International Journal of Cardiovascular ResearchISSN: 2324-8602

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Research Article, Int J Cardiovas Res Vol: 5 Issue: 5

Clinical and Angiographic Profile of Prediabetic Patients with Acute ST Elevation Myocardial Infarction

Thrudeep S*, Rajesh G, Jayakumar TG, Rupesh G, Geofi G, Gagan S and Abdulkhadar S
Department of Cardiology(Intervention),Amala Institute of Medical Science, Amala Nagar,Thrissur,Kerala,India:680555
Corresponding author : Thrudeep Sagar
Senior Resident , Department of Cardiology, Amala Institute of Medical Sciences, Amala Nagar, Thrissur-680 555, Kerala, India
Tel: +919400736897
E-mail: [email protected]
Received: May 30, 2016 Accepted: July 13, 2016 Published: July 18, 2016
Citation: Thrudeep S, Rajesh G, Jayakumar TG, Rupesh G, Geofi G, et al. (2016) Clinical and Angiographic Profile of Prediabetic Patients with Acute ST Elevation Myocardial Infarction. Int J Cardiovasc Res 5:5. doi:10.4172/2324-8602.1000280

Abstract

Background: Clinical trials had demonstrated that acute ST segment elevated myocardial infarction (STEMI) with an abnormal glucose tolerance was risk factor for future cardiovascular events. This study was aimed to analyze the various clinical outcomes, coronary angiographic results and incidence of major adverse cardiovascular event (MACE) in prediabetic patients presented with STEMI in a tertiary care centre. Methods: Prediabetic patients who were presented with STEMI in the department of Cardiology included in the study. Age and sex matched non prediabetic patients with STEMI were selected as the control group. Demographic variables, clinical presentations, findings of coronary angiogram, electrocardiogram (ECG) and 2D echo, morbidity and cardiac mortality were collected and subjected to statistical analysis. Results: Total 70 patients (35 prediabetic and 35 non prediabetic as control) were included in this retrospective study. The major findings such as Killip class III and IV (clinical presentations); Bradyarrythmia (ECG manifestations); moderate and severe left ventricular dysfunction (2D Echo findings); double and triple vessel disease, right coronary artery, left circumflex artery, use of long stent (angiographic findings), MACE and cardiac mortality were found to be more in prediabetic patients than the non prediabetic control group. Conclusion: Prediabetic group had higher Killip class, more multivessel disease, higher MACE and cardiovascular mortality as compared to non prediabetic group, which emphasizes the need for early diagnosis of prediabetes.

Keywords: Prediabetes; Acute ST elevation MI; Major adverse cardiovascular event; Cardiac mortality

Keywords

Prediabetes; Acute ST elevation MI; Major adverse cardiovascular event; Cardiac mortality

Abbreviations

HTN: Hypertension; DLP: Dyslipidemia; PVOD: Peripheral Vascular Obstructive Disease

Introduction

Diabetes mellitus has been recognized as one of the risk factors for cardiovascular disease (CVD). Diabetic patients with acute ST segment elevated myocardial infarction (STEMI) have two- to fourfold increased risk of adverse cardiovascular events compared to non-diabetic individuals [1,2]. The impaired glucose metabolism and the prediabetic state were associated with adverse clinical outcomes [3]. According to the American Diabetic Association, prediabetes can be defined as patients with fasting blood glucose between 100- 125 mg/dl or glycated hemoglobin (HbA1c) level of 5.7-6.4 % without any symptoms of diabetes [4]. Various studies had shown that not only diabetes but also prediabetes had increased risk for morbidity and mortality from CVD [5-10]. Clinical trial had demonstrated that acute STEMI with an abnormal glucose tolerance was a risk factor for future cardiovascular events [11,12,13]. Therefore, early diagnosis of prediabetes is essential for decreasing the cardiovascular mortality and morbidity.
Early diagnosis of prediabetes can prevent further cardiovascular complications like major adverse cardiovascular event (MACE). MACE was defined by Global utilization of strategies to open occluded arteries criteria as the major adverse cardiovascular events with death, myocardial infarction (MI), major bleeding and stroke. Along with this, secondary prevention for diabetes which could have a major impact on prognosis and treatment of STEMI will be advised. This study was aimed to analyze the various clinical outcomes, coronary angiographic findings in prediabetic patients presented with STEMI with those of non prediabetic patients in a tertiary care centre.

Materials and Methods

Selection of subjects
Retrospective study was conducted in the department of Cardiology, during the period Jan 2014-Jan 2015. Cases with a previous history of prediabetes presented with acute STEMI were included in the study. Age matched non prediabetic patients who were diagnosed as acute STEMI were selected as the control. HbA1C was measured by HPLC method in the hospital diagnostic laboratory, 24 hr after the admission. The fasting blood glucose level was selected from the recent medical history (preceding 2-3 months). STEMI has been defined as the ECG showing ST elevation measured at J point found in two contagious leads and ≥ 0.25 mV in men below the age of 40 years, 0.2mV in men over the age of 40 years or ≥ 0.15 mVin women in leads V2-V3 and/or ≥ 0.1 mV in other leads in absence of left ventricular hypertrophy or left bundle branch block [6]. The study design was approved by the institutional research committee, Amala Institute of Medical Sciences, Amala Nagar, Thrissur, Kerala, India. Cases of diabetes, or those with family history of CVD or any other congenital heart diseases were excluded.
Statistical analysis
The statistical analysis was performed using SPSS (version 16.0, IBM, USA). Comparisons of the distributions of categorical variables between the two groups were based on Chi Square test or Fishers exact test.Comparisons of quantitative variables between prediabetic and non pre diabetic groups were done by two sample t tests. P less than 0.05 was considered as significant.

Results

Out of total 70 patients, 35 prediabetic (52.3 ± 2.3 yrs) and 35 control (50.0 ± 2.5 yrs) were included in the study. Male predominance was present in both groups. The observations such as peripheral vascular obstructive disease, hypertension, smoking, obesity, dyslipidemia (DLP) were not significantly different among the groups (Table 1). The HbA1C level in the prediabetes and control group were 5.9 ± 0.2 and 5.3 ± 0.3% (p<0.001), respectively. Clinical presentation was found significantly different among the groups. Prediabetic patients had chest pain as major presenting complaint when compared to non prediabetic patients. Patients with Killip class II symptoms were common in both groups and were statistically non significant. The Killip class III and IV symptoms were common in prediabetic cases than that of control group (Figure 1).
Table 1: Baseline characteristics.
Figure 1: Distribution of various clinical presentations in the prediabetes and control groups.
Electrocardiography (ECG) showed statistically significant sinus tachyarrythmias (14%) in prediabetic than the non prediabetic population. Severe left ventricular (LV) dysfunction (ejection fraction <30%) was found predominately in prediabetic (4/35; 11%) than non prediabetic (1/35; 3%) (p=0.03). Moderate LV dysfunction (ejection fraction of <40%) was found in 49% (17/35) cases of prediabetes while 14% (5/35) found in the non prediabetic group (p=0.17) (Figure 2). Angiographically 57% of prediabetic and 17% cases of control groups had double vessel disease (Figure 3). Number of cases of triple vessel disease was 8.5% and 2.8% in prediabetic and non prediabetic group, respectively (p=0.02).
Figure 2: Comparison of left ventricular (LV) function among the prediabetes (SG) and control (CG) groups.
Figure 3: Comparison of cases according to number of coronary vessels involved in the prediabetes (SG) and control (CG) groups.
Percutaneous angioplasty in prediabetic population was challenging. Relatively long stents ie. length ≥ 31.5 mm (54.2%) were used in prediabetes population. Furthermore, multiple stent deployment was considered in prediabetic group than that of the control group. Average flouro time for primary percutaneous intervention (PCI) in prediabetic group was 60 ± 15 min as compared to 33 ± 12 min in non prediabetic group (Figure 4). The distribution of vessels among the group is depicted in Figure 5. More right coronary artery involved MI was found in the prediabetes patients, whereas the left circumflex artery was involved in control group (Figure 5).
Figure 4: Distribution of cases according to fluro time (min.) in the prediabetes (SG) and control (CG) groups.
Figure 5: Distribution of cases according to culprit of coronary vessel in the prediabetes (SG) and control (CG) groups. RCA: Right Coronary Artery; LCX: Left Circumflex Artery; LAD: Left Anterior Descending Coronary Artery.
Post thrombolytic era for prediabetic (15%) was associated with more adverse clinical outcomes as compared to non prediabetic. Less number of cases encountered with facilitated and failed PCIs in both groups. Post procedure accesses site hematomas were more common with prediabetes (57%) when compared to non prediabetes (17%). Mortality was more in prediabetic group (9%), while it was 3% in the control group. No cardiac death was found in the non prediabetic group when compared to the control group. Adverse clinical events such as pulmonary oedema (67%), cardiogenic shock (12%), and cardiac arrest (3.8%) were all significantly higher in pre-diabetic group than that of the control group.

Discussion

We demonstrate that the prediabetic state is cause for worse prognosis in patients with acute STEMI. Coronary angiogram analysis revealed that prediabetic group had more number of double and triple vessel disease than the non prediabetic group. Prediabetes with hyperglycemia, free fatty acids, and insulin resistance can provoke multiple molecular changes that may alter the structure of blood vessels which eventually result in vasoconstriction, inflammation and atherosclerosis [8,9]. Previous study had demonstrated the increased long term risk of adverse cardiac events in patients with prediabetes [10].
There was dilemma in ECG localization in cases with aVR STEMI in the prediabetic group. In both groups, bradyarrythmia and sinus tachyarrythmias were only few in number and statically insignificant. This observation was consistent with the previous report [11]. Although abnormal blood glucose was common among the patients with acute STEMI, at admission the hyperglycaemia does not represent abnormal glucose tolerance. Therefore, it was suggested that HbA1c levels were the independent predictor of abnormal glucose tolerance. However, Ishihara et al. demonstrated that patients diagnosed as acute STEMI with hyperglycaemia at the time of admission were associated with increased risk of mortality [10-13]. This association has been documented not only in diabetic but also in non prediabetic patients. Increased risk of mortality can be ascribed to the hyperglycaemia-induced activation of blood coagulation and inflammation. We found that the thrombus load was of grade 4 and 5 in both groups.
Although recent study was reported that diabetes may not be a predictor for short-term outcome after AMI in the PCI era, an elevated HbA1c level will be an important risk factor for long-term outcome [7]. Considering the high prevalence of abnormal glucose tolerance among prediabetes patients with acute STEMI, HbA1c can be considered routinely for the risk stratification. Various studies had reported that fasting glucose and HbA1c were good measures to predict abnormal glucose tolerance [14,15]. Kurihara et al. [7] demonstrated that the degree of coronary atherosclerosis was more in prediabetic than the non-diabetic population. This trial has further showed more multi vessel involvement in prediabetic than non prediabetic, which was similar to our study. Relatively more prediabetic patients were with Killip class III and IV which indicated the poor prognosis and hence prompt interventions with management is required to improve the outcomes. Previous report also demonstrated the moderate LV dysfunction (Killip IIIIV class) in prediabetic patients [16].
The use of long and multiple DES stents with prolonged flouro time in prediabetes patients than the control may indicate the complex coronary anatomy of culprit lesion. This was further supported by the usage of drug eluting stents in 92% cases of pre diabetes. The procedure time and post procedure complications were more in pre diabetic when compared to non prediabetic. This may probably due to the more complex coronary anatomy. The all cause mortality and cardiac mortality were more in prediabetic group. Cardiac free wall rupture was documented in an elderly prediabetic case. Pre PCI, Post PCI MACE and mortality were high in prediabetic compared to non-diabetic population. This may be due to the complex coronary anatomy and adverse LV remodeling. The cardiac pathophysiology in prediabetic population has to be defined for evaluating the progression of atherosclerosis and severity of LV function by large trial using coronary angiogram, intravenous ultra sonogram and cardiac magnetic resonance imaging. The limitations of this study include the small sample size in the retrospective design and selection of both anterior and inferior STEMI. Hence, a prospective study in a large population using only one type of STEMI warranted.

Conclusion

The results showed that prediabetic group had higher Killip class, more multivessel disease, higher MACE and cardiovascular mortality as compared to control group. Hence, an early diagnosis of prediabetes is emphasized to select the appropriate lifestyle modifications such as regular exercise and dietary modifications.

Acknowledgments

Authors are grateful to the valuable help of Dr. Razi Ahmed, Dr Ganga V, Dr Animesh Jain and Dr Pradeep H N of Department of Cardiology(Intervention), during the study and Dr Ajith TA, Professor, Department of Biochemistry, during the preparation of the manuscript. Further, Mrs Jini Department of Statistics, Amala Institute of Medical Sciences, Amala Nagar, Thrissur, Kerala, India was also acknowledged for the statistical analysis.

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