PROGNOSTIC SIGNIFICANCE OF GLYCEMIC STATUS ON ADMISSION IN DIABETIC AND NON-DIABETIC PATIENTS WITH ACUTE CORONARY SYNDROME

Objectives: The aim is to study the relationship between glycemic status at admission and outcome in diabetic and non-diabetic patients with acute coronary+ syndrome (ACS). Methods: This prospective, observational study was conducted on all patients admitted to general wards and ICCU at GMCH, Udaipur, from February 2021 to July 2022. Detailed history and clinical examination were done. HbA 1c, RBS, CBC, TROP I, and CPK-MB were done. Investigations were collected at the time of admission and discharge. Results: Among non-diabetic patients, there were 19 patients who had hyperglycemia on admission and 36 had normal sugar. Among diabetic patients, 31 patients had hyperglycemia and 24 patients had normal sugar. 31 patients with hyperglycemia on admission had high HbA 1 c. 29 patients had cardiac failure (26.36%), 30 with cardiogenic shock (27.27%), 33 with arrhythmias (30%), and 4 with pulmonary edema (3.63%), making cardiac failure the most common complication in the study population. The mean ejection fraction at admission for the non-diabetics with normal sugar was 44.52, for non-diabetics with hyperglycemia was 43, for diabetics with normal sugar was 41.88 and for diabetics with hyperglycemia was 40.95. Conclusion: We conclude that non-diabetics presenting with hyperglycemia on admission are at more risk of having complications of ACS and had more mortality compared to diabetics having normal sugar on admission.


INTRODUCTION
It is a well-known fact that diabetes and cardiovascular diseases go hand in hand together.Many patients presenting with cardiovascular diseases are either suffering from diabetes or are in the pre-diabetic state [1].Coronary artery disease (CAD) which is considered the most significant complication of DM, presents two to four folds greater risk of mortality compared to the non-diabetic population [2,3].
It is well accepted that hyperglycemia is commonly present in patients admitted with acute ST-segment elevation myocardial infarction (STEMI).It is associated with an increased risk of death or adverse cardiovascular events in patients both with and without a previous history of diabetes mellitus [4].
In patients with no prior history of diabetes who present with a macrovascular complication, that is, myocardial infarction, hyperglycemia might be due to a previously undiagnosed diabetes or due to stress hyperglycemia or due to a pre-diabetic state.This can lead to a poor outcome in patients in the form of shock, failure, or arrhythmias [5].
Hence, both stress hyperglycemia in non-diabetic patients and high random blood sugar in diabetic patients are having adverse prognostic effects in patients with ACS.However, the effect of recently elevated blood sugar as measured by HbA 1c has still not been consistently reported as a bad prognostic indicator.
Available data suggest that hyperglycemia on admission is an indicator of short-term mortality in patients admitted with acute STEMI, but its efficacy in predicting the long-term mortality is still unclear.
It has been noted that among patients with high-risk Non-ST elevation acute coronary syndrome (NSTE-ACS) also that a substantial proportion of patients admitted with high-risk NSTE-ACS had previously undiagnosed DM (12.2%) or pre-diabetes (10.8%) as defined by HbA 1c or FBS after admission.
According to a study done in 2013 by Ashraf, in non-diabetic patients, HbA 1c could be utilized for risk stratification of CAD and its severity; independent of traditional cardiovascular risk factors.These factors aroused curiosity, which led to this study, which probes into the prognostic significance of glycated hemoglobin and admission RBS in non-diabetics admitted with acute STEMI.
The Framingham study also confirms that females had a higher occurrence of diabetes compared to males,whereas in India, males have a higher occurrence of diabetes than females, according to a diabetes research study held in India [6].In acute MI, DM has been a bad prognostic factor with an increased occurrence of heart failure, higher mortality in the hospital, conduction abnormalities including atrial fibrillation, and post-infarction angina among diabetics [7,8].It has been shown that adequate control of blood sugar brings down the progression of microvascular disorders caused by diabetes.However, its influence on macrovascular complications is not well known [9].
Inadequate glycemic management is shown by elevated HbA 1c , and its elevated value during admission for ACS, increases the mortality in 1 st month.Furthermore, hyperglycemia at the time of ACS without a history of DM has increased short-term mortality [10].
Diabetes is a significant risk factor for the development of ACS and the adverse outcomes after ACS."Stress hyperglycemia" has been defined in different ways by various studies transient hyperglycemia has been recognized as a noticeable feature in ACS and is considered to be related to stress [11].Sometimes, hyperglycemia can denote pre-existing type 2

Padhiar et al.
diabetes or impaired glucose tolerance, which has not been detected before.Studies prove that uncontrolled blood sugar has poor outcome when they develop an ACS, but hyperglycemia at the time of ACS also have a similar prognostic value [12].
Moreover, this study enables risk stratification.Early identification of high-risk groups enables the initiation of specific intervention strategies and it may help us to improve the prognosis of these patients.It also helps in identifying a previously undiagnosed group of diabetics.This is of importance because there is a global increase in the number of patients suffering from cardiovascular disease with underlying insulin resistance, pre-diabetes, and overt diabetes mellitus, which go unrecognized.
Aims and objectives 1.To compare the glycemic status at admission in diabetic and nondiabetic patients with ACS 2. To study the relationship between glycemic status at admission and outcome in diabetic and non-diabetic patients with ACS in terms of:

Statistical analysis
The data were entered in MS Excel Software version 20 and analyzed using SPSS, IBM Comp, version 21.Descriptive analysis of the data was performed presenting the results as frequency and percent for qualitative variables and as mean and standard deviation for age.The relation between qualitative variables was evaluated by the Chisquare test and Fisher's exact test if needed.The descriptive data were expressed in proportions, mean, and frequency tables.The categorical data were analyzed using Chi-square test.The quantitative data were analyzed using an independent Student's t-test.p<0.05 was considered statistically significant.

DISCUSSION
Our study population included only patients admitted with ACS with or without a history of type 2 diabetes.Comorbidities such as renal disease, patients with Hb <7 mg/dL, and concurrent systemic infections were excluded, so as to study the prognosis related to diabetes and blood sugar alone.
In our study, 43 patients at admission had RBS >140 mg/dL.Among these 30 patients were known as diabetic.45% of patients had hyperglycemia on admission irrespective of their diabetic status while according to a study done by Timmer et al., 34.16% had hyperglycemia on admission irrespective of their diabetic status [13].Increased levels of free fatty acids (FFA) may also be linked to elevated glucose levels.These FFA have the potential to reduce endothelium-derived vasodilatation in

Clinical presentation
Padhiar  [15].These findings simulate our study findings.This means that non-diabetic patients had more complications than diabetic patients who had their blood sugar controlled at the time of admission.
In our study, the mortality was 8.33% in non-diabetic patients with normal sugar on admission and 15.79% in non-diabetic patients with hyperglycemia on admission, mortality was 12.5% in diabetic patients with normal sugar and 25.8% with diabetics having hyperglycemia (uncontrolled diabetes) on admission.In a study done by Zhao et al., the mortality was 5.4% in non-diabetic patients with normal sugar on admission and 6.7% in non-diabetic patients with hyperglycemia on admission, mortality was 1% in diabetic patients with normal sugar and 6.07% with hyperglycemia on admission [16].Above findings simulate with our study findings [17].Coronary artery atherosclerosis which is associated with long standing diabetes, is directly related to myocardial ischemia, and consequently, impaired glucose uptake, increased oxidative stress, and vascular endothelial dysfunction, which may promote the progression of diabetic cardiomyopathy, which leads to low ejection fraction.

Parameter
The study group was small in number.Follow-up of the patients was done only till discharge.Long-term follow-up would have shown further prognostic effects of hyperglycemia on ACS patients.

CONCLUSION
This study indicated that non-diabetics presenting with hyperglycemia on admission are at more risk of having complications of ACS and had more mortality compared to diabetics having normal sugar on admission.In terms of predicting the short-term outcome in ACS, acute glucose metabolism disturbances appear to be more significant than long-term glucose metabolism derangements.