Primary Prevention of Sudden Cardiac Death With Device Therapy in Urban and Rural Populations

Background: Implantable cardioverter defibrillators (ICDs) have shown benefit in reducing mortality in patients with heart failure, after myocardial infarction, and those with reduced ejection fraction. We sought to explore the use of this therapy in specialized heart function clinics, in rural and urban locations. Methods: This was a retrospective cohort study performed in 3 specialized heart function clinics in Nova Scotia, 2 of which were in rural locations. All patients with an initial left ventricular ejection fraction <= 35% were included from 2006 to 2011. Rates of referral, ICD implantation, and mortality were compared between urban and rural groups. Results: There were 922 patients included in the study; 636 patients in the urban clinic, 286 in the rural locations. Referral rates were higher in the urban clinic compared with the rural locations (80.4% vs 68.3%; P = 0.024). Refusal rates for referral were higher in the rural locations (13.7% vs 2.1%; P < 0.0001). Higher referral rates were associated with urban location (odds ratio [OR], 1.81; 95% confidence interval [CI], 1.01-3.26; P = 0.047), and younger age (OR, 0.96; 95% CI, 0.93-0.99; P = 0.003); lower referral rates for women was observed (OR, 2.29; 95% CI, 1.13-4.63; P = 0.021). Mortality was significantly associated with older age, lack of referral, presence of comorbidities (renal failure, diabetes, peripheral vascular disease) and a rural location. Conclusions: Specialized heart function clinics have a high rate of appropriate referral for primary prevention ICDs, but referral rates for this life-saving therapy remain lower in rural jurisdictions. This disparity in access to care is associated with increased mortality and might require particular attention to prevent unnecessary deaths.