Timing of type 2 diabetes diagnosis and long-term survival in hospitalized patients with cardiovascular disease: a prospective cohort

Purpose

To evaluate the impact of type 2 diabetes mellitus (T2DM) status on long-term survival in hospitalized patients with cardiovascular disease (CVD) and/or hypertension.

Methods

This single-center prospective study included patients admitted for cardiovascular and non-cardiovascular conditions to the therapeutic/cardiology wards of a city hospital. Key inclusion criteria were age ≥40 years and a confirmed diagnosis of CVD and/or hypertension. All patients without a history of T2DM underwent screening using fasting plasma glucose and HbA1c according to ADA criteria. The study inclusion date corresponded to hospital admission, followed by annual structured follow-up telephone interviews after discharge. The first patient was enrolled on January 9, 2018, the last on November 2, 2020, and the final follow-up contact was conducted on March 23, 2024. For patients lost to follow-up, the last documented telephone interview was considered the final contact. All-cause mortality by T2DM status was analyzed using Kaplan-Meier survival curves, and a Cox proportional hazards model with a stepwise exclusion method was applied for multivariable analysis.

Results

The study included 604 patients with a median age of 70 (60; 79) years. After T2DM screening, the distribution was as follows: 162 (26.8%) had a previously diagnosed T2DM, 91 (15.1%) were diagnosed with T2DM for the first time, 351 (58.1%) had no T2DM.

The median follow-up period was 1409 (335; 1949) days. During follow-up, 179 deaths occurred: 59 in patients with previously diagnosed T2DM (survival rate: 54.1%), 31 in patients with newly diagnosed T2DM (survival rate: 60.8%), 89 in patients without T2DM (survival rate: 66.7%).

T2DM was associated with reduced survival (Figure 1A, Log-Rank p=0.017). In three-group comparisons, early separation of survival curves was suggested by Breslow/Tarone-Ware tests, while the log-rank test was borderline (p=0.058, Figure 1B). In multivariable Cox regression, both newly diagnosed and prior T2DM were independently associated with higher all-cause mortality, as well as along with older age (per year), history of myocardial infarction, lower eGFR (per 1 mL/min/1.73 m²), and higher heart rate (per bpm), whereas RAS inhibitor use was associated with lower mortality (Figure 1C).

Conclusions

Type 2 diabetes was associated with lower long-term survival in hospitalized patients with CVD. In three-group analyses, survival differences were differences appeared to be most pronounced early after discharge in patients with newly diagnosed T2DM, supporting the clinical value of in-hospital diabetes screening and early intensification of cardiometabolic risk management.Figure 1For image description, please refer to the figure legend and surrounding text.