Diagnosis, Treatment of ST Elevation Acute Coronary syndrome- Indian Consensus Document

Recent documents have described the evidence-based diagnosis and management of acute ST segment elevation myocardial infarction (STEMI). While these are erudite and exhaustive, they are tailored to the situation in developed countries. Because of the substantially different ground reality in India, there is a need for modifications in the interpretation of the evidence and application of treatments to the Indian context.

Ministry of Health and Family Welfare, Government of India has issued the Standard Treatment Guidelines for The Diagnosis And Treatment of ST Elevation Acute Coronary syndrome. Following are the major recommendations :

This statement attempts to provide guidance to Indian physicians and healthcare providers at the grass-root level in making decisions for the optimal management of patients with STEMI.

Diagnosis of STEMI

Early diagnosis is the key to early treatment of STEMI. A history of chest pain or discomfort lasting 10-20 minutes should raise the suspicion of acute STEMI in susceptible individuals (middle-aged male patients, particularly if they have risk factors for coronary disease). It must be recognized that pain may be atypical in character or location. A 12-lead ECG must be performed as soon as possible. ECG should be interpreted within ten minutes of arrival in health care centre. If the initial ECG is not suggestive of STEMI but the patient continues to have symptoms, repeat ECGs must be obtained (every 15 minutes, not after 12 hours or next day) and compared to the first ECG. While markers of myocardial necrosis are useful in corroborating the diagnosis, it must be emphasized that they may not be elevated early after the onset of symptoms. In doubtful cases, echocardiography may be a useful adjunct in making the diagnosis, particularly among young patients without prior history of coronary disease.

Equipment, personnel and training

Every primary health center should have a functioning ECG machine available 24 hours a day. Health workers at these centers should be trained to recognize the cardinal features of STEMI so that treatment can be initiated without delay. It may not be necessary for all health centers to have access to facilities for cardiac biomarker testing. Use of qualitative test-strips in these centers may be expensive and may lead to diagnostic confusion, and their use should be discouraged.

Management of STEMI

Risk stratification

The initial assessment should include the rapid identification of patients who may be at high risk of cardiogenic shock or death. The following characteristics have been most consistently associated with adverse outcomes in patients with STEMI :

1. Older age (age ≥75 years)


2. Higher Killip class (class III or IV)


3. Lower systolic blood pressure (<100 mm Hg)


4. Higher heart rate (>100/min)


5. Anterior MI

The greater the number of risk factors, the higher is the risk. Therefore, after instituting initial treatment (which may include fibrinolytic therapy), such patients are best transferred to hospitals with coronary care units and catheterization laboratory facilities.

Initial treatment

The first treatment that should be given is 325 mg of (preferably) non enteric-coated aspirin to be chewed. All patients should receive aspirin. Clopidogrel should be administered at a loading dose of 300 to 600 mg to all patients. Patients undergoing primary PCI should receive a 600 mg loading dose.

All patients should receive medications to relieve pain. These may include opioid analgesics (morphine sulfate intravenously) where available. Sublingual or intravenous nitrates should be administered if systolic blood pressure is ≥120 mm Hg. If systolic BP is ≥ 100 mm Hg but less than 120 mm Hg, nitrates must be administered cautiously. Non steroidal anti-inflammatory drugs (NSAIDs, other than aspirin) should not be given for analgesia.

Choice of reperfusion therapy

Fibrinolytic therapy vs. primary PCI

Reperfusion therapy is the cornerstone of STEMI management and should be instituted in all patients presenting within 12 hours of onset of symptoms. The most efficacious reperfusion therapy available is timely primary PCI, but it may not be the most effective in the Indian context, given the relative paucity of PCI-capable centers. Moreover, since most of these centers are located in urban areas, the distances involved in transporting patients from rural areas become prohibitive. Fibrinolytic therapy therefore remains the most practicable reperfusion strategy for India. The most recent data from India suggests that only about 8% of patients with STEMI receive primary PCI. Nearly 60% of patients receive fibrinolysis with streptokinase as initial treatment. It should be emphasized that even among urban/semi-urban dwellers (only 17% of patients enrolled in the CREATE registry 15 were from rural areas), a third of patients did not receive any form of reperfusion therapy.

Patients presenting to PCI-capable centers should of course be treated with timely primary PCI if the door-to-balloon time is anticipated to be less than 90 minutes from the time of arrival at the hospital. It should be recognized that door-to-balloon times may be greater than 2 hours even in PCI-capable centers during off-duty hours, weekends and holidays, and immediate fibrinolysis may be the better option when delays are anticipated. Such hospitals should implement processes to minimize and monitor door-to-balloon times.

Table 1

Indications for transfer of patients (after fibrinolytic therapy) to centers with CCUs and/or PCI capabilities

1. Patients in cardiogenic shock or those who are at high risk of developing cardiogenic shock†21

2. Failed fibrinolytic therapy

3. High-risk patients‡*22

Choice of fibrinolytic agent

Traditionally, streptokinase has been the most commonly used fibrinolytic agent in India. However, streptokinase is not fibrin-specific, requires to be given as an infusion over one hour and may be associated with hypersensitivity reactions. Recently, there is some favorable evidence for the use of tenecteplase in Indian settings. Tenecteplase has theadvantage of being fibrin-specific, can be given as a bolus dose, and has a lower incidence of hypersensitivity reactions. TIMI 3 flow in the infarct related coronary artery may also occur more frequently with tenecteplase when compared to streptokinase. Tenecteplase should be administered at a dose of 0.5 mg/kg body weight

Personnel and training

Given that nearly a third of patients in urban India do not receive any reperfusion therapy, it may be worthwhile for the government to consider making tenecteplase available at primary health centers as a policy decision. This would also entail adequate training of medical and paramedical personnel at these centers so that they can administer tenecteplase without delay. Studies conducted around the world have found that administration of bolus-dose fibrinolytic agents by paramedical personnel is safe. The government should commission studies to confirm the safety of such a practice in the Indian context before its widespread implementation.

The case for pre-hospital fibrinolysis

Due to lack of awareness, lack of ambulance services and the distances involved, most patients with STEMI living in urban/semi-urban India reach hospital after a delay of 5 hours. This delay can be shortened by institution of systems to initiate pre-hospital evaluation and fibrinolysis. Pre-hospital fibrinolytic therapy has clearly shown to improve outcomes and has compared favorably with primary PCI.

Transport of patients to centers with CCUs and/or PCI capability

Recent studies in Europe and North America have suggested that transport of patients to PCI capable centers may be a better strategy than immediate fibrinolytic therapy. Such a strategy may however not be suitable for most parts of India because of the distances involved and the insurmountable logistics of transport. Nevertheless, it may be possible for small geographic units (urban or rural) to develop systems for the provision of efficient services for transporting patients to designated PCI-capable centers. Recent data from India suggests that only 6% of patients with STEMI travel to hospital by ambulance .

After administration of fibrinolytic therapy several situations may necessitate transfer of patients to centers with CCUs and/or PCI capabilities. These are listed in table 2 below.

Table 2

Indications for transfer of patients (after fibrinolytic therapy) to centers with CCUs and/or PCI capabilities

1. Patients in cardiogenic shock or those who are at high risk of developing cardiogenic shock†21

2. Failed fibrinolytic therapy

3. High-risk patients‡*22

† Age >70 years, systolic blood pressure <120 mmHg, heart rate >110/min or <60/min, and increased time since onset of symptoms.

‡ Patients with ST elevation ≥2 mm in anterior leads or 1 mm in inferior leads who have at least one of the following high-risk factors:

systolic blood pressure < 100 mm Hg,heart rate >100/min, Killip class IIor III, ST-segment depression of ≥2 mm inthe anterior leads, or ST-

22 segment elevation of ≥1 mm in right-sided lead V4 (V4R).

* PCI may then be performed as and when needed or as part of a pharmacoinvasive strategy

Adjunctive therapies

Antiplatelet treatment

Aspirin and clopidogrel should be administered as discussed in section 3.2. Glycoprotein IIb/IIIa antagonists may be used in patients undergoing primary PCI although their role in patients preloaded with clopidogrel is unclear. These agents may be administered in the catheterization laboratory, at the time of the procedure. There is no role of administering these agents within the context of a strategy to bridge the time delay before primary PCI (facilitated PCI). Abciximab, eptifibatide and tirofiban appear to be similarly effective and may be used depending upon local preferences and availability .

Antithrombotic therapy

Patients receiving fibrinolytic therapy

Following treatment with both fibrin-specific and non fibrin-specific fibrinolytic agents, there is strong evidence for the use of antithrombotic agents for reducing reinfarction or recurrent ischemia. Recent studies suggest that low molecular weight heparins (LMWH) may be better than unfractionated heparin (UFH) for this purpose. The LMWHs enoxaparin or reviparin may be administered for up to 8 days post-MI. Fondaparinux has recently been shown to reduce the occurrence of death or reinfarction while concomitantly reducing the risk of major bleeding, and may therefore be considered among patients undergoing treatment with streptokinase. There is no role for bivalirudin among patients receiving fibrinolytic therapy.

Patients undergoing primary PCI should receive periprocedural UFH or bivalirudin. Fondaparinux (without added UFH) may increase the risk of catheter thrombosis.

Patients not receiving any reperfusion therapy Fondaparinux may be the preferred agent among patients who have not received any reperfusion therapy

Beta adrenergic antagonists

Oral beta-blockers should be administered in the first 24 hours to patients who do not have heart failure, a low output state, are not at increased risk of developing cardiogenic shock (see footnote in table 2), or do not have other contraindications to beta-blocker therapy. Intravenous beta-blockers may be administered in the first 24 hours in the presence of hypertension or tachyarrhythmia, in the absence of the above contraindications2 .

ACE inhibitors and ARBs

ACE inhibitors improve survival in patients who have reduced left ventricular ejection fraction (LVEF ≤ 40%) and those who are in heart failure following STEMI. Benefits are proportionately lower among low risk patients. ACE inhibitors should be started in the first 24 hours after STEMI in the absence of contraindications. ARBs may be used in patients who do not tolerate ACE inhibitors .

Other agents

Routine use of intravenous or oral nitrates does not improve outcomes in patients with STEMI. Nitrates may be used for pain relief. There is no role for the routine use of calcium antagonists, intravenous magnesium, antiarrhythmic agents or glucose-insulin-potassium infusions, and may be associated with adverse outcomes in some cases. High dose statins should be initiated as early as possible during hospital stay as part of secondary prevention measures. The dose of statin to be used in Indian patients is not clear, but lowering LDL levels to ≤70mg/dL may be a useful target.

Management post-fibrinolytic therapy

Several studies have suggested that routine angiography and PCI of the infarct related artery may reduce the rates of re-occlusion or re-infarction 32-35. However, none of these studies have shown a reduction in mortality with this strategy. Because of the resource intensiveness of this strategy and the absence of an effect on survival, this panel favors a more conservative approach consisting of revascularization guided by the results of risk stratification by early exercise stress testing. Angiography (and revascularization) should of course be performed in the event of spontaneous ischemia or the development of mechanical complications.

After the acute phase of STEMI, therapeutic lifestyle changes (including smoking cessation, exercise and dietary modification) and drugs for secondary prevention assume critical roles in improving outcomes in the medium and long-term. Patient counseling and education is the key to maintaining adherence to therapy in the long run.