Jeanette Kuhl1, Ulrik Sartipy2, Björn Eliasson3, Thomas Nyström4, Martin J Holzmann5. 1. Division of Cardiovascular Medicine, Danderyd University Hospital, Stockholm, Sweden; Department of Internal Medicine, Karolinska Institutet, Stockholm, Sweden; Department of Clinical Sciences, Karolinska Institutet, Stockholm, Sweden. 2. Department of Cardiothoracic Surgery and Anaesthesiology, Karolinska University Hospital, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden. 3. Institute of Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden. 4. Department of Clinical Science and Education, Division of Endocrinology, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden. 5. Department of Emergency Medicine, Karolinska University Hospital, Stockholm, Sweden; Department of Internal Medicine, Karolinska Institutet, Stockholm, Sweden. Electronic address: martin.holzmann@karolinska.se.
Abstract
BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) have an increased risk of coronary heart disease and death. We aimed to investigate the association between preoperative hemoglobin A1c (HbA1c) levels and long-term mortality after coronary artery bypass grafting (CABG) among patients with T2DM. METHODS: All patients with T2DM who underwent CABG in Sweden from 2003 to 2013 were included from the SWEDEHEART register. Information about diabetes was retrieved from the Swedish National Diabetes Register. We used Cox regression to calculate hazard ratios (HR) with 95% confidence intervals (CI) for all-cause mortality and also a combination of death or a major cardiovascular event (MACE). RESULTS: In total, 6313 patients were included. During a mean follow-up time of 5.5 (±3.8) years, (34,482 person-years), 1630 (26%) patients died. After multivariable adjustment, HbA1c was associated with an increased risk of death in patients with HbA1c levels 9.1-10%, and >10% (HR (95% CI): 1.26 (1.04-1.53), and 1.33 (1.05-1.69), respectively). There was an increased risk for death or MACE at HbA1c levels 8.1-9%, 9.1-10%, and >10% (HR (95% CI): 1.17 (1.04-1.33), 1.44 (1.22-1.70), and 1.50 (1.22-1.84), respectively). In patients with insulin-treatment there was no association between HbA1c levels and death. CONCLUSIONS: In patients with T2DM who underwent CABG we found an increased risk of death at HbA1c levels above 9.0%, and also for the combination of death or MACE at HbA1c levels above 8.1%. There was no association between HbA1c levels and death in T2DM patients who were insulin-treated.
BACKGROUND:Patients with type 2 diabetes mellitus (T2DM) have an increased risk of coronary heart disease and death. We aimed to investigate the association between preoperative hemoglobin A1c (HbA1c) levels and long-term mortality after coronary artery bypass grafting (CABG) among patients with T2DM. METHODS: All patients with T2DM who underwent CABG in Sweden from 2003 to 2013 were included from the SWEDEHEART register. Information about diabetes was retrieved from the Swedish National Diabetes Register. We used Cox regression to calculate hazard ratios (HR) with 95% confidence intervals (CI) for all-cause mortality and also a combination of death or a major cardiovascular event (MACE). RESULTS: In total, 6313 patients were included. During a mean follow-up time of 5.5 (±3.8) years, (34,482 person-years), 1630 (26%) patients died. After multivariable adjustment, HbA1c was associated with an increased risk of death in patients with HbA1c levels 9.1-10%, and >10% (HR (95% CI): 1.26 (1.04-1.53), and 1.33 (1.05-1.69), respectively). There was an increased risk for death or MACE at HbA1c levels 8.1-9%, 9.1-10%, and >10% (HR (95% CI): 1.17 (1.04-1.33), 1.44 (1.22-1.70), and 1.50 (1.22-1.84), respectively). In patients with insulin-treatment there was no association between HbA1c levels and death. CONCLUSIONS: In patients with T2DM who underwent CABG we found an increased risk of death at HbA1c levels above 9.0%, and also for the combination of death or MACE at HbA1c levels above 8.1%. There was no association between HbA1c levels and death in T2DM patients who were insulin-treated.