We have consecutively performed CAG on 870 amongst first AMI survival conservatively managed patients after proper stabilization from 1^st June 2013 to 30^th May 2015 at Sri Aurobindo Medical College and PG Institute (Super specialty tertiary care hospital), Indore (M.P.). Formal consent of the patients and ethical committee approval were taken. Our inclusion criteria were: Non thrombolysed/failed thrombolysed (<50% ST segment reduction), history of post MI angina/recurrent angina, heart failure, haemodynamic instability and LVEF <40% patients were taken directly for CAG. In asymptomatic patients after AMI with LVEF >40%, Treadmill Test (TMT) was done by modified bruce protocol with target work load 5 Metabolic Equivalent (MET) /symptoms of angina/electrocardiography (ECG) changes during exercise and inadequate BP response were noted. If TMT was found positive then they were taken for CAG. Age, gender, BMI, CAD conventional risk factors such as hypertension, Type 2 diabetes mellitus (T2DM), lipid profile, smoking habit were noted and retrospectively analysed. Clinical status and history of thrombolysis were noted. Dyslipidaemia was defined according to the report of National Cholesterol Education Program (NCEP) Adult treatment panels II & III. Obesity was defined if Body Mass Index (BMI) ≥25 kg/m². Patients who smoke one pack year were classified as current smokers whereas who have left smoking for five years were classified as past smokers. Patients who never smoked in their life time were classified as nonsmoker.

Significant CAD was noted when ≥50 reduction of the diameter of epicardial coronary artery was revealed. Patients visited within 24 hours of AMI were thrombolysed by 1.5 million IU of Streptokinase in 100 ml of 0.9M NaCl in a peripheral intravenous line by constant infusion pump over 45 min.

Statistical analysis was descriptive pointing to conventional risk factors and CAG findings. One-way ANOVA test was applied to see the significant difference in mean of quantitative data in between groups. Chi-square test was used to see the difference in frequency of discrete data in between groups. A p-value of less than 0.05 was considered significant.

Their mean age was 54.96 yrs and mean BMI was 25.93 kg/m². 246/870(28.27%) patients were diabetic, 274/870(31.49%) were hypertensive, 327/870 (37.58%) were dyslipidaemic, 391/870 (44.94%) were current smoker whereas 315/870 (36.20%) subjects have left smoking 5 years back and 164/870 (18.85%) patients were nonsmoker [Table/Fig-1].

Coronary Risk Factors (RF) analysis showed ≥3 RF in 23.21%, 2 RF in 29.88% and 1RF in 45.86% of patients. Single vessel disease (SVD), Double Vessel Disease (DVD) and Triple Vessel Disease (TVD) were observed in 236 (27.13%), 220 (25.28%), 252 (28.97%) patients by CAG respectively [Table/Fig-2]. The higher the risk factor, the mores chance of multiple coronary artery involvement and it was found statistically significant (p-value<0.0001). 348/870(40%) patients were thrombolysed amongst them 80 (22.98%) patients revealed recanalization of infract related coronary artery which was found statistically significant (p-value<0.0001).

CAG showed TVD in 252/870(28.9%) patients among them 102(40.74%) had >three RF, 96 (38.09%) had two RF and 54 (21.42%) had only one RF. 220/870(25.8%) patients showed DVD amongst them 40 (18%) had >three RF, 46 (20%) had two RF and 134 (60%) had one RF. 236/870(27.13%) revealed SVD amongst them 20(8.47%) patients had three RF, 92(17.79%) patients had two RF and 174(54.35%) patients had one RF. 78/870(8.96%) patients revealed left main coronary (LMC) artery lesion amongst them 32 (41.1%) had > three RF, 20 (25%) had two RF and 26 (33.33%) showed one RF. 52/870(5.97%) patients revealed minimal lesion of which 8 patients had > three RF, 6 (11%) patient had two RF and 10 (19%) patients had one RF. 32/870(3.68%)patients revealed normal CAG who had one RF (present smoker). The aforesaid findings correlate the risk factor with CAG findings. The more the risk factor, the more number of coronary arteries involvement and it was found statistically significant (p<0.0001).

A total of 348/870 (40%) patients were thrombolised amongst them 50 (14.3%) have TVD, 70 (20.1%) have DVD, 112 (32.1%) patients were having SVD, whereas 36 (10.3%) had LMC and 48 (13.7%) had minimal lesion and 32 (9.1%) patients had normal CAG and got the benefit of thrombolysis. The aforesaid finding pointer to the fact that early thrombolytic patients had fair chance of revealing minimal and /or normal coronary artery after AMI with less number of CAD risk factor and it was found statistically significant (p-value <0.0001).

Patients with multiple vessels were older in age as compared to patients with minimal and/or normal vessel (p<0.0001). Occurrence of TVD was higher in subject with BMI >>>> 25kg/m² as compared to subjects with lower BMI (p value 0.0005).

Coronary artery disease puts significant impact on health of both urban as well as rural population. Its incidence is increasing day by day due to changes in lifestyle especially sedentary habits and lack of exercise. Other modifiable risk factors for CAD included smoking, high BMI, hypertension, presence of diabetes mellitus and older age [10–12]. Our study revealed that higher the number of CAD risk factors, more the chance of coronary arteries involvement.

Coronary angiography showed normal coronary artery in 32 AMI patients. The exact aetiology and pathogenesis of such conduction is a source of controversy. Various mechanisms has been proposed such as coronary vasospasm, concealed atherosclerosis, thrombosis in situ, embolization with spontaneous lysis, viral myocarditis vasculitis, hypercoagulable states, aortic dissection, cocaine abuse and carbon monoxide poisoning. But our patients had no such aforesaid clinical presentation. Prolonged coronary vasospasm may be the causative factor for AMI. Vasospasm for prolonged period may cause blood stagnation, platelet aggregation, thrombin generation and fibrin formation. This phenomenon may form irreversible red thrombus formation which leads to persistent coronary occlusion and AMI. Younger patients without conventional CAD risk factors except smoking and early thrombolysis has fair chance of recanalization of infarct related coronary artery [13–16].

AMI is a life threatening disease and needs urgent medical attention. It is one of the mortality and morbidity worldwide. Coronary atherosclerotic plaque fissuring and rupture is the primary event of the acute MI. Underlying subendothelial matrix is exposed by fissuring and rupturing leading to activation of platelets thereby activating coagulation cascade, which lead to the thrombus formation. The advent of Coronary Care Unit (CCU), fibrinolytic therapy and primary percutaneous coronary intervention (PCI) has made progress in lowering mortality after AMI, immediate CAG and primary PCI including stenting of the infarct related artery is superior to the thrombolysis if door to balloon time is ≤90 minutes [17–20]. Most of the patients in our country take long time to reach hospital and fail to take the benefit of fibrinolytic therapy and primary PCI. Fibrinolytic therapy should be given in all patients of ST-Elevation Myocardial Infarction (STEMI) patients within 24 hours of onset of the AMI. Primary PCI is therapy of choice for AMI but in our country a few center is available in big cities which is far away from the rural area. So primary PCI strategy is not suitable in most part of our country because of timely transportation to available primary PCI center is lacking. Fibrinolytic therapy therefore remains the most practicable reperfusion strategy. But large number of patients does not have ready access to the hospital within 24 hours thus failed to get the benefit of fibrinolytic therapy. More over increased incidence of AMI in older age group and added coronary risk factors in including diabetes, hypertension, dyslipidaemia, and smoking habit are major drawback of adequate recanalization or partial recanalization of the culprit vessel [21–23]. A total of 348/870 (40%) got the opportunity of thrombolysis and 80 (22.87%) patients revealed recanalization of the infarct related artery and found statistically significant (p-value <0.0001).

Fibrinolytic therapy should be given to all patients of STEMI patients within 24 hours of onset of the AMI before sending the patient to tertiary care center. This is a cross-sectional study which represent both urban and rural area of Madhya Pradesh, and may not represent the whole population of the country. Larger cohort studies are needed to find out the modifiable risk factors and suitable action plan should be taken to modify the risk factor so that CAD can be prevented.