A Study of ST-Elevation Acute Myocardial Infarction (STEMI) in Youngs

Introduction: Ischemic heart disease is emerging as a cause of morbidity and mortality, in developed indus- trialized world and for several decades it is an increasing cause of the same even in developing nations like India. Previously it was the disease of elderly having history of hypertension, long standing diabetes, atherosclerotic vascu- lar disease, obesity etc. Myocardial infarction among the young is somewhat preventable and treatable as emergence of risk factors is partially or totally reversible among this population subgroup. So, studying the risk factors to prevent this life threatening disease and complications to add to our knowledge the ways to prevent and manage them is the aim of this study. Material & Methods: All patients having acute STEMI, who are up to 40yrs of age are included and all the workup was done, follow up examination was also done. Results: AMI constituted about 4.0% of total adult young patients <40 years. Maximum incidence of MI was found in the age group of 30-40 years. The incidence is significantly higher among males as compared with females with male: female ratio 24:1 in patients<40 years. This is due to higher prevalence of smoking in males in India. Commoner patterns of wall involvement were extensive antero-lateral wall (34%) and inferior wall (32%). Incidence of RVMI (6%) and that of P/WMI (2%) were significantly low and they don’t occur in isolation without involvement of inferior wall. Analysis: The early presentation is much commoner. Typical retrosternal chest pain with radiation to left arm (98%), diaphoresis (46%) and dyspnoea (30%) were commoner symptoms. Incidence is high among the patients with smoking (78%), obesity (20%) and type A personality (26%). In hospital (6.0%) & post discharge(0%) mortality are lower as com- pared to those in older patients-9%( in 45-70yrs.) & 21.4% (in>70 yrs.) in hospital mortality & 10.3(in 45-70yrs.) & 24.4% (in >70yrs). Incidence of recurrence is highest within first 2 months (66.66%). Discussion: STEMI in young population is highly preventable and avoidable disease. Patient can be salvaged and better life can be offered, if proper care is taken in the management of the disease. Incidence of recurrence is highest within first 2 months (66.66%). So, regular follow-up and adherence to secondary prophylaxis is essential.


INTRODUCTION
Ischemic heart disease is emerging as an cause of morbidity and mortality, in developed industrialized world and for several decades it is an increasing cause of the same even in developing nations like India.
Myocardial infarction is one of the most severe forms of ischemic heart disease, especially in acute settings. Consequences of MI are from arrhythmias and myocardial pump failure to cardiogenic shock and sudden cardiac death.
Previously it was the disease of elderly having history of hypertension, long standing diabetes, atherosclerotic vascular disease, obesity etc. But at present incidence and prevalence is increasing among the young adults due to prevalence of smoking, early onset of risk factors like diabetes hypertension and atherosclerotic vascular disease in addition of obesity, sedentary life style etc. and is amongst the leading causes of morbidity and mortality even in young people.
Increased incidence if myocardial infarction among the young poses a significant burden over one's own life, family, society and nation as it is the most active, working subpopulation as well as carrying the burden of people in extremes of age as well as whole society.
Myocardial infarction among the young is somewhat preventable and treatable as emergence of risk factors is partially or totally reversible among this population subgroup.
Identifying and studying the etiology and risk factors of myocardial infarction among the young population may throw more light on this new emerging threat and make us more aggressive in attempting to primordially, primarily and secondarily prevent this debilitating disease in socially, economically, sexually, physically and mentally active subpopulation to serve and protect the individual, family, society as well as nation from this disability and handicap.
The patterns of clinical features as well as complications are more precise in this subgroup and though complications are commoner they are more tractable, treatable and preventable. So early treatment and monitoring prevents mortality and decreases morbidity.
So, studying the risk factors to prevent this life threatening disease and complications to add to our knowledge the ways to prevent and manage them is the aim of this study.      Incidence was high among the patients having hypertension (18%), diabetes (8%) and history of ischemic heart disease (6%).

Distribution of Clinical Signs
There is 22% of patients were presented with tachycardia and 4 % of those with bradycardia, while the remaining 74% had normal heart rate.
32% were having hypertension at the time of presentation and 6% had hypotension, while the remaining 62% were normotensive at the time of admission. 30% of the patients had signs of heart failure in form of raised JVP, S3, crepitations etc.   10% of the patients had significant pulmonary oedema on chest X-ray. All patients had some regional wall motion abnormality but 46% developed significant left ventricular dysfunction (EF<40%). Amongst the young patients, on coronary angiography; the incidence of single vessel disease is highest (78%) while that of triple vessel disease is low (2%). CAG has not been done in one patient as 2D-echocardiography and CT-aortogram were suggestive of aortic dissection from root to the origin of left subclavian artery. In addition CAG has not been done in a patient who died of cardiac arrest immediately after admission.

Figure-1 Risk Factors
Among complications, highest rate of complications was due to arrhythmias (12%), heart failure (Killip grade 2 or more) (12%) and cardiogenic shock (6%). One patient developed bleeding complication in form of hemetemesis consequent to thrombolysis. One patient had neurological complication in form of hypoxic ischemic encephalopathy due to circulatory failure.
Most of the patients develop complications early, ie: 62% within 1 hr and 31% within 1 to 6 hrs of presentation, while incidence of the same after 1 day is significantly low.
The incidence of recurrence was 6% within 2 yrs follow-up, with most case occurring within 1 year.

DISCUSSION
Higher prevalence in males which is comparable to previous studies like Hoit et el Thrombophilia study Kyoto Risk Study. Male: female ratio in incidence goes on decreasing as age advances as per cumulative analysis of the study.
Younger patients with MI have no significant predilection for any region of myocardium as revealed in different studies which is comparable to Hoit et al 3 and Gregorio Caimi at el. There is no variation in pattern of involvement of different regions of myocardium in younger patients from the middle aged and older ones which is also reflected in Hoit et al. 3 Different signs of heart failure are present in 14% on chest xray and 46% on echocardiography while those are 44% and 65% respectively in other studies. Evidence of heart failure on chest x-ray like cardiomegaly and pulmonary oedema and findings of decreased EF in echocardiography are lesser in younger age group with MI as compared to middle aged and older patients with MI in previous studies. (