Mortality in individuals with Type 2 diabetes and heart disease in a unique New Zealand population

AIMS: To determine rate and predictors of mortality in patients with Type 2 diabetes living in a population with a large proportion of Maori and Pacific peoples who were admitted to hospital with myocardial infarction (MI) or congestive cardiac failure (CCF). METHODS: The study population included 4193 individuals with Type 2 diabetes who lived in South Auckland and who participated in a primary care audit between 1994 and 1999. We studied a subgroup of 319 patients who subsequently had a hospital admission for MI or CCF between 1999 and 2001. We examined their demographics, drug treatment, vascular risk factors and mortality up to 2003. RESULTS: Following discharge, the prescription of beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, aspirin and statins had all increased significantly. Vascular risk factors including total cholesterol, high-density lipoprotein (HDL) cholesterol, systolic blood pressure and glycated haemoglobin (HbA(1c)) improved significantly. Nevertheless, mortality remained high with individuals admitted because of an MI 7.2-fold more likely to die early and those with a CCF admission 5.9-fold more likely to die early than other individuals with Type 2 diabetes. Maori patients have an 80% excess mortality. CONCLUSIONS: Patients with past admission for MI and/or CCF remain at exceptionally high risk of death for at least 4 years after hospital admission, even with improvements in management of cardiovascular risk factors. Maori individuals are at particular risk.