HF development after T2DM diagnosis associated with highest 5-year risk of death
Type 2 Diabetes Mellitus and Impact of Heart Failure on Prognosis Compared to Other Cardiovascular Diseases: A Nationwide Study
Introduction and methods
Observational studies in patients with T2DM have reported increased rates of mortality following myocardial infarction, stroke, chronic kidney disease (CKD) and heart failure (HF) [1-11]. However, the risk profile among real-life patients with newly diagnosed T2DM who develop CV and renal disease remains unknown [12,13]. Moreover, the prognostic importance in terms of mortality risk of CV and renal diagnoses in T2DM patients is still uncertain. This nationwide study estimated the absolute 5-year risk of death, the 5-year risk ratio (RR) of death and decrease in lifespan in patients with newly diagnosed T2DM who developed HF, ischemic heart disease (IHD), stroke, CKD, or peripheral artery disease (PAD) after diagnosis of T2DM.
Data were collected from 4 nationwide Danish registers: The Danish National Patient Registry, The Danish National Prescription Registry, The Danish Cause of Death Registry and The Danish Civil registry. A total of 153,405 patients with newly diagnosed T2DM between 1998 and 2015 and with no prior CV or renal diagnoses were included.
The primary outcome was all-cause death. Patients were followed until the end of the study period (December 31, 2015), death or emigration. Median follow-up was 9.7 years (IQR 5.8-13.9 years).
- Patients who developed HF had the highest 5-year risk of death among patients alive 5 years after T2DM diagnosis (47.6%, 95%CI 44.8-50.3), compared with T2DM patients who developed IHD (21.0%, 95%CI 20-22), stroke (34.5%, 95%CI 32.6-36.4), CKD (27.7%, 95%CI 25.5-30.0), and PAD (37.1%, 95%CI 34.6-39.5).
- Compared to T2DM patients without CV and renal disease, patients who developed HF within 5 years after diagnosis of T2DM had a 3 times higher 5-year RR of death (95%CI 2.9-3.1). The corresponding 5-year RR of death were lower for patients who developed IHD (RR 1.3, 95%CI 1.3-1.4), stroke (RR 2.2, 95%CI 2.1-2.2), CKD (RR 1.7, 95%CI 1.7-1.8), and PAD (RR 2.3, 95%CI 2.3-2.4).
- Patients who developed HF within 5 years following onset of T2DM had an average decrease in lifespan of 11.7 months, compared with T2DM patients free of CV and renal disease (95%CI 11.6-11.8). Smaller decreases in lifespan were found for other diagnoses: IHD (1.6 months, 95%CI 1.5-1.7), stroke (6.4 months, 95%CI 6.3-6.5), CKD (4.4 months, 95%CI 4.3-4.6), PAD (6.9 months, 95%CI 6.8-7.0).
- When looking at the prognosis after developing a combination of 2 CV or renal diseases, the highest 5-year risks of death were found in patients who developed HF in combination with stroke (54.1%, 95%CI 44.7-63.5) or CKD (63.7%, 95%CI 53.7-73.7). The 5-year risk of death in patients who developed HF in combination with PAD was 48.4% (95%CI 36.4-60.5) and 45.5% in patients who developed HF and IHD (95%CI 42.3-48.7). The 5-year risks of death in patients who developed IDH in combination with stroke, CKD, or PAD were 39.9% (95%CI 34.8-45), 38.4% (95%CI 32.7-44.1), and 39.5% (95%CI 34.4-44.5), respectively.
- The 5-year RR of death was highest among T2DM patients with HF in combination with stroke (RR 3.4, 95%CI 3.3-3.5), CKD (RR 4.0, 95%CI 3.9-4.1), or PAD (RR 3.1, 95%CI 3.0-3.1). Other combinations of CV or renal diseases did not exceed a RR estimate above 3.0.
- The lifespan in patients who developed HF within 5 years following onset of T2DM in combination with stroke, CKD, PAD, or IHD decreased by 16.2 months (95%CI 16.1-16.4), 18.2 months (95%CI 18.1-18.3), 14.3 months (95%CI 14.2-14.4), and 11 months (10.9-11.2), respectively. The lifespan in patients developing IHD in combination with stroke, CKD, or PAD decreased by 7.9 months (95%CI 7.8-8.0), 7.9 months (95%CI 7.8-8.1), or 8.6 months (95%CI 8.5-8.7), respectively.
Among patients with newly diagnosed T2DM, those who developed HF alone or in combination with stroke, CKD or PAD had the highest 5-year absolute and relative risk of death and the greatest decrease in lifespan when compared with development of other (combinations of) CV and renal diseases.