Short, Medium and Long-Term Cause-Specific Mortality Following First-Ever Heart Failure Hospitalisation in New Zealand.

BACKGROUND: Heart failure (HF) is associated with high mortality, but there are limited reports on the underlying cause of death. This study reports short-, medium- and long-term cause-specific mortality following first-ever HF hospitalisation in New Zealand.

METHOD: First-ever HF hospitalisations were identified from hospital discharge coding between 2010 and 2013. Mortality outcomes were obtained via anonymised linkage to national datasets. Short (0-30 days), medium (31-364 days), and long-term (1-5 years) mortality rates were identified. Cause of death was identified from death certification coding and classified as cardiovascular and non-cardiovascular. Cox regression analysis was performed to adjust for confounding variables.

RESULTS: A cohort of 34,264 individuals with first-ever HF hospitalisation were identified. Mean age was 75.8±13 years and 50.5% were male. A total of 21,637 (63.1%) died within 5 years of hospitalisation; 4,122 (12.0%) within the first 30 days, 6,358 (18.6%) between 31-364 days, and 11,157 (32.6%) between 1 and 5 years. Older age, male gender, Māori ethnicity, higher socioeconomic deprivation and increased comorbidity were independent factors associated with higher all-cause mortality. Cardiovascular causes accounted for 51% of total deaths. Cardiovascular mortality was 6.0%, 9.5%, and 16.7% at 30 days, 31-364 days, and 1-5 years, respectively. The most common causes of non-cardiovascular mortality were neoplasms, chronic respiratory diseases and infections, accounting for 14.6%, 11.0%, and 5.5% of total deaths respectively. Comorbidity was associated with higher non-cardiovascular mortality (hazard ratio [HR] 3.35; 95% confidence interval [CI] 3.16-3.55) but not cardiovascular mortality (HR 0.79; 95% CI 0.72-0.86).

CONCLUSIONS: In New Zealand, mortality following first-ever HF hospitalisation is high. Non-cardiovascular death is common and there are ethnic inequities.