Factors associated with stroke, myocardial infarction, ischemic heart disease, unstable angina, or mortality in patients from real world clinical practice with newly-diagnosed type 2 diabetes and early glycemic control

Abstract

Objectives: The objective of this study was to identify factors associated with stroke, myocardial infarction (MI), all-cause mortality, or a diagnosis of ischemic heart disease (IHD) or unstable angina (UA), among patients newly-diagnosed with type 2 diabetes (T2DM) with no recent history of cardiovascular (CV) events who rapidly achieve and maintain HbA_1c ≤8.0%.

Methods: Data were obtained from the Clinical Practice Research Datalink (CPRD) from January 1990 to December 2012. A nested case-control design was used with Cox proportional hazards analysis. Cases were identified by the first occurrence of stroke, MI, IHD, UA, or death within 5 years after HbA_1c ≤ 8.0% was first reached (index date) following T2DM diagnosis. Controls were selected using a risk-set sampling approach and were matched 4:1 to cases using index date, exposure time, age, gender, and HbA_1c at index date.

Results: A total of 11,426 T2DM patients met the inclusion criteria for cases. Of these, 5,261 experienced a CV event. Stroke was the most frequent CV event (40%), followed by IHD (29%), MI (22%), and UA (9%). Mean HbA1c ≥7.0% over the length of exposure (vs 6.5 to <7.0%) was associated with an increased risk of stroke, MI, and IHD. The use of anti-platelet medications at baseline was also associated with increased risk of stroke (HR = 1.82 [CI = 1.60-2.06]), MI (HR = 1.67 [CI = 1.38-2.03]), and IHD (HR = 1.85 [CI = 1.57-2.17]). Mean HbA1c < 6.0% was associated with increased risk of stroke (HR = 1.29 [CI = 1.02-1.63]) and IHD (HR = 1.65 [CI = 1.25-2.19]). Use of nitrate medications at baseline was associated with increased risk of MI (HR = 2.83 [CI = 2.24-3.57]), IHD (HR = 4.32 [CI = 3.57-5.22]), and UA (HR = 10.38 [CI = 7.67-14.03]).

Conclusions: Early and sustained HbA_1c control between 6.5 and <7.0% appears to be an important modifiable factor that helps reduce CV risk in patients with newly-diagnosed T2DM in real-world clinical practice.

Keywords: Cardiovascular events; glycemic control; ischemic heart disease; mortality; myocardial infarction; real-world evidence; stroke; type 2 diabetes; unstable angina.