Type 1 diabetes patients with chronic kidney disease before and after an acute myocardial infarction (MI) are at a higher risk of mortality and secondary cardiovascular events, suggests a recent study published in the journal Diabetes Care.¹

Data of 4217 type 1 diabetes patients from the FinnDiane (Finnish Diabetic Nephropathy) Study without prior MI or coronary revascularization was analysed in this follow-up study, which aimed to examine the prognosis after the first myocardial infarction (MI) in the study group. Analysis revealed 253 (6.0%) cases of MIs in this group, which occurred at an average age of 52.4 years.

Over a median follow-up period of 3.07 years, 187 (73.9%) post-MI deaths were recorded. After adjusting for other confounding factors such as age, sex, duration of diabetes, A1c, smoking status and antihypertensive therapy, the risk of cardiovascular and diabetes-related mortality, which was the primary endpoint of the study, increased by 3-folds with hazard ratio (HR) of 3.27 in patients with Grade 3 or moderately reduced eGFR (30–59 mL/min/1.73 m2). However, unexpectedly, the risk did not increase much as the renal function deteriorated. For grade 4 eGFR, the HR was 3.62 and for grade 5 eGFR, the HR was 4.03. A significant association was found between older age at MI and previous diagnosed coronary heart disease and risk of post-MI mortality with HR of 1.50 and 1.03 respectively.

However, patients who underwent acute revascularization lowered their mortality risk (HR 0.35) as did those who underwent subacute revascularization (HR 0.39). “In Fine and Gray competing risk analyses, kidney failure was associated with a higher risk of recurrent MI (subdistribution HR 3.27), heart failure (3.76), and coronary revascularization (3.04)”.¹

These findings illustrate the post-MI high risk of cardiovascular and diabetes-related mortality in type 1 diabetes patients. The study has also identified factors that are associated with increased mortality namely CKD, older age at MI, conservative treatment and diagnosed coronary heart disease. The mortality risk as well as risk of secondary cardiovascular events such as heart failure, coronary revascularization and recurrent MI was significantly higher in patients with poor renal function. Hence, all measures must be taken to prevent kidney disease in patients with type 1 diabetes, including in patients who have suffered a MI for better prognosis.

Reference

1. Patrik Smidtslund, et al; FinnDiane Study Group. Prognosis after first-ever myocardial infarction in type 1 diabetes is strongly affected by chronic kidney disease. Diabetes Care. 2022 Nov 18;dc221586. doi: 10.2337/dc22-1586.