Glycated Haemoglobin and Outcomes of Percutaneous Coronary Intervention Among Type Two Diabetic Patients in Saudi Arabia

Background: Glycated haemoglobin (HbA1c) is a marker that reflects the control of diabetes mellitus (DM) over a three-month period. We sought to compare cardiovascular outcomes of diabetic patients with and without controlled levels of HbA1c post percutaneous coronary intervention (PCI) presenting to King Faisal Cardiac Center. Methods: A retrospective single-center study of all patients with type two DM who were treated with PCI during the period between January 2015 and January 2018. All data were obtained from health informatics system. Demographics, clinical data, and major adverse cardiovascular and cerebrovascular events (MACCE) were collected to compare outcomes among diabetic patients with and without controlled HbA1c. Results: The study included 177 patients with type two DM who underwent PCI. The mean age was 63.3 (SD±12). Males represented 73.4% and 26.6% were females. The mean HbA1c on admission was 8.7%. At presentation 31% of the patients had relatively controlled blood sugar (HbA1c mean 7.5%, SD±0.5) and 69% presented with poorly controlled type two DM (mean HbA1c 9.1%, SD±0.25). The prevalence of hypertension and dyslipidaemia were higher among the uncontrolled group, but there were no differences between both groups in the control of blood pressure or dyslipidaemia. Patients in the uncontrolled group had higher rate of prior PCI (36.6%) compared to the controlled arm (16%, p=0.0195) The prevalence of cerebrovascular, cardiovascular, and renal impairment was similar. The use of insulin was higher among the uncontrolled arm. Patients in the controlled arm had lower incidence of composite endpoints of death and non-fatal myocardial infarction and stroke (MACCE) (14% vs 41%, p=0.001) compared to the uncontrolled arm. Conclusion: Among patients with type two DM that were treated with PCI, achieving targets of blood sugar control reflected by glycated haemoglobin is associated with improved survival and lower incidence of composite MACCE.