Renal Failure, Diabetes Linked to Increased Mortality in Post-Myocardial Infarction

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In post-myocardial infarction patients, chronically impaired renal failure and diabetes are both associated with an increased mortality risk, say researchers recently writing in Diabetes Care.

Diabetes is associated with both an increased risk of all-cause death, mainly driven by cardiovascular mortality, and poorer outcomes after acute myocardial infarction (AMI). While impaired glomerular filtration rate (GFR) is also associated with an increased risk of cardiovascular mortality, whether diabetes still confers a higher mortality risk in patients with impaired GFR remains unknown.

“The aim of this study was to assess the long-term prognostic significance of both diabetes and renal impairment in two prospective nationwide cohorts of AMI patients: FAST-MI 2005 and FAST-MI 2010,” wrote the authors, led by Louis Potier, M.D., of Université de Paris in France.

Both registries consecutively included AMI patients admitted to cardiac intensive care units within 48 hours of symptom onset during a specified one-month period. The analysis included 7,839 participants (mean age 66 years, 29 percent female, 27 percent with diabetes), of which 7,656 patients had creatinine values assessed before percutaneous coronary intervention. Researchers assessed all-cause mortality at five years according to estimated GFR (eGFR) and diabetes status at inclusion.

Five-year mortality was 38 percent in patients with diabetes versus 19 percent in patients without diabetes (adjusted hazard ratio [HR] 1.47, 95% CI 1.33–1.62, P < 0.001). According to eGFR, among all participants, five-year mortality rates were 8.1 percent for eGFR >90 mL/min, 17.7 percent for 60– 90 mL/min, 36.4 percent for 45–60 mL/ min, 57.6 percent for 30–45 mL/min, and 70.6 percent for <30 mL/min.

Further analysis suggested a gradual increase in mortality with decreasing renal function: adjusted HR versus eGFR >90 mL/min as reference 0.91 (95% CI 0.75– 1.11, P = 0.36) for eGFR 60–90 mL/min; 1.19 (0.96–1.46, P = 0.11) for 45–60 mL/ min; 1.48 (1.19–1.85, P = 0.001) for 30– 45mL/min, and 1.86 (1.48–2.35, P < 0.001) for <30 mL/min.

Moreover, increasing renal impairment was associated with an increased risk of death for participants with diabetes under a threshold of 60 mL/min but only below a threshold of 45 mL/min for participants without diabetes.

Compared with no diabetes, diabetes was associated with an increased risk of five-year death throughout eGFR categories, except for eGFR <30 mL/min: HR 1.45 (95% CI 1.01–2.09) for eGFR >90 mL/min, HR 1.54 (1.28–1.84, P < 0.001) for eGFR 60–90 mL/min, HR 1.64 (1.33–2.02, P < 0.001) for eGFR 45–60 mL/min, HR 1.28 (1.04–1.59, P = 0.02) for eGFR 30–45 mL/min.

“These results suggest that in post-myocardial infarction patients, 1) chronically impaired renal failure and diabetes are both associated with an increased risk of mortality, 2) renal function requires specific attention in patients with diabetes as soon as it is mildly impaired (45–60 mL/min), and 3) tight glycemic control, which is controversial in post-myocardial infarction patients (4), may not be essential in patients with diabetes with eGFR <30 mL/min,” the authors wrote.

The authors noted that the study was observational, with some missing data such as proteinuria in all patients and HbA1c in some patients, and that since 2010 newer glucose-lowering medications have documented an impact on cardiovascular and renal outcomes.

REFERENCE

Louis Potier, Ronan Roussel, Marianne Zeller, et al. “Chronic Kidney Disease, Diabetes, and Risk of Mortality After Acute Myocardial Infarction: Insight From the FAST-MI Program.” Diabetes Care. January 23, 2020. doi: 10.2337/dc19-2209