All-cause mortality and cardiovascular events in a Spanish nonagenarian cohort according to type 2 diabetes mellitus status and established cardiovascular disease

BACKGROUND: Despite the progressive aging of the population in industrialized countries, few studies have focused on the natural history of cardiovascular disease in the very old, and recommendations on prevention of cardiovascular disease in this population are lacking. We aimed to analyze all-cause mortality and cardiovascular events according to prevalent type 2 diabetes mellitus and established cardiovascular disease in nonagenarians from a Mediterranean population. METHODS: We analyzed the primary health records of all nonagenarians living in the Community of Madrid (N = 59,423) and collected data for 4 groups: Group 1, individuals without T2DM or established CVD (T2DM-, CVD-); Group 2, individuals without T2DM but with established CVD (T2DM-, CVD +); Group 3, individuals with T2DM but without established CVD (T2DM + , CVD-); and Group 4, individuals with both T2DM and established CVD (T2DM + , CVD +), taking into account the influence of sex on the outcomes. Follow-up was 2.5 years. The primary outcomes were cumulative incidence and incidence density rates for all-cause mortality, non-fatal myocardial infarction, non-fatal stroke (the first composite primary outcome [CPO1]), combined with heart failure (CPO2). We evaluated the adjusted effect of each group on all-cause mortality (Cox regression). RESULTS: Mean age was 93.3 ± 2.8 years (74.2% women). Hypertension, dyslipidemia, heart failure, albuminuria, and estimated glomerular filtration rate < 60 mL/min/1.73 m2 were significantly more prevalent in G4 than in the other groups (all p values < 0.001). We observed significantly higher cumulative incidence rates for all-cause mortality, CPO1, and CPO2 in participants belonging to G4 (all p values ≤ 0.001). People in G2 presented higher rates of all-cause mortality, heart failure, CPO1, and CPO2 than people in G3 (all p values ≤ 0.001). In the fully adjusted model, G4 independently predicted all-cause mortality (HR = 1.48 [95% CI, 1.40 to 1.57] vs reference G1 [p < 0.01]). In addition, significant HRs were recorded for cardiovascular disease alone (G2) and type 2 diabetes mellitus alone (G3) (1.13 and 1.14, respectively; both p values < 0.01). CONCLUSIONS: In Spanish nonagenarians, established cardiovascular disease and type 2 diabetes mellitus conferred a modest risk of all-cause mortality. However, the simultaneous presence of both conditions conferred the highest risk of all-cause mortality. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-022-02893-z.