescribing information) were reported among all discharges with a diagnosis of MS. Two cohorts were defined: (1) MS with cardiac condition of interest and (2) MS with no cardiac condition of interest. The mean adjusted cost per discharge and incremental cost per hospital day were reported. RESULTS: Among 136,542 discharges with a diagnosis of MS, 9.2% (n = 12,504) had a comorbid cardiac condition of interest based on contraindications to fingolimod in the prescribing information. Heart failure (59.4%), myocardial infarction (17.2%), and occlusion of cerebral arteries (12.4%) were the most common cardiac conditions. The mean adjusted cost per discharge was significantly higher for the MS with cardiac condition cohort compared with the MS with no cardiac condition cohort ($17,623 vs. $11,663, P less than 0.0001). The incremental cost per hospital day was $6,479 for the MS with cardiac condition cohort. CONCLUSIONS: The presence of comorbid cardiac conditions among hospital discharges in patients with MS is substantial and associated with higher hospitalization costs. Health plans should give consideration to the overlapping presence of these diseases when determining coverage criteria for immunomodulatory therapies and designing clinical programs for MS.